Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2020-10-01

The following pull-request contains BPF updates for your *net-next* tree.

We've added 90 non-merge commits during the last 8 day(s) which contain
a total of 103 files changed, 7662 insertions(+), 1894 deletions(-).

Note that once bpf(/net) tree gets merged into net-next, there will be a small
merge conflict in tools/lib/bpf/btf.c between commit 1245008122d7 ("libbpf: Fix
native endian assumption when parsing BTF") from the bpf tree and the commit
3289959b97ca ("libbpf: Support BTF loading and raw data output in both endianness")
from the bpf-next tree. Correct resolution would be to stick with bpf-next, it
should look like:

  [...]
        /* check BTF magic */
        if (fread(&magic, 1, sizeof(magic), f) < sizeof(magic)) {
                err = -EIO;
                goto err_out;
        }
        if (magic != BTF_MAGIC && magic != bswap_16(BTF_MAGIC)) {
                /* definitely not a raw BTF */
                err = -EPROTO;
                goto err_out;
        }

        /* get file size */
  [...]

The main changes are:

1) Add bpf_snprintf_btf() and bpf_seq_printf_btf() helpers to support displaying
   BTF-based kernel data structures out of BPF programs, from Alan Maguire.

2) Speed up RCU tasks trace grace periods by a factor of 50 & fix a few race
   conditions exposed by it. It was discussed to take these via BPF and
   networking tree to get better testing exposure, from Paul E. McKenney.

3) Support multi-attach for freplace programs, needed for incremental attachment
   of multiple XDP progs using libxdp dispatcher model, from Toke Høiland-Jørgensen.

4) libbpf support for appending new BTF types at the end of BTF object, allowing
   intrusive changes of prog's BTF (useful for future linking), from Andrii Nakryiko.

5) Several BPF helper improvements e.g. avoid atomic op in cookie generator and add
   a redirect helper into neighboring subsys, from Daniel Borkmann.

6) Allow map updates on sockmaps from bpf_iter context in order to migrate sockmaps
   from one to another, from Lorenz Bauer.

7) Fix 32 bit to 64 bit assignment from latest alu32 bounds tracking which caused
   a verifier issue due to type downgrade to scalar, from John Fastabend.

8) Follow-up on tail-call support in BPF subprogs which optimizes x64 JIT prologue
   and epilogue sections, from Maciej Fijalkowski.

9) Add an option to perf RB map to improve sharing of event entries by avoiding remove-
   on-close behavior. Also, add BPF_PROG_TEST_RUN for raw_tracepoint, from Song Liu.

10) Fix a crash in AF_XDP's socket_release when memory allocation for UMEMs fails,
    from Magnus Karlsson.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

64 files changed, 4993 insertions, 1055 deletions

diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index a22812561064..4f556cfcbfbe 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -414,6 +414,9 @@ enum {
 
 /* Enable memory-mapping BPF map */
 	BPF_F_MMAPABLE		= (1U << 10),
+
+/* Share perf_event among processes */
+	BPF_F_PRESERVE_ELEMS	= (1U << 11),
 };
 
 /* Flags for BPF_PROG_QUERY. */
@@ -424,6 +427,11 @@ enum {
  */
 #define BPF_F_QUERY_EFFECTIVE	(1U << 0)
 
+/* Flags for BPF_PROG_TEST_RUN */
+
+/* If set, run the test on the cpu specified by bpf_attr.test.cpu */
+#define BPF_F_TEST_RUN_ON_CPU	(1U << 0)
+
 /* type for BPF_ENABLE_STATS */
 enum bpf_stats_type {
 	/* enabled run_time_ns and run_cnt */
@@ -566,6 +574,8 @@ union bpf_attr {
 						 */
 		__aligned_u64	ctx_in;
 		__aligned_u64	ctx_out;
+		__u32		flags;
+		__u32		cpu;
 	} test;
 
 	struct { /* anonymous struct used by BPF_*_GET_*_ID */
@@ -632,8 +642,13 @@ union bpf_attr {
 		};
 		__u32		attach_type;	/* attach type */
 		__u32		flags;		/* extra flags */
-		__aligned_u64	iter_info;	/* extra bpf_iter_link_info */
-		__u32		iter_info_len;	/* iter_info length */
+		union {
+			__u32		target_btf_id;	/* btf_id of target to attach to */
+			struct {
+				__aligned_u64	iter_info;	/* extra bpf_iter_link_info */
+				__u32		iter_info_len;	/* iter_info length */
+			};
+		};
 	} link_create;
 
 	struct { /* struct used by BPF_LINK_UPDATE command */
@@ -2512,7 +2527,7 @@ union bpf_attr {
  *		result is from *reuse*\ **->socks**\ [] using the hash of the
  *		tuple.
  *
- * long bpf_sk_release(struct bpf_sock *sock)
+ * long bpf_sk_release(void *sock)
  *	Description
  *		Release the reference held by *sock*. *sock* must be a
  *		non-**NULL** pointer that was returned from
@@ -2692,7 +2707,7 @@ union bpf_attr {
  *		result is from *reuse*\ **->socks**\ [] using the hash of the
  *		tuple.
  *
- * long bpf_tcp_check_syncookie(struct bpf_sock *sk, void *iph, u32 iph_len, struct tcphdr *th, u32 th_len)
+ * long bpf_tcp_check_syncookie(void *sk, void *iph, u32 iph_len, struct tcphdr *th, u32 th_len)
  * 	Description
  * 		Check whether *iph* and *th* contain a valid SYN cookie ACK for
  * 		the listening socket in *sk*.
@@ -2861,6 +2876,7 @@ union bpf_attr {
  *		0 on success.
  *
  *		**-ENOENT** if the bpf-local-storage cannot be found.
+ *		**-EINVAL** if sk is not a fullsock (e.g. a request_sock).
  *
  * long bpf_send_signal(u32 sig)
  *	Description
@@ -2877,7 +2893,7 @@ union bpf_attr {
  *
  *		**-EAGAIN** if bpf program can try again.
  *
- * s64 bpf_tcp_gen_syncookie(struct bpf_sock *sk, void *iph, u32 iph_len, struct tcphdr *th, u32 th_len)
+ * s64 bpf_tcp_gen_syncookie(void *sk, void *iph, u32 iph_len, struct tcphdr *th, u32 th_len)
  *	Description
  *		Try to issue a SYN cookie for the packet with corresponding
  *		IP/TCP headers, *iph* and *th*, on the listening socket in *sk*.
@@ -3106,7 +3122,7 @@ union bpf_attr {
  * 	Return
  * 		The id is returned or 0 in case the id could not be retrieved.
  *
- * long bpf_sk_assign(struct sk_buff *skb, struct bpf_sock *sk, u64 flags)
+ * long bpf_sk_assign(struct sk_buff *skb, void *sk, u64 flags)
  *	Description
  *		Helper is overloaded depending on BPF program type. This
  *		description applies to **BPF_PROG_TYPE_SCHED_CLS** and
@@ -3234,11 +3250,11 @@ union bpf_attr {
  *
  *		**-EOVERFLOW** if an overflow happened: The same object will be tried again.
  *
- * u64 bpf_sk_cgroup_id(struct bpf_sock *sk)
+ * u64 bpf_sk_cgroup_id(void *sk)
  *	Description
  *		Return the cgroup v2 id of the socket *sk*.
  *
- *		*sk* must be a non-**NULL** pointer to a full socket, e.g. one
+ *		*sk* must be a non-**NULL** pointer to a socket, e.g. one
  *		returned from **bpf_sk_lookup_xxx**\ (),
  *		**bpf_sk_fullsock**\ (), etc. The format of returned id is
  *		same as in **bpf_skb_cgroup_id**\ ().
@@ -3248,7 +3264,7 @@ union bpf_attr {
  *	Return
  *		The id is returned or 0 in case the id could not be retrieved.
  *
- * u64 bpf_sk_ancestor_cgroup_id(struct bpf_sock *sk, int ancestor_level)
+ * u64 bpf_sk_ancestor_cgroup_id(void *sk, int ancestor_level)
  *	Description
  *		Return id of cgroup v2 that is ancestor of cgroup associated
  *		with the *sk* at the *ancestor_level*.  The root cgroup is at
@@ -3586,6 +3602,72 @@ union bpf_attr {
  * 		the data in *dst*. This is a wrapper of **copy_from_user**\ ().
  * 	Return
  * 		0 on success, or a negative error in case of failure.
+ *
+ * long bpf_snprintf_btf(char *str, u32 str_size, struct btf_ptr *ptr, u32 btf_ptr_size, u64 flags)
+ *	Description
+ *		Use BTF to store a string representation of *ptr*->ptr in *str*,
+ *		using *ptr*->type_id.  This value should specify the type
+ *		that *ptr*->ptr points to. LLVM __builtin_btf_type_id(type, 1)
+ *		can be used to look up vmlinux BTF type ids. Traversing the
+ *		data structure using BTF, the type information and values are
+ *		stored in the first *str_size* - 1 bytes of *str*.  Safe copy of
+ *		the pointer data is carried out to avoid kernel crashes during
+ *		operation.  Smaller types can use string space on the stack;
+ *		larger programs can use map data to store the string
+ *		representation.
+ *
+ *		The string can be subsequently shared with userspace via
+ *		bpf_perf_event_output() or ring buffer interfaces.
+ *		bpf_trace_printk() is to be avoided as it places too small
+ *		a limit on string size to be useful.
+ *
+ *		*flags* is a combination of
+ *
+ *		**BTF_F_COMPACT**
+ *			no formatting around type information
+ *		**BTF_F_NONAME**
+ *			no struct/union member names/types
+ *		**BTF_F_PTR_RAW**
+ *			show raw (unobfuscated) pointer values;
+ *			equivalent to printk specifier %px.
+ *		**BTF_F_ZERO**
+ *			show zero-valued struct/union members; they
+ *			are not displayed by default
+ *
+ *	Return
+ *		The number of bytes that were written (or would have been
+ *		written if output had to be truncated due to string size),
+ *		or a negative error in cases of failure.
+ *
+ * long bpf_seq_printf_btf(struct seq_file *m, struct btf_ptr *ptr, u32 ptr_size, u64 flags)
+ *	Description
+ *		Use BTF to write to seq_write a string representation of
+ *		*ptr*->ptr, using *ptr*->type_id as per bpf_snprintf_btf().
+ *		*flags* are identical to those used for bpf_snprintf_btf.
+ *	Return
+ *		0 on success or a negative error in case of failure.
+ *
+ * u64 bpf_skb_cgroup_classid(struct sk_buff *skb)
+ * 	Description
+ * 		See **bpf_get_cgroup_classid**\ () for the main description.
+ * 		This helper differs from **bpf_get_cgroup_classid**\ () in that
+ * 		the cgroup v1 net_cls class is retrieved only from the *skb*'s
+ * 		associated socket instead of the current process.
+ * 	Return
+ * 		The id is returned or 0 in case the id could not be retrieved.
+ *
+ * long bpf_redirect_neigh(u32 ifindex, u64 flags)
+ * 	Description
+ * 		Redirect the packet to another net device of index *ifindex*
+ * 		and fill in L2 addresses from neighboring subsystem. This helper
+ * 		is somewhat similar to **bpf_redirect**\ (), except that it
+ * 		fills in e.g. MAC addresses based on the L3 information from
+ * 		the packet. This helper is supported for IPv4 and IPv6 protocols.
+ * 		The *flags* argument is reserved and must be 0. The helper is
+ * 		currently only supported for tc BPF program types.
+ * 	Return
+ * 		The helper returns **TC_ACT_REDIRECT** on success or
+ * 		**TC_ACT_SHOT** on error.
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -3737,6 +3819,10 @@ union bpf_attr {
 	FN(inode_storage_delete),	\
 	FN(d_path),			\
 	FN(copy_from_user),		\
+	FN(snprintf_btf),		\
+	FN(seq_printf_btf),		\
+	FN(skb_cgroup_classid),		\
+	FN(redirect_neigh),		\
 	/* */
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
@@ -4845,4 +4931,34 @@ struct bpf_sk_lookup {
 	__u32 local_port;	/* Host byte order */
 };
 
+/*
+ * struct btf_ptr is used for typed pointer representation; the
+ * type id is used to render the pointer data as the appropriate type
+ * via the bpf_snprintf_btf() helper described above.  A flags field -
+ * potentially to specify additional details about the BTF pointer
+ * (rather than its mode of display) - is included for future use.
+ * Display flags - BTF_F_* - are passed to bpf_snprintf_btf separately.
+ */
+struct btf_ptr {
+	void *ptr;
+	__u32 type_id;
+	__u32 flags;		/* BTF ptr flags; unused at present. */
+};
+
+/*
+ * Flags to control bpf_snprintf_btf() behaviour.
+ *     - BTF_F_COMPACT: no formatting around type information
+ *     - BTF_F_NONAME: no struct/union member names/types
+ *     - BTF_F_PTR_RAW: show raw (unobfuscated) pointer values;
+ *       equivalent to %px.
+ *     - BTF_F_ZERO: show zero-valued struct/union members; they
+ *       are not displayed by default
+ */
+enum {
+	BTF_F_COMPACT	=	(1ULL << 0),
+	BTF_F_NONAME	=	(1ULL << 1),
+	BTF_F_PTR_RAW	=	(1ULL << 2),
+	BTF_F_ZERO	=	(1ULL << 3),
+};
+
 #endif /* _UAPI__LINUX_BPF_H__ */
diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile
index f43249696d9f..5f9abed3e226 100644
--- a/tools/lib/bpf/Makefile
+++ b/tools/lib/bpf/Makefile
@@ -98,19 +98,18 @@ PC_FILE		= libbpf.pc
 ifdef EXTRA_CFLAGS
   CFLAGS := $(EXTRA_CFLAGS)
 else
-  CFLAGS := -g -Wall
+  CFLAGS := -g -O2
 endif
 
 # Append required CFLAGS
 override CFLAGS += $(EXTRA_WARNINGS) -Wno-switch-enum
 override CFLAGS += -Werror -Wall
-override CFLAGS += -fPIC
 override CFLAGS += $(INCLUDES)
 override CFLAGS += -fvisibility=hidden
 override CFLAGS += -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64
 
 # flags specific for shared library
-SHLIB_FLAGS := -DSHARED
+SHLIB_FLAGS := -DSHARED -fPIC
 
 ifeq ($(VERBOSE),1)
   Q =
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index 2baa1308737c..d27e34133973 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -586,19 +586,31 @@ int bpf_link_create(int prog_fd, int target_fd,
 		    enum bpf_attach_type attach_type,
 		    const struct bpf_link_create_opts *opts)
 {
+	__u32 target_btf_id, iter_info_len;
 	union bpf_attr attr;
 
 	if (!OPTS_VALID(opts, bpf_link_create_opts))
 		return -EINVAL;
 
+	iter_info_len = OPTS_GET(opts, iter_info_len, 0);
+	target_btf_id = OPTS_GET(opts, target_btf_id, 0);
+
+	if (iter_info_len && target_btf_id)
+		return -EINVAL;
+
 	memset(&attr, 0, sizeof(attr));
 	attr.link_create.prog_fd = prog_fd;
 	attr.link_create.target_fd = target_fd;
 	attr.link_create.attach_type = attach_type;
 	attr.link_create.flags = OPTS_GET(opts, flags, 0);
-	attr.link_create.iter_info =
-		ptr_to_u64(OPTS_GET(opts, iter_info, (void *)0));
-	attr.link_create.iter_info_len = OPTS_GET(opts, iter_info_len, 0);
+
+	if (iter_info_len) {
+		attr.link_create.iter_info =
+			ptr_to_u64(OPTS_GET(opts, iter_info, (void *)0));
+		attr.link_create.iter_info_len = iter_info_len;
+	} else if (target_btf_id) {
+		attr.link_create.target_btf_id = target_btf_id;
+	}
 
 	return sys_bpf(BPF_LINK_CREATE, &attr, sizeof(attr));
 }
@@ -712,6 +724,37 @@ int bpf_prog_test_run_xattr(struct bpf_prog_test_run_attr *test_attr)
 	return ret;
 }
 
+int bpf_prog_test_run_opts(int prog_fd, struct bpf_test_run_opts *opts)
+{
+	union bpf_attr attr;
+	int ret;
+
+	if (!OPTS_VALID(opts, bpf_test_run_opts))
+		return -EINVAL;
+
+	memset(&attr, 0, sizeof(attr));
+	attr.test.prog_fd = prog_fd;
+	attr.test.cpu = OPTS_GET(opts, cpu, 0);
+	attr.test.flags = OPTS_GET(opts, flags, 0);
+	attr.test.repeat = OPTS_GET(opts, repeat, 0);
+	attr.test.duration = OPTS_GET(opts, duration, 0);
+	attr.test.ctx_size_in = OPTS_GET(opts, ctx_size_in, 0);
+	attr.test.ctx_size_out = OPTS_GET(opts, ctx_size_out, 0);
+	attr.test.data_size_in = OPTS_GET(opts, data_size_in, 0);
+	attr.test.data_size_out = OPTS_GET(opts, data_size_out, 0);
+	attr.test.ctx_in = ptr_to_u64(OPTS_GET(opts, ctx_in, NULL));
+	attr.test.ctx_out = ptr_to_u64(OPTS_GET(opts, ctx_out, NULL));
+	attr.test.data_in = ptr_to_u64(OPTS_GET(opts, data_in, NULL));
+	attr.test.data_out = ptr_to_u64(OPTS_GET(opts, data_out, NULL));
+
+	ret = sys_bpf(BPF_PROG_TEST_RUN, &attr, sizeof(attr));
+	OPTS_SET(opts, data_size_out, attr.test.data_size_out);
+	OPTS_SET(opts, ctx_size_out, attr.test.ctx_size_out);
+	OPTS_SET(opts, duration, attr.test.duration);
+	OPTS_SET(opts, retval, attr.test.retval);
+	return ret;
+}
+
 static int bpf_obj_get_next_id(__u32 start_id, __u32 *next_id, int cmd)
 {
 	union bpf_attr attr;
@@ -815,7 +858,7 @@ int bpf_raw_tracepoint_open(const char *name, int prog_fd)
 	return sys_bpf(BPF_RAW_TRACEPOINT_OPEN, &attr, sizeof(attr));
 }
 
-int bpf_load_btf(void *btf, __u32 btf_size, char *log_buf, __u32 log_buf_size,
+int bpf_load_btf(const void *btf, __u32 btf_size, char *log_buf, __u32 log_buf_size,
 		 bool do_log)
 {
 	union bpf_attr attr = {};
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index 8c1ac4b42f90..875dde20d56e 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -174,8 +174,9 @@ struct bpf_link_create_opts {
 	__u32 flags;
 	union bpf_iter_link_info *iter_info;
 	__u32 iter_info_len;
+	__u32 target_btf_id;
 };
-#define bpf_link_create_opts__last_field iter_info_len
+#define bpf_link_create_opts__last_field target_btf_id
 
 LIBBPF_API int bpf_link_create(int prog_fd, int target_fd,
 			       enum bpf_attach_type attach_type,
@@ -234,7 +235,7 @@ LIBBPF_API int bpf_prog_query(int target_fd, enum bpf_attach_type type,
 			      __u32 query_flags, __u32 *attach_flags,
 			      __u32 *prog_ids, __u32 *prog_cnt);
 LIBBPF_API int bpf_raw_tracepoint_open(const char *name, int prog_fd);
-LIBBPF_API int bpf_load_btf(void *btf, __u32 btf_size, char *log_buf,
+LIBBPF_API int bpf_load_btf(const void *btf, __u32 btf_size, char *log_buf,
 			    __u32 log_buf_size, bool do_log);
 LIBBPF_API int bpf_task_fd_query(int pid, int fd, __u32 flags, char *buf,
 				 __u32 *buf_len, __u32 *prog_id, __u32 *fd_type,
@@ -251,6 +252,32 @@ struct bpf_prog_bind_opts {
 
 LIBBPF_API int bpf_prog_bind_map(int prog_fd, int map_fd,
 				 const struct bpf_prog_bind_opts *opts);
+
+struct bpf_test_run_opts {
+	size_t sz; /* size of this struct for forward/backward compatibility */
+	const void *data_in; /* optional */
+	void *data_out;      /* optional */
+	__u32 data_size_in;
+	__u32 data_size_out; /* in: max length of data_out
+			      * out: length of data_out
+			      */
+	const void *ctx_in; /* optional */
+	void *ctx_out;      /* optional */
+	__u32 ctx_size_in;
+	__u32 ctx_size_out; /* in: max length of ctx_out
+			     * out: length of cxt_out
+			     */
+	__u32 retval;        /* out: return code of the BPF program */
+	int repeat;
+	__u32 duration;      /* out: average per repetition in ns */
+	__u32 flags;
+	__u32 cpu;
+};
+#define bpf_test_run_opts__last_field cpu
+
+LIBBPF_API int bpf_prog_test_run_opts(int prog_fd,
+				      struct bpf_test_run_opts *opts);
+
 #ifdef __cplusplus
 } /* extern "C" */
 #endif
diff --git a/tools/lib/bpf/bpf_helpers.h b/tools/lib/bpf/bpf_helpers.h
index 1106777df00b..2bdb7d6dbad2 100644
--- a/tools/lib/bpf/bpf_helpers.h
+++ b/tools/lib/bpf/bpf_helpers.h
@@ -54,6 +54,52 @@
 #endif
 
 /*
+ * Helper macro to throw a compilation error if __bpf_unreachable() gets
+ * built into the resulting code. This works given BPF back end does not
+ * implement __builtin_trap(). This is useful to assert that certain paths
+ * of the program code are never used and hence eliminated by the compiler.
+ *
+ * For example, consider a switch statement that covers known cases used by
+ * the program. __bpf_unreachable() can then reside in the default case. If
+ * the program gets extended such that a case is not covered in the switch
+ * statement, then it will throw a build error due to the default case not
+ * being compiled out.
+ */
+#ifndef __bpf_unreachable
+# define __bpf_unreachable()	__builtin_trap()
+#endif
+
+/*
+ * Helper function to perform a tail call with a constant/immediate map slot.
+ */
+static __always_inline void
+bpf_tail_call_static(void *ctx, const void *map, const __u32 slot)
+{
+	if (!__builtin_constant_p(slot))
+		__bpf_unreachable();
+
+	/*
+	 * Provide a hard guarantee that LLVM won't optimize setting r2 (map
+	 * pointer) and r3 (constant map index) from _different paths_ ending
+	 * up at the _same_ call insn as otherwise we won't be able to use the
+	 * jmpq/nopl retpoline-free patching by the x86-64 JIT in the kernel
+	 * given they mismatch. See also d2e4c1e6c294 ("bpf: Constant map key
+	 * tracking for prog array pokes") for details on verifier tracking.
+	 *
+	 * Note on clobber list: we need to stay in-line with BPF calling
+	 * convention, so even if we don't end up using r0, r4, r5, we need
+	 * to mark them as clobber so that LLVM doesn't end up using them
+	 * before / after the call.
+	 */
+	asm volatile("r1 = %[ctx]\n\t"
+		     "r2 = %[map]\n\t"
+		     "r3 = %[slot]\n\t"
+		     "call 12"
+		     :: [ctx]"r"(ctx), [map]"r"(map), [slot]"i"(slot)
+		     : "r0", "r1", "r2", "r3", "r4", "r5");
+}
+
+/*
  * Helper structure used by eBPF C program
  * to describe BPF map attributes to libbpf loader
  */
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index a3d259e614b0..231b07203e3d 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
 /* Copyright (c) 2018 Facebook */
 
+#include <byteswap.h>
 #include <endian.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -27,17 +28,72 @@
 static struct btf_type btf_void;
 
 struct btf {
-	union {
-		struct btf_header *hdr;
-		void *data;
-	};
-	struct btf_type **types;
-	const char *strings;
-	void *nohdr_data;
+	/* raw BTF data in native endianness */
+	void *raw_data;
+	/* raw BTF data in non-native endianness */
+	void *raw_data_swapped;
+	__u32 raw_size;
+	/* whether target endianness differs from the native one */
+	bool swapped_endian;
+
+	/*
+	 * When BTF is loaded from an ELF or raw memory it is stored
+	 * in a contiguous memory block. The hdr, type_data, and, strs_data
+	 * point inside that memory region to their respective parts of BTF
+	 * representation:
+	 *
+	 * +--------------------------------+
+	 * |  Header  |  Types  |  Strings  |
+	 * +--------------------------------+
+	 * ^          ^         ^
+	 * |          |         |
+	 * hdr        |         |
+	 * types_data-+         |
+	 * strs_data------------+
+	 *
+	 * If BTF data is later modified, e.g., due to types added or
+	 * removed, BTF deduplication performed, etc, this contiguous
+	 * representation is broken up into three independently allocated
+	 * memory regions to be able to modify them independently.
+	 * raw_data is nulled out at that point, but can be later allocated
+	 * and cached again if user calls btf__get_raw_data(), at which point
+	 * raw_data will contain a contiguous copy of header, types, and
+	 * strings:
+	 *
+	 * +----------+  +---------+  +-----------+
+	 * |  Header  |  |  Types  |  |  Strings  |
+	 * +----------+  +---------+  +-----------+
+	 * ^             ^            ^
+	 * |             |            |
+	 * hdr           |            |
+	 * types_data----+            |
+	 * strs_data------------------+
+	 *
+	 *               +----------+---------+-----------+
+	 *               |  Header  |  Types  |  Strings  |
+	 * raw_data----->+----------+---------+-----------+
+	 */
+	struct btf_header *hdr;
+
+	void *types_data;
+	size_t types_data_cap; /* used size stored in hdr->type_len */
+
+	/* type ID to `struct btf_type *` lookup index */
+	__u32 *type_offs;
+	size_t type_offs_cap;
 	__u32 nr_types;
-	__u32 types_size;
-	__u32 data_size;
+
+	void *strs_data;
+	size_t strs_data_cap; /* used size stored in hdr->str_len */
+
+	/* lookup index for each unique string in strings section */
+	struct hashmap *strs_hash;
+	/* whether strings are already deduplicated */
+	bool strs_deduped;
+	/* BTF object FD, if loaded into kernel */
 	int fd;
+
+	/* Pointer size (in bytes) for a target architecture of this BTF */
 	int ptr_sz;
 };
 
@@ -46,60 +102,114 @@ static inline __u64 ptr_to_u64(const void *ptr)
 	return (__u64) (unsigned long) ptr;
 }
 
-static int btf_add_type(struct btf *btf, struct btf_type *t)
+/* Ensure given dynamically allocated memory region pointed to by *data* with
+ * capacity of *cap_cnt* elements each taking *elem_sz* bytes has enough
+ * memory to accomodate *add_cnt* new elements, assuming *cur_cnt* elements
+ * are already used. At most *max_cnt* elements can be ever allocated.
+ * If necessary, memory is reallocated and all existing data is copied over,
+ * new pointer to the memory region is stored at *data, new memory region
+ * capacity (in number of elements) is stored in *cap.
+ * On success, memory pointer to the beginning of unused memory is returned.
+ * On error, NULL is returned.
+ */
+void *btf_add_mem(void **data, size_t *cap_cnt, size_t elem_sz,
+		  size_t cur_cnt, size_t max_cnt, size_t add_cnt)
 {
-	if (btf->types_size - btf->nr_types < 2) {
-		struct btf_type **new_types;
-		__u32 expand_by, new_size;
+	size_t new_cnt;
+	void *new_data;
 
-		if (btf->types_size == BTF_MAX_NR_TYPES)
-			return -E2BIG;
+	if (cur_cnt + add_cnt <= *cap_cnt)
+		return *data + cur_cnt * elem_sz;
 
-		expand_by = max(btf->types_size >> 2, 16U);
-		new_size = min(BTF_MAX_NR_TYPES, btf->types_size + expand_by);
+	/* requested more than the set limit */
+	if (cur_cnt + add_cnt > max_cnt)
+		return NULL;
 
-		new_types = libbpf_reallocarray(btf->types, new_size, sizeof(*new_types));
-		if (!new_types)
-			return -ENOMEM;
+	new_cnt = *cap_cnt;
+	new_cnt += new_cnt / 4;		  /* expand by 25% */
+	if (new_cnt < 16)		  /* but at least 16 elements */
+		new_cnt = 16;
+	if (new_cnt > max_cnt)		  /* but not exceeding a set limit */
+		new_cnt = max_cnt;
+	if (new_cnt < cur_cnt + add_cnt)  /* also ensure we have enough memory */
+		new_cnt = cur_cnt + add_cnt;
+
+	new_data = libbpf_reallocarray(*data, new_cnt, elem_sz);
+	if (!new_data)
+		return NULL;
 
-		if (btf->nr_types == 0)
-			new_types[0] = &btf_void;
+	/* zero out newly allocated portion of memory */
+	memset(new_data + (*cap_cnt) * elem_sz, 0, (new_cnt - *cap_cnt) * elem_sz);
 
-		btf->types = new_types;
-		btf->types_size = new_size;
-	}
+	*data = new_data;
+	*cap_cnt = new_cnt;
+	return new_data + cur_cnt * elem_sz;
+}
+
+/* Ensure given dynamically allocated memory region has enough allocated space
+ * to accommodate *need_cnt* elements of size *elem_sz* bytes each
+ */
+int btf_ensure_mem(void **data, size_t *cap_cnt, size_t elem_sz, size_t need_cnt)
+{
+	void *p;
+
+	if (need_cnt <= *cap_cnt)
+		return 0;
+
+	p = btf_add_mem(data, cap_cnt, elem_sz, *cap_cnt, SIZE_MAX, need_cnt - *cap_cnt);
+	if (!p)
+		return -ENOMEM;
+
+	return 0;
+}
 
-	btf->types[++(btf->nr_types)] = t;
+static int btf_add_type_idx_entry(struct btf *btf, __u32 type_off)
+{
+	__u32 *p;
 
+	p = btf_add_mem((void **)&btf->type_offs, &btf->type_offs_cap, sizeof(__u32),
+			btf->nr_types + 1, BTF_MAX_NR_TYPES, 1);
+	if (!p)
+		return -ENOMEM;
+
+	*p = type_off;
 	return 0;
 }
 
+static void btf_bswap_hdr(struct btf_header *h)
+{
+	h->magic = bswap_16(h->magic);
+	h->hdr_len = bswap_32(h->hdr_len);
+	h->type_off = bswap_32(h->type_off);
+	h->type_len = bswap_32(h->type_len);
+	h->str_off = bswap_32(h->str_off);
+	h->str_len = bswap_32(h->str_len);
+}
+
 static int btf_parse_hdr(struct btf *btf)
 {
-	const struct btf_header *hdr = btf->hdr;
+	struct btf_header *hdr = btf->hdr;
 	__u32 meta_left;
 
-	if (btf->data_size < sizeof(struct btf_header)) {
+	if (btf->raw_size < sizeof(struct btf_header)) {
 		pr_debug("BTF header not found\n");
 		return -EINVAL;
 	}
 
-	if (hdr->magic != BTF_MAGIC) {
+	if (hdr->magic == bswap_16(BTF_MAGIC)) {
+		btf->swapped_endian = true;
+		if (bswap_32(hdr->hdr_len) != sizeof(struct btf_header)) {
+			pr_warn("Can't load BTF with non-native endianness due to unsupported header length %u\n",
+				bswap_32(hdr->hdr_len));
+			return -ENOTSUP;
+		}
+		btf_bswap_hdr(hdr);
+	} else if (hdr->magic != BTF_MAGIC) {
 		pr_debug("Invalid BTF magic:%x\n", hdr->magic);
 		return -EINVAL;
 	}
 
-	if (hdr->version != BTF_VERSION) {
-		pr_debug("Unsupported BTF version:%u\n", hdr->version);
-		return -ENOTSUP;
-	}
-
-	if (hdr->flags) {
-		pr_debug("Unsupported BTF flags:%x\n", hdr->flags);
-		return -ENOTSUP;
-	}
-
-	meta_left = btf->data_size - sizeof(*hdr);
+	meta_left = btf->raw_size - sizeof(*hdr);
 	if (!meta_left) {
 		pr_debug("BTF has no data\n");
 		return -EINVAL;
@@ -125,15 +235,13 @@ static int btf_parse_hdr(struct btf *btf)
 		return -EINVAL;
 	}
 
-	btf->nohdr_data = btf->hdr + 1;
-
 	return 0;
 }
 
 static int btf_parse_str_sec(struct btf *btf)
 {
 	const struct btf_header *hdr = btf->hdr;
-	const char *start = btf->nohdr_data + hdr->str_off;
+	const char *start = btf->strs_data;
 	const char *end = start + btf->hdr->str_len;
 
 	if (!hdr->str_len || hdr->str_len - 1 > BTF_MAX_STR_OFFSET ||
@@ -142,14 +250,12 @@ static int btf_parse_str_sec(struct btf *btf)
 		return -EINVAL;
 	}
 
-	btf->strings = start;
-
 	return 0;
 }
 
-static int btf_type_size(struct btf_type *t)
+static int btf_type_size(const struct btf_type *t)
 {
-	int base_size = sizeof(struct btf_type);
+	const int base_size = sizeof(struct btf_type);
 	__u16 vlen = btf_vlen(t);
 
 	switch (btf_kind(t)) {
@@ -182,25 +288,120 @@ static int btf_type_size(struct btf_type *t)
 	}
 }
 
+static void btf_bswap_type_base(struct btf_type *t)
+{
+	t->name_off = bswap_32(t->name_off);
+	t->info = bswap_32(t->info);
+	t->type = bswap_32(t->type);
+}
+
+static int btf_bswap_type_rest(struct btf_type *t)
+{
+	struct btf_var_secinfo *v;
+	struct btf_member *m;
+	struct btf_array *a;
+	struct btf_param *p;
+	struct btf_enum *e;
+	__u16 vlen = btf_vlen(t);
+	int i;
+
+	switch (btf_kind(t)) {
+	case BTF_KIND_FWD:
+	case BTF_KIND_CONST:
+	case BTF_KIND_VOLATILE:
+	case BTF_KIND_RESTRICT:
+	case BTF_KIND_PTR:
+	case BTF_KIND_TYPEDEF:
+	case BTF_KIND_FUNC:
+		return 0;
+	case BTF_KIND_INT:
+		*(__u32 *)(t + 1) = bswap_32(*(__u32 *)(t + 1));
+		return 0;
+	case BTF_KIND_ENUM:
+		for (i = 0, e = btf_enum(t); i < vlen; i++, e++) {
+			e->name_off = bswap_32(e->name_off);
+			e->val = bswap_32(e->val);
+		}
+		return 0;
+	case BTF_KIND_ARRAY:
+		a = btf_array(t);
+		a->type = bswap_32(a->type);
+		a->index_type = bswap_32(a->index_type);
+		a->nelems = bswap_32(a->nelems);
+		return 0;
+	case BTF_KIND_STRUCT:
+	case BTF_KIND_UNION:
+		for (i = 0, m = btf_members(t); i < vlen; i++, m++) {
+			m->name_off = bswap_32(m->name_off);
+			m->type = bswap_32(m->type);
+			m->offset = bswap_32(m->offset);
+		}
+		return 0;
+	case BTF_KIND_FUNC_PROTO:
+		for (i = 0, p = btf_params(t); i < vlen; i++, p++) {
+			p->name_off = bswap_32(p->name_off);
+			p->type = bswap_32(p->type);
+		}
+		return 0;
+	case BTF_KIND_VAR:
+		btf_var(t)->linkage = bswap_32(btf_var(t)->linkage);
+		return 0;
+	case BTF_KIND_DATASEC:
+		for (i = 0, v = btf_var_secinfos(t); i < vlen; i++, v++) {
+			v->type = bswap_32(v->type);
+			v->offset = bswap_32(v->offset);
+			v->size = bswap_32(v->size);
+		}
+		return 0;
+	default:
+		pr_debug("Unsupported BTF_KIND:%u\n", btf_kind(t));
+		return -EINVAL;
+	}
+}
+
 static int btf_parse_type_sec(struct btf *btf)
 {
 	struct btf_header *hdr = btf->hdr;
-	void *nohdr_data = btf->nohdr_data;
-	void *next_type = nohdr_data + hdr->type_off;
-	void *end_type = nohdr_data + hdr->str_off;
+	void *next_type = btf->types_data;
+	void *end_type = next_type + hdr->type_len;
+	int err, i = 0, type_size;
 
-	while (next_type < end_type) {
-		struct btf_type *t = next_type;
-		int type_size;
-		int err;
+	/* VOID (type_id == 0) is specially handled by btf__get_type_by_id(),
+	 * so ensure we can never properly use its offset from index by
+	 * setting it to a large value
+	 */
+	err = btf_add_type_idx_entry(btf, UINT_MAX);
+	if (err)
+		return err;
+
+	while (next_type + sizeof(struct btf_type) <= end_type) {
+		i++;
+
+		if (btf->swapped_endian)
+			btf_bswap_type_base(next_type);
 
-		type_size = btf_type_size(t);
+		type_size = btf_type_size(next_type);
 		if (type_size < 0)
 			return type_size;
-		next_type += type_size;
-		err = btf_add_type(btf, t);
+		if (next_type + type_size > end_type) {
+			pr_warn("BTF type [%d] is malformed\n", i);
+			return -EINVAL;
+		}
+
+		if (btf->swapped_endian && btf_bswap_type_rest(next_type))
+			return -EINVAL;
+
+		err = btf_add_type_idx_entry(btf, next_type - btf->types_data);
 		if (err)
 			return err;
+
+		next_type += type_size;
+		btf->nr_types++;
+	}
+
+	if (next_type != end_type) {
+		pr_warn("BTF types data is malformed\n");
+		return -EINVAL;
 	}
 
 	return 0;
@@ -211,12 +412,20 @@ __u32 btf__get_nr_types(const struct btf *btf)
 	return btf->nr_types;
 }
 
+/* internal helper returning non-const pointer to a type */
+static struct btf_type *btf_type_by_id(struct btf *btf, __u32 type_id)
+{
+	if (type_id == 0)
+		return &btf_void;
+
+	return btf->types_data + btf->type_offs[type_id];
+}
+
 const struct btf_type *btf__type_by_id(const struct btf *btf, __u32 type_id)
 {
 	if (type_id > btf->nr_types)
 		return NULL;
-
-	return btf->types[type_id];
+	return btf_type_by_id((struct btf *)btf, type_id);
 }
 
 static int determine_ptr_size(const struct btf *btf)
@@ -283,6 +492,38 @@ int btf__set_pointer_size(struct btf *btf, size_t ptr_sz)
 	return 0;
 }
 
+static bool is_host_big_endian(void)
+{
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+	return false;
+#elif __BYTE_ORDER == __BIG_ENDIAN
+	return true;
+#else
+# error "Unrecognized __BYTE_ORDER__"
+#endif
+}
+
+enum btf_endianness btf__endianness(const struct btf *btf)
+{
+	if (is_host_big_endian())
+		return btf->swapped_endian ? BTF_LITTLE_ENDIAN : BTF_BIG_ENDIAN;
+	else
+		return btf->swapped_endian ? BTF_BIG_ENDIAN : BTF_LITTLE_ENDIAN;
+}
+
+int btf__set_endianness(struct btf *btf, enum btf_endianness endian)
+{
+	if (endian != BTF_LITTLE_ENDIAN && endian != BTF_BIG_ENDIAN)
+		return -EINVAL;
+
+	btf->swapped_endian = is_host_big_endian() != (endian == BTF_BIG_ENDIAN);
+	if (!btf->swapped_endian) {
+		free(btf->raw_data_swapped);
+		btf->raw_data_swapped = NULL;
+	}
+	return 0;
+}
+
 static bool btf_type_is_void(const struct btf_type *t)
 {
 	return t == &btf_void || btf_is_fwd(t);
@@ -414,7 +655,7 @@ __s32 btf__find_by_name(const struct btf *btf, const char *type_name)
 		return 0;
 
 	for (i = 1; i <= btf->nr_types; i++) {
-		const struct btf_type *t = btf->types[i];
+		const struct btf_type *t = btf__type_by_id(btf, i);
 		const char *name = btf__name_by_offset(btf, t->name_off);
 
 		if (name && !strcmp(type_name, name))
@@ -433,7 +674,7 @@ __s32 btf__find_by_name_kind(const struct btf *btf, const char *type_name,
 		return 0;
 
 	for (i = 1; i <= btf->nr_types; i++) {
-		const struct btf_type *t = btf->types[i];
+		const struct btf_type *t = btf__type_by_id(btf, i);
 		const char *name;
 
 		if (btf_kind(t) != kind)
@@ -446,6 +687,11 @@ __s32 btf__find_by_name_kind(const struct btf *btf, const char *type_name,
 	return -ENOENT;
 }
 
+static bool btf_is_modifiable(const struct btf *btf)
+{
+	return (void *)btf->hdr != btf->raw_data;
+}
+
 void btf__free(struct btf *btf)
 {
 	if (IS_ERR_OR_NULL(btf))
@@ -454,11 +700,55 @@ void btf__free(struct btf *btf)
 	if (btf->fd >= 0)
 		close(btf->fd);
 
-	free(btf->data);
-	free(btf->types);
+	if (btf_is_modifiable(btf)) {
+		/* if BTF was modified after loading, it will have a split
+		 * in-memory representation for header, types, and strings
+		 * sections, so we need to free all of them individually. It
+		 * might still have a cached contiguous raw data present,
+		 * which will be unconditionally freed below.
+		 */
+		free(btf->hdr);
+		free(btf->types_data);
+		free(btf->strs_data);
+	}
+	free(btf->raw_data);
+	free(btf->raw_data_swapped);
+	free(btf->type_offs);
 	free(btf);
 }
 
+struct btf *btf__new_empty(void)
+{
+	struct btf *btf;
+
+	btf = calloc(1, sizeof(*btf));
+	if (!btf)
+		return ERR_PTR(-ENOMEM);
+
+	btf->fd = -1;
+	btf->ptr_sz = sizeof(void *);
+	btf->swapped_endian = false;
+
+	/* +1 for empty string at offset 0 */
+	btf->raw_size = sizeof(struct btf_header) + 1;
+	btf->raw_data = calloc(1, btf->raw_size);
+	if (!btf->raw_data) {
+		free(btf);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	btf->hdr = btf->raw_data;
+	btf->hdr->hdr_len = sizeof(struct btf_header);
+	btf->hdr->magic = BTF_MAGIC;
+	btf->hdr->version = BTF_VERSION;
+
+	btf->types_data = btf->raw_data + btf->hdr->hdr_len;
+	btf->strs_data = btf->raw_data + btf->hdr->hdr_len;
+	btf->hdr->str_len = 1; /* empty string at offset 0 */
+
+	return btf;
+}
+
 struct btf *btf__new(const void *data, __u32 size)
 {
 	struct btf *btf;
@@ -468,26 +758,28 @@ struct btf *btf__new(const void *data, __u32 size)
 	if (!btf)
 		return ERR_PTR(-ENOMEM);
 
-	btf->fd = -1;
-
-	btf->data = malloc(size);
-	if (!btf->data) {
+	btf->raw_data = malloc(size);
+	if (!btf->raw_data) {
 		err = -ENOMEM;
 		goto done;
 	}
+	memcpy(btf->raw_data, data, size);
+	btf->raw_size = size;
 
-	memcpy(btf->data, data, size);
-	btf->data_size = size;
-
+	btf->hdr = btf->raw_data;
 	err = btf_parse_hdr(btf);
 	if (err)
 		goto done;
 
+	btf->strs_data = btf->raw_data + btf->hdr->hdr_len + btf->hdr->str_off;
+	btf->types_data = btf->raw_data + btf->hdr->hdr_len + btf->hdr->type_off;
+
 	err = btf_parse_str_sec(btf);
+	err = err ?: btf_parse_type_sec(btf);
 	if (err)
 		goto done;
 
-	err = btf_parse_type_sec(btf);
+	btf->fd = -1;
 
 done:
 	if (err) {
@@ -498,17 +790,6 @@ done:
 	return btf;
 }
 
-static bool btf_check_endianness(const GElf_Ehdr *ehdr)
-{
-#if __BYTE_ORDER == __LITTLE_ENDIAN
-	return ehdr->e_ident[EI_DATA] == ELFDATA2LSB;
-#elif __BYTE_ORDER == __BIG_ENDIAN
-	return ehdr->e_ident[EI_DATA] == ELFDATA2MSB;
-#else
-# error "Unrecognized __BYTE_ORDER__"
-#endif
-}
-
 struct btf *btf__parse_elf(const char *path, struct btf_ext **btf_ext)
 {
 	Elf_Data *btf_data = NULL, *btf_ext_data = NULL;
@@ -541,10 +822,6 @@ struct btf *btf__parse_elf(const char *path, struct btf_ext **btf_ext)
 		pr_warn("failed to get EHDR from %s\n", path);
 		goto done;
 	}
-	if (!btf_check_endianness(&ehdr)) {
-		pr_warn("non-native ELF endianness is not supported\n");
-		goto done;
-	}
 	if (!elf_rawdata(elf_getscn(elf, ehdr.e_shstrndx), NULL)) {
 		pr_warn("failed to get e_shstrndx from %s\n", path);
 		goto done;
@@ -656,7 +933,7 @@ struct btf *btf__parse_raw(const char *path)
 		err = -EIO;
 		goto err_out;
 	}
-	if (magic != BTF_MAGIC) {
+	if (magic != BTF_MAGIC && magic != bswap_16(BTF_MAGIC)) {
 		/* definitely not a raw BTF */
 		err = -EPROTO;
 		goto err_out;
@@ -789,7 +1066,7 @@ int btf__finalize_data(struct bpf_object *obj, struct btf *btf)
 	__u32 i;
 
 	for (i = 1; i <= btf->nr_types; i++) {
-		struct btf_type *t = btf->types[i];
+		struct btf_type *t = btf_type_by_id(btf, i);
 
 		/* Loader needs to fix up some of the things compiler
 		 * couldn't get its hands on while emitting BTF. This
@@ -806,10 +1083,13 @@ int btf__finalize_data(struct bpf_object *obj, struct btf *btf)
 	return err;
 }
 
+static void *btf_get_raw_data(const struct btf *btf, __u32 *size, bool swap_endian);
+
 int btf__load(struct btf *btf)
 {
-	__u32 log_buf_size = 0;
+	__u32 log_buf_size = 0, raw_size;
 	char *log_buf = NULL;
+	void *raw_data;
 	int err = 0;
 
 	if (btf->fd >= 0)
@@ -824,8 +1104,16 @@ retry_load:
 		*log_buf = 0;
 	}
 
-	btf->fd = bpf_load_btf(btf->data, btf->data_size,
-			       log_buf, log_buf_size, false);
+	raw_data = btf_get_raw_data(btf, &raw_size, false);
+	if (!raw_data) {
+		err = -ENOMEM;
+		goto done;
+	}
+	/* cache native raw data representation */
+	btf->raw_size = raw_size;
+	btf->raw_data = raw_data;
+
+	btf->fd = bpf_load_btf(raw_data, raw_size, log_buf, log_buf_size, false);
 	if (btf->fd < 0) {
 		if (!log_buf || errno == ENOSPC) {
 			log_buf_size = max((__u32)BPF_LOG_BUF_SIZE,
@@ -856,20 +1144,88 @@ void btf__set_fd(struct btf *btf, int fd)
 	btf->fd = fd;
 }
 
-const void *btf__get_raw_data(const struct btf *btf, __u32 *size)
+static void *btf_get_raw_data(const struct btf *btf, __u32 *size, bool swap_endian)
+{
+	struct btf_header *hdr = btf->hdr;
+	struct btf_type *t;
+	void *data, *p;
+	__u32 data_sz;
+	int i;
+
+	data = swap_endian ? btf->raw_data_swapped : btf->raw_data;
+	if (data) {
+		*size = btf->raw_size;
+		return data;
+	}
+
+	data_sz = hdr->hdr_len + hdr->type_len + hdr->str_len;
+	data = calloc(1, data_sz);
+	if (!data)
+		return NULL;
+	p = data;
+
+	memcpy(p, hdr, hdr->hdr_len);
+	if (swap_endian)
+		btf_bswap_hdr(p);
+	p += hdr->hdr_len;
+
+	memcpy(p, btf->types_data, hdr->type_len);
+	if (swap_endian) {
+		for (i = 1; i <= btf->nr_types; i++) {
+			t = p  + btf->type_offs[i];
+			/* btf_bswap_type_rest() relies on native t->info, so
+			 * we swap base type info after we swapped all the
+			 * additional information
+			 */
+			if (btf_bswap_type_rest(t))
+				goto err_out;
+			btf_bswap_type_base(t);
+		}
+	}
+	p += hdr->type_len;
+
+	memcpy(p, btf->strs_data, hdr->str_len);
+	p += hdr->str_len;
+
+	*size = data_sz;
+	return data;
+err_out:
+	free(data);
+	return NULL;
+}
+
+const void *btf__get_raw_data(const struct btf *btf_ro, __u32 *size)
 {
-	*size = btf->data_size;
-	return btf->data;
+	struct btf *btf = (struct btf *)btf_ro;
+	__u32 data_sz;
+	void *data;
+
+	data = btf_get_raw_data(btf, &data_sz, btf->swapped_endian);
+	if (!data)
+		return NULL;
+
+	btf->raw_size = data_sz;
+	if (btf->swapped_endian)
+		btf->raw_data_swapped = data;
+	else
+		btf->raw_data = data;
+	*size = data_sz;
+	return data;
 }
 
-const char *btf__name_by_offset(const struct btf *btf, __u32 offset)
+const char *btf__str_by_offset(const struct btf *btf, __u32 offset)
 {
 	if (offset < btf->hdr->str_len)
-		return &btf->strings[offset];
+		return btf->strs_data + offset;
 	else
 		return NULL;
 }
 
+const char *btf__name_by_offset(const struct btf *btf, __u32 offset)
+{
+	return btf__str_by_offset(btf, offset);
+}
+
 int btf__get_from_id(__u32 id, struct btf **btf)
 {
 	struct bpf_btf_info btf_info = { 0 };
@@ -1005,6 +1361,970 @@ int btf__get_map_kv_tids(const struct btf *btf, const char *map_name,
 	return 0;
 }
 
+static size_t strs_hash_fn(const void *key, void *ctx)
+{
+	struct btf *btf = ctx;
+	const char *str = btf->strs_data + (long)key;
+
+	return str_hash(str);
+}
+
+static bool strs_hash_equal_fn(const void *key1, const void *key2, void *ctx)
+{
+	struct btf *btf = ctx;
+	const char *str1 = btf->strs_data + (long)key1;
+	const char *str2 = btf->strs_data + (long)key2;
+
+	return strcmp(str1, str2) == 0;
+}
+
+static void btf_invalidate_raw_data(struct btf *btf)
+{
+	if (btf->raw_data) {
+		free(btf->raw_data);
+		btf->raw_data = NULL;
+	}
+	if (btf->raw_data_swapped) {
+		free(btf->raw_data_swapped);
+		btf->raw_data_swapped = NULL;
+	}
+}
+
+/* Ensure BTF is ready to be modified (by splitting into a three memory
+ * regions for header, types, and strings). Also invalidate cached
+ * raw_data, if any.
+ */
+static int btf_ensure_modifiable(struct btf *btf)
+{
+	void *hdr, *types, *strs, *strs_end, *s;
+	struct hashmap *hash = NULL;
+	long off;
+	int err;
+
+	if (btf_is_modifiable(btf)) {
+		/* any BTF modification invalidates raw_data */
+		btf_invalidate_raw_data(btf);
+		return 0;
+	}
+
+	/* split raw data into three memory regions */
+	hdr = malloc(btf->hdr->hdr_len);
+	types = malloc(btf->hdr->type_len);
+	strs = malloc(btf->hdr->str_len);
+	if (!hdr || !types || !strs)
+		goto err_out;
+
+	memcpy(hdr, btf->hdr, btf->hdr->hdr_len);
+	memcpy(types, btf->types_data, btf->hdr->type_len);
+	memcpy(strs, btf->strs_data, btf->hdr->str_len);
+
+	/* build lookup index for all strings */
+	hash = hashmap__new(strs_hash_fn, strs_hash_equal_fn, btf);
+	if (IS_ERR(hash)) {
+		err = PTR_ERR(hash);
+		hash = NULL;
+		goto err_out;
+	}
+
+	strs_end = strs + btf->hdr->str_len;
+	for (off = 0, s = strs; s < strs_end; off += strlen(s) + 1, s = strs + off) {
+		/* hashmap__add() returns EEXIST if string with the same
+		 * content already is in the hash map
+		 */
+		err = hashmap__add(hash, (void *)off, (void *)off);
+		if (err == -EEXIST)
+			continue; /* duplicate */
+		if (err)
+			goto err_out;
+	}
+
+	/* only when everything was successful, update internal state */
+	btf->hdr = hdr;
+	btf->types_data = types;
+	btf->types_data_cap = btf->hdr->type_len;
+	btf->strs_data = strs;
+	btf->strs_data_cap = btf->hdr->str_len;
+	btf->strs_hash = hash;
+	/* if BTF was created from scratch, all strings are guaranteed to be
+	 * unique and deduplicated
+	 */
+	btf->strs_deduped = btf->hdr->str_len <= 1;
+
+	/* invalidate raw_data representation */
+	btf_invalidate_raw_data(btf);
+
+	return 0;
+
+err_out:
+	hashmap__free(hash);
+	free(hdr);
+	free(types);
+	free(strs);
+	return -ENOMEM;
+}
+
+static void *btf_add_str_mem(struct btf *btf, size_t add_sz)
+{
+	return btf_add_mem(&btf->strs_data, &btf->strs_data_cap, 1,
+			   btf->hdr->str_len, BTF_MAX_STR_OFFSET, add_sz);
+}
+
+/* Find an offset in BTF string section that corresponds to a given string *s*.
+ * Returns:
+ *   - >0 offset into string section, if string is found;
+ *   - -ENOENT, if string is not in the string section;
+ *   - <0, on any other error.
+ */
+int btf__find_str(struct btf *btf, const char *s)
+{
+	long old_off, new_off, len;
+	void *p;
+
+	/* BTF needs to be in a modifiable state to build string lookup index */
+	if (btf_ensure_modifiable(btf))
+		return -ENOMEM;
+
+	/* see btf__add_str() for why we do this */
+	len = strlen(s) + 1;
+	p = btf_add_str_mem(btf, len);
+	if (!p)
+		return -ENOMEM;
+
+	new_off = btf->hdr->str_len;
+	memcpy(p, s, len);
+
+	if (hashmap__find(btf->strs_hash, (void *)new_off, (void **)&old_off))
+		return old_off;
+
+	return -ENOENT;
+}
+
+/* Add a string s to the BTF string section.
+ * Returns:
+ *   - > 0 offset into string section, on success;
+ *   - < 0, on error.
+ */
+int btf__add_str(struct btf *btf, const char *s)
+{
+	long old_off, new_off, len;
+	void *p;
+	int err;
+
+	if (btf_ensure_modifiable(btf))
+		return -ENOMEM;
+
+	/* Hashmap keys are always offsets within btf->strs_data, so to even
+	 * look up some string from the "outside", we need to first append it
+	 * at the end, so that it can be addressed with an offset. Luckily,
+	 * until btf->hdr->str_len is incremented, that string is just a piece
+	 * of garbage for the rest of BTF code, so no harm, no foul. On the
+	 * other hand, if the string is unique, it's already appended and
+	 * ready to be used, only a simple btf->hdr->str_len increment away.
+	 */
+	len = strlen(s) + 1;
+	p = btf_add_str_mem(btf, len);
+	if (!p)
+		return -ENOMEM;
+
+	new_off = btf->hdr->str_len;
+	memcpy(p, s, len);
+
+	/* Now attempt to add the string, but only if the string with the same
+	 * contents doesn't exist already (HASHMAP_ADD strategy). If such
+	 * string exists, we'll get its offset in old_off (that's old_key).
+	 */
+	err = hashmap__insert(btf->strs_hash, (void *)new_off, (void *)new_off,
+			      HASHMAP_ADD, (const void **)&old_off, NULL);
+	if (err == -EEXIST)
+		return old_off; /* duplicated string, return existing offset */
+	if (err)
+		return err;
+
+	btf->hdr->str_len += len; /* new unique string, adjust data length */
+	return new_off;
+}
+
+static void *btf_add_type_mem(struct btf *btf, size_t add_sz)
+{
+	return btf_add_mem(&btf->types_data, &btf->types_data_cap, 1,
+			   btf->hdr->type_len, UINT_MAX, add_sz);
+}
+
+static __u32 btf_type_info(int kind, int vlen, int kflag)
+{
+	return (kflag << 31) | (kind << 24) | vlen;
+}
+
+static void btf_type_inc_vlen(struct btf_type *t)
+{
+	t->info = btf_type_info(btf_kind(t), btf_vlen(t) + 1, btf_kflag(t));
+}
+
+/*
+ * Append new BTF_KIND_INT type with:
+ *   - *name* - non-empty, non-NULL type name;
+ *   - *sz* - power-of-2 (1, 2, 4, ..) size of the type, in bytes;
+ *   - encoding is a combination of BTF_INT_SIGNED, BTF_INT_CHAR, BTF_INT_BOOL.
+ * Returns:
+ *   - >0, type ID of newly added BTF type;
+ *   - <0, on error.
+ */
+int btf__add_int(struct btf *btf, const char *name, size_t byte_sz, int encoding)
+{
+	struct btf_type *t;
+	int sz, err, name_off;
+
+	/* non-empty name */
+	if (!name || !name[0])
+		return -EINVAL;
+	/* byte_sz must be power of 2 */
+	if (!byte_sz || (byte_sz & (byte_sz - 1)) || byte_sz > 16)
+		return -EINVAL;
+	if (encoding & ~(BTF_INT_SIGNED | BTF_INT_CHAR | BTF_INT_BOOL))
+		return -EINVAL;
+
+	/* deconstruct BTF, if necessary, and invalidate raw_data */
+	if (btf_ensure_modifiable(btf))
+		return -ENOMEM;
+
+	sz = sizeof(struct btf_type) + sizeof(int);
+	t = btf_add_type_mem(btf, sz);
+	if (!t)
+		return -ENOMEM;
+
+	/* if something goes wrong later, we might end up with an extra string,
+	 * but that shouldn't be a problem, because BTF can't be constructed
+	 * completely anyway and will most probably be just discarded
+	 */
+	name_off = btf__add_str(btf, name);
+	if (name_off < 0)
+		return name_off;
+
+	t->name_off = name_off;
+	t->info = btf_type_info(BTF_KIND_INT, 0, 0);
+	t->size = byte_sz;
+	/* set INT info, we don't allow setting legacy bit offset/size */
+	*(__u32 *)(t + 1) = (encoding << 24) | (byte_sz * 8);
+
+	err = btf_add_type_idx_entry(btf, btf->hdr->type_len);
+	if (err)
+		return err;
+
+	btf->hdr->type_len += sz;
+	btf->hdr->str_off += sz;
+	btf->nr_types++;
+	return btf->nr_types;
+}
+
+/* it's completely legal to append BTF types with type IDs pointing forward to
+ * types that haven't been appended yet, so we only make sure that id looks
+ * sane, we can't guarantee that ID will always be valid
+ */
+static int validate_type_id(int id)
+{
+	if (id < 0 || id > BTF_MAX_NR_TYPES)
+		return -EINVAL;
+	return 0;
+}
+
+/* generic append function for PTR, TYPEDEF, CONST/VOLATILE/RESTRICT */
+static int btf_add_ref_kind(struct btf *btf, int kind, const char *name, int ref_type_id)
+{
+	struct btf_type *t;
+	int sz, name_off = 0, err;
+
+	if (validate_type_id(ref_type_id))
+		return -EINVAL;
+
+	if (btf_ensure_modifiable(btf))
+		return -ENOMEM;
+
+	sz = sizeof(struct btf_type);
+	t = btf_add_type_mem(btf, sz);
+	if (!t)
+		return -ENOMEM;
+
+	if (name && name[0]) {
+		name_off = btf__add_str(btf, name);
+		if (name_off < 0)
+			return name_off;
+	}
+
+	t->name_off = name_off;
+	t->info = btf_type_info(kind, 0, 0);
+	t->type = ref_type_id;
+
+	err = btf_add_type_idx_entry(btf, btf->hdr->type_len);
+	if (err)
+		return err;
+
+	btf->hdr->type_len += sz;
+	btf->hdr->str_off += sz;
+	btf->nr_types++;
+	return btf->nr_types;
+}
+
+/*
+ * Append new BTF_KIND_PTR type with:
+ *   - *ref_type_id* - referenced type ID, it might not exist yet;
+ * Returns:
+ *   - >0, type ID of newly added BTF type;
+ *   - <0, on error.
+ */
+int btf__add_ptr(struct btf *btf, int ref_type_id)
+{
+	return btf_add_ref_kind(btf, BTF_KIND_PTR, NULL, ref_type_id);
+}
+
+/*
+ * Append new BTF_KIND_ARRAY type with:
+ *   - *index_type_id* - type ID of the type describing array index;
+ *   - *elem_type_id* - type ID of the type describing array element;
+ *   - *nr_elems* - the size of the array;
+ * Returns:
+ *   - >0, type ID of newly added BTF type;
+ *   - <0, on error.
+ */
+int btf__add_array(struct btf *btf, int index_type_id, int elem_type_id, __u32 nr_elems)
+{
+	struct btf_type *t;
+	struct btf_array *a;
+	int sz, err;
+
+	if (validate_type_id(index_type_id) || validate_type_id(elem_type_id))
+		return -EINVAL;
+
+	if (btf_ensure_modifiable(btf))
+		return -ENOMEM;
+
+	sz = sizeof(struct btf_type) + sizeof(struct btf_array);
+	t = btf_add_type_mem(btf, sz);
+	if (!t)
+		return -ENOMEM;
+
+	t->name_off = 0;
+	t->info = btf_type_info(BTF_KIND_ARRAY, 0, 0);
+	t->size = 0;
+
+	a = btf_array(t);
+	a->type = elem_type_id;
+	a->index_type = index_type_id;
+	a->nelems = nr_elems;
+
+	err = btf_add_type_idx_entry(btf, btf->hdr->type_len);
+	if (err)
+		return err;
+
+	btf->hdr->type_len += sz;
+	btf->hdr->str_off += sz;
+	btf->nr_types++;
+	return btf->nr_types;
+}
+
+/* generic STRUCT/UNION append function */
+static int btf_add_composite(struct btf *btf, int kind, const char *name, __u32 bytes_sz)
+{
+	struct btf_type *t;
+	int sz, err, name_off = 0;
+
+	if (btf_ensure_modifiable(btf))
+		return -ENOMEM;
+
+	sz = sizeof(struct btf_type);
+	t = btf_add_type_mem(btf, sz);
+	if (!t)
+		return -ENOMEM;
+
+	if (name && name[0]) {
+		name_off = btf__add_str(btf, name);
+		if (name_off < 0)
+			return name_off;
+	}
+
+	/* start out with vlen=0 and no kflag; this will be adjusted when
+	 * adding each member
+	 */
+	t->name_off = name_off;
+	t->info = btf_type_info(kind, 0, 0);
+	t->size = bytes_sz;
+
+	err = btf_add_type_idx_entry(btf, btf->hdr->type_len);
+	if (err)
+		return err;
+
+	btf->hdr->type_len += sz;
+	btf->hdr->str_off += sz;
+	btf->nr_types++;
+	return btf->nr_types;
+}
+
+/*
+ * Append new BTF_KIND_STRUCT type with:
+ *   - *name* - name of the struct, can be NULL or empty for anonymous structs;
+ *   - *byte_sz* - size of the struct, in bytes;
+ *
+ * Struct initially has no fields in it. Fields can be added by
+ * btf__add_field() right after btf__add_struct() succeeds. 
+ *
+ * Returns:
+ *   - >0, type ID of newly added BTF type;
+ *   - <0, on error.
+ */
+int btf__add_struct(struct btf *btf, const char *name, __u32 byte_sz)
+{
+	return btf_add_composite(btf, BTF_KIND_STRUCT, name, byte_sz);
+}
+
+/*
+ * Append new BTF_KIND_UNION type with:
+ *   - *name* - name of the union, can be NULL or empty for anonymous union;
+ *   - *byte_sz* - size of the union, in bytes;
+ *
+ * Union initially has no fields in it. Fields can be added by
+ * btf__add_field() right after btf__add_union() succeeds. All fields
+ * should have *bit_offset* of 0.
+ *
+ * Returns:
+ *   - >0, type ID of newly added BTF type;
+ *   - <0, on error.
+ */
+int btf__add_union(struct btf *btf, const char *name, __u32 byte_sz)
+{
+	return btf_add_composite(btf, BTF_KIND_UNION, name, byte_sz);
+}
+
+/*
+ * Append new field for the current STRUCT/UNION type with:
+ *   - *name* - name of the field, can be NULL or empty for anonymous field;
+ *   - *type_id* - type ID for the type describing field type;
+ *   - *bit_offset* - bit offset of the start of the field within struct/union;
+ *   - *bit_size* - bit size of a bitfield, 0 for non-bitfield fields;
+ * Returns:
+ *   -  0, on success;
+ *   - <0, on error.
+ */
+int btf__add_field(struct btf *btf, const char *name, int type_id,
+		   __u32 bit_offset, __u32 bit_size)
+{
+	struct btf_type *t;
+	struct btf_member *m;
+	bool is_bitfield;
+	int sz, name_off = 0;
+
+	/* last type should be union/struct */
+	if (btf->nr_types == 0)
+		return -EINVAL;
+	t = btf_type_by_id(btf, btf->nr_types);
+	if (!btf_is_composite(t))
+		return -EINVAL;
+
+	if (validate_type_id(type_id))
+		return -EINVAL;
+	/* best-effort bit field offset/size enforcement */
+	is_bitfield = bit_size || (bit_offset % 8 != 0);
+	if (is_bitfield && (bit_size == 0 || bit_size > 255 || bit_offset > 0xffffff))
+		return -EINVAL;
+
+	/* only offset 0 is allowed for unions */
+	if (btf_is_union(t) && bit_offset)
+		return -EINVAL;
+
+	/* decompose and invalidate raw data */
+	if (btf_ensure_modifiable(btf))
+		return -ENOMEM;
+
+	sz = sizeof(struct btf_member);
+	m = btf_add_type_mem(btf, sz);
+	if (!m)
+		return -ENOMEM;
+
+	if (name && name[0]) {
+		name_off = btf__add_str(btf, name);
+		if (name_off < 0)
+			return name_off;
+	}
+
+	m->name_off = name_off;
+	m->type = type_id;
+	m->offset = bit_offset | (bit_size << 24);
+
+	/* btf_add_type_mem can invalidate t pointer */
+	t = btf_type_by_id(btf, btf->nr_types);
+	/* update parent type's vlen and kflag */
+	t->info = btf_type_info(btf_kind(t), btf_vlen(t) + 1, is_bitfield || btf_kflag(t));
+
+	btf->hdr->type_len += sz;
+	btf->hdr->str_off += sz;
+	return 0;
+}
+
+/*
+ * Append new BTF_KIND_ENUM type with:
+ *   - *name* - name of the enum, can be NULL or empty for anonymous enums;
+ *   - *byte_sz* - size of the enum, in bytes.
+ *
+ * Enum initially has no enum values in it (and corresponds to enum forward
+ * declaration). Enumerator values can be added by btf__add_enum_value()
+ * immediately after btf__add_enum() succeeds.
+ *
+ * Returns:
+ *   - >0, type ID of newly added BTF type;
+ *   - <0, on error.
+ */
+int btf__add_enum(struct btf *btf, const char *name, __u32 byte_sz)
+{
+	struct btf_type *t;
+	int sz, err, name_off = 0;
+
+	/* byte_sz must be power of 2 */
+	if (!byte_sz || (byte_sz & (byte_sz - 1)) || byte_sz > 8)
+		return -EINVAL;
+
+	if (btf_ensure_modifiable(btf))
+		return -ENOMEM;
+
+	sz = sizeof(struct btf_type);
+	t = btf_add_type_mem(btf, sz);
+	if (!t)
+		return -ENOMEM;
+
+	if (name && name[0]) {
+		name_off = btf__add_str(btf, name);
+		if (name_off < 0)
+			return name_off;
+	}
+
+	/* start out with vlen=0; it will be adjusted when adding enum values */
+	t->name_off = name_off;
+	t->info = btf_type_info(BTF_KIND_ENUM, 0, 0);
+	t->size = byte_sz;
+
+	err = btf_add_type_idx_entry(btf, btf->hdr->type_len);
+	if (err)
+		return err;
+
+	btf->hdr->type_len += sz;
+	btf->hdr->str_off += sz;
+	btf->nr_types++;
+	return btf->nr_types;
+}
+
+/*
+ * Append new enum value for the current ENUM type with:
+ *   - *name* - name of the enumerator value, can't be NULL or empty;
+ *   - *value* - integer value corresponding to enum value *name*;
+ * Returns:
+ *   -  0, on success;
+ *   - <0, on error.
+ */
+int btf__add_enum_value(struct btf *btf, const char *name, __s64 value)
+{
+	struct btf_type *t;
+	struct btf_enum *v;
+	int sz, name_off;
+
+	/* last type should be BTF_KIND_ENUM */
+	if (btf->nr_types == 0)
+		return -EINVAL;
+	t = btf_type_by_id(btf, btf->nr_types);
+	if (!btf_is_enum(t))
+		return -EINVAL;
+
+	/* non-empty name */
+	if (!name || !name[0])
+		return -EINVAL;
+	if (value < INT_MIN || value > UINT_MAX)
+		return -E2BIG;
+
+	/* decompose and invalidate raw data */
+	if (btf_ensure_modifiable(btf))
+		return -ENOMEM;
+
+	sz = sizeof(struct btf_enum);
+	v = btf_add_type_mem(btf, sz);
+	if (!v)
+		return -ENOMEM;
+
+	name_off = btf__add_str(btf, name);
+	if (name_off < 0)
+		return name_off;
+
+	v->name_off = name_off;
+	v->val = value;
+
+	/* update parent type's vlen */
+	t = btf_type_by_id(btf, btf->nr_types);
+	btf_type_inc_vlen(t);
+
+	btf->hdr->type_len += sz;
+	btf->hdr->str_off += sz;
+	return 0;
+}
+
+/*
+ * Append new BTF_KIND_FWD type with:
+ *   - *name*, non-empty/non-NULL name;
+ *   - *fwd_kind*, kind of forward declaration, one of BTF_FWD_STRUCT,
+ *     BTF_FWD_UNION, or BTF_FWD_ENUM;
+ * Returns:
+ *   - >0, type ID of newly added BTF type;
+ *   - <0, on error.
+ */
+int btf__add_fwd(struct btf *btf, const char *name, enum btf_fwd_kind fwd_kind)
+{
+	if (!name || !name[0])
+		return -EINVAL;
+
+	switch (fwd_kind) {
+	case BTF_FWD_STRUCT:
+	case BTF_FWD_UNION: {
+		struct btf_type *t;
+		int id;
+
+		id = btf_add_ref_kind(btf, BTF_KIND_FWD, name, 0);
+		if (id <= 0)
+			return id;
+		t = btf_type_by_id(btf, id);
+		t->info = btf_type_info(BTF_KIND_FWD, 0, fwd_kind == BTF_FWD_UNION);
+		return id;
+	}
+	case BTF_FWD_ENUM:
+		/* enum forward in BTF currently is just an enum with no enum
+		 * values; we also assume a standard 4-byte size for it
+		 */
+		return btf__add_enum(btf, name, sizeof(int));
+	default:
+		return -EINVAL;
+	}
+}
+
+/*
+ * Append new BTF_KING_TYPEDEF type with:
+ *   - *name*, non-empty/non-NULL name;
+ *   - *ref_type_id* - referenced type ID, it might not exist yet;
+ * Returns:
+ *   - >0, type ID of newly added BTF type;
+ *   - <0, on error.
+ */
+int btf__add_typedef(struct btf *btf, const char *name, int ref_type_id)
+{
+	if (!name || !name[0])
+		return -EINVAL;
+
+	return btf_add_ref_kind(btf, BTF_KIND_TYPEDEF, name, ref_type_id);
+}
+
+/*
+ * Append new BTF_KIND_VOLATILE type with:
+ *   - *ref_type_id* - referenced type ID, it might not exist yet;
+ * Returns:
+ *   - >0, type ID of newly added BTF type;
+ *   - <0, on error.
+ */
+int btf__add_volatile(struct btf *btf, int ref_type_id)
+{
+	return btf_add_ref_kind(btf, BTF_KIND_VOLATILE, NULL, ref_type_id);
+}
+
+/*
+ * Append new BTF_KIND_CONST type with:
+ *   - *ref_type_id* - referenced type ID, it might not exist yet;
+ * Returns:
+ *   - >0, type ID of newly added BTF type;
+ *   - <0, on error.
+ */
+int btf__add_const(struct btf *btf, int ref_type_id)
+{
+	return btf_add_ref_kind(btf, BTF_KIND_CONST, NULL, ref_type_id);
+}
+
+/*
+ * Append new BTF_KIND_RESTRICT type with:
+ *   - *ref_type_id* - referenced type ID, it might not exist yet;
+ * Returns:
+ *   - >0, type ID of newly added BTF type;
+ *   - <0, on error.
+ */
+int btf__add_restrict(struct btf *btf, int ref_type_id)
+{
+	return btf_add_ref_kind(btf, BTF_KIND_RESTRICT, NULL, ref_type_id);
+}
+
+/*
+ * Append new BTF_KIND_FUNC type with:
+ *   - *name*, non-empty/non-NULL name;
+ *   - *proto_type_id* - FUNC_PROTO's type ID, it might not exist yet;
+ * Returns:
+ *   - >0, type ID of newly added BTF type;
+ *   - <0, on error.
+ */
+int btf__add_func(struct btf *btf, const char *name,
+		  enum btf_func_linkage linkage, int proto_type_id)
+{
+	int id;
+
+	if (!name || !name[0])
+		return -EINVAL;
+	if (linkage != BTF_FUNC_STATIC && linkage != BTF_FUNC_GLOBAL &&
+	    linkage != BTF_FUNC_EXTERN)
+		return -EINVAL;
+
+	id = btf_add_ref_kind(btf, BTF_KIND_FUNC, name, proto_type_id);
+	if (id > 0) {
+		struct btf_type *t = btf_type_by_id(btf, id);
+
+		t->info = btf_type_info(BTF_KIND_FUNC, linkage, 0);
+	}
+	return id;
+}
+
+/*
+ * Append new BTF_KIND_FUNC_PROTO with:
+ *   - *ret_type_id* - type ID for return result of a function.
+ *
+ * Function prototype initially has no arguments, but they can be added by
+ * btf__add_func_param() one by one, immediately after
+ * btf__add_func_proto() succeeded.
+ *
+ * Returns:
+ *   - >0, type ID of newly added BTF type;
+ *   - <0, on error.
+ */
+int btf__add_func_proto(struct btf *btf, int ret_type_id)
+{
+	struct btf_type *t;
+	int sz, err;
+
+	if (validate_type_id(ret_type_id))
+		return -EINVAL;
+
+	if (btf_ensure_modifiable(btf))
+		return -ENOMEM;
+
+	sz = sizeof(struct btf_type);
+	t = btf_add_type_mem(btf, sz);
+	if (!t)
+		return -ENOMEM;
+
+	/* start out with vlen=0; this will be adjusted when adding enum
+	 * values, if necessary
+	 */
+	t->name_off = 0;
+	t->info = btf_type_info(BTF_KIND_FUNC_PROTO, 0, 0);
+	t->type = ret_type_id;
+
+	err = btf_add_type_idx_entry(btf, btf->hdr->type_len);
+	if (err)
+		return err;
+
+	btf->hdr->type_len += sz;
+	btf->hdr->str_off += sz;
+	btf->nr_types++;
+	return btf->nr_types;
+}
+
+/*
+ * Append new function parameter for current FUNC_PROTO type with:
+ *   - *name* - parameter name, can be NULL or empty;
+ *   - *type_id* - type ID describing the type of the parameter.
+ * Returns:
+ *   -  0, on success;
+ *   - <0, on error.
+ */
+int btf__add_func_param(struct btf *btf, const char *name, int type_id)
+{
+	struct btf_type *t;
+	struct btf_param *p;
+	int sz, name_off = 0;
+
+	if (validate_type_id(type_id))
+		return -EINVAL;
+
+	/* last type should be BTF_KIND_FUNC_PROTO */
+	if (btf->nr_types == 0)
+		return -EINVAL;
+	t = btf_type_by_id(btf, btf->nr_types);
+	if (!btf_is_func_proto(t))
+		return -EINVAL;
+
+	/* decompose and invalidate raw data */
+	if (btf_ensure_modifiable(btf))
+		return -ENOMEM;
+
+	sz = sizeof(struct btf_param);
+	p = btf_add_type_mem(btf, sz);
+	if (!p)
+		return -ENOMEM;
+
+	if (name && name[0]) {
+		name_off = btf__add_str(btf, name);
+		if (name_off < 0)
+			return name_off;
+	}
+
+	p->name_off = name_off;
+	p->type = type_id;
+
+	/* update parent type's vlen */
+	t = btf_type_by_id(btf, btf->nr_types);
+	btf_type_inc_vlen(t);
+
+	btf->hdr->type_len += sz;
+	btf->hdr->str_off += sz;
+	return 0;
+}
+
+/*
+ * Append new BTF_KIND_VAR type with:
+ *   - *name* - non-empty/non-NULL name;
+ *   - *linkage* - variable linkage, one of BTF_VAR_STATIC,
+ *     BTF_VAR_GLOBAL_ALLOCATED, or BTF_VAR_GLOBAL_EXTERN;
+ *   - *type_id* - type ID of the type describing the type of the variable.
+ * Returns:
+ *   - >0, type ID of newly added BTF type;
+ *   - <0, on error.
+ */
+int btf__add_var(struct btf *btf, const char *name, int linkage, int type_id)
+{
+	struct btf_type *t;
+	struct btf_var *v;
+	int sz, err, name_off;
+
+	/* non-empty name */
+	if (!name || !name[0])
+		return -EINVAL;
+	if (linkage != BTF_VAR_STATIC && linkage != BTF_VAR_GLOBAL_ALLOCATED &&
+	    linkage != BTF_VAR_GLOBAL_EXTERN)
+		return -EINVAL;
+	if (validate_type_id(type_id))
+		return -EINVAL;
+
+	/* deconstruct BTF, if necessary, and invalidate raw_data */
+	if (btf_ensure_modifiable(btf))
+		return -ENOMEM;
+
+	sz = sizeof(struct btf_type) + sizeof(struct btf_var);
+	t = btf_add_type_mem(btf, sz);
+	if (!t)
+		return -ENOMEM;
+
+	name_off = btf__add_str(btf, name);
+	if (name_off < 0)
+		return name_off;
+
+	t->name_off = name_off;
+	t->info = btf_type_info(BTF_KIND_VAR, 0, 0);
+	t->type = type_id;
+
+	v = btf_var(t);
+	v->linkage = linkage;
+
+	err = btf_add_type_idx_entry(btf, btf->hdr->type_len);
+	if (err)
+		return err;
+
+	btf->hdr->type_len += sz;
+	btf->hdr->str_off += sz;
+	btf->nr_types++;
+	return btf->nr_types;
+}
+
+/*
+ * Append new BTF_KIND_DATASEC type with:
+ *   - *name* - non-empty/non-NULL name;
+ *   - *byte_sz* - data section size, in bytes.
+ *
+ * Data section is initially empty. Variables info can be added with
+ * btf__add_datasec_var_info() calls, after btf__add_datasec() succeeds.
+ *
+ * Returns:
+ *   - >0, type ID of newly added BTF type;
+ *   - <0, on error.
+ */
+int btf__add_datasec(struct btf *btf, const char *name, __u32 byte_sz)
+{
+	struct btf_type *t;
+	int sz, err, name_off;
+
+	/* non-empty name */
+	if (!name || !name[0])
+		return -EINVAL;
+
+	if (btf_ensure_modifiable(btf))
+		return -ENOMEM;
+
+	sz = sizeof(struct btf_type);
+	t = btf_add_type_mem(btf, sz);
+	if (!t)
+		return -ENOMEM;
+
+	name_off = btf__add_str(btf, name);
+	if (name_off < 0)
+		return name_off;
+
+	/* start with vlen=0, which will be update as var_secinfos are added */
+	t->name_off = name_off;
+	t->info = btf_type_info(BTF_KIND_DATASEC, 0, 0);
+	t->size = byte_sz;
+
+	err = btf_add_type_idx_entry(btf, btf->hdr->type_len);
+	if (err)
+		return err;
+
+	btf->hdr->type_len += sz;
+	btf->hdr->str_off += sz;
+	btf->nr_types++;
+	return btf->nr_types;
+}
+
+/*
+ * Append new data section variable information entry for current DATASEC type:
+ *   - *var_type_id* - type ID, describing type of the variable;
+ *   - *offset* - variable offset within data section, in bytes;
+ *   - *byte_sz* - variable size, in bytes.
+ *
+ * Returns:
+ *   -  0, on success;
+ *   - <0, on error.
+ */
+int btf__add_datasec_var_info(struct btf *btf, int var_type_id, __u32 offset, __u32 byte_sz)
+{
+	struct btf_type *t;
+	struct btf_var_secinfo *v;
+	int sz;
+
+	/* last type should be BTF_KIND_DATASEC */
+	if (btf->nr_types == 0)
+		return -EINVAL;
+	t = btf_type_by_id(btf, btf->nr_types);
+	if (!btf_is_datasec(t))
+		return -EINVAL;
+
+	if (validate_type_id(var_type_id))
+		return -EINVAL;
+
+	/* decompose and invalidate raw data */
+	if (btf_ensure_modifiable(btf))
+		return -ENOMEM;
+
+	sz = sizeof(struct btf_var_secinfo);
+	v = btf_add_type_mem(btf, sz);
+	if (!v)
+		return -ENOMEM;
+
+	v->type = var_type_id;
+	v->offset = offset;
+	v->size = byte_sz;
+
+	/* update parent type's vlen */
+	t = btf_type_by_id(btf, btf->nr_types);
+	btf_type_inc_vlen(t);
+
+	btf->hdr->type_len += sz;
+	btf->hdr->str_off += sz;
+	return 0;
+}
+
 struct btf_ext_sec_setup_param {
 	__u32 off;
 	__u32 len;
@@ -1151,7 +2471,10 @@ static int btf_ext_parse_hdr(__u8 *data, __u32 data_size)
 		return -EINVAL;
 	}
 
-	if (hdr->magic != BTF_MAGIC) {
+	if (hdr->magic == bswap_16(BTF_MAGIC)) {
+		pr_warn("BTF.ext in non-native endianness is not supported\n");
+		return -ENOTSUP;
+	} else if (hdr->magic != BTF_MAGIC) {
 		pr_debug("Invalid BTF.ext magic:%x\n", hdr->magic);
 		return -EINVAL;
 	}
@@ -1471,6 +2794,9 @@ int btf__dedup(struct btf *btf, struct btf_ext *btf_ext,
 		return -EINVAL;
 	}
 
+	if (btf_ensure_modifiable(btf))
+		return -ENOMEM;
+
 	err = btf_dedup_strings(d);
 	if (err < 0) {
 		pr_debug("btf_dedup_strings failed:%d\n", err);
@@ -1655,7 +2981,7 @@ static struct btf_dedup *btf_dedup_new(struct btf *btf, struct btf_ext *btf_ext,
 	/* special BTF "void" type is made canonical immediately */
 	d->map[0] = 0;
 	for (i = 1; i <= btf->nr_types; i++) {
-		struct btf_type *t = d->btf->types[i];
+		struct btf_type *t = btf_type_by_id(d->btf, i);
 
 		/* VAR and DATASEC are never deduped and are self-canonical */
 		if (btf_is_var(t) || btf_is_datasec(t))
@@ -1694,7 +3020,7 @@ static int btf_for_each_str_off(struct btf_dedup *d, str_off_fn_t fn, void *ctx)
 	struct btf_type *t;
 
 	for (i = 1; i <= d->btf->nr_types; i++) {
-		t = d->btf->types[i];
+		t = btf_type_by_id(d->btf, i);
 		r = fn(&t->name_off, ctx);
 		if (r)
 			return r;
@@ -1848,8 +3174,7 @@ static int btf_str_remap_offset(__u32 *str_off_ptr, void *ctx)
  */
 static int btf_dedup_strings(struct btf_dedup *d)
 {
-	const struct btf_header *hdr = d->btf->hdr;
-	char *start = (char *)d->btf->nohdr_data + hdr->str_off;
+	char *start = d->btf->strs_data;
 	char *end = start + d->btf->hdr->str_len;
 	char *p = start, *tmp_strs = NULL;
 	struct btf_str_ptrs strs = {
@@ -1861,6 +3186,9 @@ static int btf_dedup_strings(struct btf_dedup *d)
 	int i, j, err = 0, grp_idx;
 	bool grp_used;
 
+	if (d->btf->strs_deduped)
+		return 0;
+
 	/* build index of all strings */
 	while (p < end) {
 		if (strs.cnt + 1 > strs.cap) {
@@ -1953,6 +3281,7 @@ static int btf_dedup_strings(struct btf_dedup *d)
 		goto done;
 
 	d->btf->hdr->str_len = end - start;
+	d->btf->strs_deduped = true;
 
 done:
 	free(tmp_strs);
@@ -2229,7 +3558,7 @@ static bool btf_compat_fnproto(struct btf_type *t1, struct btf_type *t2)
  */
 static int btf_dedup_prim_type(struct btf_dedup *d, __u32 type_id)
 {
-	struct btf_type *t = d->btf->types[type_id];
+	struct btf_type *t = btf_type_by_id(d->btf, type_id);
 	struct hashmap_entry *hash_entry;
 	struct btf_type *cand;
 	/* if we don't find equivalent type, then we are canonical */
@@ -2256,7 +3585,7 @@ static int btf_dedup_prim_type(struct btf_dedup *d, __u32 type_id)
 		h = btf_hash_int(t);
 		for_each_dedup_cand(d, hash_entry, h) {
 			cand_id = (__u32)(long)hash_entry->value;
-			cand = d->btf->types[cand_id];
+			cand = btf_type_by_id(d->btf, cand_id);
 			if (btf_equal_int(t, cand)) {
 				new_id = cand_id;
 				break;
@@ -2268,7 +3597,7 @@ static int btf_dedup_prim_type(struct btf_dedup *d, __u32 type_id)
 		h = btf_hash_enum(t);
 		for_each_dedup_cand(d, hash_entry, h) {
 			cand_id = (__u32)(long)hash_entry->value;
-			cand = d->btf->types[cand_id];
+			cand = btf_type_by_id(d->btf, cand_id);
 			if (btf_equal_enum(t, cand)) {
 				new_id = cand_id;
 				break;
@@ -2291,7 +3620,7 @@ static int btf_dedup_prim_type(struct btf_dedup *d, __u32 type_id)
 		h = btf_hash_common(t);
 		for_each_dedup_cand(d, hash_entry, h) {
 			cand_id = (__u32)(long)hash_entry->value;
-			cand = d->btf->types[cand_id];
+			cand = btf_type_by_id(d->btf, cand_id);
 			if (btf_equal_common(t, cand)) {
 				new_id = cand_id;
 				break;
@@ -2350,13 +3679,13 @@ static uint32_t resolve_fwd_id(struct btf_dedup *d, uint32_t type_id)
 {
 	__u32 orig_type_id = type_id;
 
-	if (!btf_is_fwd(d->btf->types[type_id]))
+	if (!btf_is_fwd(btf__type_by_id(d->btf, type_id)))
 		return type_id;
 
 	while (is_type_mapped(d, type_id) && d->map[type_id] != type_id)
 		type_id = d->map[type_id];
 
-	if (!btf_is_fwd(d->btf->types[type_id]))
+	if (!btf_is_fwd(btf__type_by_id(d->btf, type_id)))
 		return type_id;
 
 	return orig_type_id;
@@ -2484,8 +3813,8 @@ static int btf_dedup_is_equiv(struct btf_dedup *d, __u32 cand_id,
 	if (btf_dedup_hypot_map_add(d, canon_id, cand_id))
 		return -ENOMEM;
 
-	cand_type = d->btf->types[cand_id];
-	canon_type = d->btf->types[canon_id];
+	cand_type = btf_type_by_id(d->btf, cand_id);
+	canon_type = btf_type_by_id(d->btf, canon_id);
 	cand_kind = btf_kind(cand_type);
 	canon_kind = btf_kind(canon_type);
 
@@ -2636,8 +3965,8 @@ static void btf_dedup_merge_hypot_map(struct btf_dedup *d)
 		targ_type_id = d->hypot_map[cand_type_id];
 		t_id = resolve_type_id(d, targ_type_id);
 		c_id = resolve_type_id(d, cand_type_id);
-		t_kind = btf_kind(d->btf->types[t_id]);
-		c_kind = btf_kind(d->btf->types[c_id]);
+		t_kind = btf_kind(btf__type_by_id(d->btf, t_id));
+		c_kind = btf_kind(btf__type_by_id(d->btf, c_id));
 		/*
 		 * Resolve FWD into STRUCT/UNION.
 		 * It's ok to resolve FWD into STRUCT/UNION that's not yet
@@ -2705,7 +4034,7 @@ static int btf_dedup_struct_type(struct btf_dedup *d, __u32 type_id)
 	if (d->map[type_id] <= BTF_MAX_NR_TYPES)
 		return 0;
 
-	t = d->btf->types[type_id];
+	t = btf_type_by_id(d->btf, type_id);
 	kind = btf_kind(t);
 
 	if (kind != BTF_KIND_STRUCT && kind != BTF_KIND_UNION)
@@ -2726,7 +4055,7 @@ static int btf_dedup_struct_type(struct btf_dedup *d, __u32 type_id)
 		 * creating a loop (FWD -> STRUCT and STRUCT -> FWD), because
 		 * FWD and compatible STRUCT/UNION are considered equivalent.
 		 */
-		cand_type = d->btf->types[cand_id];
+		cand_type = btf_type_by_id(d->btf, cand_id);
 		if (!btf_shallow_equal_struct(t, cand_type))
 			continue;
 
@@ -2798,7 +4127,7 @@ static int btf_dedup_ref_type(struct btf_dedup *d, __u32 type_id)
 	if (d->map[type_id] <= BTF_MAX_NR_TYPES)
 		return resolve_type_id(d, type_id);
 
-	t = d->btf->types[type_id];
+	t = btf_type_by_id(d->btf, type_id);
 	d->map[type_id] = BTF_IN_PROGRESS_ID;
 
 	switch (btf_kind(t)) {
@@ -2816,7 +4145,7 @@ static int btf_dedup_ref_type(struct btf_dedup *d, __u32 type_id)
 		h = btf_hash_common(t);
 		for_each_dedup_cand(d, hash_entry, h) {
 			cand_id = (__u32)(long)hash_entry->value;
-			cand = d->btf->types[cand_id];
+			cand = btf_type_by_id(d->btf, cand_id);
 			if (btf_equal_common(t, cand)) {
 				new_id = cand_id;
 				break;
@@ -2840,7 +4169,7 @@ static int btf_dedup_ref_type(struct btf_dedup *d, __u32 type_id)
 		h = btf_hash_array(t);
 		for_each_dedup_cand(d, hash_entry, h) {
 			cand_id = (__u32)(long)hash_entry->value;
-			cand = d->btf->types[cand_id];
+			cand = btf_type_by_id(d->btf, cand_id);
 			if (btf_equal_array(t, cand)) {
 				new_id = cand_id;
 				break;
@@ -2872,7 +4201,7 @@ static int btf_dedup_ref_type(struct btf_dedup *d, __u32 type_id)
 		h = btf_hash_fnproto(t);
 		for_each_dedup_cand(d, hash_entry, h) {
 			cand_id = (__u32)(long)hash_entry->value;
-			cand = d->btf->types[cand_id];
+			cand = btf_type_by_id(d->btf, cand_id);
 			if (btf_equal_fnproto(t, cand)) {
 				new_id = cand_id;
 				break;
@@ -2920,9 +4249,9 @@ static int btf_dedup_ref_types(struct btf_dedup *d)
  */
 static int btf_dedup_compact_types(struct btf_dedup *d)
 {
-	struct btf_type **new_types;
+	__u32 *new_offs;
 	__u32 next_type_id = 1;
-	char *types_start, *p;
+	void *p;
 	int i, len;
 
 	/* we are going to reuse hypot_map to store compaction remapping */
@@ -2930,41 +4259,34 @@ static int btf_dedup_compact_types(struct btf_dedup *d)
 	for (i = 1; i <= d->btf->nr_types; i++)
 		d->hypot_map[i] = BTF_UNPROCESSED_ID;
 
-	types_start = d->btf->nohdr_data + d->btf->hdr->type_off;
-	p = types_start;
+	p = d->btf->types_data;
 
 	for (i = 1; i <= d->btf->nr_types; i++) {
 		if (d->map[i] != i)
 			continue;
 
-		len = btf_type_size(d->btf->types[i]);
+		len = btf_type_size(btf__type_by_id(d->btf, i));
 		if (len < 0)
 			return len;
 
-		memmove(p, d->btf->types[i], len);
+		memmove(p, btf__type_by_id(d->btf, i), len);
 		d->hypot_map[i] = next_type_id;
-		d->btf->types[next_type_id] = (struct btf_type *)p;
+		d->btf->type_offs[next_type_id] = p - d->btf->types_data;
 		p += len;
 		next_type_id++;
 	}
 
 	/* shrink struct btf's internal types index and update btf_header */
 	d->btf->nr_types = next_type_id - 1;
-	d->btf->types_size = d->btf->nr_types;
-	d->btf->hdr->type_len = p - types_start;
-	new_types = libbpf_reallocarray(d->btf->types, (1 + d->btf->nr_types),
-					sizeof(struct btf_type *));
-	if (!new_types)
+	d->btf->type_offs_cap = d->btf->nr_types + 1;
+	d->btf->hdr->type_len = p - d->btf->types_data;
+	new_offs = libbpf_reallocarray(d->btf->type_offs, d->btf->type_offs_cap,
+				       sizeof(*new_offs));
+	if (!new_offs)
 		return -ENOMEM;
-	d->btf->types = new_types;
-
-	/* make sure string section follows type information without gaps */
-	d->btf->hdr->str_off = p - (char *)d->btf->nohdr_data;
-	memmove(p, d->btf->strings, d->btf->hdr->str_len);
-	d->btf->strings = p;
-	p += d->btf->hdr->str_len;
-
-	d->btf->data_size = p - (char *)d->btf->data;
+	d->btf->type_offs = new_offs;
+	d->btf->hdr->str_off = d->btf->hdr->type_len;
+	d->btf->raw_size = d->btf->hdr->hdr_len + d->btf->hdr->type_len + d->btf->hdr->str_len;
 	return 0;
 }
 
@@ -2997,7 +4319,7 @@ static int btf_dedup_remap_type_id(struct btf_dedup *d, __u32 type_id)
  */
 static int btf_dedup_remap_type(struct btf_dedup *d, __u32 type_id)
 {
-	struct btf_type *t = d->btf->types[type_id];
+	struct btf_type *t = btf_type_by_id(d->btf, type_id);
 	int i, r;
 
 	switch (btf_kind(t)) {
diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
index 2a55320d87d0..57247240a20a 100644
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -5,6 +5,7 @@
 #define __LIBBPF_BTF_H
 
 #include <stdarg.h>
+#include <stdbool.h>
 #include <linux/btf.h>
 #include <linux/types.h>
 
@@ -24,8 +25,14 @@ struct btf_type;
 
 struct bpf_object;
 
+enum btf_endianness {
+	BTF_LITTLE_ENDIAN = 0,
+	BTF_BIG_ENDIAN = 1,
+};
+
 LIBBPF_API void btf__free(struct btf *btf);
 LIBBPF_API struct btf *btf__new(const void *data, __u32 size);
+LIBBPF_API struct btf *btf__new_empty(void);
 LIBBPF_API struct btf *btf__parse(const char *path, struct btf_ext **btf_ext);
 LIBBPF_API struct btf *btf__parse_elf(const char *path, struct btf_ext **btf_ext);
 LIBBPF_API struct btf *btf__parse_raw(const char *path);
@@ -40,6 +47,8 @@ LIBBPF_API const struct btf_type *btf__type_by_id(const struct btf *btf,
 						  __u32 id);
 LIBBPF_API size_t btf__pointer_size(const struct btf *btf);
 LIBBPF_API int btf__set_pointer_size(struct btf *btf, size_t ptr_sz);
+LIBBPF_API enum btf_endianness btf__endianness(const struct btf *btf);
+LIBBPF_API int btf__set_endianness(struct btf *btf, enum btf_endianness endian);
 LIBBPF_API __s64 btf__resolve_size(const struct btf *btf, __u32 type_id);
 LIBBPF_API int btf__resolve_type(const struct btf *btf, __u32 type_id);
 LIBBPF_API int btf__align_of(const struct btf *btf, __u32 id);
@@ -47,6 +56,7 @@ LIBBPF_API int btf__fd(const struct btf *btf);
 LIBBPF_API void btf__set_fd(struct btf *btf, int fd);
 LIBBPF_API const void *btf__get_raw_data(const struct btf *btf, __u32 *size);
 LIBBPF_API const char *btf__name_by_offset(const struct btf *btf, __u32 offset);
+LIBBPF_API const char *btf__str_by_offset(const struct btf *btf, __u32 offset);
 LIBBPF_API int btf__get_from_id(__u32 id, struct btf **btf);
 LIBBPF_API int btf__get_map_kv_tids(const struct btf *btf, const char *map_name,
 				    __u32 expected_key_size,
@@ -72,6 +82,47 @@ LIBBPF_API __u32 btf_ext__line_info_rec_size(const struct btf_ext *btf_ext);
 
 LIBBPF_API struct btf *libbpf_find_kernel_btf(void);
 
+LIBBPF_API int btf__find_str(struct btf *btf, const char *s);
+LIBBPF_API int btf__add_str(struct btf *btf, const char *s);
+
+LIBBPF_API int btf__add_int(struct btf *btf, const char *name, size_t byte_sz, int encoding);
+LIBBPF_API int btf__add_ptr(struct btf *btf, int ref_type_id);
+LIBBPF_API int btf__add_array(struct btf *btf,
+			      int index_type_id, int elem_type_id, __u32 nr_elems);
+/* struct/union construction APIs */
+LIBBPF_API int btf__add_struct(struct btf *btf, const char *name, __u32 sz);
+LIBBPF_API int btf__add_union(struct btf *btf, const char *name, __u32 sz);
+LIBBPF_API int btf__add_field(struct btf *btf, const char *name, int field_type_id,
+			      __u32 bit_offset, __u32 bit_size);
+
+/* enum construction APIs */
+LIBBPF_API int btf__add_enum(struct btf *btf, const char *name, __u32 bytes_sz);
+LIBBPF_API int btf__add_enum_value(struct btf *btf, const char *name, __s64 value);
+
+enum btf_fwd_kind {
+	BTF_FWD_STRUCT = 0,
+	BTF_FWD_UNION = 1,
+	BTF_FWD_ENUM = 2,
+};
+
+LIBBPF_API int btf__add_fwd(struct btf *btf, const char *name, enum btf_fwd_kind fwd_kind);
+LIBBPF_API int btf__add_typedef(struct btf *btf, const char *name, int ref_type_id);
+LIBBPF_API int btf__add_volatile(struct btf *btf, int ref_type_id);
+LIBBPF_API int btf__add_const(struct btf *btf, int ref_type_id);
+LIBBPF_API int btf__add_restrict(struct btf *btf, int ref_type_id);
+
+/* func and func_proto construction APIs */
+LIBBPF_API int btf__add_func(struct btf *btf, const char *name,
+			     enum btf_func_linkage linkage, int proto_type_id);
+LIBBPF_API int btf__add_func_proto(struct btf *btf, int ret_type_id);
+LIBBPF_API int btf__add_func_param(struct btf *btf, const char *name, int type_id);
+
+/* var & datasec construction APIs */
+LIBBPF_API int btf__add_var(struct btf *btf, const char *name, int linkage, int type_id);
+LIBBPF_API int btf__add_datasec(struct btf *btf, const char *name, __u32 byte_sz);
+LIBBPF_API int btf__add_datasec_var_info(struct btf *btf, int var_type_id,
+					 __u32 offset, __u32 byte_sz);
+
 struct btf_dedup_opts {
 	unsigned int dedup_table_size;
 	bool dont_resolve_fwds;
diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c
index 6c079b3c8679..2f9d685bd522 100644
--- a/tools/lib/bpf/btf_dump.c
+++ b/tools/lib/bpf/btf_dump.c
@@ -60,11 +60,14 @@ struct btf_dump {
 	struct btf_dump_opts opts;
 	int ptr_sz;
 	bool strip_mods;
+	int last_id;
 
 	/* per-type auxiliary state */
 	struct btf_dump_type_aux_state *type_states;
+	size_t type_states_cap;
 	/* per-type optional cached unique name, must be freed, if present */
 	const char **cached_names;
+	size_t cached_names_cap;
 
 	/* topo-sorted list of dependent type definitions */
 	__u32 *emit_queue;
@@ -90,14 +93,7 @@ struct btf_dump {
 
 static size_t str_hash_fn(const void *key, void *ctx)
 {
-	const char *s = key;
-	size_t h = 0;
-
-	while (*s) {
-		h = h * 31 + *s;
-		s++;
-	}
-	return h;
+	return str_hash(key);
 }
 
 static bool str_equal_fn(const void *a, const void *b, void *ctx)
@@ -120,6 +116,7 @@ static void btf_dump_printf(const struct btf_dump *d, const char *fmt, ...)
 }
 
 static int btf_dump_mark_referenced(struct btf_dump *d);
+static int btf_dump_resize(struct btf_dump *d);
 
 struct btf_dump *btf_dump__new(const struct btf *btf,
 			       const struct btf_ext *btf_ext,
@@ -151,25 +148,8 @@ struct btf_dump *btf_dump__new(const struct btf *btf,
 		d->ident_names = NULL;
 		goto err;
 	}
-	d->type_states = calloc(1 + btf__get_nr_types(d->btf),
-				sizeof(d->type_states[0]));
-	if (!d->type_states) {
-		err = -ENOMEM;
-		goto err;
-	}
-	d->cached_names = calloc(1 + btf__get_nr_types(d->btf),
-				 sizeof(d->cached_names[0]));
-	if (!d->cached_names) {
-		err = -ENOMEM;
-		goto err;
-	}
 
-	/* VOID is special */
-	d->type_states[0].order_state = ORDERED;
-	d->type_states[0].emit_state = EMITTED;
-
-	/* eagerly determine referenced types for anon enums */
-	err = btf_dump_mark_referenced(d);
+	err = btf_dump_resize(d);
 	if (err)
 		goto err;
 
@@ -179,9 +159,38 @@ err:
 	return ERR_PTR(err);
 }
 
+static int btf_dump_resize(struct btf_dump *d)
+{
+	int err, last_id = btf__get_nr_types(d->btf);
+
+	if (last_id <= d->last_id)
+		return 0;
+
+	if (btf_ensure_mem((void **)&d->type_states, &d->type_states_cap,
+			   sizeof(*d->type_states), last_id + 1))
+		return -ENOMEM;
+	if (btf_ensure_mem((void **)&d->cached_names, &d->cached_names_cap,
+			   sizeof(*d->cached_names), last_id + 1))
+		return -ENOMEM;
+
+	if (d->last_id == 0) {
+		/* VOID is special */
+		d->type_states[0].order_state = ORDERED;
+		d->type_states[0].emit_state = EMITTED;
+	}
+
+	/* eagerly determine referenced types for anon enums */
+	err = btf_dump_mark_referenced(d);
+	if (err)
+		return err;
+
+	d->last_id = last_id;
+	return 0;
+}
+
 void btf_dump__free(struct btf_dump *d)
 {
-	int i, cnt;
+	int i;
 
 	if (IS_ERR_OR_NULL(d))
 		return;
@@ -189,7 +198,7 @@ void btf_dump__free(struct btf_dump *d)
 	free(d->type_states);
 	if (d->cached_names) {
 		/* any set cached name is owned by us and should be freed */
-		for (i = 0, cnt = btf__get_nr_types(d->btf); i <= cnt; i++) {
+		for (i = 0; i <= d->last_id; i++) {
 			if (d->cached_names[i])
 				free((void *)d->cached_names[i]);
 		}
@@ -229,6 +238,10 @@ int btf_dump__dump_type(struct btf_dump *d, __u32 id)
 	if (id > btf__get_nr_types(d->btf))
 		return -EINVAL;
 
+	err = btf_dump_resize(d);
+	if (err)
+		return err;
+
 	d->emit_queue_cnt = 0;
 	err = btf_dump_order_type(d, id, false);
 	if (err < 0)
@@ -258,7 +271,7 @@ static int btf_dump_mark_referenced(struct btf_dump *d)
 	const struct btf_type *t;
 	__u16 vlen;
 
-	for (i = 1; i <= n; i++) {
+	for (i = d->last_id + 1; i <= n; i++) {
 		t = btf__type_by_id(d->btf, i);
 		vlen = btf_vlen(t);
 
@@ -313,6 +326,7 @@ static int btf_dump_mark_referenced(struct btf_dump *d)
 	}
 	return 0;
 }
+
 static int btf_dump_add_emit_queue_id(struct btf_dump *d, __u32 id)
 {
 	__u32 *new_queue;
@@ -1056,11 +1070,15 @@ int btf_dump__emit_type_decl(struct btf_dump *d, __u32 id,
 			     const struct btf_dump_emit_type_decl_opts *opts)
 {
 	const char *fname;
-	int lvl;
+	int lvl, err;
 
 	if (!OPTS_VALID(opts, btf_dump_emit_type_decl_opts))
 		return -EINVAL;
 
+	err = btf_dump_resize(d);
+	if (err)
+		return -EINVAL;
+
 	fname = OPTS_GET(opts, field_name, "");
 	lvl = OPTS_GET(opts, indent_level, 0);
 	d->strip_mods = OPTS_GET(opts, strip_mods, false);
diff --git a/tools/lib/bpf/hashmap.h b/tools/lib/bpf/hashmap.h
index e0af36b0e5d8..d9b385fe808c 100644
--- a/tools/lib/bpf/hashmap.h
+++ b/tools/lib/bpf/hashmap.h
@@ -25,6 +25,18 @@ static inline size_t hash_bits(size_t h, int bits)
 #endif
 }
 
+/* generic C-string hashing function */
+static inline size_t str_hash(const char *s)
+{
+	size_t h = 0;
+
+	while (*s) {
+		h = h * 31 + *s;
+		s++;
+	}
+	return h;
+}
+
 typedef size_t (*hashmap_hash_fn)(const void *key, void *ctx);
 typedef bool (*hashmap_equal_fn)(const void *key1, const void *key2, void *ctx);
 
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 32dc444224d8..a4f55f8a460d 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -9390,9 +9390,11 @@ static struct bpf_link *attach_iter(const struct bpf_sec_def *sec,
 }
 
 static struct bpf_link *
-bpf_program__attach_fd(struct bpf_program *prog, int target_fd,
+bpf_program__attach_fd(struct bpf_program *prog, int target_fd, int btf_id,
 		       const char *target_name)
 {
+	DECLARE_LIBBPF_OPTS(bpf_link_create_opts, opts,
+			    .target_btf_id = btf_id);
 	enum bpf_attach_type attach_type;
 	char errmsg[STRERR_BUFSIZE];
 	struct bpf_link *link;
@@ -9410,7 +9412,7 @@ bpf_program__attach_fd(struct bpf_program *prog, int target_fd,
 	link->detach = &bpf_link__detach_fd;
 
 	attach_type = bpf_program__get_expected_attach_type(prog);
-	link_fd = bpf_link_create(prog_fd, target_fd, attach_type, NULL);
+	link_fd = bpf_link_create(prog_fd, target_fd, attach_type, &opts);
 	if (link_fd < 0) {
 		link_fd = -errno;
 		free(link);
@@ -9426,19 +9428,51 @@ bpf_program__attach_fd(struct bpf_program *prog, int target_fd,
 struct bpf_link *
 bpf_program__attach_cgroup(struct bpf_program *prog, int cgroup_fd)
 {
-	return bpf_program__attach_fd(prog, cgroup_fd, "cgroup");
+	return bpf_program__attach_fd(prog, cgroup_fd, 0, "cgroup");
 }
 
 struct bpf_link *
 bpf_program__attach_netns(struct bpf_program *prog, int netns_fd)
 {
-	return bpf_program__attach_fd(prog, netns_fd, "netns");
+	return bpf_program__attach_fd(prog, netns_fd, 0, "netns");
 }
 
 struct bpf_link *bpf_program__attach_xdp(struct bpf_program *prog, int ifindex)
 {
 	/* target_fd/target_ifindex use the same field in LINK_CREATE */
-	return bpf_program__attach_fd(prog, ifindex, "xdp");
+	return bpf_program__attach_fd(prog, ifindex, 0, "xdp");
+}
+
+struct bpf_link *bpf_program__attach_freplace(struct bpf_program *prog,
+					      int target_fd,
+					      const char *attach_func_name)
+{
+	int btf_id;
+
+	if (!!target_fd != !!attach_func_name) {
+		pr_warn("prog '%s': supply none or both of target_fd and attach_func_name\n",
+			prog->name);
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (prog->type != BPF_PROG_TYPE_EXT) {
+		pr_warn("prog '%s': only BPF_PROG_TYPE_EXT can attach as freplace",
+			prog->name);
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (target_fd) {
+		btf_id = libbpf_find_prog_btf_id(attach_func_name, target_fd);
+		if (btf_id < 0)
+			return ERR_PTR(btf_id);
+
+		return bpf_program__attach_fd(prog, target_fd, btf_id, "freplace");
+	} else {
+		/* no target, so use raw_tracepoint_open for compatibility
+		 * with old kernels
+		 */
+		return bpf_program__attach_trace(prog);
+	}
 }
 
 struct bpf_link *
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index a750f67a23f6..6909ee81113a 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -261,6 +261,9 @@ LIBBPF_API struct bpf_link *
 bpf_program__attach_netns(struct bpf_program *prog, int netns_fd);
 LIBBPF_API struct bpf_link *
 bpf_program__attach_xdp(struct bpf_program *prog, int ifindex);
+LIBBPF_API struct bpf_link *
+bpf_program__attach_freplace(struct bpf_program *prog,
+			     int target_fd, const char *attach_func_name);
 
 struct bpf_map;
 
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index 5f054dadf082..4ebfadf45b47 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -303,7 +303,34 @@ LIBBPF_0.1.0 {
 LIBBPF_0.2.0 {
 	global:
 		bpf_prog_bind_map;
+		bpf_prog_test_run_opts;
+		bpf_program__attach_freplace;
 		bpf_program__section_name;
+		btf__add_array;
+		btf__add_const;
+		btf__add_enum;
+		btf__add_enum_value;
+		btf__add_datasec;
+		btf__add_datasec_var_info;
+		btf__add_field;
+		btf__add_func;
+		btf__add_func_param;
+		btf__add_func_proto;
+		btf__add_fwd;
+		btf__add_int;
+		btf__add_ptr;
+		btf__add_restrict;
+		btf__add_str;
+		btf__add_struct;
+		btf__add_typedef;
+		btf__add_union;
+		btf__add_var;
+		btf__add_volatile;
+		btf__endianness;
+		btf__find_str;
+		btf__new_empty;
+		btf__set_endianness;
+		btf__str_by_offset;
 		perf_buffer__buffer_cnt;
 		perf_buffer__buffer_fd;
 		perf_buffer__epoll_fd;
diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h
index 4d1c366fca2c..d99bc847bf84 100644
--- a/tools/lib/bpf/libbpf_internal.h
+++ b/tools/lib/bpf/libbpf_internal.h
@@ -105,6 +105,10 @@ static inline void *libbpf_reallocarray(void *ptr, size_t nmemb, size_t size)
 	return realloc(ptr, total);
 }
 
+void *btf_add_mem(void **data, size_t *cap_cnt, size_t elem_sz,
+		  size_t cur_cnt, size_t max_cnt, size_t add_cnt);
+int btf_ensure_mem(void **data, size_t *cap_cnt, size_t elem_sz, size_t need_cnt);
+
 static inline bool libbpf_validate_opts(const char *opts,
 					size_t opts_sz, size_t user_sz,
 					const char *type_name)
@@ -136,6 +140,11 @@ static inline bool libbpf_validate_opts(const char *opts,
 	((opts) && opts->sz >= offsetofend(typeof(*(opts)), field))
 #define OPTS_GET(opts, field, fallback_value) \
 	(OPTS_HAS(opts, field) ? (opts)->field : fallback_value)
+#define OPTS_SET(opts, field, value)		\
+	do {					\
+		if (OPTS_HAS(opts, field))	\
+			(opts)->field = value;	\
+	} while (0)
 
 int parse_cpu_mask_str(const char *s, bool **mask, int *mask_sz);
 int parse_cpu_mask_file(const char *fcpu, bool **mask, int *mask_sz);
diff --git a/tools/testing/selftests/bpf/.gitignore b/tools/testing/selftests/bpf/.gitignore
index e8fed558b8b8..3ab1200e172f 100644
--- a/tools/testing/selftests/bpf/.gitignore
+++ b/tools/testing/selftests/bpf/.gitignore
@@ -13,7 +13,6 @@ test_verifier_log
 feature
 test_sock
 test_sock_addr
-test_sock_fields
 urandom_read
 test_sockmap
 test_lirc_mode2_user
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 59a5fa5fe837..bdbeafec371b 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -35,7 +35,7 @@ TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test
 	test_verifier_log test_dev_cgroup test_tcpbpf_user \
 	test_sock test_sockmap get_cgroup_id_user test_socket_cookie \
 	test_cgroup_storage \
-	test_netcnt test_tcpnotify_user test_sock_fields test_sysctl \
+	test_netcnt test_tcpnotify_user test_sysctl \
 	test_progs-no_alu32 \
 	test_current_pid_tgid_new_ns
 
diff --git a/tools/testing/selftests/bpf/bench.c b/tools/testing/selftests/bpf/bench.c
index 1a427685a8a8..332ed2f7b402 100644
--- a/tools/testing/selftests/bpf/bench.c
+++ b/tools/testing/selftests/bpf/bench.c
@@ -311,7 +311,6 @@ extern const struct bench bench_rename_kretprobe;
 extern const struct bench bench_rename_rawtp;
 extern const struct bench bench_rename_fentry;
 extern const struct bench bench_rename_fexit;
-extern const struct bench bench_rename_fmodret;
 extern const struct bench bench_trig_base;
 extern const struct bench bench_trig_tp;
 extern const struct bench bench_trig_rawtp;
@@ -333,7 +332,6 @@ static const struct bench *benchs[] = {
 	&bench_rename_rawtp,
 	&bench_rename_fentry,
 	&bench_rename_fexit,
-	&bench_rename_fmodret,
 	&bench_trig_base,
 	&bench_trig_tp,
 	&bench_trig_rawtp,
@@ -464,4 +462,3 @@ int main(int argc, char **argv)
 
 	return 0;
 }
-
diff --git a/tools/testing/selftests/bpf/benchs/bench_rename.c b/tools/testing/selftests/bpf/benchs/bench_rename.c
index e74cff40f4fe..a967674098ad 100644
--- a/tools/testing/selftests/bpf/benchs/bench_rename.c
+++ b/tools/testing/selftests/bpf/benchs/bench_rename.c
@@ -106,12 +106,6 @@ static void setup_fexit()
 	attach_bpf(ctx.skel->progs.prog5);
 }
 
-static void setup_fmodret()
-{
-	setup_ctx();
-	attach_bpf(ctx.skel->progs.prog6);
-}
-
 static void *consumer(void *input)
 {
 	return NULL;
@@ -182,14 +176,3 @@ const struct bench bench_rename_fexit = {
 	.report_progress = hits_drops_report_progress,
 	.report_final = hits_drops_report_final,
 };
-
-const struct bench bench_rename_fmodret = {
-	.name = "rename-fmodret",
-	.validate = validate,
-	.setup = setup_fmodret,
-	.producer_thread = producer,
-	.consumer_thread = consumer,
-	.measure = measure,
-	.report_progress = hits_drops_report_progress,
-	.report_final = hits_drops_report_final,
-};
diff --git a/tools/testing/selftests/bpf/bpf_tcp_helpers.h b/tools/testing/selftests/bpf/bpf_tcp_helpers.h
index 5bf2fe9b1efa..2915664c335d 100644
--- a/tools/testing/selftests/bpf/bpf_tcp_helpers.h
+++ b/tools/testing/selftests/bpf/bpf_tcp_helpers.h
@@ -16,6 +16,7 @@ BPF_PROG(name, args)
 
 struct sock_common {
 	unsigned char	skc_state;
+	__u16		skc_num;
 } __attribute__((preserve_access_index));
 
 enum sk_pacing {
@@ -45,6 +46,10 @@ struct inet_connection_sock {
 	__u64			  icsk_ca_priv[104 / sizeof(__u64)];
 } __attribute__((preserve_access_index));
 
+struct request_sock {
+	struct sock_common		__req_common;
+} __attribute__((preserve_access_index));
+
 struct tcp_sock {
 	struct inet_connection_sock	inet_conn;
 
@@ -115,14 +120,6 @@ enum tcp_ca_event {
 	CA_EVENT_ECN_IS_CE = 5,
 };
 
-enum tcp_ca_state {
-	TCP_CA_Open = 0,
-	TCP_CA_Disorder = 1,
-	TCP_CA_CWR = 2,
-	TCP_CA_Recovery = 3,
-	TCP_CA_Loss = 4
-};
-
 struct ack_sample {
 	__u32 pkts_acked;
 	__s32 rtt_us;
diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c
index fe1a83b9875c..448885b95eed 100644
--- a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c
+++ b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c
@@ -7,6 +7,7 @@
 #include "bpf_iter_task.skel.h"
 #include "bpf_iter_task_stack.skel.h"
 #include "bpf_iter_task_file.skel.h"
+#include "bpf_iter_task_btf.skel.h"
 #include "bpf_iter_tcp4.skel.h"
 #include "bpf_iter_tcp6.skel.h"
 #include "bpf_iter_udp4.skel.h"
@@ -167,6 +168,83 @@ done:
 	bpf_iter_task_file__destroy(skel);
 }
 
+#define TASKBUFSZ		32768
+
+static char taskbuf[TASKBUFSZ];
+
+static int do_btf_read(struct bpf_iter_task_btf *skel)
+{
+	struct bpf_program *prog = skel->progs.dump_task_struct;
+	struct bpf_iter_task_btf__bss *bss = skel->bss;
+	int iter_fd = -1, len = 0, bufleft = TASKBUFSZ;
+	struct bpf_link *link;
+	char *buf = taskbuf;
+	int ret = 0;
+
+	link = bpf_program__attach_iter(prog, NULL);
+	if (CHECK(IS_ERR(link), "attach_iter", "attach_iter failed\n"))
+		return ret;
+
+	iter_fd = bpf_iter_create(bpf_link__fd(link));
+	if (CHECK(iter_fd < 0, "create_iter", "create_iter failed\n"))
+		goto free_link;
+
+	do {
+		len = read(iter_fd, buf, bufleft);
+		if (len > 0) {
+			buf += len;
+			bufleft -= len;
+		}
+	} while (len > 0);
+
+	if (bss->skip) {
+		printf("%s:SKIP:no __builtin_btf_type_id\n", __func__);
+		ret = 1;
+		test__skip();
+		goto free_link;
+	}
+
+	if (CHECK(len < 0, "read", "read failed: %s\n", strerror(errno)))
+		goto free_link;
+
+	CHECK(strstr(taskbuf, "(struct task_struct)") == NULL,
+	      "check for btf representation of task_struct in iter data",
+	      "struct task_struct not found");
+free_link:
+	if (iter_fd > 0)
+		close(iter_fd);
+	bpf_link__destroy(link);
+	return ret;
+}
+
+static void test_task_btf(void)
+{
+	struct bpf_iter_task_btf__bss *bss;
+	struct bpf_iter_task_btf *skel;
+	int ret;
+
+	skel = bpf_iter_task_btf__open_and_load();
+	if (CHECK(!skel, "bpf_iter_task_btf__open_and_load",
+		  "skeleton open_and_load failed\n"))
+		return;
+
+	bss = skel->bss;
+
+	ret = do_btf_read(skel);
+	if (ret)
+		goto cleanup;
+
+	if (CHECK(bss->tasks == 0, "check if iterated over tasks",
+		  "no task iteration, did BPF program run?\n"))
+		goto cleanup;
+
+	CHECK(bss->seq_err != 0, "check for unexpected err",
+	      "bpf_seq_printf_btf returned %ld", bss->seq_err);
+
+cleanup:
+	bpf_iter_task_btf__destroy(skel);
+}
+
 static void test_tcp4(void)
 {
 	struct bpf_iter_tcp4 *skel;
@@ -352,7 +430,7 @@ static void test_overflow(bool test_e2big_overflow, bool ret1)
 	struct bpf_map_info map_info = {};
 	struct bpf_iter_test_kern4 *skel;
 	struct bpf_link *link;
-	__u32 page_size;
+	__u32 iter_size;
 	char *buf;
 
 	skel = bpf_iter_test_kern4__open();
@@ -374,19 +452,19 @@ static void test_overflow(bool test_e2big_overflow, bool ret1)
 		  "map_creation failed: %s\n", strerror(errno)))
 		goto free_map1;
 
-	/* bpf_seq_printf kernel buffer is one page, so one map
+	/* bpf_seq_printf kernel buffer is 8 pages, so one map
 	 * bpf_seq_write will mostly fill it, and the other map
 	 * will partially fill and then trigger overflow and need
 	 * bpf_seq_read restart.
 	 */
-	page_size = sysconf(_SC_PAGE_SIZE);
+	iter_size = sysconf(_SC_PAGE_SIZE) << 3;
 
 	if (test_e2big_overflow) {
-		skel->rodata->print_len = (page_size + 8) / 8;
-		expected_read_len = 2 * (page_size + 8);
+		skel->rodata->print_len = (iter_size + 8) / 8;
+		expected_read_len = 2 * (iter_size + 8);
 	} else if (!ret1) {
-		skel->rodata->print_len = (page_size - 8) / 8;
-		expected_read_len = 2 * (page_size - 8);
+		skel->rodata->print_len = (iter_size - 8) / 8;
+		expected_read_len = 2 * (iter_size - 8);
 	} else {
 		skel->rodata->print_len = 1;
 		expected_read_len = 2 * 8;
@@ -957,6 +1035,8 @@ void test_bpf_iter(void)
 		test_task_stack();
 	if (test__start_subtest("task_file"))
 		test_task_file();
+	if (test__start_subtest("task_btf"))
+		test_task_btf();
 	if (test__start_subtest("tcp4"))
 		test_tcp4();
 	if (test__start_subtest("tcp6"))
diff --git a/tools/testing/selftests/bpf/prog_tests/btf_dump.c b/tools/testing/selftests/bpf/prog_tests/btf_dump.c
index 39fb81d9daeb..c60091ee8a21 100644
--- a/tools/testing/selftests/bpf/prog_tests/btf_dump.c
+++ b/tools/testing/selftests/bpf/prog_tests/btf_dump.c
@@ -129,6 +129,109 @@ done:
 	return err;
 }
 
+static char *dump_buf;
+static size_t dump_buf_sz;
+static FILE *dump_buf_file;
+
+void test_btf_dump_incremental(void)
+{
+	struct btf *btf = NULL;
+	struct btf_dump *d = NULL;
+	struct btf_dump_opts opts;
+	int id, err, i;
+
+	dump_buf_file = open_memstream(&dump_buf, &dump_buf_sz);
+	if (!ASSERT_OK_PTR(dump_buf_file, "dump_memstream"))
+		return;
+	btf = btf__new_empty();
+	if (!ASSERT_OK_PTR(btf, "new_empty"))
+		goto err_out;
+	opts.ctx = dump_buf_file;
+	d = btf_dump__new(btf, NULL, &opts, btf_dump_printf);
+	if (!ASSERT_OK(libbpf_get_error(d), "btf_dump__new"))
+		goto err_out;
+
+	/* First, generate BTF corresponding to the following C code:
+	 *
+	 * enum { VAL = 1 };
+	 *
+	 * struct s { int x; };
+	 *
+	 */
+	id = btf__add_enum(btf, NULL, 4);
+	ASSERT_EQ(id, 1, "enum_id");
+	err = btf__add_enum_value(btf, "VAL", 1);
+	ASSERT_OK(err, "enum_val_ok");
+
+	id = btf__add_int(btf, "int", 4, BTF_INT_SIGNED);
+	ASSERT_EQ(id, 2, "int_id");
+
+	id = btf__add_struct(btf, "s", 4);
+	ASSERT_EQ(id, 3, "struct_id");
+	err = btf__add_field(btf, "x", 2, 0, 0);
+	ASSERT_OK(err, "field_ok");
+
+	for (i = 1; i <= btf__get_nr_types(btf); i++) {
+		err = btf_dump__dump_type(d, i);
+		ASSERT_OK(err, "dump_type_ok");
+	}
+
+	fflush(dump_buf_file);
+	dump_buf[dump_buf_sz] = 0; /* some libc implementations don't do this */
+	ASSERT_STREQ(dump_buf,
+"enum {\n"
+"	VAL = 1,\n"
+"};\n"
+"\n"
+"struct s {\n"
+"	int x;\n"
+"};\n\n", "c_dump1");
+
+	/* Now, after dumping original BTF, append another struct that embeds
+	 * anonymous enum. It also has a name conflict with the first struct:
+	 *
+	 * struct s___2 {
+	 *     enum { VAL___2 = 1 } x;
+	 *     struct s s;
+	 * };
+	 *
+	 * This will test that btf_dump'er maintains internal state properly.
+	 * Note that VAL___2 enum value. It's because we've already emitted
+	 * that enum as a global anonymous enum, so btf_dump will ensure that
+	 * enum values don't conflict;
+	 *
+	 */
+	fseek(dump_buf_file, 0, SEEK_SET);
+
+	id = btf__add_struct(btf, "s", 4);
+	ASSERT_EQ(id, 4, "struct_id");
+	err = btf__add_field(btf, "x", 1, 0, 0);
+	ASSERT_OK(err, "field_ok");
+	err = btf__add_field(btf, "s", 3, 32, 0);
+	ASSERT_OK(err, "field_ok");
+
+	for (i = 1; i <= btf__get_nr_types(btf); i++) {
+		err = btf_dump__dump_type(d, i);
+		ASSERT_OK(err, "dump_type_ok");
+	}
+
+	fflush(dump_buf_file);
+	dump_buf[dump_buf_sz] = 0; /* some libc implementations don't do this */
+	ASSERT_STREQ(dump_buf,
+"struct s___2 {\n"
+"	enum {\n"
+"		VAL___2 = 1,\n"
+"	} x;\n"
+"	struct s s;\n"
+"};\n\n" , "c_dump1");
+
+err_out:
+	fclose(dump_buf_file);
+	free(dump_buf);
+	btf_dump__free(d);
+	btf__free(btf);
+}
+
 void test_btf_dump() {
 	int i;
 
@@ -140,4 +243,6 @@ void test_btf_dump() {
 
 		test_btf_dump_case(i, &btf_dump_test_cases[i]);
 	}
+	if (test__start_subtest("btf_dump: incremental"))
+		test_btf_dump_incremental();
 }
diff --git a/tools/testing/selftests/bpf/prog_tests/btf_endian.c b/tools/testing/selftests/bpf/prog_tests/btf_endian.c
new file mode 100644
index 000000000000..8c52d72c876e
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/btf_endian.c
@@ -0,0 +1,101 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020 Facebook */
+#define _GNU_SOURCE
+#include <string.h>
+#include <byteswap.h>
+#include <test_progs.h>
+#include <bpf/btf.h>
+
+static int duration = 0;
+
+void test_btf_endian() {
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+	enum btf_endianness endian = BTF_LITTLE_ENDIAN;
+#elif __BYTE_ORDER == __BIG_ENDIAN
+	enum btf_endianness endian = BTF_BIG_ENDIAN;
+#else
+#error "Unrecognized __BYTE_ORDER"
+#endif
+	enum btf_endianness swap_endian = 1 - endian;
+	struct btf *btf = NULL, *swap_btf = NULL;
+	const void *raw_data, *swap_raw_data;
+	const struct btf_type *t;
+	const struct btf_header *hdr;
+	__u32 raw_sz, swap_raw_sz;
+	int var_id;
+
+	/* Load BTF in native endianness */
+	btf = btf__parse_elf("btf_dump_test_case_syntax.o", NULL);
+	if (!ASSERT_OK_PTR(btf, "parse_native_btf"))
+		goto err_out;
+
+	ASSERT_EQ(btf__endianness(btf), endian, "endian");
+	btf__set_endianness(btf, swap_endian);
+	ASSERT_EQ(btf__endianness(btf), swap_endian, "endian");
+
+	/* Get raw BTF data in non-native endianness... */
+	raw_data = btf__get_raw_data(btf, &raw_sz);
+	if (!ASSERT_OK_PTR(raw_data, "raw_data_inverted"))
+		goto err_out;
+
+	/* ...and open it as a new BTF instance */
+	swap_btf = btf__new(raw_data, raw_sz);
+	if (!ASSERT_OK_PTR(swap_btf, "parse_swap_btf"))
+		goto err_out;
+
+	ASSERT_EQ(btf__endianness(swap_btf), swap_endian, "endian");
+	ASSERT_EQ(btf__get_nr_types(swap_btf), btf__get_nr_types(btf), "nr_types");
+
+	swap_raw_data = btf__get_raw_data(swap_btf, &swap_raw_sz);
+	if (!ASSERT_OK_PTR(swap_raw_data, "swap_raw_data"))
+		goto err_out;
+
+	/* both raw data should be identical (with non-native endianness) */
+	ASSERT_OK(memcmp(raw_data, swap_raw_data, raw_sz), "mem_identical");
+
+	/* make sure that at least BTF header data is really swapped */
+	hdr = swap_raw_data;
+	ASSERT_EQ(bswap_16(hdr->magic), BTF_MAGIC, "btf_magic_swapped");
+	ASSERT_EQ(raw_sz, swap_raw_sz, "raw_sizes");
+
+	/* swap it back to native endianness */
+	btf__set_endianness(swap_btf, endian);
+	swap_raw_data = btf__get_raw_data(swap_btf, &swap_raw_sz);
+	if (!ASSERT_OK_PTR(swap_raw_data, "swap_raw_data"))
+		goto err_out;
+
+	/* now header should have native BTF_MAGIC */
+	hdr = swap_raw_data;
+	ASSERT_EQ(hdr->magic, BTF_MAGIC, "btf_magic_native");
+	ASSERT_EQ(raw_sz, swap_raw_sz, "raw_sizes");
+
+	/* now modify original BTF */
+	var_id = btf__add_var(btf, "some_var", BTF_VAR_GLOBAL_ALLOCATED, 1);
+	CHECK(var_id <= 0, "var_id", "failed %d\n", var_id);
+
+	btf__free(swap_btf);
+	swap_btf = NULL;
+
+	btf__set_endianness(btf, swap_endian);
+	raw_data = btf__get_raw_data(btf, &raw_sz);
+	if (!ASSERT_OK_PTR(raw_data, "raw_data_inverted"))
+		goto err_out;
+
+	/* and re-open swapped raw data again */
+	swap_btf = btf__new(raw_data, raw_sz);
+	if (!ASSERT_OK_PTR(swap_btf, "parse_swap_btf"))
+		goto err_out;
+
+	ASSERT_EQ(btf__endianness(swap_btf), swap_endian, "endian");
+	ASSERT_EQ(btf__get_nr_types(swap_btf), btf__get_nr_types(btf), "nr_types");
+
+	/* the type should appear as if it was stored in native endianness */
+	t = btf__type_by_id(swap_btf, var_id);
+	ASSERT_STREQ(btf__str_by_offset(swap_btf, t->name_off), "some_var", "var_name");
+	ASSERT_EQ(btf_var(t)->linkage, BTF_VAR_GLOBAL_ALLOCATED, "var_linkage");
+	ASSERT_EQ(t->type, 1, "var_type");
+
+err_out:
+	btf__free(btf);
+	btf__free(swap_btf);
+}
diff --git a/tools/testing/selftests/bpf/prog_tests/btf_skc_cls_ingress.c b/tools/testing/selftests/bpf/prog_tests/btf_skc_cls_ingress.c
new file mode 100644
index 000000000000..86ccf37e26b3
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/btf_skc_cls_ingress.c
@@ -0,0 +1,234 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020 Facebook */
+
+#define _GNU_SOURCE
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <sched.h>
+#include <linux/compiler.h>
+#include <bpf/libbpf.h>
+
+#include "network_helpers.h"
+#include "test_progs.h"
+#include "test_btf_skc_cls_ingress.skel.h"
+
+static struct test_btf_skc_cls_ingress *skel;
+struct sockaddr_in6 srv_sa6;
+static __u32 duration;
+
+#define PROG_PIN_FILE "/sys/fs/bpf/btf_skc_cls_ingress"
+
+static int write_sysctl(const char *sysctl, const char *value)
+{
+	int fd, err, len;
+
+	fd = open(sysctl, O_WRONLY);
+	if (CHECK(fd == -1, "open sysctl", "open(%s): %s (%d)\n",
+		  sysctl, strerror(errno), errno))
+		return -1;
+
+	len = strlen(value);
+	err = write(fd, value, len);
+	close(fd);
+	if (CHECK(err != len, "write sysctl",
+		  "write(%s, %s, %d): err:%d %s (%d)\n",
+		  sysctl, value, len, err, strerror(errno), errno))
+		return -1;
+
+	return 0;
+}
+
+static int prepare_netns(void)
+{
+	if (CHECK(unshare(CLONE_NEWNET), "create netns",
+		  "unshare(CLONE_NEWNET): %s (%d)",
+		  strerror(errno), errno))
+		return -1;
+
+	if (CHECK(system("ip link set dev lo up"),
+		  "ip link set dev lo up", "failed\n"))
+		return -1;
+
+	if (CHECK(system("tc qdisc add dev lo clsact"),
+		  "tc qdisc add dev lo clsact", "failed\n"))
+		return -1;
+
+	if (CHECK(system("tc filter add dev lo ingress bpf direct-action object-pinned " PROG_PIN_FILE),
+		  "install tc cls-prog at ingress", "failed\n"))
+		return -1;
+
+	/* Ensure 20 bytes options (i.e. in total 40 bytes tcp header) for the
+	 * bpf_tcp_gen_syncookie() helper.
+	 */
+	if (write_sysctl("/proc/sys/net/ipv4/tcp_window_scaling", "1") ||
+	    write_sysctl("/proc/sys/net/ipv4/tcp_timestamps", "1") ||
+	    write_sysctl("/proc/sys/net/ipv4/tcp_sack", "1"))
+		return -1;
+
+	return 0;
+}
+
+static void reset_test(void)
+{
+	memset(&skel->bss->srv_sa6, 0, sizeof(skel->bss->srv_sa6));
+	skel->bss->listen_tp_sport = 0;
+	skel->bss->req_sk_sport = 0;
+	skel->bss->recv_cookie = 0;
+	skel->bss->gen_cookie = 0;
+	skel->bss->linum = 0;
+}
+
+static void print_err_line(void)
+{
+	if (skel->bss->linum)
+		printf("bpf prog error at line %u\n", skel->bss->linum);
+}
+
+static void test_conn(void)
+{
+	int listen_fd = -1, cli_fd = -1, err;
+	socklen_t addrlen = sizeof(srv_sa6);
+	int srv_port;
+
+	if (write_sysctl("/proc/sys/net/ipv4/tcp_syncookies", "1"))
+		return;
+
+	listen_fd = start_server(AF_INET6, SOCK_STREAM, "::1", 0, 0);
+	if (CHECK_FAIL(listen_fd == -1))
+		return;
+
+	err = getsockname(listen_fd, (struct sockaddr *)&srv_sa6, &addrlen);
+	if (CHECK(err, "getsockname(listen_fd)", "err:%d errno:%d\n", err,
+		  errno))
+		goto done;
+	memcpy(&skel->bss->srv_sa6, &srv_sa6, sizeof(srv_sa6));
+	srv_port = ntohs(srv_sa6.sin6_port);
+
+	cli_fd = connect_to_fd(listen_fd, 0);
+	if (CHECK_FAIL(cli_fd == -1))
+		goto done;
+
+	if (CHECK(skel->bss->listen_tp_sport != srv_port ||
+		  skel->bss->req_sk_sport != srv_port,
+		  "Unexpected sk src port",
+		  "listen_tp_sport:%u req_sk_sport:%u expected:%u\n",
+		  skel->bss->listen_tp_sport, skel->bss->req_sk_sport,
+		  srv_port))
+		goto done;
+
+	if (CHECK(skel->bss->gen_cookie || skel->bss->recv_cookie,
+		  "Unexpected syncookie states",
+		  "gen_cookie:%u recv_cookie:%u\n",
+		  skel->bss->gen_cookie, skel->bss->recv_cookie))
+		goto done;
+
+	CHECK(skel->bss->linum, "bpf prog detected error", "at line %u\n",
+	      skel->bss->linum);
+
+done:
+	if (listen_fd != -1)
+		close(listen_fd);
+	if (cli_fd != -1)
+		close(cli_fd);
+}
+
+static void test_syncookie(void)
+{
+	int listen_fd = -1, cli_fd = -1, err;
+	socklen_t addrlen = sizeof(srv_sa6);
+	int srv_port;
+
+	/* Enforce syncookie mode */
+	if (write_sysctl("/proc/sys/net/ipv4/tcp_syncookies", "2"))
+		return;
+
+	listen_fd = start_server(AF_INET6, SOCK_STREAM, "::1", 0, 0);
+	if (CHECK_FAIL(listen_fd == -1))
+		return;
+
+	err = getsockname(listen_fd, (struct sockaddr *)&srv_sa6, &addrlen);
+	if (CHECK(err, "getsockname(listen_fd)", "err:%d errno:%d\n", err,
+		  errno))
+		goto done;
+	memcpy(&skel->bss->srv_sa6, &srv_sa6, sizeof(srv_sa6));
+	srv_port = ntohs(srv_sa6.sin6_port);
+
+	cli_fd = connect_to_fd(listen_fd, 0);
+	if (CHECK_FAIL(cli_fd == -1))
+		goto done;
+
+	if (CHECK(skel->bss->listen_tp_sport != srv_port,
+		  "Unexpected tp src port",
+		  "listen_tp_sport:%u expected:%u\n",
+		  skel->bss->listen_tp_sport, srv_port))
+		goto done;
+
+	if (CHECK(skel->bss->req_sk_sport,
+		  "Unexpected req_sk src port",
+		  "req_sk_sport:%u expected:0\n",
+		   skel->bss->req_sk_sport))
+		goto done;
+
+	if (CHECK(!skel->bss->gen_cookie ||
+		  skel->bss->gen_cookie != skel->bss->recv_cookie,
+		  "Unexpected syncookie states",
+		  "gen_cookie:%u recv_cookie:%u\n",
+		  skel->bss->gen_cookie, skel->bss->recv_cookie))
+		goto done;
+
+	CHECK(skel->bss->linum, "bpf prog detected error", "at line %u\n",
+	      skel->bss->linum);
+
+done:
+	if (listen_fd != -1)
+		close(listen_fd);
+	if (cli_fd != -1)
+		close(cli_fd);
+}
+
+struct test {
+	const char *desc;
+	void (*run)(void);
+};
+
+#define DEF_TEST(name) { #name, test_##name }
+static struct test tests[] = {
+	DEF_TEST(conn),
+	DEF_TEST(syncookie),
+};
+
+void test_btf_skc_cls_ingress(void)
+{
+	int i, err;
+
+	skel = test_btf_skc_cls_ingress__open_and_load();
+	if (CHECK(!skel, "test_btf_skc_cls_ingress__open_and_load", "failed\n"))
+		return;
+
+	err = bpf_program__pin(skel->progs.cls_ingress, PROG_PIN_FILE);
+	if (CHECK(err, "bpf_program__pin",
+		  "cannot pin bpf prog to %s. err:%d\n", PROG_PIN_FILE, err)) {
+		test_btf_skc_cls_ingress__destroy(skel);
+		return;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(tests); i++) {
+		if (!test__start_subtest(tests[i].desc))
+			continue;
+
+		if (prepare_netns())
+			break;
+
+		tests[i].run();
+
+		print_err_line();
+		reset_test();
+	}
+
+	bpf_program__unpin(skel->progs.cls_ingress, PROG_PIN_FILE);
+	test_btf_skc_cls_ingress__destroy(skel);
+}
diff --git a/tools/testing/selftests/bpf/prog_tests/btf_write.c b/tools/testing/selftests/bpf/prog_tests/btf_write.c
new file mode 100644
index 000000000000..314e1e7c36df
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/btf_write.c
@@ -0,0 +1,244 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020 Facebook */
+#include <test_progs.h>
+#include <bpf/btf.h>
+
+static int duration = 0;
+
+void test_btf_write() {
+	const struct btf_var_secinfo *vi;
+	const struct btf_type *t;
+	const struct btf_member *m;
+	const struct btf_enum *v;
+	const struct btf_param *p;
+	struct btf *btf;
+	int id, err, str_off;
+
+	btf = btf__new_empty();
+	if (CHECK(IS_ERR(btf), "new_empty", "failed: %ld\n", PTR_ERR(btf)))
+		return;
+
+	str_off = btf__find_str(btf, "int");
+	ASSERT_EQ(str_off, -ENOENT, "int_str_missing_off");
+
+	str_off = btf__add_str(btf, "int");
+	ASSERT_EQ(str_off, 1, "int_str_off");
+
+	str_off = btf__find_str(btf, "int");
+	ASSERT_EQ(str_off, 1, "int_str_found_off");
+
+	/* BTF_KIND_INT */
+	id = btf__add_int(btf, "int", 4,  BTF_INT_SIGNED);
+	ASSERT_EQ(id, 1, "int_id");
+
+	t = btf__type_by_id(btf, 1);
+	/* should re-use previously added "int" string */
+	ASSERT_EQ(t->name_off, str_off, "int_name_off");
+	ASSERT_STREQ(btf__str_by_offset(btf, t->name_off), "int", "int_name");
+	ASSERT_EQ(btf_kind(t), BTF_KIND_INT, "int_kind");
+	ASSERT_EQ(t->size, 4, "int_sz");
+	ASSERT_EQ(btf_int_encoding(t), BTF_INT_SIGNED, "int_enc");
+	ASSERT_EQ(btf_int_bits(t), 32, "int_bits");
+
+	/* invalid int size */
+	id = btf__add_int(btf, "bad sz int", 7, 0);
+	ASSERT_ERR(id, "int_bad_sz");
+	/* invalid encoding */
+	id = btf__add_int(btf, "bad enc int", 4, 123);
+	ASSERT_ERR(id, "int_bad_enc");
+	/* NULL name */
+	id = btf__add_int(btf, NULL, 4, 0);
+	ASSERT_ERR(id, "int_bad_null_name");
+	/* empty name */
+	id = btf__add_int(btf, "", 4, 0);
+	ASSERT_ERR(id, "int_bad_empty_name");
+
+	/* PTR/CONST/VOLATILE/RESTRICT */
+	id = btf__add_ptr(btf, 1);
+	ASSERT_EQ(id, 2, "ptr_id");
+	t = btf__type_by_id(btf, 2);
+	ASSERT_EQ(btf_kind(t), BTF_KIND_PTR, "ptr_kind");
+	ASSERT_EQ(t->type, 1, "ptr_type");
+
+	id = btf__add_const(btf, 5); /* points forward to restrict */
+	ASSERT_EQ(id, 3, "const_id");
+	t = btf__type_by_id(btf, 3);
+	ASSERT_EQ(btf_kind(t), BTF_KIND_CONST, "const_kind");
+	ASSERT_EQ(t->type, 5, "const_type");
+
+	id = btf__add_volatile(btf, 3);
+	ASSERT_EQ(id, 4, "volatile_id");
+	t = btf__type_by_id(btf, 4);
+	ASSERT_EQ(btf_kind(t), BTF_KIND_VOLATILE, "volatile_kind");
+	ASSERT_EQ(t->type, 3, "volatile_type");
+
+	id = btf__add_restrict(btf, 4);
+	ASSERT_EQ(id, 5, "restrict_id");
+	t = btf__type_by_id(btf, 5);
+	ASSERT_EQ(btf_kind(t), BTF_KIND_RESTRICT, "restrict_kind");
+	ASSERT_EQ(t->type, 4, "restrict_type");
+
+	/* ARRAY */
+	id = btf__add_array(btf, 1, 2, 10); /* int *[10] */
+	ASSERT_EQ(id, 6, "array_id");
+	t = btf__type_by_id(btf, 6);
+	ASSERT_EQ(btf_kind(t), BTF_KIND_ARRAY, "array_kind");
+	ASSERT_EQ(btf_array(t)->index_type, 1, "array_index_type");
+	ASSERT_EQ(btf_array(t)->type, 2, "array_elem_type");
+	ASSERT_EQ(btf_array(t)->nelems, 10, "array_nelems");
+
+	/* STRUCT */
+	err = btf__add_field(btf, "field", 1, 0, 0);
+	ASSERT_ERR(err, "no_struct_field");
+	id = btf__add_struct(btf, "s1", 8);
+	ASSERT_EQ(id, 7, "struct_id");
+	err = btf__add_field(btf, "f1", 1, 0, 0);
+	ASSERT_OK(err, "f1_res");
+	err = btf__add_field(btf, "f2", 1, 32, 16);
+	ASSERT_OK(err, "f2_res");
+
+	t = btf__type_by_id(btf, 7);
+	ASSERT_STREQ(btf__str_by_offset(btf, t->name_off), "s1", "struct_name");
+	ASSERT_EQ(btf_kind(t), BTF_KIND_STRUCT, "struct_kind");
+	ASSERT_EQ(btf_vlen(t), 2, "struct_vlen");
+	ASSERT_EQ(btf_kflag(t), true, "struct_kflag");
+	ASSERT_EQ(t->size, 8, "struct_sz");
+	m = btf_members(t) + 0;
+	ASSERT_STREQ(btf__str_by_offset(btf, m->name_off), "f1", "f1_name");
+	ASSERT_EQ(m->type, 1, "f1_type");
+	ASSERT_EQ(btf_member_bit_offset(t, 0), 0, "f1_bit_off");
+	ASSERT_EQ(btf_member_bitfield_size(t, 0), 0, "f1_bit_sz");
+	m = btf_members(t) + 1;
+	ASSERT_STREQ(btf__str_by_offset(btf, m->name_off), "f2", "f2_name");
+	ASSERT_EQ(m->type, 1, "f2_type");
+	ASSERT_EQ(btf_member_bit_offset(t, 1), 32, "f2_bit_off");
+	ASSERT_EQ(btf_member_bitfield_size(t, 1), 16, "f2_bit_sz");
+
+	/* UNION */
+	id = btf__add_union(btf, "u1", 8);
+	ASSERT_EQ(id, 8, "union_id");
+
+	/* invalid, non-zero offset */
+	err = btf__add_field(btf, "field", 1, 1, 0);
+	ASSERT_ERR(err, "no_struct_field");
+
+	err = btf__add_field(btf, "f1", 1, 0, 16);
+	ASSERT_OK(err, "f1_res");
+
+	t = btf__type_by_id(btf, 8);
+	ASSERT_STREQ(btf__str_by_offset(btf, t->name_off), "u1", "union_name");
+	ASSERT_EQ(btf_kind(t), BTF_KIND_UNION, "union_kind");
+	ASSERT_EQ(btf_vlen(t), 1, "union_vlen");
+	ASSERT_EQ(btf_kflag(t), true, "union_kflag");
+	ASSERT_EQ(t->size, 8, "union_sz");
+	m = btf_members(t) + 0;
+	ASSERT_STREQ(btf__str_by_offset(btf, m->name_off), "f1", "f1_name");
+	ASSERT_EQ(m->type, 1, "f1_type");
+	ASSERT_EQ(btf_member_bit_offset(t, 0), 0, "f1_bit_off");
+	ASSERT_EQ(btf_member_bitfield_size(t, 0), 16, "f1_bit_sz");
+
+	/* ENUM */
+	id = btf__add_enum(btf, "e1", 4);
+	ASSERT_EQ(id, 9, "enum_id");
+	err = btf__add_enum_value(btf, "v1", 1);
+	ASSERT_OK(err, "v1_res");
+	err = btf__add_enum_value(btf, "v2", 2);
+	ASSERT_OK(err, "v2_res");
+
+	t = btf__type_by_id(btf, 9);
+	ASSERT_STREQ(btf__str_by_offset(btf, t->name_off), "e1", "enum_name");
+	ASSERT_EQ(btf_kind(t), BTF_KIND_ENUM, "enum_kind");
+	ASSERT_EQ(btf_vlen(t), 2, "enum_vlen");
+	ASSERT_EQ(t->size, 4, "enum_sz");
+	v = btf_enum(t) + 0;
+	ASSERT_STREQ(btf__str_by_offset(btf, v->name_off), "v1", "v1_name");
+	ASSERT_EQ(v->val, 1, "v1_val");
+	v = btf_enum(t) + 1;
+	ASSERT_STREQ(btf__str_by_offset(btf, v->name_off), "v2", "v2_name");
+	ASSERT_EQ(v->val, 2, "v2_val");
+
+	/* FWDs */
+	id = btf__add_fwd(btf, "struct_fwd", BTF_FWD_STRUCT);
+	ASSERT_EQ(id, 10, "struct_fwd_id");
+	t = btf__type_by_id(btf, 10);
+	ASSERT_STREQ(btf__str_by_offset(btf, t->name_off), "struct_fwd", "fwd_name");
+	ASSERT_EQ(btf_kind(t), BTF_KIND_FWD, "fwd_kind");
+	ASSERT_EQ(btf_kflag(t), 0, "fwd_kflag");
+
+	id = btf__add_fwd(btf, "union_fwd", BTF_FWD_UNION);
+	ASSERT_EQ(id, 11, "union_fwd_id");
+	t = btf__type_by_id(btf, 11);
+	ASSERT_STREQ(btf__str_by_offset(btf, t->name_off), "union_fwd", "fwd_name");
+	ASSERT_EQ(btf_kind(t), BTF_KIND_FWD, "fwd_kind");
+	ASSERT_EQ(btf_kflag(t), 1, "fwd_kflag");
+
+	id = btf__add_fwd(btf, "enum_fwd", BTF_FWD_ENUM);
+	ASSERT_EQ(id, 12, "enum_fwd_id");
+	t = btf__type_by_id(btf, 12);
+	ASSERT_STREQ(btf__str_by_offset(btf, t->name_off), "enum_fwd", "fwd_name");
+	ASSERT_EQ(btf_kind(t), BTF_KIND_ENUM, "enum_fwd_kind");
+	ASSERT_EQ(btf_vlen(t), 0, "enum_fwd_kind");
+	ASSERT_EQ(t->size, 4, "enum_fwd_sz");
+
+	/* TYPEDEF */
+	id = btf__add_typedef(btf, "typedef1", 1);
+	ASSERT_EQ(id, 13, "typedef_fwd_id");
+	t = btf__type_by_id(btf, 13);
+	ASSERT_STREQ(btf__str_by_offset(btf, t->name_off), "typedef1", "typedef_name");
+	ASSERT_EQ(btf_kind(t), BTF_KIND_TYPEDEF, "typedef_kind");
+	ASSERT_EQ(t->type, 1, "typedef_type");
+
+	/* FUNC & FUNC_PROTO */
+	id = btf__add_func(btf, "func1", BTF_FUNC_GLOBAL, 15);
+	ASSERT_EQ(id, 14, "func_id");
+	t = btf__type_by_id(btf, 14);
+	ASSERT_STREQ(btf__str_by_offset(btf, t->name_off), "func1", "func_name");
+	ASSERT_EQ(t->type, 15, "func_type");
+	ASSERT_EQ(btf_kind(t), BTF_KIND_FUNC, "func_kind");
+	ASSERT_EQ(btf_vlen(t), BTF_FUNC_GLOBAL, "func_vlen");
+
+	id = btf__add_func_proto(btf, 1);
+	ASSERT_EQ(id, 15, "func_proto_id");
+	err = btf__add_func_param(btf, "p1", 1);
+	ASSERT_OK(err, "p1_res");
+	err = btf__add_func_param(btf, "p2", 2);
+	ASSERT_OK(err, "p2_res");
+
+	t = btf__type_by_id(btf, 15);
+	ASSERT_EQ(btf_kind(t), BTF_KIND_FUNC_PROTO, "func_proto_kind");
+	ASSERT_EQ(btf_vlen(t), 2, "func_proto_vlen");
+	ASSERT_EQ(t->type, 1, "func_proto_ret_type");
+	p = btf_params(t) + 0;
+	ASSERT_STREQ(btf__str_by_offset(btf, p->name_off), "p1", "p1_name");
+	ASSERT_EQ(p->type, 1, "p1_type");
+	p = btf_params(t) + 1;
+	ASSERT_STREQ(btf__str_by_offset(btf, p->name_off), "p2", "p2_name");
+	ASSERT_EQ(p->type, 2, "p2_type");
+
+	/* VAR */
+	id = btf__add_var(btf, "var1", BTF_VAR_GLOBAL_ALLOCATED, 1);
+	ASSERT_EQ(id, 16, "var_id");
+	t = btf__type_by_id(btf, 16);
+	ASSERT_STREQ(btf__str_by_offset(btf, t->name_off), "var1", "var_name");
+	ASSERT_EQ(btf_kind(t), BTF_KIND_VAR, "var_kind");
+	ASSERT_EQ(t->type, 1, "var_type");
+	ASSERT_EQ(btf_var(t)->linkage, BTF_VAR_GLOBAL_ALLOCATED, "var_type");
+
+	/* DATASECT */
+	id = btf__add_datasec(btf, "datasec1", 12);
+	ASSERT_EQ(id, 17, "datasec_id");
+	err = btf__add_datasec_var_info(btf, 1, 4, 8);
+	ASSERT_OK(err, "v1_res");
+
+	t = btf__type_by_id(btf, 17);
+	ASSERT_STREQ(btf__str_by_offset(btf, t->name_off), "datasec1", "datasec_name");
+	ASSERT_EQ(t->size, 12, "datasec_sz");
+	ASSERT_EQ(btf_kind(t), BTF_KIND_DATASEC, "datasec_kind");
+	ASSERT_EQ(btf_vlen(t), 1, "datasec_vlen");
+	vi = btf_var_secinfos(t) + 0;
+	ASSERT_EQ(vi->type, 1, "v1_type");
+	ASSERT_EQ(vi->offset, 4, "v1_off");
+	ASSERT_EQ(vi->size, 8, "v1_sz");
+
+	btf__free(btf);
+}
diff --git a/tools/testing/selftests/bpf/prog_tests/fexit_bpf2bpf.c b/tools/testing/selftests/bpf/prog_tests/fexit_bpf2bpf.c
index eda682727787..5c0448910426 100644
--- a/tools/testing/selftests/bpf/prog_tests/fexit_bpf2bpf.c
+++ b/tools/testing/selftests/bpf/prog_tests/fexit_bpf2bpf.c
@@ -2,36 +2,79 @@
 /* Copyright (c) 2019 Facebook */
 #include <test_progs.h>
 #include <network_helpers.h>
+#include <bpf/btf.h>
+
+typedef int (*test_cb)(struct bpf_object *obj);
+
+static int check_data_map(struct bpf_object *obj, int prog_cnt, bool reset)
+{
+	struct bpf_map *data_map = NULL, *map;
+	__u64 *result = NULL;
+	const int zero = 0;
+	__u32 duration = 0;
+	int ret = -1, i;
+
+	result = malloc((prog_cnt + 32 /* spare */) * sizeof(__u64));
+	if (CHECK(!result, "alloc_memory", "failed to alloc memory"))
+		return -ENOMEM;
+
+	bpf_object__for_each_map(map, obj)
+		if (bpf_map__is_internal(map)) {
+			data_map = map;
+			break;
+		}
+	if (CHECK(!data_map, "find_data_map", "data map not found\n"))
+		goto out;
+
+	ret = bpf_map_lookup_elem(bpf_map__fd(data_map), &zero, result);
+	if (CHECK(ret, "get_result",
+		  "failed to get output data: %d\n", ret))
+		goto out;
+
+	for (i = 0; i < prog_cnt; i++) {
+		if (CHECK(result[i] != 1, "result",
+			  "fexit_bpf2bpf result[%d] failed err %llu\n",
+			  i, result[i]))
+			goto out;
+		result[i] = 0;
+	}
+	if (reset) {
+		ret = bpf_map_update_elem(bpf_map__fd(data_map), &zero, result, 0);
+		if (CHECK(ret, "reset_result", "failed to reset result\n"))
+			goto out;
+	}
+
+	ret = 0;
+out:
+	free(result);
+	return ret;
+}
 
 static void test_fexit_bpf2bpf_common(const char *obj_file,
 				      const char *target_obj_file,
 				      int prog_cnt,
 				      const char **prog_name,
-				      bool run_prog)
+				      bool run_prog,
+				      test_cb cb)
 {
-	struct bpf_object *obj = NULL, *pkt_obj;
-	int err, pkt_fd, i;
-	struct bpf_link **link = NULL;
+	struct bpf_object *obj = NULL, *tgt_obj;
 	struct bpf_program **prog = NULL;
+	struct bpf_link **link = NULL;
 	__u32 duration = 0, retval;
-	struct bpf_map *data_map;
-	const int zero = 0;
-	__u64 *result = NULL;
+	int err, tgt_fd, i;
 
 	err = bpf_prog_load(target_obj_file, BPF_PROG_TYPE_UNSPEC,
-			    &pkt_obj, &pkt_fd);
+			    &tgt_obj, &tgt_fd);
 	if (CHECK(err, "tgt_prog_load", "file %s err %d errno %d\n",
 		  target_obj_file, err, errno))
 		return;
 	DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts,
-			    .attach_prog_fd = pkt_fd,
+			    .attach_prog_fd = tgt_fd,
 			   );
 
 	link = calloc(sizeof(struct bpf_link *), prog_cnt);
 	prog = calloc(sizeof(struct bpf_program *), prog_cnt);
-	result = malloc((prog_cnt + 32 /* spare */) * sizeof(__u64));
-	if (CHECK(!link || !prog || !result, "alloc_memory",
-		  "failed to alloc memory"))
+	if (CHECK(!link || !prog, "alloc_memory", "failed to alloc memory"))
 		goto close_prog;
 
 	obj = bpf_object__open_file(obj_file, &opts);
@@ -53,39 +96,33 @@ static void test_fexit_bpf2bpf_common(const char *obj_file,
 			goto close_prog;
 	}
 
-	if (!run_prog)
-		goto close_prog;
+	if (cb) {
+		err = cb(obj);
+		if (err)
+			goto close_prog;
+	}
 
-	data_map = bpf_object__find_map_by_name(obj, "fexit_bp.bss");
-	if (CHECK(!data_map, "find_data_map", "data map not found\n"))
+	if (!run_prog)
 		goto close_prog;
 
-	err = bpf_prog_test_run(pkt_fd, 1, &pkt_v6, sizeof(pkt_v6),
+	err = bpf_prog_test_run(tgt_fd, 1, &pkt_v6, sizeof(pkt_v6),
 				NULL, NULL, &retval, &duration);
 	CHECK(err || retval, "ipv6",
 	      "err %d errno %d retval %d duration %d\n",
 	      err, errno, retval, duration);
 
-	err = bpf_map_lookup_elem(bpf_map__fd(data_map), &zero, result);
-	if (CHECK(err, "get_result",
-		  "failed to get output data: %d\n", err))
+	if (check_data_map(obj, prog_cnt, false))
 		goto close_prog;
 
-	for (i = 0; i < prog_cnt; i++)
-		if (CHECK(result[i] != 1, "result", "fexit_bpf2bpf failed err %llu\n",
-			  result[i]))
-			goto close_prog;
-
 close_prog:
 	for (i = 0; i < prog_cnt; i++)
 		if (!IS_ERR_OR_NULL(link[i]))
 			bpf_link__destroy(link[i]);
 	if (!IS_ERR_OR_NULL(obj))
 		bpf_object__close(obj);
-	bpf_object__close(pkt_obj);
+	bpf_object__close(tgt_obj);
 	free(link);
 	free(prog);
-	free(result);
 }
 
 static void test_target_no_callees(void)
@@ -96,7 +133,7 @@ static void test_target_no_callees(void)
 	test_fexit_bpf2bpf_common("./fexit_bpf2bpf_simple.o",
 				  "./test_pkt_md_access.o",
 				  ARRAY_SIZE(prog_name),
-				  prog_name, true);
+				  prog_name, true, NULL);
 }
 
 static void test_target_yes_callees(void)
@@ -110,7 +147,7 @@ static void test_target_yes_callees(void)
 	test_fexit_bpf2bpf_common("./fexit_bpf2bpf.o",
 				  "./test_pkt_access.o",
 				  ARRAY_SIZE(prog_name),
-				  prog_name, true);
+				  prog_name, true, NULL);
 }
 
 static void test_func_replace(void)
@@ -128,7 +165,7 @@ static void test_func_replace(void)
 	test_fexit_bpf2bpf_common("./fexit_bpf2bpf.o",
 				  "./test_pkt_access.o",
 				  ARRAY_SIZE(prog_name),
-				  prog_name, true);
+				  prog_name, true, NULL);
 }
 
 static void test_func_replace_verify(void)
@@ -139,9 +176,116 @@ static void test_func_replace_verify(void)
 	test_fexit_bpf2bpf_common("./freplace_connect4.o",
 				  "./connect4_prog.o",
 				  ARRAY_SIZE(prog_name),
-				  prog_name, false);
+				  prog_name, false, NULL);
 }
 
+static int test_second_attach(struct bpf_object *obj)
+{
+	const char *prog_name = "freplace/get_constant";
+	const char *tgt_name = prog_name + 9; /* cut off freplace/ */
+	const char *tgt_obj_file = "./test_pkt_access.o";
+	struct bpf_program *prog = NULL;
+	struct bpf_object *tgt_obj;
+	__u32 duration = 0, retval;
+	struct bpf_link *link;
+	int err = 0, tgt_fd;
+
+	prog = bpf_object__find_program_by_title(obj, prog_name);
+	if (CHECK(!prog, "find_prog", "prog %s not found\n", prog_name))
+		return -ENOENT;
+
+	err = bpf_prog_load(tgt_obj_file, BPF_PROG_TYPE_UNSPEC,
+			    &tgt_obj, &tgt_fd);
+	if (CHECK(err, "second_prog_load", "file %s err %d errno %d\n",
+		  tgt_obj_file, err, errno))
+		return err;
+
+	link = bpf_program__attach_freplace(prog, tgt_fd, tgt_name);
+	if (CHECK(IS_ERR(link), "second_link", "failed to attach second link prog_fd %d tgt_fd %d\n", bpf_program__fd(prog), tgt_fd))
+		goto out;
+
+	err = bpf_prog_test_run(tgt_fd, 1, &pkt_v6, sizeof(pkt_v6),
+				NULL, NULL, &retval, &duration);
+	if (CHECK(err || retval, "ipv6",
+		  "err %d errno %d retval %d duration %d\n",
+		  err, errno, retval, duration))
+		goto out;
+
+	err = check_data_map(obj, 1, true);
+	if (err)
+		goto out;
+
+out:
+	bpf_link__destroy(link);
+	bpf_object__close(tgt_obj);
+	return err;
+}
+
+static void test_func_replace_multi(void)
+{
+	const char *prog_name[] = {
+		"freplace/get_constant",
+	};
+	test_fexit_bpf2bpf_common("./freplace_get_constant.o",
+				  "./test_pkt_access.o",
+				  ARRAY_SIZE(prog_name),
+				  prog_name, true, test_second_attach);
+}
+
+static void test_fmod_ret_freplace(void)
+{
+	struct bpf_object *freplace_obj = NULL, *pkt_obj, *fmod_obj = NULL;
+	const char *freplace_name = "./freplace_get_constant.o";
+	const char *fmod_ret_name = "./fmod_ret_freplace.o";
+	DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts);
+	const char *tgt_name = "./test_pkt_access.o";
+	struct bpf_link *freplace_link = NULL;
+	struct bpf_program *prog;
+	__u32 duration = 0;
+	int err, pkt_fd;
+
+	err = bpf_prog_load(tgt_name, BPF_PROG_TYPE_UNSPEC,
+			    &pkt_obj, &pkt_fd);
+	/* the target prog should load fine */
+	if (CHECK(err, "tgt_prog_load", "file %s err %d errno %d\n",
+		  tgt_name, err, errno))
+		return;
+	opts.attach_prog_fd = pkt_fd;
+
+	freplace_obj = bpf_object__open_file(freplace_name, &opts);
+	if (CHECK(IS_ERR_OR_NULL(freplace_obj), "freplace_obj_open",
+		  "failed to open %s: %ld\n", freplace_name,
+		  PTR_ERR(freplace_obj)))
+		goto out;
+
+	err = bpf_object__load(freplace_obj);
+	if (CHECK(err, "freplace_obj_load", "err %d\n", err))
+		goto out;
+
+	prog = bpf_program__next(NULL, freplace_obj);
+	freplace_link = bpf_program__attach_trace(prog);
+	if (CHECK(IS_ERR(freplace_link), "freplace_attach_trace", "failed to link\n"))
+		goto out;
+
+	opts.attach_prog_fd = bpf_program__fd(prog);
+	fmod_obj = bpf_object__open_file(fmod_ret_name, &opts);
+	if (CHECK(IS_ERR_OR_NULL(fmod_obj), "fmod_obj_open",
+		  "failed to open %s: %ld\n", fmod_ret_name,
+		  PTR_ERR(fmod_obj)))
+		goto out;
+
+	err = bpf_object__load(fmod_obj);
+	if (CHECK(!err, "fmod_obj_load", "loading fmod_ret should fail\n"))
+		goto out;
+
+out:
+	bpf_link__destroy(freplace_link);
+	bpf_object__close(freplace_obj);
+	bpf_object__close(fmod_obj);
+	bpf_object__close(pkt_obj);
+}
+
+
 static void test_func_sockmap_update(void)
 {
 	const char *prog_name[] = {
@@ -150,7 +294,7 @@ static void test_func_sockmap_update(void)
 	test_fexit_bpf2bpf_common("./freplace_cls_redirect.o",
 				  "./test_cls_redirect.o",
 				  ARRAY_SIZE(prog_name),
-				  prog_name, false);
+				  prog_name, false, NULL);
 }
 
 static void test_obj_load_failure_common(const char *obj_file,
@@ -222,4 +366,8 @@ void test_fexit_bpf2bpf(void)
 		test_func_replace_return_code();
 	if (test__start_subtest("func_map_prog_compatibility"))
 		test_func_map_prog_compatibility();
+	if (test__start_subtest("func_replace_multi"))
+		test_func_replace_multi();
+	if (test__start_subtest("fmod_ret_freplace"))
+		test_fmod_ret_freplace();
 }
diff --git a/tools/testing/selftests/bpf/prog_tests/pe_preserve_elems.c b/tools/testing/selftests/bpf/prog_tests/pe_preserve_elems.c
new file mode 100644
index 000000000000..673d38395253
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/pe_preserve_elems.c
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2019 Facebook */
+#include <test_progs.h>
+#include <linux/bpf.h>
+#include "test_pe_preserve_elems.skel.h"
+
+static int duration;
+
+static void test_one_map(struct bpf_map *map, struct bpf_program *prog,
+			 bool has_share_pe)
+{
+	int err, key = 0, pfd = -1, mfd = bpf_map__fd(map);
+	DECLARE_LIBBPF_OPTS(bpf_test_run_opts, opts);
+	struct perf_event_attr attr = {
+		.size = sizeof(struct perf_event_attr),
+		.type = PERF_TYPE_SOFTWARE,
+		.config = PERF_COUNT_SW_CPU_CLOCK,
+	};
+
+	pfd = syscall(__NR_perf_event_open, &attr, 0 /* pid */,
+		      -1 /* cpu 0 */, -1 /* group id */, 0 /* flags */);
+	if (CHECK(pfd < 0, "perf_event_open", "failed\n"))
+		return;
+
+	err = bpf_map_update_elem(mfd, &key, &pfd, BPF_ANY);
+	close(pfd);
+	if (CHECK(err < 0, "bpf_map_update_elem", "failed\n"))
+		return;
+
+	err = bpf_prog_test_run_opts(bpf_program__fd(prog), &opts);
+	if (CHECK(err < 0, "bpf_prog_test_run_opts", "failed\n"))
+		return;
+	if (CHECK(opts.retval != 0, "bpf_perf_event_read_value",
+		  "failed with %d\n", opts.retval))
+		return;
+
+	/* closing mfd, prog still holds a reference on map */
+	close(mfd);
+
+	err = bpf_prog_test_run_opts(bpf_program__fd(prog), &opts);
+	if (CHECK(err < 0, "bpf_prog_test_run_opts", "failed\n"))
+		return;
+
+	if (has_share_pe) {
+		CHECK(opts.retval != 0, "bpf_perf_event_read_value",
+		      "failed with %d\n", opts.retval);
+	} else {
+		CHECK(opts.retval != -ENOENT, "bpf_perf_event_read_value",
+		      "should have failed with %d, but got %d\n", -ENOENT,
+		      opts.retval);
+	}
+}
+
+void test_pe_preserve_elems(void)
+{
+	struct test_pe_preserve_elems *skel;
+
+	skel = test_pe_preserve_elems__open_and_load();
+	if (CHECK(!skel, "skel_open", "failed to open skeleton\n"))
+		return;
+
+	test_one_map(skel->maps.array_1, skel->progs.read_array_1, false);
+	test_one_map(skel->maps.array_2, skel->progs.read_array_2, true);
+
+	test_pe_preserve_elems__destroy(skel);
+}
diff --git a/tools/testing/selftests/bpf/prog_tests/raw_tp_test_run.c b/tools/testing/selftests/bpf/prog_tests/raw_tp_test_run.c
new file mode 100644
index 000000000000..c5fb191874ac
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/raw_tp_test_run.c
@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2019 Facebook */
+#include <test_progs.h>
+#include <linux/bpf.h>
+#include "bpf/libbpf_internal.h"
+#include "test_raw_tp_test_run.skel.h"
+
+static int duration;
+
+void test_raw_tp_test_run(void)
+{
+	struct bpf_prog_test_run_attr test_attr = {};
+	int comm_fd = -1, err, nr_online, i, prog_fd;
+	__u64 args[2] = {0x1234ULL, 0x5678ULL};
+	int expected_retval = 0x1234 + 0x5678;
+	struct test_raw_tp_test_run *skel;
+	char buf[] = "new_name";
+	bool *online = NULL;
+	DECLARE_LIBBPF_OPTS(bpf_test_run_opts, opts,
+			    .ctx_in = args,
+			    .ctx_size_in = sizeof(args),
+			    .flags = BPF_F_TEST_RUN_ON_CPU,
+		);
+
+	err = parse_cpu_mask_file("/sys/devices/system/cpu/online", &online,
+				  &nr_online);
+	if (CHECK(err, "parse_cpu_mask_file", "err %d\n", err))
+		return;
+
+	skel = test_raw_tp_test_run__open_and_load();
+	if (CHECK(!skel, "skel_open", "failed to open skeleton\n"))
+		goto cleanup;
+
+	err = test_raw_tp_test_run__attach(skel);
+	if (CHECK(err, "skel_attach", "skeleton attach failed: %d\n", err))
+		goto cleanup;
+
+	comm_fd = open("/proc/self/comm", O_WRONLY|O_TRUNC);
+	if (CHECK(comm_fd < 0, "open /proc/self/comm", "err %d\n", errno))
+		goto cleanup;
+
+	err = write(comm_fd, buf, sizeof(buf));
+	CHECK(err < 0, "task rename", "err %d", errno);
+
+	CHECK(skel->bss->count == 0, "check_count", "didn't increase\n");
+	CHECK(skel->data->on_cpu != 0xffffffff, "check_on_cpu", "got wrong value\n");
+
+	prog_fd = bpf_program__fd(skel->progs.rename);
+	test_attr.prog_fd = prog_fd;
+	test_attr.ctx_in = args;
+	test_attr.ctx_size_in = sizeof(__u64);
+
+	err = bpf_prog_test_run_xattr(&test_attr);
+	CHECK(err == 0, "test_run", "should fail for too small ctx\n");
+
+	test_attr.ctx_size_in = sizeof(args);
+	err = bpf_prog_test_run_xattr(&test_attr);
+	CHECK(err < 0, "test_run", "err %d\n", errno);
+	CHECK(test_attr.retval != expected_retval, "check_retval",
+	      "expect 0x%x, got 0x%x\n", expected_retval, test_attr.retval);
+
+	for (i = 0; i < nr_online; i++) {
+		if (!online[i])
+			continue;
+
+		opts.cpu = i;
+		opts.retval = 0;
+		err = bpf_prog_test_run_opts(prog_fd, &opts);
+		CHECK(err < 0, "test_run_opts", "err %d\n", errno);
+		CHECK(skel->data->on_cpu != i, "check_on_cpu",
+		      "expect %d got %d\n", i, skel->data->on_cpu);
+		CHECK(opts.retval != expected_retval,
+		      "check_retval", "expect 0x%x, got 0x%x\n",
+		      expected_retval, opts.retval);
+	}
+
+	/* invalid cpu ID should fail with ENXIO */
+	opts.cpu = 0xffffffff;
+	err = bpf_prog_test_run_opts(prog_fd, &opts);
+	CHECK(err != -1 || errno != ENXIO,
+	      "test_run_opts_fail",
+	      "should failed with ENXIO\n");
+
+	/* non-zero cpu w/o BPF_F_TEST_RUN_ON_CPU should fail with EINVAL */
+	opts.cpu = 1;
+	opts.flags = 0;
+	err = bpf_prog_test_run_opts(prog_fd, &opts);
+	CHECK(err != -1 || errno != EINVAL,
+	      "test_run_opts_fail",
+	      "should failed with EINVAL\n");
+
+cleanup:
+	close(comm_fd);
+	test_raw_tp_test_run__destroy(skel);
+	free(online);
+}
diff --git a/tools/testing/selftests/bpf/prog_tests/resolve_btfids.c b/tools/testing/selftests/bpf/prog_tests/resolve_btfids.c
index 8826c652adad..6ace5e9efec1 100644
--- a/tools/testing/selftests/bpf/prog_tests/resolve_btfids.c
+++ b/tools/testing/selftests/bpf/prog_tests/resolve_btfids.c
@@ -28,6 +28,12 @@ struct symbol test_symbols[] = {
 	{ "func",    BTF_KIND_FUNC,    -1 },
 };
 
+/* Align the .BTF_ids section to 4 bytes */
+asm (
+".pushsection " BTF_IDS_SECTION " ,\"a\"; \n"
+".balign 4, 0;                            \n"
+".popsection;                             \n");
+
 BTF_ID_LIST(test_list_local)
 BTF_ID_UNUSED
 BTF_ID(typedef, S)
diff --git a/tools/testing/selftests/bpf/prog_tests/snprintf_btf.c b/tools/testing/selftests/bpf/prog_tests/snprintf_btf.c
new file mode 100644
index 000000000000..686b40f11a45
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/snprintf_btf.c
@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <test_progs.h>
+#include <linux/btf.h>
+#include "netif_receive_skb.skel.h"
+
+/* Demonstrate that bpf_snprintf_btf succeeds and that various data types
+ * are formatted correctly.
+ */
+void test_snprintf_btf(void)
+{
+	struct netif_receive_skb *skel;
+	struct netif_receive_skb__bss *bss;
+	int err, duration = 0;
+
+	skel = netif_receive_skb__open();
+	if (CHECK(!skel, "skel_open", "failed to open skeleton\n"))
+		return;
+
+	err = netif_receive_skb__load(skel);
+	if (CHECK(err, "skel_load", "failed to load skeleton: %d\n", err))
+		goto cleanup;
+
+	bss = skel->bss;
+
+	err = netif_receive_skb__attach(skel);
+	if (CHECK(err, "skel_attach", "skeleton attach failed: %d\n", err))
+		goto cleanup;
+
+	/* generate receive event */
+	err = system("ping -c 1 127.0.0.1 > /dev/null");
+	if (CHECK(err, "system", "ping failed: %d\n", err))
+		goto cleanup;
+
+	if (bss->skip) {
+		printf("%s:SKIP:no __builtin_btf_type_id\n", __func__);
+		test__skip();
+		goto cleanup;
+	}
+
+	/*
+	 * Make sure netif_receive_skb program was triggered
+	 * and it set expected return values from bpf_trace_printk()s
+	 * and all tests ran.
+	 */
+	if (CHECK(bss->ret <= 0,
+		  "bpf_snprintf_btf: got return value",
+		  "ret <= 0 %ld test %d\n", bss->ret, bss->ran_subtests))
+		goto cleanup;
+
+	if (CHECK(bss->ran_subtests == 0, "check if subtests ran",
+		  "no subtests ran, did BPF program run?"))
+		goto cleanup;
+
+	if (CHECK(bss->num_subtests != bss->ran_subtests,
+		  "check all subtests ran",
+		  "only ran %d of %d tests\n", bss->num_subtests,
+		  bss->ran_subtests))
+		goto cleanup;
+
+cleanup:
+	netif_receive_skb__destroy(skel);
+}
diff --git a/tools/testing/selftests/bpf/prog_tests/sock_fields.c b/tools/testing/selftests/bpf/prog_tests/sock_fields.c
new file mode 100644
index 000000000000..af87118e748e
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/sock_fields.c
@@ -0,0 +1,382 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2019 Facebook */
+
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+#include <linux/compiler.h>
+
+#include "network_helpers.h"
+#include "cgroup_helpers.h"
+#include "test_progs.h"
+#include "bpf_rlimit.h"
+#include "test_sock_fields.skel.h"
+
+enum bpf_linum_array_idx {
+	EGRESS_LINUM_IDX,
+	INGRESS_LINUM_IDX,
+	__NR_BPF_LINUM_ARRAY_IDX,
+};
+
+struct bpf_spinlock_cnt {
+	struct bpf_spin_lock lock;
+	__u32 cnt;
+};
+
+#define PARENT_CGROUP	"/test-bpf-sock-fields"
+#define CHILD_CGROUP	"/test-bpf-sock-fields/child"
+#define DATA "Hello BPF!"
+#define DATA_LEN sizeof(DATA)
+
+static struct sockaddr_in6 srv_sa6, cli_sa6;
+static int sk_pkt_out_cnt10_fd;
+static struct test_sock_fields *skel;
+static int sk_pkt_out_cnt_fd;
+static __u64 parent_cg_id;
+static __u64 child_cg_id;
+static int linum_map_fd;
+static __u32 duration;
+
+static __u32 egress_linum_idx = EGRESS_LINUM_IDX;
+static __u32 ingress_linum_idx = INGRESS_LINUM_IDX;
+
+static void print_sk(const struct bpf_sock *sk, const char *prefix)
+{
+	char src_ip4[24], dst_ip4[24];
+	char src_ip6[64], dst_ip6[64];
+
+	inet_ntop(AF_INET, &sk->src_ip4, src_ip4, sizeof(src_ip4));
+	inet_ntop(AF_INET6, &sk->src_ip6, src_ip6, sizeof(src_ip6));
+	inet_ntop(AF_INET, &sk->dst_ip4, dst_ip4, sizeof(dst_ip4));
+	inet_ntop(AF_INET6, &sk->dst_ip6, dst_ip6, sizeof(dst_ip6));
+
+	printf("%s: state:%u bound_dev_if:%u family:%u type:%u protocol:%u mark:%u priority:%u "
+	       "src_ip4:%x(%s) src_ip6:%x:%x:%x:%x(%s) src_port:%u "
+	       "dst_ip4:%x(%s) dst_ip6:%x:%x:%x:%x(%s) dst_port:%u\n",
+	       prefix,
+	       sk->state, sk->bound_dev_if, sk->family, sk->type, sk->protocol,
+	       sk->mark, sk->priority,
+	       sk->src_ip4, src_ip4,
+	       sk->src_ip6[0], sk->src_ip6[1], sk->src_ip6[2], sk->src_ip6[3],
+	       src_ip6, sk->src_port,
+	       sk->dst_ip4, dst_ip4,
+	       sk->dst_ip6[0], sk->dst_ip6[1], sk->dst_ip6[2], sk->dst_ip6[3],
+	       dst_ip6, ntohs(sk->dst_port));
+}
+
+static void print_tp(const struct bpf_tcp_sock *tp, const char *prefix)
+{
+	printf("%s: snd_cwnd:%u srtt_us:%u rtt_min:%u snd_ssthresh:%u rcv_nxt:%u "
+	       "snd_nxt:%u snd:una:%u mss_cache:%u ecn_flags:%u "
+	       "rate_delivered:%u rate_interval_us:%u packets_out:%u "
+	       "retrans_out:%u total_retrans:%u segs_in:%u data_segs_in:%u "
+	       "segs_out:%u data_segs_out:%u lost_out:%u sacked_out:%u "
+	       "bytes_received:%llu bytes_acked:%llu\n",
+	       prefix,
+	       tp->snd_cwnd, tp->srtt_us, tp->rtt_min, tp->snd_ssthresh,
+	       tp->rcv_nxt, tp->snd_nxt, tp->snd_una, tp->mss_cache,
+	       tp->ecn_flags, tp->rate_delivered, tp->rate_interval_us,
+	       tp->packets_out, tp->retrans_out, tp->total_retrans,
+	       tp->segs_in, tp->data_segs_in, tp->segs_out,
+	       tp->data_segs_out, tp->lost_out, tp->sacked_out,
+	       tp->bytes_received, tp->bytes_acked);
+}
+
+static void check_result(void)
+{
+	struct bpf_tcp_sock srv_tp, cli_tp, listen_tp;
+	struct bpf_sock srv_sk, cli_sk, listen_sk;
+	__u32 ingress_linum, egress_linum;
+	int err;
+
+	err = bpf_map_lookup_elem(linum_map_fd, &egress_linum_idx,
+				  &egress_linum);
+	CHECK(err == -1, "bpf_map_lookup_elem(linum_map_fd)",
+	      "err:%d errno:%d\n", err, errno);
+
+	err = bpf_map_lookup_elem(linum_map_fd, &ingress_linum_idx,
+				  &ingress_linum);
+	CHECK(err == -1, "bpf_map_lookup_elem(linum_map_fd)",
+	      "err:%d errno:%d\n", err, errno);
+
+	memcpy(&srv_sk, &skel->bss->srv_sk, sizeof(srv_sk));
+	memcpy(&srv_tp, &skel->bss->srv_tp, sizeof(srv_tp));
+	memcpy(&cli_sk, &skel->bss->cli_sk, sizeof(cli_sk));
+	memcpy(&cli_tp, &skel->bss->cli_tp, sizeof(cli_tp));
+	memcpy(&listen_sk, &skel->bss->listen_sk, sizeof(listen_sk));
+	memcpy(&listen_tp, &skel->bss->listen_tp, sizeof(listen_tp));
+
+	print_sk(&listen_sk, "listen_sk");
+	print_sk(&srv_sk, "srv_sk");
+	print_sk(&cli_sk, "cli_sk");
+	print_tp(&listen_tp, "listen_tp");
+	print_tp(&srv_tp, "srv_tp");
+	print_tp(&cli_tp, "cli_tp");
+
+	CHECK(listen_sk.state != 10 ||
+	      listen_sk.family != AF_INET6 ||
+	      listen_sk.protocol != IPPROTO_TCP ||
+	      memcmp(listen_sk.src_ip6, &in6addr_loopback,
+		     sizeof(listen_sk.src_ip6)) ||
+	      listen_sk.dst_ip6[0] || listen_sk.dst_ip6[1] ||
+	      listen_sk.dst_ip6[2] || listen_sk.dst_ip6[3] ||
+	      listen_sk.src_port != ntohs(srv_sa6.sin6_port) ||
+	      listen_sk.dst_port,
+	      "listen_sk",
+	      "Unexpected. Check listen_sk output. ingress_linum:%u\n",
+	      ingress_linum);
+
+	CHECK(srv_sk.state == 10 ||
+	      !srv_sk.state ||
+	      srv_sk.family != AF_INET6 ||
+	      srv_sk.protocol != IPPROTO_TCP ||
+	      memcmp(srv_sk.src_ip6, &in6addr_loopback,
+		     sizeof(srv_sk.src_ip6)) ||
+	      memcmp(srv_sk.dst_ip6, &in6addr_loopback,
+		     sizeof(srv_sk.dst_ip6)) ||
+	      srv_sk.src_port != ntohs(srv_sa6.sin6_port) ||
+	      srv_sk.dst_port != cli_sa6.sin6_port,
+	      "srv_sk", "Unexpected. Check srv_sk output. egress_linum:%u\n",
+	      egress_linum);
+
+	CHECK(!skel->bss->lsndtime, "srv_tp", "Unexpected lsndtime:0\n");
+
+	CHECK(cli_sk.state == 10 ||
+	      !cli_sk.state ||
+	      cli_sk.family != AF_INET6 ||
+	      cli_sk.protocol != IPPROTO_TCP ||
+	      memcmp(cli_sk.src_ip6, &in6addr_loopback,
+		     sizeof(cli_sk.src_ip6)) ||
+	      memcmp(cli_sk.dst_ip6, &in6addr_loopback,
+		     sizeof(cli_sk.dst_ip6)) ||
+	      cli_sk.src_port != ntohs(cli_sa6.sin6_port) ||
+	      cli_sk.dst_port != srv_sa6.sin6_port,
+	      "cli_sk", "Unexpected. Check cli_sk output. egress_linum:%u\n",
+	      egress_linum);
+
+	CHECK(listen_tp.data_segs_out ||
+	      listen_tp.data_segs_in ||
+	      listen_tp.total_retrans ||
+	      listen_tp.bytes_acked,
+	      "listen_tp",
+	      "Unexpected. Check listen_tp output. ingress_linum:%u\n",
+	      ingress_linum);
+
+	CHECK(srv_tp.data_segs_out != 2 ||
+	      srv_tp.data_segs_in ||
+	      srv_tp.snd_cwnd != 10 ||
+	      srv_tp.total_retrans ||
+	      srv_tp.bytes_acked < 2 * DATA_LEN,
+	      "srv_tp", "Unexpected. Check srv_tp output. egress_linum:%u\n",
+	      egress_linum);
+
+	CHECK(cli_tp.data_segs_out ||
+	      cli_tp.data_segs_in != 2 ||
+	      cli_tp.snd_cwnd != 10 ||
+	      cli_tp.total_retrans ||
+	      cli_tp.bytes_received < 2 * DATA_LEN,
+	      "cli_tp", "Unexpected. Check cli_tp output. egress_linum:%u\n",
+	      egress_linum);
+
+	CHECK(skel->bss->parent_cg_id != parent_cg_id,
+	      "parent_cg_id", "%zu != %zu\n",
+	      (size_t)skel->bss->parent_cg_id, (size_t)parent_cg_id);
+
+	CHECK(skel->bss->child_cg_id != child_cg_id,
+	      "child_cg_id", "%zu != %zu\n",
+	       (size_t)skel->bss->child_cg_id, (size_t)child_cg_id);
+}
+
+static void check_sk_pkt_out_cnt(int accept_fd, int cli_fd)
+{
+	struct bpf_spinlock_cnt pkt_out_cnt = {}, pkt_out_cnt10 = {};
+	int err;
+
+	pkt_out_cnt.cnt = ~0;
+	pkt_out_cnt10.cnt = ~0;
+	err = bpf_map_lookup_elem(sk_pkt_out_cnt_fd, &accept_fd, &pkt_out_cnt);
+	if (!err)
+		err = bpf_map_lookup_elem(sk_pkt_out_cnt10_fd, &accept_fd,
+					  &pkt_out_cnt10);
+
+	/* The bpf prog only counts for fullsock and
+	 * passive connection did not become fullsock until 3WHS
+	 * had been finished, so the bpf prog only counted two data
+	 * packet out.
+	 */
+	CHECK(err || pkt_out_cnt.cnt < 0xeB9F + 2 ||
+	      pkt_out_cnt10.cnt < 0xeB9F + 20,
+	      "bpf_map_lookup_elem(sk_pkt_out_cnt, &accept_fd)",
+	      "err:%d errno:%d pkt_out_cnt:%u pkt_out_cnt10:%u\n",
+	      err, errno, pkt_out_cnt.cnt, pkt_out_cnt10.cnt);
+
+	pkt_out_cnt.cnt = ~0;
+	pkt_out_cnt10.cnt = ~0;
+	err = bpf_map_lookup_elem(sk_pkt_out_cnt_fd, &cli_fd, &pkt_out_cnt);
+	if (!err)
+		err = bpf_map_lookup_elem(sk_pkt_out_cnt10_fd, &cli_fd,
+					  &pkt_out_cnt10);
+	/* Active connection is fullsock from the beginning.
+	 * 1 SYN and 1 ACK during 3WHS
+	 * 2 Acks on data packet.
+	 *
+	 * The bpf_prog initialized it to 0xeB9F.
+	 */
+	CHECK(err || pkt_out_cnt.cnt < 0xeB9F + 4 ||
+	      pkt_out_cnt10.cnt < 0xeB9F + 40,
+	      "bpf_map_lookup_elem(sk_pkt_out_cnt, &cli_fd)",
+	      "err:%d errno:%d pkt_out_cnt:%u pkt_out_cnt10:%u\n",
+	      err, errno, pkt_out_cnt.cnt, pkt_out_cnt10.cnt);
+}
+
+static int init_sk_storage(int sk_fd, __u32 pkt_out_cnt)
+{
+	struct bpf_spinlock_cnt scnt = {};
+	int err;
+
+	scnt.cnt = pkt_out_cnt;
+	err = bpf_map_update_elem(sk_pkt_out_cnt_fd, &sk_fd, &scnt,
+				  BPF_NOEXIST);
+	if (CHECK(err, "bpf_map_update_elem(sk_pkt_out_cnt_fd)",
+		  "err:%d errno:%d\n", err, errno))
+		return err;
+
+	err = bpf_map_update_elem(sk_pkt_out_cnt10_fd, &sk_fd, &scnt,
+				  BPF_NOEXIST);
+	if (CHECK(err, "bpf_map_update_elem(sk_pkt_out_cnt10_fd)",
+		  "err:%d errno:%d\n", err, errno))
+		return err;
+
+	return 0;
+}
+
+static void test(void)
+{
+	int listen_fd = -1, cli_fd = -1, accept_fd = -1, err, i;
+	socklen_t addrlen = sizeof(struct sockaddr_in6);
+	char buf[DATA_LEN];
+
+	/* Prepare listen_fd */
+	listen_fd = start_server(AF_INET6, SOCK_STREAM, "::1", 0, 0);
+	/* start_server() has logged the error details */
+	if (CHECK_FAIL(listen_fd == -1))
+		goto done;
+
+	err = getsockname(listen_fd, (struct sockaddr *)&srv_sa6, &addrlen);
+	if (CHECK(err, "getsockname(listen_fd)", "err:%d errno:%d\n", err,
+		  errno))
+		goto done;
+	memcpy(&skel->bss->srv_sa6, &srv_sa6, sizeof(srv_sa6));
+
+	cli_fd = connect_to_fd(listen_fd, 0);
+	if (CHECK_FAIL(cli_fd == -1))
+		goto done;
+
+	err = getsockname(cli_fd, (struct sockaddr *)&cli_sa6, &addrlen);
+	if (CHECK(err, "getsockname(cli_fd)", "err:%d errno:%d\n",
+		  err, errno))
+		goto done;
+
+	accept_fd = accept(listen_fd, NULL, NULL);
+	if (CHECK(accept_fd == -1, "accept(listen_fd)",
+		  "accept_fd:%d errno:%d\n",
+		  accept_fd, errno))
+		goto done;
+
+	if (init_sk_storage(accept_fd, 0xeB9F))
+		goto done;
+
+	for (i = 0; i < 2; i++) {
+		/* Send some data from accept_fd to cli_fd.
+		 * MSG_EOR to stop kernel from coalescing two pkts.
+		 */
+		err = send(accept_fd, DATA, DATA_LEN, MSG_EOR);
+		if (CHECK(err != DATA_LEN, "send(accept_fd)",
+			  "err:%d errno:%d\n", err, errno))
+			goto done;
+
+		err = recv(cli_fd, buf, DATA_LEN, 0);
+		if (CHECK(err != DATA_LEN, "recv(cli_fd)", "err:%d errno:%d\n",
+			  err, errno))
+			goto done;
+	}
+
+	shutdown(cli_fd, SHUT_WR);
+	err = recv(accept_fd, buf, 1, 0);
+	if (CHECK(err, "recv(accept_fd) for fin", "err:%d errno:%d\n",
+		  err, errno))
+		goto done;
+	shutdown(accept_fd, SHUT_WR);
+	err = recv(cli_fd, buf, 1, 0);
+	if (CHECK(err, "recv(cli_fd) for fin", "err:%d errno:%d\n",
+		  err, errno))
+		goto done;
+	check_sk_pkt_out_cnt(accept_fd, cli_fd);
+	check_result();
+
+done:
+	if (accept_fd != -1)
+		close(accept_fd);
+	if (cli_fd != -1)
+		close(cli_fd);
+	if (listen_fd != -1)
+		close(listen_fd);
+}
+
+void test_sock_fields(void)
+{
+	struct bpf_link *egress_link = NULL, *ingress_link = NULL;
+	int parent_cg_fd = -1, child_cg_fd = -1;
+
+	/* Create a cgroup, get fd, and join it */
+	parent_cg_fd = test__join_cgroup(PARENT_CGROUP);
+	if (CHECK_FAIL(parent_cg_fd < 0))
+		return;
+	parent_cg_id = get_cgroup_id(PARENT_CGROUP);
+	if (CHECK_FAIL(!parent_cg_id))
+		goto done;
+
+	child_cg_fd = test__join_cgroup(CHILD_CGROUP);
+	if (CHECK_FAIL(child_cg_fd < 0))
+		goto done;
+	child_cg_id = get_cgroup_id(CHILD_CGROUP);
+	if (CHECK_FAIL(!child_cg_id))
+		goto done;
+
+	skel = test_sock_fields__open_and_load();
+	if (CHECK(!skel, "test_sock_fields__open_and_load", "failed\n"))
+		goto done;
+
+	egress_link = bpf_program__attach_cgroup(skel->progs.egress_read_sock_fields,
+						 child_cg_fd);
+	if (CHECK(IS_ERR(egress_link), "attach_cgroup(egress)", "err:%ld\n",
+		  PTR_ERR(egress_link)))
+		goto done;
+
+	ingress_link = bpf_program__attach_cgroup(skel->progs.ingress_read_sock_fields,
+						  child_cg_fd);
+	if (CHECK(IS_ERR(ingress_link), "attach_cgroup(ingress)", "err:%ld\n",
+		  PTR_ERR(ingress_link)))
+		goto done;
+
+	linum_map_fd = bpf_map__fd(skel->maps.linum_map);
+	sk_pkt_out_cnt_fd = bpf_map__fd(skel->maps.sk_pkt_out_cnt);
+	sk_pkt_out_cnt10_fd = bpf_map__fd(skel->maps.sk_pkt_out_cnt10);
+
+	test();
+
+done:
+	bpf_link__destroy(egress_link);
+	bpf_link__destroy(ingress_link);
+	test_sock_fields__destroy(skel);
+	if (child_cg_fd != -1)
+		close(child_cg_fd);
+	if (parent_cg_fd != -1)
+		close(parent_cg_fd);
+}
diff --git a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
index 4b7a527e7e82..4c4224e3e10a 100644
--- a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
+++ b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
@@ -8,8 +8,6 @@
 #include "test_sockmap_invalid_update.skel.h"
 #include "bpf_iter_sockmap.skel.h"
 
-#include "progs/bpf_iter_sockmap.h"
-
 #define TCP_REPAIR		19	/* TCP sock is under repair right now */
 
 #define TCP_REPAIR_ON		1
@@ -50,6 +48,37 @@ error:
 	return -1;
 }
 
+static void compare_cookies(struct bpf_map *src, struct bpf_map *dst)
+{
+	__u32 i, max_entries = bpf_map__max_entries(src);
+	int err, duration = 0, src_fd, dst_fd;
+
+	src_fd = bpf_map__fd(src);
+	dst_fd = bpf_map__fd(dst);
+
+	for (i = 0; i < max_entries; i++) {
+		__u64 src_cookie, dst_cookie;
+
+		err = bpf_map_lookup_elem(src_fd, &i, &src_cookie);
+		if (err && errno == ENOENT) {
+			err = bpf_map_lookup_elem(dst_fd, &i, &dst_cookie);
+			CHECK(!err, "map_lookup_elem(dst)", "element %u not deleted\n", i);
+			CHECK(err && errno != ENOENT, "map_lookup_elem(dst)", "%s\n",
+			      strerror(errno));
+			continue;
+		}
+		if (CHECK(err, "lookup_elem(src)", "%s\n", strerror(errno)))
+			continue;
+
+		err = bpf_map_lookup_elem(dst_fd, &i, &dst_cookie);
+		if (CHECK(err, "lookup_elem(dst)", "%s\n", strerror(errno)))
+			continue;
+
+		CHECK(dst_cookie != src_cookie, "cookie mismatch",
+		      "%llu != %llu (pos %u)\n", dst_cookie, src_cookie, i);
+	}
+}
+
 /* Create a map, populate it with one socket, and free the map. */
 static void test_sockmap_create_update_free(enum bpf_map_type map_type)
 {
@@ -109,9 +138,9 @@ out:
 static void test_sockmap_update(enum bpf_map_type map_type)
 {
 	struct bpf_prog_test_run_attr tattr;
-	int err, prog, src, dst, duration = 0;
+	int err, prog, src, duration = 0;
 	struct test_sockmap_update *skel;
-	__u64 src_cookie, dst_cookie;
+	struct bpf_map *dst_map;
 	const __u32 zero = 0;
 	char dummy[14] = {0};
 	__s64 sk;
@@ -127,18 +156,14 @@ static void test_sockmap_update(enum bpf_map_type map_type)
 	prog = bpf_program__fd(skel->progs.copy_sock_map);
 	src = bpf_map__fd(skel->maps.src);
 	if (map_type == BPF_MAP_TYPE_SOCKMAP)
-		dst = bpf_map__fd(skel->maps.dst_sock_map);
+		dst_map = skel->maps.dst_sock_map;
 	else
-		dst = bpf_map__fd(skel->maps.dst_sock_hash);
+		dst_map = skel->maps.dst_sock_hash;
 
 	err = bpf_map_update_elem(src, &zero, &sk, BPF_NOEXIST);
 	if (CHECK(err, "update_elem(src)", "errno=%u\n", errno))
 		goto out;
 
-	err = bpf_map_lookup_elem(src, &zero, &src_cookie);
-	if (CHECK(err, "lookup_elem(src, cookie)", "errno=%u\n", errno))
-		goto out;
-
 	tattr = (struct bpf_prog_test_run_attr){
 		.prog_fd = prog,
 		.repeat = 1,
@@ -151,12 +176,7 @@ static void test_sockmap_update(enum bpf_map_type map_type)
 		       "errno=%u retval=%u\n", errno, tattr.retval))
 		goto out;
 
-	err = bpf_map_lookup_elem(dst, &zero, &dst_cookie);
-	if (CHECK(err, "lookup_elem(dst, cookie)", "errno=%u\n", errno))
-		goto out;
-
-	CHECK(dst_cookie != src_cookie, "cookie mismatch", "%llu != %llu\n",
-	      dst_cookie, src_cookie);
+	compare_cookies(skel->maps.src, dst_map);
 
 out:
 	test_sockmap_update__destroy(skel);
@@ -174,14 +194,14 @@ static void test_sockmap_invalid_update(void)
 		test_sockmap_invalid_update__destroy(skel);
 }
 
-static void test_sockmap_iter(enum bpf_map_type map_type)
+static void test_sockmap_copy(enum bpf_map_type map_type)
 {
 	DECLARE_LIBBPF_OPTS(bpf_iter_attach_opts, opts);
 	int err, len, src_fd, iter_fd, duration = 0;
 	union bpf_iter_link_info linfo = {0};
-	__s64 sock_fd[SOCKMAP_MAX_ENTRIES];
-	__u32 i, num_sockets, max_elems;
+	__u32 i, num_sockets, num_elems;
 	struct bpf_iter_sockmap *skel;
+	__s64 *sock_fd = NULL;
 	struct bpf_link *link;
 	struct bpf_map *src;
 	char buf[64];
@@ -190,22 +210,23 @@ static void test_sockmap_iter(enum bpf_map_type map_type)
 	if (CHECK(!skel, "bpf_iter_sockmap__open_and_load", "skeleton open_and_load failed\n"))
 		return;
 
-	for (i = 0; i < ARRAY_SIZE(sock_fd); i++)
-		sock_fd[i] = -1;
-
-	/* Make sure we have at least one "empty" entry to test iteration of
-	 * an empty slot.
-	 */
-	num_sockets = ARRAY_SIZE(sock_fd) - 1;
-
 	if (map_type == BPF_MAP_TYPE_SOCKMAP) {
 		src = skel->maps.sockmap;
-		max_elems = bpf_map__max_entries(src);
+		num_elems = bpf_map__max_entries(src);
+		num_sockets = num_elems - 1;
 	} else {
 		src = skel->maps.sockhash;
-		max_elems = num_sockets;
+		num_elems = bpf_map__max_entries(src) - 1;
+		num_sockets = num_elems;
 	}
 
+	sock_fd = calloc(num_sockets, sizeof(*sock_fd));
+	if (CHECK(!sock_fd, "calloc(sock_fd)", "failed to allocate\n"))
+		goto out;
+
+	for (i = 0; i < num_sockets; i++)
+		sock_fd[i] = -1;
+
 	src_fd = bpf_map__fd(src);
 
 	for (i = 0; i < num_sockets; i++) {
@@ -221,7 +242,7 @@ static void test_sockmap_iter(enum bpf_map_type map_type)
 	linfo.map.map_fd = src_fd;
 	opts.link_info = &linfo;
 	opts.link_info_len = sizeof(linfo);
-	link = bpf_program__attach_iter(skel->progs.count_elems, &opts);
+	link = bpf_program__attach_iter(skel->progs.copy, &opts);
 	if (CHECK(IS_ERR(link), "attach_iter", "attach_iter failed\n"))
 		goto out;
 
@@ -236,23 +257,26 @@ static void test_sockmap_iter(enum bpf_map_type map_type)
 		goto close_iter;
 
 	/* test results */
-	if (CHECK(skel->bss->elems != max_elems, "elems", "got %u expected %u\n",
-		  skel->bss->elems, max_elems))
+	if (CHECK(skel->bss->elems != num_elems, "elems", "got %u expected %u\n",
+		  skel->bss->elems, num_elems))
 		goto close_iter;
 
 	if (CHECK(skel->bss->socks != num_sockets, "socks", "got %u expected %u\n",
 		  skel->bss->socks, num_sockets))
 		goto close_iter;
 
+	compare_cookies(src, skel->maps.dst);
+
 close_iter:
 	close(iter_fd);
 free_link:
 	bpf_link__destroy(link);
 out:
-	for (i = 0; i < num_sockets; i++) {
+	for (i = 0; sock_fd && i < num_sockets; i++)
 		if (sock_fd[i] >= 0)
 			close(sock_fd[i]);
-	}
+	if (sock_fd)
+		free(sock_fd);
 	bpf_iter_sockmap__destroy(skel);
 }
 
@@ -272,8 +296,8 @@ void test_sockmap_basic(void)
 		test_sockmap_update(BPF_MAP_TYPE_SOCKHASH);
 	if (test__start_subtest("sockmap update in unsafe context"))
 		test_sockmap_invalid_update();
-	if (test__start_subtest("sockmap iter"))
-		test_sockmap_iter(BPF_MAP_TYPE_SOCKMAP);
-	if (test__start_subtest("sockhash iter"))
-		test_sockmap_iter(BPF_MAP_TYPE_SOCKHASH);
+	if (test__start_subtest("sockmap copy"))
+		test_sockmap_copy(BPF_MAP_TYPE_SOCKMAP);
+	if (test__start_subtest("sockhash copy"))
+		test_sockmap_copy(BPF_MAP_TYPE_SOCKHASH);
 }
diff --git a/tools/testing/selftests/bpf/prog_tests/test_overhead.c b/tools/testing/selftests/bpf/prog_tests/test_overhead.c
index 2702df2b2343..9966685866fd 100644
--- a/tools/testing/selftests/bpf/prog_tests/test_overhead.c
+++ b/tools/testing/selftests/bpf/prog_tests/test_overhead.c
@@ -61,10 +61,9 @@ void test_test_overhead(void)
 	const char *raw_tp_name = "raw_tp/task_rename";
 	const char *fentry_name = "fentry/__set_task_comm";
 	const char *fexit_name = "fexit/__set_task_comm";
-	const char *fmodret_name = "fmod_ret/__set_task_comm";
 	const char *kprobe_func = "__set_task_comm";
 	struct bpf_program *kprobe_prog, *kretprobe_prog, *raw_tp_prog;
-	struct bpf_program *fentry_prog, *fexit_prog, *fmodret_prog;
+	struct bpf_program *fentry_prog, *fexit_prog;
 	struct bpf_object *obj;
 	struct bpf_link *link;
 	int err, duration = 0;
@@ -97,11 +96,6 @@ void test_test_overhead(void)
 	if (CHECK(!fexit_prog, "find_probe",
 		  "prog '%s' not found\n", fexit_name))
 		goto cleanup;
-	fmodret_prog = bpf_object__find_program_by_title(obj, fmodret_name);
-	if (CHECK(!fmodret_prog, "find_probe",
-		  "prog '%s' not found\n", fmodret_name))
-		goto cleanup;
-
 	err = bpf_object__load(obj);
 	if (CHECK(err, "obj_load", "err %d\n", err))
 		goto cleanup;
@@ -148,12 +142,6 @@ void test_test_overhead(void)
 	test_run("fexit");
 	bpf_link__destroy(link);
 
-	/* attach fmod_ret */
-	link = bpf_program__attach_trace(fmodret_prog);
-	if (CHECK(IS_ERR(link), "attach fmod_ret", "err %ld\n", PTR_ERR(link)))
-		goto cleanup;
-	test_run("fmod_ret");
-	bpf_link__destroy(link);
 cleanup:
 	prctl(PR_SET_NAME, comm, 0L, 0L, 0L);
 	bpf_object__close(obj);
diff --git a/tools/testing/selftests/bpf/prog_tests/trace_ext.c b/tools/testing/selftests/bpf/prog_tests/trace_ext.c
new file mode 100644
index 000000000000..924441d4362d
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/trace_ext.c
@@ -0,0 +1,111 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define _GNU_SOURCE
+#include <test_progs.h>
+#include <network_helpers.h>
+#include <sys/stat.h>
+#include <linux/sched.h>
+#include <sys/syscall.h>
+
+#include "test_pkt_md_access.skel.h"
+#include "test_trace_ext.skel.h"
+#include "test_trace_ext_tracing.skel.h"
+
+static __u32 duration;
+
+void test_trace_ext(void)
+{
+	struct test_pkt_md_access *skel_pkt = NULL;
+	struct test_trace_ext_tracing *skel_trace = NULL;
+	struct test_trace_ext_tracing__bss *bss_trace;
+	struct test_trace_ext *skel_ext = NULL;
+	struct test_trace_ext__bss *bss_ext;
+	int err, pkt_fd, ext_fd;
+	struct bpf_program *prog;
+	char buf[100];
+	__u32 retval;
+	__u64 len;
+
+	/* open/load/attach test_pkt_md_access */
+	skel_pkt = test_pkt_md_access__open_and_load();
+	if (CHECK(!skel_pkt, "setup", "classifier/test_pkt_md_access open failed\n"))
+		goto cleanup;
+
+	err = test_pkt_md_access__attach(skel_pkt);
+	if (CHECK(err, "setup", "classifier/test_pkt_md_access attach failed: %d\n", err))
+		goto cleanup;
+
+	prog = skel_pkt->progs.test_pkt_md_access;
+	pkt_fd = bpf_program__fd(prog);
+
+	/* open extension */
+	skel_ext = test_trace_ext__open();
+	if (CHECK(!skel_ext, "setup", "freplace/test_pkt_md_access open failed\n"))
+		goto cleanup;
+
+	/* set extension's attach target - test_pkt_md_access  */
+	prog = skel_ext->progs.test_pkt_md_access_new;
+	bpf_program__set_attach_target(prog, pkt_fd, "test_pkt_md_access");
+
+	/* load/attach extension */
+	err = test_trace_ext__load(skel_ext);
+	if (CHECK(err, "setup", "freplace/test_pkt_md_access load failed\n")) {
+		libbpf_strerror(err, buf, sizeof(buf));
+		fprintf(stderr, "%s\n", buf);
+		goto cleanup;
+	}
+
+	err = test_trace_ext__attach(skel_ext);
+	if (CHECK(err, "setup", "freplace/test_pkt_md_access attach failed: %d\n", err))
+		goto cleanup;
+
+	prog = skel_ext->progs.test_pkt_md_access_new;
+	ext_fd = bpf_program__fd(prog);
+
+	/* open tracing  */
+	skel_trace = test_trace_ext_tracing__open();
+	if (CHECK(!skel_trace, "setup", "tracing/test_pkt_md_access_new open failed\n"))
+		goto cleanup;
+
+	/* set tracing's attach target - fentry */
+	prog = skel_trace->progs.fentry;
+	bpf_program__set_attach_target(prog, ext_fd, "test_pkt_md_access_new");
+
+	/* set tracing's attach target - fexit */
+	prog = skel_trace->progs.fexit;
+	bpf_program__set_attach_target(prog, ext_fd, "test_pkt_md_access_new");
+
+	/* load/attach tracing */
+	err = test_trace_ext_tracing__load(skel_trace);
+	if (CHECK(err, "setup", "tracing/test_pkt_md_access_new load failed\n")) {
+		libbpf_strerror(err, buf, sizeof(buf));
+		fprintf(stderr, "%s\n", buf);
+		goto cleanup;
+	}
+
+	err = test_trace_ext_tracing__attach(skel_trace);
+	if (CHECK(err, "setup", "tracing/test_pkt_md_access_new attach failed: %d\n", err))
+		goto cleanup;
+
+	/* trigger the test */
+	err = bpf_prog_test_run(pkt_fd, 1, &pkt_v4, sizeof(pkt_v4),
+				NULL, NULL, &retval, &duration);
+	CHECK(err || retval, "run", "err %d errno %d retval %d\n", err, errno, retval);
+
+	bss_ext = skel_ext->bss;
+	bss_trace = skel_trace->bss;
+
+	len = bss_ext->ext_called;
+
+	CHECK(bss_ext->ext_called == 0,
+		"check", "failed to trigger freplace/test_pkt_md_access\n");
+	CHECK(bss_trace->fentry_called != len,
+		"check", "failed to trigger fentry/test_pkt_md_access_new\n");
+	CHECK(bss_trace->fexit_called != len,
+		"check", "failed to trigger fexit/test_pkt_md_access_new\n");
+
+cleanup:
+	test_trace_ext_tracing__destroy(skel_trace);
+	test_trace_ext__destroy(skel_ext);
+	test_pkt_md_access__destroy(skel_pkt);
+}
diff --git a/tools/testing/selftests/bpf/progs/bpf_cubic.c b/tools/testing/selftests/bpf/progs/bpf_cubic.c
index ef574087f1e1..6939bfd8690f 100644
--- a/tools/testing/selftests/bpf/progs/bpf_cubic.c
+++ b/tools/testing/selftests/bpf/progs/bpf_cubic.c
@@ -15,6 +15,8 @@
  */
 
 #include <linux/bpf.h>
+#include <linux/stddef.h>
+#include <linux/tcp.h>
 #include "bpf_tcp_helpers.h"
 
 char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/progs/bpf_dctcp.c b/tools/testing/selftests/bpf/progs/bpf_dctcp.c
index 3fb4260570b1..4dc1a967776a 100644
--- a/tools/testing/selftests/bpf/progs/bpf_dctcp.c
+++ b/tools/testing/selftests/bpf/progs/bpf_dctcp.c
@@ -9,6 +9,8 @@
 #include <stddef.h>
 #include <linux/bpf.h>
 #include <linux/types.h>
+#include <linux/stddef.h>
+#include <linux/tcp.h>
 #include <bpf/bpf_helpers.h>
 #include <bpf/bpf_tracing.h>
 #include "bpf_tcp_helpers.h"
diff --git a/tools/testing/selftests/bpf/progs/bpf_flow.c b/tools/testing/selftests/bpf/progs/bpf_flow.c
index de6de9221518..5a65f6b51377 100644
--- a/tools/testing/selftests/bpf/progs/bpf_flow.c
+++ b/tools/testing/selftests/bpf/progs/bpf_flow.c
@@ -118,18 +118,18 @@ static __always_inline int parse_eth_proto(struct __sk_buff *skb, __be16 proto)
 
 	switch (proto) {
 	case bpf_htons(ETH_P_IP):
-		bpf_tail_call(skb, &jmp_table, IP);
+		bpf_tail_call_static(skb, &jmp_table, IP);
 		break;
 	case bpf_htons(ETH_P_IPV6):
-		bpf_tail_call(skb, &jmp_table, IPV6);
+		bpf_tail_call_static(skb, &jmp_table, IPV6);
 		break;
 	case bpf_htons(ETH_P_MPLS_MC):
 	case bpf_htons(ETH_P_MPLS_UC):
-		bpf_tail_call(skb, &jmp_table, MPLS);
+		bpf_tail_call_static(skb, &jmp_table, MPLS);
 		break;
 	case bpf_htons(ETH_P_8021Q):
 	case bpf_htons(ETH_P_8021AD):
-		bpf_tail_call(skb, &jmp_table, VLAN);
+		bpf_tail_call_static(skb, &jmp_table, VLAN);
 		break;
 	default:
 		/* Protocol not supported */
@@ -246,10 +246,10 @@ static __always_inline int parse_ipv6_proto(struct __sk_buff *skb, __u8 nexthdr)
 	switch (nexthdr) {
 	case IPPROTO_HOPOPTS:
 	case IPPROTO_DSTOPTS:
-		bpf_tail_call(skb, &jmp_table, IPV6OP);
+		bpf_tail_call_static(skb, &jmp_table, IPV6OP);
 		break;
 	case IPPROTO_FRAGMENT:
-		bpf_tail_call(skb, &jmp_table, IPV6FR);
+		bpf_tail_call_static(skb, &jmp_table, IPV6FR);
 		break;
 	default:
 		return parse_ip_proto(skb, nexthdr);
diff --git a/tools/testing/selftests/bpf/progs/bpf_iter.h b/tools/testing/selftests/bpf/progs/bpf_iter.h
index df682af75510..6a1255465fd6 100644
--- a/tools/testing/selftests/bpf/progs/bpf_iter.h
+++ b/tools/testing/selftests/bpf/progs/bpf_iter.h
@@ -14,6 +14,11 @@
 #define bpf_iter__bpf_map_elem bpf_iter__bpf_map_elem___not_used
 #define bpf_iter__bpf_sk_storage_map bpf_iter__bpf_sk_storage_map___not_used
 #define bpf_iter__sockmap bpf_iter__sockmap___not_used
+#define btf_ptr btf_ptr___not_used
+#define BTF_F_COMPACT BTF_F_COMPACT___not_used
+#define BTF_F_NONAME BTF_F_NONAME___not_used
+#define BTF_F_PTR_RAW BTF_F_PTR_RAW___not_used
+#define BTF_F_ZERO BTF_F_ZERO___not_used
 #include "vmlinux.h"
 #undef bpf_iter_meta
 #undef bpf_iter__bpf_map
@@ -28,6 +33,11 @@
 #undef bpf_iter__bpf_map_elem
 #undef bpf_iter__bpf_sk_storage_map
 #undef bpf_iter__sockmap
+#undef btf_ptr
+#undef BTF_F_COMPACT
+#undef BTF_F_NONAME
+#undef BTF_F_PTR_RAW
+#undef BTF_F_ZERO
 
 struct bpf_iter_meta {
 	struct seq_file *seq;
@@ -105,3 +115,16 @@ struct bpf_iter__sockmap {
 	void *key;
 	struct sock *sk;
 };
+
+struct btf_ptr {
+	void *ptr;
+	__u32 type_id;
+	__u32 flags;
+};
+
+enum {
+	BTF_F_COMPACT	=	(1ULL << 0),
+	BTF_F_NONAME	=	(1ULL << 1),
+	BTF_F_PTR_RAW	=	(1ULL << 2),
+	BTF_F_ZERO	=	(1ULL << 3),
+};
diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_sockmap.c b/tools/testing/selftests/bpf/progs/bpf_iter_sockmap.c
index 0e27f73dd803..f3af0e30cead 100644
--- a/tools/testing/selftests/bpf/progs/bpf_iter_sockmap.c
+++ b/tools/testing/selftests/bpf/progs/bpf_iter_sockmap.c
@@ -2,7 +2,6 @@
 /* Copyright (c) 2020 Cloudflare */
 #include "bpf_iter.h"
 #include "bpf_tracing_net.h"
-#include "bpf_iter_sockmap.h"
 #include <bpf/bpf_helpers.h>
 #include <bpf/bpf_tracing.h>
 #include <errno.h>
@@ -11,33 +10,50 @@ char _license[] SEC("license") = "GPL";
 
 struct {
 	__uint(type, BPF_MAP_TYPE_SOCKMAP);
-	__uint(max_entries, SOCKMAP_MAX_ENTRIES);
+	__uint(max_entries, 64);
 	__type(key, __u32);
 	__type(value, __u64);
 } sockmap SEC(".maps");
 
 struct {
 	__uint(type, BPF_MAP_TYPE_SOCKHASH);
-	__uint(max_entries, SOCKMAP_MAX_ENTRIES);
+	__uint(max_entries, 64);
 	__type(key, __u32);
 	__type(value, __u64);
 } sockhash SEC(".maps");
 
+struct {
+	__uint(type, BPF_MAP_TYPE_SOCKHASH);
+	__uint(max_entries, 64);
+	__type(key, __u32);
+	__type(value, __u64);
+} dst SEC(".maps");
+
 __u32 elems = 0;
 __u32 socks = 0;
 
 SEC("iter/sockmap")
-int count_elems(struct bpf_iter__sockmap *ctx)
+int copy(struct bpf_iter__sockmap *ctx)
 {
 	struct sock *sk = ctx->sk;
 	__u32 tmp, *key = ctx->key;
 	int ret;
 
-	if (key)
-		elems++;
+	if (!key)
+		return 0;
+
+	elems++;
+
+	/* We need a temporary buffer on the stack, since the verifier doesn't
+	 * let us use the pointer from the context as an argument to the helper.
+	 */
+	tmp = *key;
 
-	if (sk)
+	if (sk) {
 		socks++;
+		return bpf_map_update_elem(&dst, &tmp, sk, 0) != 0;
+	}
 
-	return 0;
+	ret = bpf_map_delete_elem(&dst, &tmp);
+	return ret && ret != -ENOENT;
 }
diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_sockmap.h b/tools/testing/selftests/bpf/progs/bpf_iter_sockmap.h
deleted file mode 100644
index 35a675d13c0f..000000000000
--- a/tools/testing/selftests/bpf/progs/bpf_iter_sockmap.h
+++ /dev/null
@@ -1,3 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-
-#define SOCKMAP_MAX_ENTRIES (64)
diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_task_btf.c b/tools/testing/selftests/bpf/progs/bpf_iter_task_btf.c
new file mode 100644
index 000000000000..a1ddc36f13ec
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/bpf_iter_task_btf.c
@@ -0,0 +1,50 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020, Oracle and/or its affiliates. */
+#include "bpf_iter.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_core_read.h>
+
+#include <errno.h>
+
+char _license[] SEC("license") = "GPL";
+
+long tasks = 0;
+long seq_err = 0;
+bool skip = false;
+
+SEC("iter/task")
+int dump_task_struct(struct bpf_iter__task *ctx)
+{
+	struct seq_file *seq = ctx->meta->seq;
+	struct task_struct *task = ctx->task;
+	static struct btf_ptr ptr = { };
+	long ret;
+
+#if __has_builtin(__builtin_btf_type_id)
+	ptr.type_id = bpf_core_type_id_kernel(struct task_struct);
+	ptr.ptr = task;
+
+	if (ctx->meta->seq_num == 0)
+		BPF_SEQ_PRINTF(seq, "Raw BTF task\n");
+
+	ret = bpf_seq_printf_btf(seq, &ptr, sizeof(ptr), 0);
+	switch (ret) {
+	case 0:
+		tasks++;
+		break;
+	case -ERANGE:
+		/* NULL task or task->fs, don't count it as an error. */
+		break;
+	case -E2BIG:
+		return 1;
+	default:
+		seq_err = ret;
+		break;
+	}
+#else
+	skip = true;
+#endif
+
+	return 0;
+}
diff --git a/tools/testing/selftests/bpf/progs/btf_ptr.h b/tools/testing/selftests/bpf/progs/btf_ptr.h
new file mode 100644
index 000000000000..c3c9797c67db
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/btf_ptr.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2020, Oracle and/or its affiliates. */
+/* "undefine" structs in vmlinux.h, because we "override" them below */
+#define btf_ptr btf_ptr___not_used
+#define BTF_F_COMPACT BTF_F_COMPACT___not_used
+#define BTF_F_NONAME BTF_F_NONAME___not_used
+#define BTF_F_PTR_RAW BTF_F_PTR_RAW___not_used
+#define BTF_F_ZERO BTF_F_ZERO___not_used
+#include "vmlinux.h"
+#undef btf_ptr
+#undef BTF_F_COMPACT
+#undef BTF_F_NONAME
+#undef BTF_F_PTR_RAW
+#undef BTF_F_ZERO
+
+struct btf_ptr {
+	void *ptr;
+	__u32 type_id;
+	__u32 flags;
+};
+
+enum {
+	BTF_F_COMPACT	=	(1ULL << 0),
+	BTF_F_NONAME	=	(1ULL << 1),
+	BTF_F_PTR_RAW	=	(1ULL << 2),
+	BTF_F_ZERO	=	(1ULL << 3),
+};
diff --git a/tools/testing/selftests/bpf/progs/fmod_ret_freplace.c b/tools/testing/selftests/bpf/progs/fmod_ret_freplace.c
new file mode 100644
index 000000000000..c8943ccee6c0
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/fmod_ret_freplace.c
@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+volatile __u64 test_fmod_ret = 0;
+SEC("fmod_ret/security_new_get_constant")
+int BPF_PROG(fmod_ret_test, long val, int ret)
+{
+	test_fmod_ret = 1;
+	return 120;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/progs/freplace_get_constant.c b/tools/testing/selftests/bpf/progs/freplace_get_constant.c
new file mode 100644
index 000000000000..705e4b64dfc2
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/freplace_get_constant.c
@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+
+volatile __u64 test_get_constant = 0;
+SEC("freplace/get_constant")
+int security_new_get_constant(long val)
+{
+	if (val != 123)
+		return 0;
+	test_get_constant = 1;
+	return test_get_constant; /* original get_constant() returns val - 122 */
+}
+char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/progs/netif_receive_skb.c b/tools/testing/selftests/bpf/progs/netif_receive_skb.c
new file mode 100644
index 000000000000..6b670039ea67
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/netif_receive_skb.c
@@ -0,0 +1,249 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020, Oracle and/or its affiliates. */
+
+#include "btf_ptr.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_core_read.h>
+
+#include <errno.h>
+
+long ret = 0;
+int num_subtests = 0;
+int ran_subtests = 0;
+bool skip = false;
+
+#define STRSIZE			2048
+#define EXPECTED_STRSIZE	256
+
+#ifndef ARRAY_SIZE
+#define ARRAY_SIZE(x)	(sizeof(x) / sizeof((x)[0]))
+#endif
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__uint(max_entries, 1);
+	__type(key, __u32);
+	__type(value, char[STRSIZE]);
+} strdata SEC(".maps");
+
+static int __strncmp(const void *m1, const void *m2, size_t len)
+{
+	const unsigned char *s1 = m1;
+	const unsigned char *s2 = m2;
+	int i, delta = 0;
+
+	for (i = 0; i < len; i++) {
+		delta = s1[i] - s2[i];
+		if (delta || s1[i] == 0 || s2[i] == 0)
+			break;
+	}
+	return delta;
+}
+
+#if __has_builtin(__builtin_btf_type_id)
+#define	TEST_BTF(_str, _type, _flags, _expected, ...)			\
+	do {								\
+		static const char _expectedval[EXPECTED_STRSIZE] =	\
+							_expected;	\
+		static const char _ptrtype[64] = #_type;		\
+		__u64 _hflags = _flags | BTF_F_COMPACT;			\
+		static _type _ptrdata = __VA_ARGS__;			\
+		static struct btf_ptr _ptr = { };			\
+		int _cmp;						\
+									\
+		++num_subtests;						\
+		if (ret < 0)						\
+			break;						\
+		++ran_subtests;						\
+		_ptr.ptr = &_ptrdata;					\
+		_ptr.type_id = bpf_core_type_id_kernel(_type);		\
+		if (_ptr.type_id <= 0) {				\
+			ret = -EINVAL;					\
+			break;						\
+		}							\
+		ret = bpf_snprintf_btf(_str, STRSIZE,			\
+				       &_ptr, sizeof(_ptr), _hflags);	\
+		if (ret)						\
+			break;						\
+		_cmp = __strncmp(_str, _expectedval, EXPECTED_STRSIZE);	\
+		if (_cmp != 0) {					\
+			bpf_printk("(%d) got %s", _cmp, _str);		\
+			bpf_printk("(%d) expected %s", _cmp,		\
+				   _expectedval);			\
+			ret = -EBADMSG;					\
+			break;						\
+		}							\
+	} while (0)
+#endif
+
+/* Use where expected data string matches its stringified declaration */
+#define TEST_BTF_C(_str, _type, _flags, ...)				\
+	TEST_BTF(_str, _type, _flags, "(" #_type ")" #__VA_ARGS__,	\
+		 __VA_ARGS__)
+
+/* TRACE_EVENT(netif_receive_skb,
+ *	TP_PROTO(struct sk_buff *skb),
+ */
+SEC("tp_btf/netif_receive_skb")
+int BPF_PROG(trace_netif_receive_skb, struct sk_buff *skb)
+{
+	static __u64 flags[] = { 0, BTF_F_COMPACT, BTF_F_ZERO, BTF_F_PTR_RAW,
+				 BTF_F_NONAME, BTF_F_COMPACT | BTF_F_ZERO |
+				 BTF_F_PTR_RAW | BTF_F_NONAME };
+	static struct btf_ptr p = { };
+	__u32 key = 0;
+	int i, __ret;
+	char *str;
+
+#if __has_builtin(__builtin_btf_type_id)
+	str = bpf_map_lookup_elem(&strdata, &key);
+	if (!str)
+		return 0;
+
+	/* Ensure we can write skb string representation */
+	p.type_id = bpf_core_type_id_kernel(struct sk_buff);
+	p.ptr = skb;
+	for (i = 0; i < ARRAY_SIZE(flags); i++) {
+		++num_subtests;
+		ret = bpf_snprintf_btf(str, STRSIZE, &p, sizeof(p), 0);
+		if (ret < 0)
+			bpf_printk("returned %d when writing skb", ret);
+		++ran_subtests;
+	}
+
+	/* Check invalid ptr value */
+	p.ptr = 0;
+	__ret = bpf_snprintf_btf(str, STRSIZE, &p, sizeof(p), 0);
+	if (__ret >= 0) {
+		bpf_printk("printing NULL should generate error, got (%d)",
+			   __ret);
+		ret = -ERANGE;
+	}
+
+	/* Verify type display for various types. */
+
+	/* simple int */
+	TEST_BTF_C(str, int, 0, 1234);
+	TEST_BTF(str, int, BTF_F_NONAME, "1234", 1234);
+	/* zero value should be printed at toplevel */
+	TEST_BTF(str, int, 0, "(int)0", 0);
+	TEST_BTF(str, int, BTF_F_NONAME, "0", 0);
+	TEST_BTF(str, int, BTF_F_ZERO, "(int)0", 0);
+	TEST_BTF(str, int, BTF_F_NONAME | BTF_F_ZERO, "0", 0);
+	TEST_BTF_C(str, int, 0, -4567);
+	TEST_BTF(str, int, BTF_F_NONAME, "-4567", -4567);
+
+	/* simple char */
+	TEST_BTF_C(str, char, 0, 100);
+	TEST_BTF(str, char, BTF_F_NONAME, "100", 100);
+	/* zero value should be printed at toplevel */
+	TEST_BTF(str, char, 0, "(char)0", 0);
+	TEST_BTF(str, char, BTF_F_NONAME, "0", 0);
+	TEST_BTF(str, char, BTF_F_ZERO, "(char)0", 0);
+	TEST_BTF(str, char, BTF_F_NONAME | BTF_F_ZERO, "0", 0);
+
+	/* simple typedef */
+	TEST_BTF_C(str, uint64_t, 0, 100);
+	TEST_BTF(str, u64, BTF_F_NONAME, "1", 1);
+	/* zero value should be printed at toplevel */
+	TEST_BTF(str, u64, 0, "(u64)0", 0);
+	TEST_BTF(str, u64, BTF_F_NONAME, "0", 0);
+	TEST_BTF(str, u64, BTF_F_ZERO, "(u64)0", 0);
+	TEST_BTF(str, u64, BTF_F_NONAME|BTF_F_ZERO, "0", 0);
+
+	/* typedef struct */
+	TEST_BTF_C(str, atomic_t, 0, {.counter = (int)1,});
+	TEST_BTF(str, atomic_t, BTF_F_NONAME, "{1,}", {.counter = 1,});
+	/* typedef with 0 value should be printed at toplevel */
+	TEST_BTF(str, atomic_t, 0, "(atomic_t){}", {.counter = 0,});
+	TEST_BTF(str, atomic_t, BTF_F_NONAME, "{}", {.counter = 0,});
+	TEST_BTF(str, atomic_t, BTF_F_ZERO, "(atomic_t){.counter = (int)0,}",
+		 {.counter = 0,});
+	TEST_BTF(str, atomic_t, BTF_F_NONAME|BTF_F_ZERO,
+		 "{0,}", {.counter = 0,});
+
+	/* enum where enum value does (and does not) exist */
+	TEST_BTF_C(str, enum bpf_cmd, 0, BPF_MAP_CREATE);
+	TEST_BTF(str, enum bpf_cmd, 0, "(enum bpf_cmd)BPF_MAP_CREATE", 0);
+	TEST_BTF(str, enum bpf_cmd, BTF_F_NONAME, "BPF_MAP_CREATE",
+		 BPF_MAP_CREATE);
+	TEST_BTF(str, enum bpf_cmd, BTF_F_NONAME|BTF_F_ZERO,
+		 "BPF_MAP_CREATE", 0);
+
+	TEST_BTF(str, enum bpf_cmd, BTF_F_ZERO, "(enum bpf_cmd)BPF_MAP_CREATE",
+		 BPF_MAP_CREATE);
+	TEST_BTF(str, enum bpf_cmd, BTF_F_NONAME|BTF_F_ZERO,
+		 "BPF_MAP_CREATE", BPF_MAP_CREATE);
+	TEST_BTF_C(str, enum bpf_cmd, 0, 2000);
+	TEST_BTF(str, enum bpf_cmd, BTF_F_NONAME, "2000", 2000);
+
+	/* simple struct */
+	TEST_BTF_C(str, struct btf_enum, 0,
+		   {.name_off = (__u32)3,.val = (__s32)-1,});
+	TEST_BTF(str, struct btf_enum, BTF_F_NONAME, "{3,-1,}",
+		 { .name_off = 3, .val = -1,});
+	TEST_BTF(str, struct btf_enum, BTF_F_NONAME, "{-1,}",
+		 { .name_off = 0, .val = -1,});
+	TEST_BTF(str, struct btf_enum, BTF_F_NONAME|BTF_F_ZERO, "{0,-1,}",
+		 { .name_off = 0, .val = -1,});
+	/* empty struct should be printed */
+	TEST_BTF(str, struct btf_enum, 0, "(struct btf_enum){}",
+		 { .name_off = 0, .val = 0,});
+	TEST_BTF(str, struct btf_enum, BTF_F_NONAME, "{}",
+		 { .name_off = 0, .val = 0,});
+	TEST_BTF(str, struct btf_enum, BTF_F_ZERO,
+		 "(struct btf_enum){.name_off = (__u32)0,.val = (__s32)0,}",
+		 { .name_off = 0, .val = 0,});
+
+	/* struct with pointers */
+	TEST_BTF(str, struct list_head, BTF_F_PTR_RAW,
+		 "(struct list_head){.next = (struct list_head *)0x0000000000000001,}",
+		 { .next = (struct list_head *)1 });
+	/* NULL pointer should not be displayed */
+	TEST_BTF(str, struct list_head, BTF_F_PTR_RAW,
+		 "(struct list_head){}",
+		 { .next = (struct list_head *)0 });
+
+	/* struct with char array */
+	TEST_BTF(str, struct bpf_prog_info, 0,
+		 "(struct bpf_prog_info){.name = (char[])['f','o','o',],}",
+		 { .name = "foo",});
+	TEST_BTF(str, struct bpf_prog_info, BTF_F_NONAME,
+		 "{['f','o','o',],}",
+		 {.name = "foo",});
+	/* leading null char means do not display string */
+	TEST_BTF(str, struct bpf_prog_info, 0,
+		 "(struct bpf_prog_info){}",
+		 {.name = {'\0', 'f', 'o', 'o'}});
+	/* handle non-printable characters */
+	TEST_BTF(str, struct bpf_prog_info, 0,
+		 "(struct bpf_prog_info){.name = (char[])[1,2,3,],}",
+		 { .name = {1, 2, 3, 0}});
+
+	/* struct with non-char array */
+	TEST_BTF(str, struct __sk_buff, 0,
+		 "(struct __sk_buff){.cb = (__u32[])[1,2,3,4,5,],}",
+		 { .cb = {1, 2, 3, 4, 5,},});
+	TEST_BTF(str, struct __sk_buff, BTF_F_NONAME,
+		 "{[1,2,3,4,5,],}",
+		 { .cb = { 1, 2, 3, 4, 5},});
+	/* For non-char, arrays, show non-zero values only */
+	TEST_BTF(str, struct __sk_buff, 0,
+		 "(struct __sk_buff){.cb = (__u32[])[1,],}",
+		 { .cb = { 0, 0, 1, 0, 0},});
+
+	/* struct with bitfields */
+	TEST_BTF_C(str, struct bpf_insn, 0,
+		   {.code = (__u8)1,.dst_reg = (__u8)0x2,.src_reg = (__u8)0x3,.off = (__s16)4,.imm = (__s32)5,});
+	TEST_BTF(str, struct bpf_insn, BTF_F_NONAME, "{1,0x2,0x3,4,5,}",
+		 {.code = 1, .dst_reg = 0x2, .src_reg = 0x3, .off = 4,
+		  .imm = 5,});
+#else
+	skip = true;
+#endif
+
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/progs/tailcall1.c b/tools/testing/selftests/bpf/progs/tailcall1.c
index 1f407e65ae52..7115bcefbe8a 100644
--- a/tools/testing/selftests/bpf/progs/tailcall1.c
+++ b/tools/testing/selftests/bpf/progs/tailcall1.c
@@ -26,20 +26,20 @@ int entry(struct __sk_buff *skb)
 	/* Multiple locations to make sure we patch
 	 * all of them.
 	 */
-	bpf_tail_call(skb, &jmp_table, 0);
-	bpf_tail_call(skb, &jmp_table, 0);
-	bpf_tail_call(skb, &jmp_table, 0);
-	bpf_tail_call(skb, &jmp_table, 0);
-
-	bpf_tail_call(skb, &jmp_table, 1);
-	bpf_tail_call(skb, &jmp_table, 1);
-	bpf_tail_call(skb, &jmp_table, 1);
-	bpf_tail_call(skb, &jmp_table, 1);
-
-	bpf_tail_call(skb, &jmp_table, 2);
-	bpf_tail_call(skb, &jmp_table, 2);
-	bpf_tail_call(skb, &jmp_table, 2);
-	bpf_tail_call(skb, &jmp_table, 2);
+	bpf_tail_call_static(skb, &jmp_table, 0);
+	bpf_tail_call_static(skb, &jmp_table, 0);
+	bpf_tail_call_static(skb, &jmp_table, 0);
+	bpf_tail_call_static(skb, &jmp_table, 0);
+
+	bpf_tail_call_static(skb, &jmp_table, 1);
+	bpf_tail_call_static(skb, &jmp_table, 1);
+	bpf_tail_call_static(skb, &jmp_table, 1);
+	bpf_tail_call_static(skb, &jmp_table, 1);
+
+	bpf_tail_call_static(skb, &jmp_table, 2);
+	bpf_tail_call_static(skb, &jmp_table, 2);
+	bpf_tail_call_static(skb, &jmp_table, 2);
+	bpf_tail_call_static(skb, &jmp_table, 2);
 
 	return 3;
 }
diff --git a/tools/testing/selftests/bpf/progs/tailcall2.c b/tools/testing/selftests/bpf/progs/tailcall2.c
index a093e739cf0e..0431e4fe7efd 100644
--- a/tools/testing/selftests/bpf/progs/tailcall2.c
+++ b/tools/testing/selftests/bpf/progs/tailcall2.c
@@ -13,14 +13,14 @@ struct {
 SEC("classifier/0")
 int bpf_func_0(struct __sk_buff *skb)
 {
-	bpf_tail_call(skb, &jmp_table, 1);
+	bpf_tail_call_static(skb, &jmp_table, 1);
 	return 0;
 }
 
 SEC("classifier/1")
 int bpf_func_1(struct __sk_buff *skb)
 {
-	bpf_tail_call(skb, &jmp_table, 2);
+	bpf_tail_call_static(skb, &jmp_table, 2);
 	return 1;
 }
 
@@ -33,25 +33,25 @@ int bpf_func_2(struct __sk_buff *skb)
 SEC("classifier/3")
 int bpf_func_3(struct __sk_buff *skb)
 {
-	bpf_tail_call(skb, &jmp_table, 4);
+	bpf_tail_call_static(skb, &jmp_table, 4);
 	return 3;
 }
 
 SEC("classifier/4")
 int bpf_func_4(struct __sk_buff *skb)
 {
-	bpf_tail_call(skb, &jmp_table, 3);
+	bpf_tail_call_static(skb, &jmp_table, 3);
 	return 4;
 }
 
 SEC("classifier")
 int entry(struct __sk_buff *skb)
 {
-	bpf_tail_call(skb, &jmp_table, 0);
+	bpf_tail_call_static(skb, &jmp_table, 0);
 	/* Check multi-prog update. */
-	bpf_tail_call(skb, &jmp_table, 2);
+	bpf_tail_call_static(skb, &jmp_table, 2);
 	/* Check tail call limit. */
-	bpf_tail_call(skb, &jmp_table, 3);
+	bpf_tail_call_static(skb, &jmp_table, 3);
 	return 3;
 }
 
diff --git a/tools/testing/selftests/bpf/progs/tailcall3.c b/tools/testing/selftests/bpf/progs/tailcall3.c
index cabda877cf0a..739dc2a51e74 100644
--- a/tools/testing/selftests/bpf/progs/tailcall3.c
+++ b/tools/testing/selftests/bpf/progs/tailcall3.c
@@ -16,14 +16,14 @@ SEC("classifier/0")
 int bpf_func_0(struct __sk_buff *skb)
 {
 	count++;
-	bpf_tail_call(skb, &jmp_table, 0);
+	bpf_tail_call_static(skb, &jmp_table, 0);
 	return 1;
 }
 
 SEC("classifier")
 int entry(struct __sk_buff *skb)
 {
-	bpf_tail_call(skb, &jmp_table, 0);
+	bpf_tail_call_static(skb, &jmp_table, 0);
 	return 0;
 }
 
diff --git a/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf1.c b/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf1.c
index b5d9c8e778ae..0103f3dd9f02 100644
--- a/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf1.c
+++ b/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf1.c
@@ -21,7 +21,7 @@ TAIL_FUNC(1)
 static __noinline
 int subprog_tail(struct __sk_buff *skb)
 {
-	bpf_tail_call(skb, &jmp_table, 0);
+	bpf_tail_call_static(skb, &jmp_table, 0);
 
 	return skb->len * 2;
 }
@@ -29,7 +29,7 @@ int subprog_tail(struct __sk_buff *skb)
 SEC("classifier")
 int entry(struct __sk_buff *skb)
 {
-	bpf_tail_call(skb, &jmp_table, 1);
+	bpf_tail_call_static(skb, &jmp_table, 1);
 
 	return subprog_tail(skb);
 }
diff --git a/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf2.c b/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf2.c
index a004ab28ce28..7b1c04183824 100644
--- a/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf2.c
+++ b/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf2.c
@@ -14,9 +14,9 @@ static __noinline
 int subprog_tail(struct __sk_buff *skb)
 {
 	if (load_byte(skb, 0))
-		bpf_tail_call(skb, &jmp_table, 1);
+		bpf_tail_call_static(skb, &jmp_table, 1);
 	else
-		bpf_tail_call(skb, &jmp_table, 0);
+		bpf_tail_call_static(skb, &jmp_table, 0);
 	return 1;
 }
 
@@ -32,7 +32,7 @@ int bpf_func_0(struct __sk_buff *skb)
 SEC("classifier")
 int entry(struct __sk_buff *skb)
 {
-	bpf_tail_call(skb, &jmp_table, 0);
+	bpf_tail_call_static(skb, &jmp_table, 0);
 
 	return 0;
 }
diff --git a/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf3.c b/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf3.c
index 96dbef2b6b7c..0d5482bea6c9 100644
--- a/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf3.c
+++ b/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf3.c
@@ -16,9 +16,9 @@ int subprog_tail2(struct __sk_buff *skb)
 	volatile char arr[64] = {};
 
 	if (load_word(skb, 0) || load_half(skb, 0))
-		bpf_tail_call(skb, &jmp_table, 10);
+		bpf_tail_call_static(skb, &jmp_table, 10);
 	else
-		bpf_tail_call(skb, &jmp_table, 1);
+		bpf_tail_call_static(skb, &jmp_table, 1);
 
 	return skb->len;
 }
@@ -28,7 +28,7 @@ int subprog_tail(struct __sk_buff *skb)
 {
 	volatile char arr[64] = {};
 
-	bpf_tail_call(skb, &jmp_table, 0);
+	bpf_tail_call_static(skb, &jmp_table, 0);
 
 	return skb->len * 2;
 }
diff --git a/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf4.c b/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf4.c
index 98b40a95bc67..9a1b166b7fbe 100644
--- a/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf4.c
+++ b/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf4.c
@@ -14,21 +14,21 @@ static volatile int count;
 __noinline
 int subprog_tail_2(struct __sk_buff *skb)
 {
-	bpf_tail_call(skb, &jmp_table, 2);
+	bpf_tail_call_static(skb, &jmp_table, 2);
 	return skb->len * 3;
 }
 
 __noinline
 int subprog_tail_1(struct __sk_buff *skb)
 {
-	bpf_tail_call(skb, &jmp_table, 1);
+	bpf_tail_call_static(skb, &jmp_table, 1);
 	return skb->len * 2;
 }
 
 __noinline
 int subprog_tail(struct __sk_buff *skb)
 {
-	bpf_tail_call(skb, &jmp_table, 0);
+	bpf_tail_call_static(skb, &jmp_table, 0);
 	return skb->len;
 }
 
diff --git a/tools/testing/selftests/bpf/progs/test_btf_skc_cls_ingress.c b/tools/testing/selftests/bpf/progs/test_btf_skc_cls_ingress.c
new file mode 100644
index 000000000000..9a6b85dd52d2
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_btf_skc_cls_ingress.c
@@ -0,0 +1,174 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020 Facebook */
+
+#include <string.h>
+#include <errno.h>
+#include <netinet/in.h>
+#include <linux/stddef.h>
+#include <linux/bpf.h>
+#include <linux/ipv6.h>
+#include <linux/tcp.h>
+#include <linux/if_ether.h>
+#include <linux/pkt_cls.h>
+
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+#include "bpf_tcp_helpers.h"
+
+struct sockaddr_in6 srv_sa6 = {};
+__u16 listen_tp_sport = 0;
+__u16 req_sk_sport = 0;
+__u32 recv_cookie = 0;
+__u32 gen_cookie = 0;
+__u32 linum = 0;
+
+#define LOG() ({ if (!linum) linum = __LINE__; })
+
+static void test_syncookie_helper(struct ipv6hdr *ip6h, struct tcphdr *th,
+				  struct tcp_sock *tp,
+				  struct __sk_buff *skb)
+{
+	if (th->syn) {
+		__s64 mss_cookie;
+		void *data_end;
+
+		data_end = (void *)(long)(skb->data_end);
+
+		if (th->doff * 4 != 40) {
+			LOG();
+			return;
+		}
+
+		if ((void *)th + 40 > data_end) {
+			LOG();
+			return;
+		}
+
+		mss_cookie = bpf_tcp_gen_syncookie(tp, ip6h, sizeof(*ip6h),
+						   th, 40);
+		if (mss_cookie < 0) {
+			if (mss_cookie != -ENOENT)
+				LOG();
+		} else {
+			gen_cookie = (__u32)mss_cookie;
+		}
+	} else if (gen_cookie) {
+		/* It was in cookie mode */
+		int ret = bpf_tcp_check_syncookie(tp, ip6h, sizeof(*ip6h),
+						  th, sizeof(*th));
+
+		if (ret < 0) {
+			if (ret != -ENOENT)
+				LOG();
+		} else {
+			recv_cookie = bpf_ntohl(th->ack_seq) - 1;
+		}
+	}
+}
+
+static int handle_ip6_tcp(struct ipv6hdr *ip6h, struct __sk_buff *skb)
+{
+	struct bpf_sock_tuple *tuple;
+	struct bpf_sock *bpf_skc;
+	unsigned int tuple_len;
+	struct tcphdr *th;
+	void *data_end;
+
+	data_end = (void *)(long)(skb->data_end);
+
+	th = (struct tcphdr *)(ip6h + 1);
+	if (th + 1 > data_end)
+		return TC_ACT_OK;
+
+	/* Is it the testing traffic? */
+	if (th->dest != srv_sa6.sin6_port)
+		return TC_ACT_OK;
+
+	tuple_len = sizeof(tuple->ipv6);
+	tuple = (struct bpf_sock_tuple *)&ip6h->saddr;
+	if ((void *)tuple + tuple_len > data_end) {
+		LOG();
+		return TC_ACT_OK;
+	}
+
+	bpf_skc = bpf_skc_lookup_tcp(skb, tuple, tuple_len,
+				     BPF_F_CURRENT_NETNS, 0);
+	if (!bpf_skc) {
+		LOG();
+		return TC_ACT_OK;
+	}
+
+	if (bpf_skc->state == BPF_TCP_NEW_SYN_RECV) {
+		struct request_sock *req_sk;
+
+		req_sk = (struct request_sock *)bpf_skc_to_tcp_request_sock(bpf_skc);
+		if (!req_sk) {
+			LOG();
+			goto release;
+		}
+
+		if (bpf_sk_assign(skb, req_sk, 0)) {
+			LOG();
+			goto release;
+		}
+
+		req_sk_sport = req_sk->__req_common.skc_num;
+
+		bpf_sk_release(req_sk);
+		return TC_ACT_OK;
+	} else if (bpf_skc->state == BPF_TCP_LISTEN) {
+		struct tcp_sock *tp;
+
+		tp = bpf_skc_to_tcp_sock(bpf_skc);
+		if (!tp) {
+			LOG();
+			goto release;
+		}
+
+		if (bpf_sk_assign(skb, tp, 0)) {
+			LOG();
+			goto release;
+		}
+
+		listen_tp_sport = tp->inet_conn.icsk_inet.sk.__sk_common.skc_num;
+
+		test_syncookie_helper(ip6h, th, tp, skb);
+		bpf_sk_release(tp);
+		return TC_ACT_OK;
+	}
+
+	if (bpf_sk_assign(skb, bpf_skc, 0))
+		LOG();
+
+release:
+	bpf_sk_release(bpf_skc);
+	return TC_ACT_OK;
+}
+
+SEC("classifier/ingress")
+int cls_ingress(struct __sk_buff *skb)
+{
+	struct ipv6hdr *ip6h;
+	struct ethhdr *eth;
+	void *data_end;
+
+	data_end = (void *)(long)(skb->data_end);
+
+	eth = (struct ethhdr *)(long)(skb->data);
+	if (eth + 1 > data_end)
+		return TC_ACT_OK;
+
+	if (eth->h_proto != bpf_htons(ETH_P_IPV6))
+		return TC_ACT_OK;
+
+	ip6h = (struct ipv6hdr *)(eth + 1);
+	if (ip6h + 1 > data_end)
+		return TC_ACT_OK;
+
+	if (ip6h->nexthdr == IPPROTO_TCP)
+		return handle_ip6_tcp(ip6h, skb);
+
+	return TC_ACT_OK;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/progs/test_overhead.c b/tools/testing/selftests/bpf/progs/test_overhead.c
index 42403d088abc..abb7344b531f 100644
--- a/tools/testing/selftests/bpf/progs/test_overhead.c
+++ b/tools/testing/selftests/bpf/progs/test_overhead.c
@@ -39,10 +39,4 @@ int BPF_PROG(prog5, struct task_struct *tsk, const char *buf, bool exec)
 	return 0;
 }
 
-SEC("fmod_ret/__set_task_comm")
-int BPF_PROG(prog6, struct task_struct *tsk, const char *buf, bool exec)
-{
-	return !tsk;
-}
-
 char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/progs/test_pe_preserve_elems.c b/tools/testing/selftests/bpf/progs/test_pe_preserve_elems.c
new file mode 100644
index 000000000000..fb22de7c365d
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_pe_preserve_elems.c
@@ -0,0 +1,38 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2020 Facebook
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
+	__uint(max_entries, 1);
+	__uint(key_size, sizeof(int));
+	__uint(value_size, sizeof(int));
+} array_1 SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
+	__uint(max_entries, 1);
+	__uint(key_size, sizeof(int));
+	__uint(value_size, sizeof(int));
+	__uint(map_flags, BPF_F_PRESERVE_ELEMS);
+} array_2 SEC(".maps");
+
+SEC("raw_tp/sched_switch")
+int BPF_PROG(read_array_1)
+{
+	struct bpf_perf_event_value val;
+
+	return bpf_perf_event_read_value(&array_1, 0, &val, sizeof(val));
+}
+
+SEC("raw_tp/task_rename")
+int BPF_PROG(read_array_2)
+{
+	struct bpf_perf_event_value val;
+
+	return bpf_perf_event_read_value(&array_2, 0, &val, sizeof(val));
+}
+
+char LICENSE[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/progs/test_raw_tp_test_run.c b/tools/testing/selftests/bpf/progs/test_raw_tp_test_run.c
new file mode 100644
index 000000000000..4c63cc87b9d0
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_raw_tp_test_run.c
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020 Facebook */
+
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+__u32 count = 0;
+__u32 on_cpu = 0xffffffff;
+
+SEC("raw_tp/task_rename")
+int BPF_PROG(rename, struct task_struct *task, char *comm)
+{
+
+	count++;
+	if ((__u64) task == 0x1234ULL && (__u64) comm == 0x5678ULL) {
+		on_cpu = bpf_get_smp_processor_id();
+		return (long)task + (long)comm;
+	}
+
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/progs/test_sk_lookup.c b/tools/testing/selftests/bpf/progs/test_sk_lookup.c
index bbf8296f4d66..1032b292af5b 100644
--- a/tools/testing/selftests/bpf/progs/test_sk_lookup.c
+++ b/tools/testing/selftests/bpf/progs/test_sk_lookup.c
@@ -19,6 +19,17 @@
 #define IP6(aaaa, bbbb, cccc, dddd)			\
 	{ bpf_htonl(aaaa), bpf_htonl(bbbb), bpf_htonl(cccc), bpf_htonl(dddd) }
 
+/* Macros for least-significant byte and word accesses. */
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+#define LSE_INDEX(index, size) (index)
+#else
+#define LSE_INDEX(index, size) ((size) - (index) - 1)
+#endif
+#define LSB(value, index)				\
+	(((__u8 *)&(value))[LSE_INDEX((index), sizeof(value))])
+#define LSW(value, index)				\
+	(((__u16 *)&(value))[LSE_INDEX((index), sizeof(value) / 2)])
+
 #define MAX_SOCKS 32
 
 struct {
@@ -369,171 +380,146 @@ int ctx_narrow_access(struct bpf_sk_lookup *ctx)
 {
 	struct bpf_sock *sk;
 	int err, family;
-	__u16 *half;
-	__u8 *byte;
 	bool v4;
 
 	v4 = (ctx->family == AF_INET);
 
 	/* Narrow loads from family field */
-	byte = (__u8 *)&ctx->family;
-	half = (__u16 *)&ctx->family;
-	if (byte[0] != (v4 ? AF_INET : AF_INET6) ||
-	    byte[1] != 0 || byte[2] != 0 || byte[3] != 0)
+	if (LSB(ctx->family, 0) != (v4 ? AF_INET : AF_INET6) ||
+	    LSB(ctx->family, 1) != 0 || LSB(ctx->family, 2) != 0 || LSB(ctx->family, 3) != 0)
 		return SK_DROP;
-	if (half[0] != (v4 ? AF_INET : AF_INET6))
+	if (LSW(ctx->family, 0) != (v4 ? AF_INET : AF_INET6))
 		return SK_DROP;
 
-	byte = (__u8 *)&ctx->protocol;
-	if (byte[0] != IPPROTO_TCP ||
-	    byte[1] != 0 || byte[2] != 0 || byte[3] != 0)
+	/* Narrow loads from protocol field */
+	if (LSB(ctx->protocol, 0) != IPPROTO_TCP ||
+	    LSB(ctx->protocol, 1) != 0 || LSB(ctx->protocol, 2) != 0 || LSB(ctx->protocol, 3) != 0)
 		return SK_DROP;
-	half = (__u16 *)&ctx->protocol;
-	if (half[0] != IPPROTO_TCP)
+	if (LSW(ctx->protocol, 0) != IPPROTO_TCP)
 		return SK_DROP;
 
 	/* Narrow loads from remote_port field. Expect non-0 value. */
-	byte = (__u8 *)&ctx->remote_port;
-	if (byte[0] == 0 && byte[1] == 0 && byte[2] == 0 && byte[3] == 0)
+	if (LSB(ctx->remote_port, 0) == 0 && LSB(ctx->remote_port, 1) == 0 &&
+	    LSB(ctx->remote_port, 2) == 0 && LSB(ctx->remote_port, 3) == 0)
 		return SK_DROP;
-	half = (__u16 *)&ctx->remote_port;
-	if (half[0] == 0)
+	if (LSW(ctx->remote_port, 0) == 0)
 		return SK_DROP;
 
 	/* Narrow loads from local_port field. Expect DST_PORT. */
-	byte = (__u8 *)&ctx->local_port;
-	if (byte[0] != ((DST_PORT >> 0) & 0xff) ||
-	    byte[1] != ((DST_PORT >> 8) & 0xff) ||
-	    byte[2] != 0 || byte[3] != 0)
+	if (LSB(ctx->local_port, 0) != ((DST_PORT >> 0) & 0xff) ||
+	    LSB(ctx->local_port, 1) != ((DST_PORT >> 8) & 0xff) ||
+	    LSB(ctx->local_port, 2) != 0 || LSB(ctx->local_port, 3) != 0)
 		return SK_DROP;
-	half = (__u16 *)&ctx->local_port;
-	if (half[0] != DST_PORT)
+	if (LSW(ctx->local_port, 0) != DST_PORT)
 		return SK_DROP;
 
 	/* Narrow loads from IPv4 fields */
 	if (v4) {
 		/* Expect non-0.0.0.0 in remote_ip4 */
-		byte = (__u8 *)&ctx->remote_ip4;
-		if (byte[0] == 0 && byte[1] == 0 &&
-		    byte[2] == 0 && byte[3] == 0)
+		if (LSB(ctx->remote_ip4, 0) == 0 && LSB(ctx->remote_ip4, 1) == 0 &&
+		    LSB(ctx->remote_ip4, 2) == 0 && LSB(ctx->remote_ip4, 3) == 0)
 			return SK_DROP;
-		half = (__u16 *)&ctx->remote_ip4;
-		if (half[0] == 0 && half[1] == 0)
+		if (LSW(ctx->remote_ip4, 0) == 0 && LSW(ctx->remote_ip4, 1) == 0)
 			return SK_DROP;
 
 		/* Expect DST_IP4 in local_ip4 */
-		byte = (__u8 *)&ctx->local_ip4;
-		if (byte[0] != ((DST_IP4 >>  0) & 0xff) ||
-		    byte[1] != ((DST_IP4 >>  8) & 0xff) ||
-		    byte[2] != ((DST_IP4 >> 16) & 0xff) ||
-		    byte[3] != ((DST_IP4 >> 24) & 0xff))
+		if (LSB(ctx->local_ip4, 0) != ((DST_IP4 >> 0) & 0xff) ||
+		    LSB(ctx->local_ip4, 1) != ((DST_IP4 >> 8) & 0xff) ||
+		    LSB(ctx->local_ip4, 2) != ((DST_IP4 >> 16) & 0xff) ||
+		    LSB(ctx->local_ip4, 3) != ((DST_IP4 >> 24) & 0xff))
 			return SK_DROP;
-		half = (__u16 *)&ctx->local_ip4;
-		if (half[0] != ((DST_IP4 >>  0) & 0xffff) ||
-		    half[1] != ((DST_IP4 >> 16) & 0xffff))
+		if (LSW(ctx->local_ip4, 0) != ((DST_IP4 >> 0) & 0xffff) ||
+		    LSW(ctx->local_ip4, 1) != ((DST_IP4 >> 16) & 0xffff))
 			return SK_DROP;
 	} else {
 		/* Expect 0.0.0.0 IPs when family != AF_INET */
-		byte = (__u8 *)&ctx->remote_ip4;
-		if (byte[0] != 0 || byte[1] != 0 &&
-		    byte[2] != 0 || byte[3] != 0)
+		if (LSB(ctx->remote_ip4, 0) != 0 || LSB(ctx->remote_ip4, 1) != 0 ||
+		    LSB(ctx->remote_ip4, 2) != 0 || LSB(ctx->remote_ip4, 3) != 0)
 			return SK_DROP;
-		half = (__u16 *)&ctx->remote_ip4;
-		if (half[0] != 0 || half[1] != 0)
+		if (LSW(ctx->remote_ip4, 0) != 0 || LSW(ctx->remote_ip4, 1) != 0)
 			return SK_DROP;
 
-		byte = (__u8 *)&ctx->local_ip4;
-		if (byte[0] != 0 || byte[1] != 0 &&
-		    byte[2] != 0 || byte[3] != 0)
+		if (LSB(ctx->local_ip4, 0) != 0 || LSB(ctx->local_ip4, 1) != 0 ||
+		    LSB(ctx->local_ip4, 2) != 0 || LSB(ctx->local_ip4, 3) != 0)
 			return SK_DROP;
-		half = (__u16 *)&ctx->local_ip4;
-		if (half[0] != 0 || half[1] != 0)
+		if (LSW(ctx->local_ip4, 0) != 0 || LSW(ctx->local_ip4, 1) != 0)
 			return SK_DROP;
 	}
 
 	/* Narrow loads from IPv6 fields */
 	if (!v4) {
-		/* Expenct non-:: IP in remote_ip6 */
-		byte = (__u8 *)&ctx->remote_ip6;
-		if (byte[0] == 0 && byte[1] == 0 &&
-		    byte[2] == 0 && byte[3] == 0 &&
-		    byte[4] == 0 && byte[5] == 0 &&
-		    byte[6] == 0 && byte[7] == 0 &&
-		    byte[8] == 0 && byte[9] == 0 &&
-		    byte[10] == 0 && byte[11] == 0 &&
-		    byte[12] == 0 && byte[13] == 0 &&
-		    byte[14] == 0 && byte[15] == 0)
+		/* Expect non-:: IP in remote_ip6 */
+		if (LSB(ctx->remote_ip6[0], 0) == 0 && LSB(ctx->remote_ip6[0], 1) == 0 &&
+		    LSB(ctx->remote_ip6[0], 2) == 0 && LSB(ctx->remote_ip6[0], 3) == 0 &&
+		    LSB(ctx->remote_ip6[1], 0) == 0 && LSB(ctx->remote_ip6[1], 1) == 0 &&
+		    LSB(ctx->remote_ip6[1], 2) == 0 && LSB(ctx->remote_ip6[1], 3) == 0 &&
+		    LSB(ctx->remote_ip6[2], 0) == 0 && LSB(ctx->remote_ip6[2], 1) == 0 &&
+		    LSB(ctx->remote_ip6[2], 2) == 0 && LSB(ctx->remote_ip6[2], 3) == 0 &&
+		    LSB(ctx->remote_ip6[3], 0) == 0 && LSB(ctx->remote_ip6[3], 1) == 0 &&
+		    LSB(ctx->remote_ip6[3], 2) == 0 && LSB(ctx->remote_ip6[3], 3) == 0)
 			return SK_DROP;
-		half = (__u16 *)&ctx->remote_ip6;
-		if (half[0] == 0 && half[1] == 0 &&
-		    half[2] == 0 && half[3] == 0 &&
-		    half[4] == 0 && half[5] == 0 &&
-		    half[6] == 0 && half[7] == 0)
+		if (LSW(ctx->remote_ip6[0], 0) == 0 && LSW(ctx->remote_ip6[0], 1) == 0 &&
+		    LSW(ctx->remote_ip6[1], 0) == 0 && LSW(ctx->remote_ip6[1], 1) == 0 &&
+		    LSW(ctx->remote_ip6[2], 0) == 0 && LSW(ctx->remote_ip6[2], 1) == 0 &&
+		    LSW(ctx->remote_ip6[3], 0) == 0 && LSW(ctx->remote_ip6[3], 1) == 0)
 			return SK_DROP;
-
 		/* Expect DST_IP6 in local_ip6 */
-		byte = (__u8 *)&ctx->local_ip6;
-		if (byte[0] != ((DST_IP6[0] >>  0) & 0xff) ||
-		    byte[1] != ((DST_IP6[0] >>  8) & 0xff) ||
-		    byte[2] != ((DST_IP6[0] >> 16) & 0xff) ||
-		    byte[3] != ((DST_IP6[0] >> 24) & 0xff) ||
-		    byte[4] != ((DST_IP6[1] >>  0) & 0xff) ||
-		    byte[5] != ((DST_IP6[1] >>  8) & 0xff) ||
-		    byte[6] != ((DST_IP6[1] >> 16) & 0xff) ||
-		    byte[7] != ((DST_IP6[1] >> 24) & 0xff) ||
-		    byte[8] != ((DST_IP6[2] >>  0) & 0xff) ||
-		    byte[9] != ((DST_IP6[2] >>  8) & 0xff) ||
-		    byte[10] != ((DST_IP6[2] >> 16) & 0xff) ||
-		    byte[11] != ((DST_IP6[2] >> 24) & 0xff) ||
-		    byte[12] != ((DST_IP6[3] >>  0) & 0xff) ||
-		    byte[13] != ((DST_IP6[3] >>  8) & 0xff) ||
-		    byte[14] != ((DST_IP6[3] >> 16) & 0xff) ||
-		    byte[15] != ((DST_IP6[3] >> 24) & 0xff))
+		if (LSB(ctx->local_ip6[0], 0) != ((DST_IP6[0] >> 0) & 0xff) ||
+		    LSB(ctx->local_ip6[0], 1) != ((DST_IP6[0] >> 8) & 0xff) ||
+		    LSB(ctx->local_ip6[0], 2) != ((DST_IP6[0] >> 16) & 0xff) ||
+		    LSB(ctx->local_ip6[0], 3) != ((DST_IP6[0] >> 24) & 0xff) ||
+		    LSB(ctx->local_ip6[1], 0) != ((DST_IP6[1] >> 0) & 0xff) ||
+		    LSB(ctx->local_ip6[1], 1) != ((DST_IP6[1] >> 8) & 0xff) ||
+		    LSB(ctx->local_ip6[1], 2) != ((DST_IP6[1] >> 16) & 0xff) ||
+		    LSB(ctx->local_ip6[1], 3) != ((DST_IP6[1] >> 24) & 0xff) ||
+		    LSB(ctx->local_ip6[2], 0) != ((DST_IP6[2] >> 0) & 0xff) ||
+		    LSB(ctx->local_ip6[2], 1) != ((DST_IP6[2] >> 8) & 0xff) ||
+		    LSB(ctx->local_ip6[2], 2) != ((DST_IP6[2] >> 16) & 0xff) ||
+		    LSB(ctx->local_ip6[2], 3) != ((DST_IP6[2] >> 24) & 0xff) ||
+		    LSB(ctx->local_ip6[3], 0) != ((DST_IP6[3] >> 0) & 0xff) ||
+		    LSB(ctx->local_ip6[3], 1) != ((DST_IP6[3] >> 8) & 0xff) ||
+		    LSB(ctx->local_ip6[3], 2) != ((DST_IP6[3] >> 16) & 0xff) ||
+		    LSB(ctx->local_ip6[3], 3) != ((DST_IP6[3] >> 24) & 0xff))
 			return SK_DROP;
-		half = (__u16 *)&ctx->local_ip6;
-		if (half[0] != ((DST_IP6[0] >>  0) & 0xffff) ||
-		    half[1] != ((DST_IP6[0] >> 16) & 0xffff) ||
-		    half[2] != ((DST_IP6[1] >>  0) & 0xffff) ||
-		    half[3] != ((DST_IP6[1] >> 16) & 0xffff) ||
-		    half[4] != ((DST_IP6[2] >>  0) & 0xffff) ||
-		    half[5] != ((DST_IP6[2] >> 16) & 0xffff) ||
-		    half[6] != ((DST_IP6[3] >>  0) & 0xffff) ||
-		    half[7] != ((DST_IP6[3] >> 16) & 0xffff))
+		if (LSW(ctx->local_ip6[0], 0) != ((DST_IP6[0] >> 0) & 0xffff) ||
+		    LSW(ctx->local_ip6[0], 1) != ((DST_IP6[0] >> 16) & 0xffff) ||
+		    LSW(ctx->local_ip6[1], 0) != ((DST_IP6[1] >> 0) & 0xffff) ||
+		    LSW(ctx->local_ip6[1], 1) != ((DST_IP6[1] >> 16) & 0xffff) ||
+		    LSW(ctx->local_ip6[2], 0) != ((DST_IP6[2] >> 0) & 0xffff) ||
+		    LSW(ctx->local_ip6[2], 1) != ((DST_IP6[2] >> 16) & 0xffff) ||
+		    LSW(ctx->local_ip6[3], 0) != ((DST_IP6[3] >> 0) & 0xffff) ||
+		    LSW(ctx->local_ip6[3], 1) != ((DST_IP6[3] >> 16) & 0xffff))
 			return SK_DROP;
 	} else {
 		/* Expect :: IPs when family != AF_INET6 */
-		byte = (__u8 *)&ctx->remote_ip6;
-		if (byte[0] != 0 || byte[1] != 0 ||
-		    byte[2] != 0 || byte[3] != 0 ||
-		    byte[4] != 0 || byte[5] != 0 ||
-		    byte[6] != 0 || byte[7] != 0 ||
-		    byte[8] != 0 || byte[9] != 0 ||
-		    byte[10] != 0 || byte[11] != 0 ||
-		    byte[12] != 0 || byte[13] != 0 ||
-		    byte[14] != 0 || byte[15] != 0)
+		if (LSB(ctx->remote_ip6[0], 0) != 0 || LSB(ctx->remote_ip6[0], 1) != 0 ||
+		    LSB(ctx->remote_ip6[0], 2) != 0 || LSB(ctx->remote_ip6[0], 3) != 0 ||
+		    LSB(ctx->remote_ip6[1], 0) != 0 || LSB(ctx->remote_ip6[1], 1) != 0 ||
+		    LSB(ctx->remote_ip6[1], 2) != 0 || LSB(ctx->remote_ip6[1], 3) != 0 ||
+		    LSB(ctx->remote_ip6[2], 0) != 0 || LSB(ctx->remote_ip6[2], 1) != 0 ||
+		    LSB(ctx->remote_ip6[2], 2) != 0 || LSB(ctx->remote_ip6[2], 3) != 0 ||
+		    LSB(ctx->remote_ip6[3], 0) != 0 || LSB(ctx->remote_ip6[3], 1) != 0 ||
+		    LSB(ctx->remote_ip6[3], 2) != 0 || LSB(ctx->remote_ip6[3], 3) != 0)
 			return SK_DROP;
-		half = (__u16 *)&ctx->remote_ip6;
-		if (half[0] != 0 || half[1] != 0 ||
-		    half[2] != 0 || half[3] != 0 ||
-		    half[4] != 0 || half[5] != 0 ||
-		    half[6] != 0 || half[7] != 0)
+		if (LSW(ctx->remote_ip6[0], 0) != 0 || LSW(ctx->remote_ip6[0], 1) != 0 ||
+		    LSW(ctx->remote_ip6[1], 0) != 0 || LSW(ctx->remote_ip6[1], 1) != 0 ||
+		    LSW(ctx->remote_ip6[2], 0) != 0 || LSW(ctx->remote_ip6[2], 1) != 0 ||
+		    LSW(ctx->remote_ip6[3], 0) != 0 || LSW(ctx->remote_ip6[3], 1) != 0)
 			return SK_DROP;
 
-		byte = (__u8 *)&ctx->local_ip6;
-		if (byte[0] != 0 || byte[1] != 0 ||
-		    byte[2] != 0 || byte[3] != 0 ||
-		    byte[4] != 0 || byte[5] != 0 ||
-		    byte[6] != 0 || byte[7] != 0 ||
-		    byte[8] != 0 || byte[9] != 0 ||
-		    byte[10] != 0 || byte[11] != 0 ||
-		    byte[12] != 0 || byte[13] != 0 ||
-		    byte[14] != 0 || byte[15] != 0)
+		if (LSB(ctx->local_ip6[0], 0) != 0 || LSB(ctx->local_ip6[0], 1) != 0 ||
+		    LSB(ctx->local_ip6[0], 2) != 0 || LSB(ctx->local_ip6[0], 3) != 0 ||
+		    LSB(ctx->local_ip6[1], 0) != 0 || LSB(ctx->local_ip6[1], 1) != 0 ||
+		    LSB(ctx->local_ip6[1], 2) != 0 || LSB(ctx->local_ip6[1], 3) != 0 ||
+		    LSB(ctx->local_ip6[2], 0) != 0 || LSB(ctx->local_ip6[2], 1) != 0 ||
+		    LSB(ctx->local_ip6[2], 2) != 0 || LSB(ctx->local_ip6[2], 3) != 0 ||
+		    LSB(ctx->local_ip6[3], 0) != 0 || LSB(ctx->local_ip6[3], 1) != 0 ||
+		    LSB(ctx->local_ip6[3], 2) != 0 || LSB(ctx->local_ip6[3], 3) != 0)
 			return SK_DROP;
-		half = (__u16 *)&ctx->local_ip6;
-		if (half[0] != 0 || half[1] != 0 ||
-		    half[2] != 0 || half[3] != 0 ||
-		    half[4] != 0 || half[5] != 0 ||
-		    half[6] != 0 || half[7] != 0)
+		if (LSW(ctx->remote_ip6[0], 0) != 0 || LSW(ctx->remote_ip6[0], 1) != 0 ||
+		    LSW(ctx->remote_ip6[1], 0) != 0 || LSW(ctx->remote_ip6[1], 1) != 0 ||
+		    LSW(ctx->remote_ip6[2], 0) != 0 || LSW(ctx->remote_ip6[2], 1) != 0 ||
+		    LSW(ctx->remote_ip6[3], 0) != 0 || LSW(ctx->remote_ip6[3], 1) != 0)
 			return SK_DROP;
 	}
 
diff --git a/tools/testing/selftests/bpf/progs/test_sock_fields_kern.c b/tools/testing/selftests/bpf/progs/test_sock_fields.c
index 9bcaa37f476a..81b57b9aaaea 100644
--- a/tools/testing/selftests/bpf/progs/test_sock_fields_kern.c
+++ b/tools/testing/selftests/bpf/progs/test_sock_fields.c
@@ -7,19 +7,7 @@
 
 #include <bpf/bpf_helpers.h>
 #include <bpf/bpf_endian.h>
-
-enum bpf_addr_array_idx {
-	ADDR_SRV_IDX,
-	ADDR_CLI_IDX,
-	__NR_BPF_ADDR_ARRAY_IDX,
-};
-
-enum bpf_result_array_idx {
-	EGRESS_SRV_IDX,
-	EGRESS_CLI_IDX,
-	INGRESS_LISTEN_IDX,
-	__NR_BPF_RESULT_ARRAY_IDX,
-};
+#include "bpf_tcp_helpers.h"
 
 enum bpf_linum_array_idx {
 	EGRESS_LINUM_IDX,
@@ -29,27 +17,6 @@ enum bpf_linum_array_idx {
 
 struct {
 	__uint(type, BPF_MAP_TYPE_ARRAY);
-	__uint(max_entries, __NR_BPF_ADDR_ARRAY_IDX);
-	__type(key, __u32);
-	__type(value, struct sockaddr_in6);
-} addr_map SEC(".maps");
-
-struct {
-	__uint(type, BPF_MAP_TYPE_ARRAY);
-	__uint(max_entries, __NR_BPF_RESULT_ARRAY_IDX);
-	__type(key, __u32);
-	__type(value, struct bpf_sock);
-} sock_result_map SEC(".maps");
-
-struct {
-	__uint(type, BPF_MAP_TYPE_ARRAY);
-	__uint(max_entries, __NR_BPF_RESULT_ARRAY_IDX);
-	__type(key, __u32);
-	__type(value, struct bpf_tcp_sock);
-} tcp_sock_result_map SEC(".maps");
-
-struct {
-	__uint(type, BPF_MAP_TYPE_ARRAY);
 	__uint(max_entries, __NR_BPF_LINUM_ARRAY_IDX);
 	__type(key, __u32);
 	__type(value, __u32);
@@ -74,6 +41,17 @@ struct {
 	__type(value, struct bpf_spinlock_cnt);
 } sk_pkt_out_cnt10 SEC(".maps");
 
+struct bpf_tcp_sock listen_tp = {};
+struct sockaddr_in6 srv_sa6 = {};
+struct bpf_tcp_sock cli_tp = {};
+struct bpf_tcp_sock srv_tp = {};
+struct bpf_sock listen_sk = {};
+struct bpf_sock srv_sk = {};
+struct bpf_sock cli_sk = {};
+__u64 parent_cg_id = 0;
+__u64 child_cg_id = 0;
+__u64 lsndtime = 0;
+
 static bool is_loopback6(__u32 *a6)
 {
 	return !a6[0] && !a6[1] && !a6[2] && a6[3] == bpf_htonl(1);
@@ -130,62 +108,86 @@ static void tpcpy(struct bpf_tcp_sock *dst,
 	dst->bytes_acked = src->bytes_acked;
 }
 
-#define RETURN {						\
+/* Always return CG_OK so that no pkt will be filtered out */
+#define CG_OK 1
+
+#define RET_LOG() ({						\
 	linum = __LINE__;					\
-	bpf_map_update_elem(&linum_map, &linum_idx, &linum, 0);	\
-	return 1;						\
-}
+	bpf_map_update_elem(&linum_map, &linum_idx, &linum, BPF_NOEXIST);	\
+	return CG_OK;						\
+})
 
 SEC("cgroup_skb/egress")
 int egress_read_sock_fields(struct __sk_buff *skb)
 {
 	struct bpf_spinlock_cnt cli_cnt_init = { .lock = 0, .cnt = 0xeB9F };
-	__u32 srv_idx = ADDR_SRV_IDX, cli_idx = ADDR_CLI_IDX, result_idx;
 	struct bpf_spinlock_cnt *pkt_out_cnt, *pkt_out_cnt10;
-	struct sockaddr_in6 *srv_sa6, *cli_sa6;
 	struct bpf_tcp_sock *tp, *tp_ret;
 	struct bpf_sock *sk, *sk_ret;
 	__u32 linum, linum_idx;
+	struct tcp_sock *ktp;
 
 	linum_idx = EGRESS_LINUM_IDX;
 
 	sk = skb->sk;
-	if (!sk || sk->state == 10)
-		RETURN;
+	if (!sk)
+		RET_LOG();
 
+	/* Not the testing egress traffic or
+	 * TCP_LISTEN (10) socket will be copied at the ingress side.
+	 */
+	if (sk->family != AF_INET6 || !is_loopback6(sk->src_ip6) ||
+	    sk->state == 10)
+		return CG_OK;
+
+	if (sk->src_port == bpf_ntohs(srv_sa6.sin6_port)) {
+		/* Server socket */
+		sk_ret = &srv_sk;
+		tp_ret = &srv_tp;
+	} else if (sk->dst_port == srv_sa6.sin6_port) {
+		/* Client socket */
+		sk_ret = &cli_sk;
+		tp_ret = &cli_tp;
+	} else {
+		/* Not the testing egress traffic */
+		return CG_OK;
+	}
+
+	/* It must be a fullsock for cgroup_skb/egress prog */
 	sk = bpf_sk_fullsock(sk);
-	if (!sk || sk->family != AF_INET6 || sk->protocol != IPPROTO_TCP ||
-	    !is_loopback6(sk->src_ip6))
-		RETURN;
+	if (!sk)
+		RET_LOG();
+
+	/* Not the testing egress traffic */
+	if (sk->protocol != IPPROTO_TCP)
+		return CG_OK;
 
 	tp = bpf_tcp_sock(sk);
 	if (!tp)
-		RETURN;
+		RET_LOG();
 
-	srv_sa6 = bpf_map_lookup_elem(&addr_map, &srv_idx);
-	cli_sa6 = bpf_map_lookup_elem(&addr_map, &cli_idx);
-	if (!srv_sa6 || !cli_sa6)
-		RETURN;
+	skcpy(sk_ret, sk);
+	tpcpy(tp_ret, tp);
 
-	if (sk->src_port == bpf_ntohs(srv_sa6->sin6_port))
-		result_idx = EGRESS_SRV_IDX;
-	else if (sk->src_port == bpf_ntohs(cli_sa6->sin6_port))
-		result_idx = EGRESS_CLI_IDX;
-	else
-		RETURN;
+	if (sk_ret == &srv_sk) {
+		ktp = bpf_skc_to_tcp_sock(sk);
 
-	sk_ret = bpf_map_lookup_elem(&sock_result_map, &result_idx);
-	tp_ret = bpf_map_lookup_elem(&tcp_sock_result_map, &result_idx);
-	if (!sk_ret || !tp_ret)
-		RETURN;
+		if (!ktp)
+			RET_LOG();
 
-	skcpy(sk_ret, sk);
-	tpcpy(tp_ret, tp);
+		lsndtime = ktp->lsndtime;
+
+		child_cg_id = bpf_sk_cgroup_id(ktp);
+		if (!child_cg_id)
+			RET_LOG();
+
+		parent_cg_id = bpf_sk_ancestor_cgroup_id(ktp, 2);
+		if (!parent_cg_id)
+			RET_LOG();
 
-	if (result_idx == EGRESS_SRV_IDX) {
 		/* The userspace has created it for srv sk */
-		pkt_out_cnt = bpf_sk_storage_get(&sk_pkt_out_cnt, sk, 0, 0);
-		pkt_out_cnt10 = bpf_sk_storage_get(&sk_pkt_out_cnt10, sk,
+		pkt_out_cnt = bpf_sk_storage_get(&sk_pkt_out_cnt, ktp, 0, 0);
+		pkt_out_cnt10 = bpf_sk_storage_get(&sk_pkt_out_cnt10, ktp,
 						   0, 0);
 	} else {
 		pkt_out_cnt = bpf_sk_storage_get(&sk_pkt_out_cnt, sk,
@@ -197,7 +199,7 @@ int egress_read_sock_fields(struct __sk_buff *skb)
 	}
 
 	if (!pkt_out_cnt || !pkt_out_cnt10)
-		RETURN;
+		RET_LOG();
 
 	/* Even both cnt and cnt10 have lock defined in their BTF,
 	 * intentionally one cnt takes lock while one does not
@@ -208,48 +210,44 @@ int egress_read_sock_fields(struct __sk_buff *skb)
 	pkt_out_cnt10->cnt += 10;
 	bpf_spin_unlock(&pkt_out_cnt10->lock);
 
-	RETURN;
+	return CG_OK;
 }
 
 SEC("cgroup_skb/ingress")
 int ingress_read_sock_fields(struct __sk_buff *skb)
 {
-	__u32 srv_idx = ADDR_SRV_IDX, result_idx = INGRESS_LISTEN_IDX;
-	struct bpf_tcp_sock *tp, *tp_ret;
-	struct bpf_sock *sk, *sk_ret;
-	struct sockaddr_in6 *srv_sa6;
+	struct bpf_tcp_sock *tp;
 	__u32 linum, linum_idx;
+	struct bpf_sock *sk;
 
 	linum_idx = INGRESS_LINUM_IDX;
 
 	sk = skb->sk;
-	if (!sk || sk->family != AF_INET6 || !is_loopback6(sk->src_ip6))
-		RETURN;
+	if (!sk)
+		RET_LOG();
 
-	srv_sa6 = bpf_map_lookup_elem(&addr_map, &srv_idx);
-	if (!srv_sa6 || sk->src_port != bpf_ntohs(srv_sa6->sin6_port))
-		RETURN;
+	/* Not the testing ingress traffic to the server */
+	if (sk->family != AF_INET6 || !is_loopback6(sk->src_ip6) ||
+	    sk->src_port != bpf_ntohs(srv_sa6.sin6_port))
+		return CG_OK;
 
-	if (sk->state != 10 && sk->state != 12)
-		RETURN;
+	/* Only interested in TCP_LISTEN */
+	if (sk->state != 10)
+		return CG_OK;
 
-	sk = bpf_get_listener_sock(sk);
+	/* It must be a fullsock for cgroup_skb/ingress prog */
+	sk = bpf_sk_fullsock(sk);
 	if (!sk)
-		RETURN;
+		RET_LOG();
 
 	tp = bpf_tcp_sock(sk);
 	if (!tp)
-		RETURN;
-
-	sk_ret = bpf_map_lookup_elem(&sock_result_map, &result_idx);
-	tp_ret = bpf_map_lookup_elem(&tcp_sock_result_map, &result_idx);
-	if (!sk_ret || !tp_ret)
-		RETURN;
+		RET_LOG();
 
-	skcpy(sk_ret, sk);
-	tpcpy(tp_ret, tp);
+	skcpy(&listen_sk, sk);
+	tpcpy(&listen_tp, tp);
 
-	RETURN;
+	return CG_OK;
 }
 
 char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/progs/test_tc_neigh.c b/tools/testing/selftests/bpf/progs/test_tc_neigh.c
new file mode 100644
index 000000000000..889a72c3024f
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_tc_neigh.c
@@ -0,0 +1,144 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdint.h>
+#include <stdbool.h>
+
+#include <linux/bpf.h>
+#include <linux/stddef.h>
+#include <linux/pkt_cls.h>
+#include <linux/if_ether.h>
+#include <linux/in.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+
+#ifndef barrier_data
+# define barrier_data(ptr)	asm volatile("": :"r"(ptr) :"memory")
+#endif
+
+#ifndef ctx_ptr
+# define ctx_ptr(field)		(void *)(long)(field)
+#endif
+
+#define dst_to_src_tmp		0xeeddddeeU
+#define src_to_dst_tmp		0xeeffffeeU
+
+#define ip4_src			0xac100164 /* 172.16.1.100 */
+#define ip4_dst			0xac100264 /* 172.16.2.100 */
+
+#define ip6_src			{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
+				  0x00, 0x01, 0xde, 0xad, 0xbe, 0xef, 0xca, 0xfe }
+#define ip6_dst			{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
+				  0x00, 0x02, 0xde, 0xad, 0xbe, 0xef, 0xca, 0xfe }
+
+#ifndef v6_equal
+# define v6_equal(a, b)		(a.s6_addr32[0] == b.s6_addr32[0] && \
+				 a.s6_addr32[1] == b.s6_addr32[1] && \
+				 a.s6_addr32[2] == b.s6_addr32[2] && \
+				 a.s6_addr32[3] == b.s6_addr32[3])
+#endif
+
+static __always_inline bool is_remote_ep_v4(struct __sk_buff *skb,
+					    __be32 addr)
+{
+	void *data_end = ctx_ptr(skb->data_end);
+	void *data = ctx_ptr(skb->data);
+	struct iphdr *ip4h;
+
+	if (data + sizeof(struct ethhdr) > data_end)
+		return false;
+
+	ip4h = (struct iphdr *)(data + sizeof(struct ethhdr));
+	if ((void *)(ip4h + 1) > data_end)
+		return false;
+
+	return ip4h->daddr == addr;
+}
+
+static __always_inline bool is_remote_ep_v6(struct __sk_buff *skb,
+					    struct in6_addr addr)
+{
+	void *data_end = ctx_ptr(skb->data_end);
+	void *data = ctx_ptr(skb->data);
+	struct ipv6hdr *ip6h;
+
+	if (data + sizeof(struct ethhdr) > data_end)
+		return false;
+
+	ip6h = (struct ipv6hdr *)(data + sizeof(struct ethhdr));
+	if ((void *)(ip6h + 1) > data_end)
+		return false;
+
+	return v6_equal(ip6h->daddr, addr);
+}
+
+SEC("chk_neigh") int tc_chk(struct __sk_buff *skb)
+{
+	void *data_end = ctx_ptr(skb->data_end);
+	void *data = ctx_ptr(skb->data);
+	__u32 *raw = data;
+
+	if (data + sizeof(struct ethhdr) > data_end)
+		return TC_ACT_SHOT;
+
+	return !raw[0] && !raw[1] && !raw[2] ? TC_ACT_SHOT : TC_ACT_OK;
+}
+
+SEC("dst_ingress") int tc_dst(struct __sk_buff *skb)
+{
+	int idx = dst_to_src_tmp;
+	__u8 zero[ETH_ALEN * 2];
+	bool redirect = false;
+
+	switch (skb->protocol) {
+	case __bpf_constant_htons(ETH_P_IP):
+		redirect = is_remote_ep_v4(skb, __bpf_constant_htonl(ip4_src));
+		break;
+	case __bpf_constant_htons(ETH_P_IPV6):
+		redirect = is_remote_ep_v6(skb, (struct in6_addr)ip6_src);
+		break;
+	}
+
+	if (!redirect)
+		return TC_ACT_OK;
+
+	barrier_data(&idx);
+	idx = bpf_ntohl(idx);
+
+	__builtin_memset(&zero, 0, sizeof(zero));
+	if (bpf_skb_store_bytes(skb, 0, &zero, sizeof(zero), 0) < 0)
+		return TC_ACT_SHOT;
+
+	return bpf_redirect_neigh(idx, 0);
+}
+
+SEC("src_ingress") int tc_src(struct __sk_buff *skb)
+{
+	int idx = src_to_dst_tmp;
+	__u8 zero[ETH_ALEN * 2];
+	bool redirect = false;
+
+	switch (skb->protocol) {
+	case __bpf_constant_htons(ETH_P_IP):
+		redirect = is_remote_ep_v4(skb, __bpf_constant_htonl(ip4_dst));
+		break;
+	case __bpf_constant_htons(ETH_P_IPV6):
+		redirect = is_remote_ep_v6(skb, (struct in6_addr)ip6_dst);
+		break;
+	}
+
+	if (!redirect)
+		return TC_ACT_OK;
+
+	barrier_data(&idx);
+	idx = bpf_ntohl(idx);
+
+	__builtin_memset(&zero, 0, sizeof(zero));
+	if (bpf_skb_store_bytes(skb, 0, &zero, sizeof(zero), 0) < 0)
+		return TC_ACT_SHOT;
+
+	return bpf_redirect_neigh(idx, 0);
+}
+
+char __license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/progs/test_trace_ext.c b/tools/testing/selftests/bpf/progs/test_trace_ext.c
new file mode 100644
index 000000000000..d19a634d0e78
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_trace_ext.c
@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2019 Facebook
+#include <linux/bpf.h>
+#include <stdbool.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+#include <bpf/bpf_tracing.h>
+
+__u64 ext_called = 0;
+
+SEC("freplace/test_pkt_md_access")
+int test_pkt_md_access_new(struct __sk_buff *skb)
+{
+	ext_called = skb->len;
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/progs/test_trace_ext_tracing.c b/tools/testing/selftests/bpf/progs/test_trace_ext_tracing.c
new file mode 100644
index 000000000000..52f3baf98f20
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_trace_ext_tracing.c
@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+__u64 fentry_called = 0;
+
+SEC("fentry/test_pkt_md_access_new")
+int BPF_PROG(fentry, struct sk_buff *skb)
+{
+	fentry_called = skb->len;
+	return 0;
+}
+
+__u64 fexit_called = 0;
+
+SEC("fexit/test_pkt_md_access_new")
+int BPF_PROG(fexit, struct sk_buff *skb)
+{
+	fexit_called = skb->len;
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/test_progs.h b/tools/testing/selftests/bpf/test_progs.h
index dbb820dde138..238f5f61189e 100644
--- a/tools/testing/selftests/bpf/test_progs.h
+++ b/tools/testing/selftests/bpf/test_progs.h
@@ -130,6 +130,69 @@ extern int test__join_cgroup(const char *path);
 #define CHECK_ATTR(condition, tag, format...) \
 	_CHECK(condition, tag, tattr.duration, format)
 
+#define ASSERT_EQ(actual, expected, name) ({				\
+	static int duration = 0;					\
+	typeof(actual) ___act = (actual);				\
+	typeof(expected) ___exp = (expected);				\
+	bool ___ok = ___act == ___exp;					\
+	CHECK(!___ok, (name),						\
+	      "unexpected %s: actual %lld != expected %lld\n",		\
+	      (name), (long long)(___act), (long long)(___exp));	\
+	___ok;								\
+})
+
+#define ASSERT_STREQ(actual, expected, name) ({				\
+	static int duration = 0;					\
+	const char *___act = actual;					\
+	const char *___exp = expected;					\
+	bool ___ok = strcmp(___act, ___exp) == 0;			\
+	CHECK(!___ok, (name),						\
+	      "unexpected %s: actual '%s' != expected '%s'\n",		\
+	      (name), ___act, ___exp);					\
+	___ok;								\
+})
+
+#define ASSERT_OK(res, name) ({						\
+	static int duration = 0;					\
+	long long ___res = (res);					\
+	bool ___ok = ___res == 0;					\
+	CHECK(!___ok, (name), "unexpected error: %lld\n", ___res);	\
+	___ok;								\
+})
+
+#define ASSERT_ERR(res, name) ({					\
+	static int duration = 0;					\
+	long long ___res = (res);					\
+	bool ___ok = ___res < 0;					\
+	CHECK(!___ok, (name), "unexpected success: %lld\n", ___res);	\
+	___ok;								\
+})
+
+#define ASSERT_NULL(ptr, name) ({					\
+	static int duration = 0;					\
+	const void *___res = (ptr);					\
+	bool ___ok = !___res;						\
+	CHECK(!___ok, (name), "unexpected pointer: %p\n", ___res);	\
+	___ok;								\
+})
+
+#define ASSERT_OK_PTR(ptr, name) ({					\
+	static int duration = 0;					\
+	const void *___res = (ptr);					\
+	bool ___ok = !IS_ERR_OR_NULL(___res);				\
+	CHECK(!___ok, (name),						\
+	      "unexpected error: %ld\n", PTR_ERR(___res));		\
+	___ok;								\
+})
+
+#define ASSERT_ERR_PTR(ptr, name) ({					\
+	static int duration = 0;					\
+	const void *___res = (ptr);					\
+	bool ___ok = IS_ERR(___res)					\
+	CHECK(!___ok, (name), "unexpected pointer: %p\n", ___res);	\
+	___ok;								\
+})
+
 static inline __u64 ptr_to_u64(const void *ptr)
 {
 	return (__u64) (unsigned long) ptr;
diff --git a/tools/testing/selftests/bpf/test_sock_fields.c b/tools/testing/selftests/bpf/test_sock_fields.c
deleted file mode 100644
index 6c9f269c396d..000000000000
--- a/tools/testing/selftests/bpf/test_sock_fields.c
+++ /dev/null
@@ -1,482 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/* Copyright (c) 2019 Facebook */
-
-#include <sys/socket.h>
-#include <sys/epoll.h>
-#include <netinet/in.h>
-#include <arpa/inet.h>
-#include <unistd.h>
-#include <stdlib.h>
-#include <string.h>
-#include <errno.h>
-
-#include <bpf/bpf.h>
-#include <bpf/libbpf.h>
-
-#include "cgroup_helpers.h"
-#include "bpf_rlimit.h"
-
-enum bpf_addr_array_idx {
-	ADDR_SRV_IDX,
-	ADDR_CLI_IDX,
-	__NR_BPF_ADDR_ARRAY_IDX,
-};
-
-enum bpf_result_array_idx {
-	EGRESS_SRV_IDX,
-	EGRESS_CLI_IDX,
-	INGRESS_LISTEN_IDX,
-	__NR_BPF_RESULT_ARRAY_IDX,
-};
-
-enum bpf_linum_array_idx {
-	EGRESS_LINUM_IDX,
-	INGRESS_LINUM_IDX,
-	__NR_BPF_LINUM_ARRAY_IDX,
-};
-
-struct bpf_spinlock_cnt {
-	struct bpf_spin_lock lock;
-	__u32 cnt;
-};
-
-#define CHECK(condition, tag, format...) ({				\
-	int __ret = !!(condition);					\
-	if (__ret) {							\
-		printf("%s(%d):FAIL:%s ", __func__, __LINE__, tag);	\
-		printf(format);						\
-		printf("\n");						\
-		exit(-1);						\
-	}								\
-})
-
-#define TEST_CGROUP "/test-bpf-sock-fields"
-#define DATA "Hello BPF!"
-#define DATA_LEN sizeof(DATA)
-
-static struct sockaddr_in6 srv_sa6, cli_sa6;
-static int sk_pkt_out_cnt10_fd;
-static int sk_pkt_out_cnt_fd;
-static int linum_map_fd;
-static int addr_map_fd;
-static int tp_map_fd;
-static int sk_map_fd;
-
-static __u32 addr_srv_idx = ADDR_SRV_IDX;
-static __u32 addr_cli_idx = ADDR_CLI_IDX;
-
-static __u32 egress_srv_idx = EGRESS_SRV_IDX;
-static __u32 egress_cli_idx = EGRESS_CLI_IDX;
-static __u32 ingress_listen_idx = INGRESS_LISTEN_IDX;
-
-static __u32 egress_linum_idx = EGRESS_LINUM_IDX;
-static __u32 ingress_linum_idx = INGRESS_LINUM_IDX;
-
-static void init_loopback6(struct sockaddr_in6 *sa6)
-{
-	memset(sa6, 0, sizeof(*sa6));
-	sa6->sin6_family = AF_INET6;
-	sa6->sin6_addr = in6addr_loopback;
-}
-
-static void print_sk(const struct bpf_sock *sk)
-{
-	char src_ip4[24], dst_ip4[24];
-	char src_ip6[64], dst_ip6[64];
-
-	inet_ntop(AF_INET, &sk->src_ip4, src_ip4, sizeof(src_ip4));
-	inet_ntop(AF_INET6, &sk->src_ip6, src_ip6, sizeof(src_ip6));
-	inet_ntop(AF_INET, &sk->dst_ip4, dst_ip4, sizeof(dst_ip4));
-	inet_ntop(AF_INET6, &sk->dst_ip6, dst_ip6, sizeof(dst_ip6));
-
-	printf("state:%u bound_dev_if:%u family:%u type:%u protocol:%u mark:%u priority:%u "
-	       "src_ip4:%x(%s) src_ip6:%x:%x:%x:%x(%s) src_port:%u "
-	       "dst_ip4:%x(%s) dst_ip6:%x:%x:%x:%x(%s) dst_port:%u\n",
-	       sk->state, sk->bound_dev_if, sk->family, sk->type, sk->protocol,
-	       sk->mark, sk->priority,
-	       sk->src_ip4, src_ip4,
-	       sk->src_ip6[0], sk->src_ip6[1], sk->src_ip6[2], sk->src_ip6[3],
-	       src_ip6, sk->src_port,
-	       sk->dst_ip4, dst_ip4,
-	       sk->dst_ip6[0], sk->dst_ip6[1], sk->dst_ip6[2], sk->dst_ip6[3],
-	       dst_ip6, ntohs(sk->dst_port));
-}
-
-static void print_tp(const struct bpf_tcp_sock *tp)
-{
-	printf("snd_cwnd:%u srtt_us:%u rtt_min:%u snd_ssthresh:%u rcv_nxt:%u "
-	       "snd_nxt:%u snd:una:%u mss_cache:%u ecn_flags:%u "
-	       "rate_delivered:%u rate_interval_us:%u packets_out:%u "
-	       "retrans_out:%u total_retrans:%u segs_in:%u data_segs_in:%u "
-	       "segs_out:%u data_segs_out:%u lost_out:%u sacked_out:%u "
-	       "bytes_received:%llu bytes_acked:%llu\n",
-	       tp->snd_cwnd, tp->srtt_us, tp->rtt_min, tp->snd_ssthresh,
-	       tp->rcv_nxt, tp->snd_nxt, tp->snd_una, tp->mss_cache,
-	       tp->ecn_flags, tp->rate_delivered, tp->rate_interval_us,
-	       tp->packets_out, tp->retrans_out, tp->total_retrans,
-	       tp->segs_in, tp->data_segs_in, tp->segs_out,
-	       tp->data_segs_out, tp->lost_out, tp->sacked_out,
-	       tp->bytes_received, tp->bytes_acked);
-}
-
-static void check_result(void)
-{
-	struct bpf_tcp_sock srv_tp, cli_tp, listen_tp;
-	struct bpf_sock srv_sk, cli_sk, listen_sk;
-	__u32 ingress_linum, egress_linum;
-	int err;
-
-	err = bpf_map_lookup_elem(linum_map_fd, &egress_linum_idx,
-				  &egress_linum);
-	CHECK(err == -1, "bpf_map_lookup_elem(linum_map_fd)",
-	      "err:%d errno:%d", err, errno);
-
-	err = bpf_map_lookup_elem(linum_map_fd, &ingress_linum_idx,
-				  &ingress_linum);
-	CHECK(err == -1, "bpf_map_lookup_elem(linum_map_fd)",
-	      "err:%d errno:%d", err, errno);
-
-	err = bpf_map_lookup_elem(sk_map_fd, &egress_srv_idx, &srv_sk);
-	CHECK(err == -1, "bpf_map_lookup_elem(sk_map_fd, &egress_srv_idx)",
-	      "err:%d errno:%d", err, errno);
-	err = bpf_map_lookup_elem(tp_map_fd, &egress_srv_idx, &srv_tp);
-	CHECK(err == -1, "bpf_map_lookup_elem(tp_map_fd, &egress_srv_idx)",
-	      "err:%d errno:%d", err, errno);
-
-	err = bpf_map_lookup_elem(sk_map_fd, &egress_cli_idx, &cli_sk);
-	CHECK(err == -1, "bpf_map_lookup_elem(sk_map_fd, &egress_cli_idx)",
-	      "err:%d errno:%d", err, errno);
-	err = bpf_map_lookup_elem(tp_map_fd, &egress_cli_idx, &cli_tp);
-	CHECK(err == -1, "bpf_map_lookup_elem(tp_map_fd, &egress_cli_idx)",
-	      "err:%d errno:%d", err, errno);
-
-	err = bpf_map_lookup_elem(sk_map_fd, &ingress_listen_idx, &listen_sk);
-	CHECK(err == -1, "bpf_map_lookup_elem(sk_map_fd, &ingress_listen_idx)",
-	      "err:%d errno:%d", err, errno);
-	err = bpf_map_lookup_elem(tp_map_fd, &ingress_listen_idx, &listen_tp);
-	CHECK(err == -1, "bpf_map_lookup_elem(tp_map_fd, &ingress_listen_idx)",
-	      "err:%d errno:%d", err, errno);
-
-	printf("listen_sk: ");
-	print_sk(&listen_sk);
-	printf("\n");
-
-	printf("srv_sk: ");
-	print_sk(&srv_sk);
-	printf("\n");
-
-	printf("cli_sk: ");
-	print_sk(&cli_sk);
-	printf("\n");
-
-	printf("listen_tp: ");
-	print_tp(&listen_tp);
-	printf("\n");
-
-	printf("srv_tp: ");
-	print_tp(&srv_tp);
-	printf("\n");
-
-	printf("cli_tp: ");
-	print_tp(&cli_tp);
-	printf("\n");
-
-	CHECK(listen_sk.state != 10 ||
-	      listen_sk.family != AF_INET6 ||
-	      listen_sk.protocol != IPPROTO_TCP ||
-	      memcmp(listen_sk.src_ip6, &in6addr_loopback,
-		     sizeof(listen_sk.src_ip6)) ||
-	      listen_sk.dst_ip6[0] || listen_sk.dst_ip6[1] ||
-	      listen_sk.dst_ip6[2] || listen_sk.dst_ip6[3] ||
-	      listen_sk.src_port != ntohs(srv_sa6.sin6_port) ||
-	      listen_sk.dst_port,
-	      "Unexpected listen_sk",
-	      "Check listen_sk output. ingress_linum:%u",
-	      ingress_linum);
-
-	CHECK(srv_sk.state == 10 ||
-	      !srv_sk.state ||
-	      srv_sk.family != AF_INET6 ||
-	      srv_sk.protocol != IPPROTO_TCP ||
-	      memcmp(srv_sk.src_ip6, &in6addr_loopback,
-		     sizeof(srv_sk.src_ip6)) ||
-	      memcmp(srv_sk.dst_ip6, &in6addr_loopback,
-		     sizeof(srv_sk.dst_ip6)) ||
-	      srv_sk.src_port != ntohs(srv_sa6.sin6_port) ||
-	      srv_sk.dst_port != cli_sa6.sin6_port,
-	      "Unexpected srv_sk", "Check srv_sk output. egress_linum:%u",
-	      egress_linum);
-
-	CHECK(cli_sk.state == 10 ||
-	      !cli_sk.state ||
-	      cli_sk.family != AF_INET6 ||
-	      cli_sk.protocol != IPPROTO_TCP ||
-	      memcmp(cli_sk.src_ip6, &in6addr_loopback,
-		     sizeof(cli_sk.src_ip6)) ||
-	      memcmp(cli_sk.dst_ip6, &in6addr_loopback,
-		     sizeof(cli_sk.dst_ip6)) ||
-	      cli_sk.src_port != ntohs(cli_sa6.sin6_port) ||
-	      cli_sk.dst_port != srv_sa6.sin6_port,
-	      "Unexpected cli_sk", "Check cli_sk output. egress_linum:%u",
-	      egress_linum);
-
-	CHECK(listen_tp.data_segs_out ||
-	      listen_tp.data_segs_in ||
-	      listen_tp.total_retrans ||
-	      listen_tp.bytes_acked,
-	      "Unexpected listen_tp", "Check listen_tp output. ingress_linum:%u",
-	      ingress_linum);
-
-	CHECK(srv_tp.data_segs_out != 2 ||
-	      srv_tp.data_segs_in ||
-	      srv_tp.snd_cwnd != 10 ||
-	      srv_tp.total_retrans ||
-	      srv_tp.bytes_acked != 2 * DATA_LEN,
-	      "Unexpected srv_tp", "Check srv_tp output. egress_linum:%u",
-	      egress_linum);
-
-	CHECK(cli_tp.data_segs_out ||
-	      cli_tp.data_segs_in != 2 ||
-	      cli_tp.snd_cwnd != 10 ||
-	      cli_tp.total_retrans ||
-	      cli_tp.bytes_received != 2 * DATA_LEN,
-	      "Unexpected cli_tp", "Check cli_tp output. egress_linum:%u",
-	      egress_linum);
-}
-
-static void check_sk_pkt_out_cnt(int accept_fd, int cli_fd)
-{
-	struct bpf_spinlock_cnt pkt_out_cnt = {}, pkt_out_cnt10 = {};
-	int err;
-
-	pkt_out_cnt.cnt = ~0;
-	pkt_out_cnt10.cnt = ~0;
-	err = bpf_map_lookup_elem(sk_pkt_out_cnt_fd, &accept_fd, &pkt_out_cnt);
-	if (!err)
-		err = bpf_map_lookup_elem(sk_pkt_out_cnt10_fd, &accept_fd,
-					  &pkt_out_cnt10);
-
-	/* The bpf prog only counts for fullsock and
-	 * passive conneciton did not become fullsock until 3WHS
-	 * had been finished.
-	 * The bpf prog only counted two data packet out but we
-	 * specially init accept_fd's pkt_out_cnt by 2 in
-	 * init_sk_storage().  Hence, 4 here.
-	 */
-	CHECK(err || pkt_out_cnt.cnt != 4 || pkt_out_cnt10.cnt != 40,
-	      "bpf_map_lookup_elem(sk_pkt_out_cnt, &accept_fd)",
-	      "err:%d errno:%d pkt_out_cnt:%u pkt_out_cnt10:%u",
-	      err, errno, pkt_out_cnt.cnt, pkt_out_cnt10.cnt);
-
-	pkt_out_cnt.cnt = ~0;
-	pkt_out_cnt10.cnt = ~0;
-	err = bpf_map_lookup_elem(sk_pkt_out_cnt_fd, &cli_fd, &pkt_out_cnt);
-	if (!err)
-		err = bpf_map_lookup_elem(sk_pkt_out_cnt10_fd, &cli_fd,
-					  &pkt_out_cnt10);
-	/* Active connection is fullsock from the beginning.
-	 * 1 SYN and 1 ACK during 3WHS
-	 * 2 Acks on data packet.
-	 *
-	 * The bpf_prog initialized it to 0xeB9F.
-	 */
-	CHECK(err || pkt_out_cnt.cnt != 0xeB9F + 4 ||
-	      pkt_out_cnt10.cnt != 0xeB9F + 40,
-	      "bpf_map_lookup_elem(sk_pkt_out_cnt, &cli_fd)",
-	      "err:%d errno:%d pkt_out_cnt:%u pkt_out_cnt10:%u",
-	      err, errno, pkt_out_cnt.cnt, pkt_out_cnt10.cnt);
-}
-
-static void init_sk_storage(int sk_fd, __u32 pkt_out_cnt)
-{
-	struct bpf_spinlock_cnt scnt = {};
-	int err;
-
-	scnt.cnt = pkt_out_cnt;
-	err = bpf_map_update_elem(sk_pkt_out_cnt_fd, &sk_fd, &scnt,
-				  BPF_NOEXIST);
-	CHECK(err, "bpf_map_update_elem(sk_pkt_out_cnt_fd)",
-	      "err:%d errno:%d", err, errno);
-
-	scnt.cnt *= 10;
-	err = bpf_map_update_elem(sk_pkt_out_cnt10_fd, &sk_fd, &scnt,
-				  BPF_NOEXIST);
-	CHECK(err, "bpf_map_update_elem(sk_pkt_out_cnt10_fd)",
-	      "err:%d errno:%d", err, errno);
-}
-
-static void test(void)
-{
-	int listen_fd, cli_fd, accept_fd, epfd, err;
-	struct epoll_event ev;
-	socklen_t addrlen;
-	int i;
-
-	addrlen = sizeof(struct sockaddr_in6);
-	ev.events = EPOLLIN;
-
-	epfd = epoll_create(1);
-	CHECK(epfd == -1, "epoll_create()", "epfd:%d errno:%d", epfd, errno);
-
-	/* Prepare listen_fd */
-	listen_fd = socket(AF_INET6, SOCK_STREAM | SOCK_NONBLOCK, 0);
-	CHECK(listen_fd == -1, "socket()", "listen_fd:%d errno:%d",
-	      listen_fd, errno);
-
-	init_loopback6(&srv_sa6);
-	err = bind(listen_fd, (struct sockaddr *)&srv_sa6, sizeof(srv_sa6));
-	CHECK(err, "bind(listen_fd)", "err:%d errno:%d", err, errno);
-
-	err = getsockname(listen_fd, (struct sockaddr *)&srv_sa6, &addrlen);
-	CHECK(err, "getsockname(listen_fd)", "err:%d errno:%d", err, errno);
-
-	err = listen(listen_fd, 1);
-	CHECK(err, "listen(listen_fd)", "err:%d errno:%d", err, errno);
-
-	/* Prepare cli_fd */
-	cli_fd = socket(AF_INET6, SOCK_STREAM | SOCK_NONBLOCK, 0);
-	CHECK(cli_fd == -1, "socket()", "cli_fd:%d errno:%d", cli_fd, errno);
-
-	init_loopback6(&cli_sa6);
-	err = bind(cli_fd, (struct sockaddr *)&cli_sa6, sizeof(cli_sa6));
-	CHECK(err, "bind(cli_fd)", "err:%d errno:%d", err, errno);
-
-	err = getsockname(cli_fd, (struct sockaddr *)&cli_sa6, &addrlen);
-	CHECK(err, "getsockname(cli_fd)", "err:%d errno:%d",
-	      err, errno);
-
-	/* Update addr_map with srv_sa6 and cli_sa6 */
-	err = bpf_map_update_elem(addr_map_fd, &addr_srv_idx, &srv_sa6, 0);
-	CHECK(err, "map_update", "err:%d errno:%d", err, errno);
-
-	err = bpf_map_update_elem(addr_map_fd, &addr_cli_idx, &cli_sa6, 0);
-	CHECK(err, "map_update", "err:%d errno:%d", err, errno);
-
-	/* Connect from cli_sa6 to srv_sa6 */
-	err = connect(cli_fd, (struct sockaddr *)&srv_sa6, addrlen);
-	printf("srv_sa6.sin6_port:%u cli_sa6.sin6_port:%u\n\n",
-	       ntohs(srv_sa6.sin6_port), ntohs(cli_sa6.sin6_port));
-	CHECK(err && errno != EINPROGRESS,
-	      "connect(cli_fd)", "err:%d errno:%d", err, errno);
-
-	ev.data.fd = listen_fd;
-	err = epoll_ctl(epfd, EPOLL_CTL_ADD, listen_fd, &ev);
-	CHECK(err, "epoll_ctl(EPOLL_CTL_ADD, listen_fd)", "err:%d errno:%d",
-	      err, errno);
-
-	/* Accept the connection */
-	/* Have some timeout in accept(listen_fd). Just in case. */
-	err = epoll_wait(epfd, &ev, 1, 1000);
-	CHECK(err != 1 || ev.data.fd != listen_fd,
-	      "epoll_wait(listen_fd)",
-	      "err:%d errno:%d ev.data.fd:%d listen_fd:%d",
-	      err, errno, ev.data.fd, listen_fd);
-
-	accept_fd = accept(listen_fd, NULL, NULL);
-	CHECK(accept_fd == -1, "accept(listen_fd)", "accept_fd:%d errno:%d",
-	      accept_fd, errno);
-	close(listen_fd);
-
-	ev.data.fd = cli_fd;
-	err = epoll_ctl(epfd, EPOLL_CTL_ADD, cli_fd, &ev);
-	CHECK(err, "epoll_ctl(EPOLL_CTL_ADD, cli_fd)", "err:%d errno:%d",
-	      err, errno);
-
-	init_sk_storage(accept_fd, 2);
-
-	for (i = 0; i < 2; i++) {
-		/* Send some data from accept_fd to cli_fd */
-		err = send(accept_fd, DATA, DATA_LEN, 0);
-		CHECK(err != DATA_LEN, "send(accept_fd)", "err:%d errno:%d",
-		      err, errno);
-
-		/* Have some timeout in recv(cli_fd). Just in case. */
-		err = epoll_wait(epfd, &ev, 1, 1000);
-		CHECK(err != 1 || ev.data.fd != cli_fd,
-		      "epoll_wait(cli_fd)", "err:%d errno:%d ev.data.fd:%d cli_fd:%d",
-		      err, errno, ev.data.fd, cli_fd);
-
-		err = recv(cli_fd, NULL, 0, MSG_TRUNC);
-		CHECK(err, "recv(cli_fd)", "err:%d errno:%d", err, errno);
-	}
-
-	check_sk_pkt_out_cnt(accept_fd, cli_fd);
-
-	close(epfd);
-	close(accept_fd);
-	close(cli_fd);
-
-	check_result();
-}
-
-int main(int argc, char **argv)
-{
-	struct bpf_prog_load_attr attr = {
-		.file = "test_sock_fields_kern.o",
-		.prog_type = BPF_PROG_TYPE_CGROUP_SKB,
-		.prog_flags = BPF_F_TEST_RND_HI32,
-	};
-	int cgroup_fd, egress_fd, ingress_fd, err;
-	struct bpf_program *ingress_prog;
-	struct bpf_object *obj;
-	struct bpf_map *map;
-
-	/* Create a cgroup, get fd, and join it */
-	cgroup_fd = cgroup_setup_and_join(TEST_CGROUP);
-	CHECK(cgroup_fd < 0, "cgroup_setup_and_join()",
-	      "cgroup_fd:%d errno:%d", cgroup_fd, errno);
-	atexit(cleanup_cgroup_environment);
-
-	err = bpf_prog_load_xattr(&attr, &obj, &egress_fd);
-	CHECK(err, "bpf_prog_load_xattr()", "err:%d", err);
-
-	ingress_prog = bpf_object__find_program_by_title(obj,
-							 "cgroup_skb/ingress");
-	CHECK(!ingress_prog,
-	      "bpf_object__find_program_by_title(cgroup_skb/ingress)",
-	      "not found");
-	ingress_fd = bpf_program__fd(ingress_prog);
-
-	err = bpf_prog_attach(egress_fd, cgroup_fd, BPF_CGROUP_INET_EGRESS, 0);
-	CHECK(err == -1, "bpf_prog_attach(CPF_CGROUP_INET_EGRESS)",
-	      "err:%d errno%d", err, errno);
-
-	err = bpf_prog_attach(ingress_fd, cgroup_fd,
-			      BPF_CGROUP_INET_INGRESS, 0);
-	CHECK(err == -1, "bpf_prog_attach(CPF_CGROUP_INET_INGRESS)",
-	      "err:%d errno%d", err, errno);
-	close(cgroup_fd);
-
-	map = bpf_object__find_map_by_name(obj, "addr_map");
-	CHECK(!map, "cannot find addr_map", "(null)");
-	addr_map_fd = bpf_map__fd(map);
-
-	map = bpf_object__find_map_by_name(obj, "sock_result_map");
-	CHECK(!map, "cannot find sock_result_map", "(null)");
-	sk_map_fd = bpf_map__fd(map);
-
-	map = bpf_object__find_map_by_name(obj, "tcp_sock_result_map");
-	CHECK(!map, "cannot find tcp_sock_result_map", "(null)");
-	tp_map_fd = bpf_map__fd(map);
-
-	map = bpf_object__find_map_by_name(obj, "linum_map");
-	CHECK(!map, "cannot find linum_map", "(null)");
-	linum_map_fd = bpf_map__fd(map);
-
-	map = bpf_object__find_map_by_name(obj, "sk_pkt_out_cnt");
-	CHECK(!map, "cannot find sk_pkt_out_cnt", "(null)");
-	sk_pkt_out_cnt_fd = bpf_map__fd(map);
-
-	map = bpf_object__find_map_by_name(obj, "sk_pkt_out_cnt10");
-	CHECK(!map, "cannot find sk_pkt_out_cnt10", "(null)");
-	sk_pkt_out_cnt10_fd = bpf_map__fd(map);
-
-	test();
-
-	bpf_object__close(obj);
-	cleanup_cgroup_environment();
-
-	printf("PASS\n");
-
-	return 0;
-}
diff --git a/tools/testing/selftests/bpf/test_tc_neigh.sh b/tools/testing/selftests/bpf/test_tc_neigh.sh
new file mode 100755
index 000000000000..31d8c3df8b24
--- /dev/null
+++ b/tools/testing/selftests/bpf/test_tc_neigh.sh
@@ -0,0 +1,168 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# This test sets up 3 netns (src <-> fwd <-> dst). There is no direct veth link
+# between src and dst. The netns fwd has veth links to each src and dst. The
+# client is in src and server in dst. The test installs a TC BPF program to each
+# host facing veth in fwd which calls into bpf_redirect_peer() to perform the
+# neigh addr population and redirect; it also installs a dropper prog on the
+# egress side to drop skbs if neigh addrs were not populated.
+
+if [[ $EUID -ne 0 ]]; then
+	echo "This script must be run as root"
+	echo "FAIL"
+	exit 1
+fi
+
+# check that nc, dd, ping, ping6 and timeout are present
+command -v nc >/dev/null 2>&1 || \
+	{ echo >&2 "nc is not available"; exit 1; }
+command -v dd >/dev/null 2>&1 || \
+	{ echo >&2 "dd is not available"; exit 1; }
+command -v timeout >/dev/null 2>&1 || \
+	{ echo >&2 "timeout is not available"; exit 1; }
+command -v ping >/dev/null 2>&1 || \
+	{ echo >&2 "ping is not available"; exit 1; }
+command -v ping6 >/dev/null 2>&1 || \
+	{ echo >&2 "ping6 is not available"; exit 1; }
+
+readonly GREEN='\033[0;92m'
+readonly RED='\033[0;31m'
+readonly NC='\033[0m' # No Color
+
+readonly PING_ARG="-c 3 -w 10 -q"
+
+readonly TIMEOUT=10
+
+readonly NS_SRC="ns-src-$(mktemp -u XXXXXX)"
+readonly NS_FWD="ns-fwd-$(mktemp -u XXXXXX)"
+readonly NS_DST="ns-dst-$(mktemp -u XXXXXX)"
+
+readonly IP4_SRC="172.16.1.100"
+readonly IP4_DST="172.16.2.100"
+
+readonly IP6_SRC="::1:dead:beef:cafe"
+readonly IP6_DST="::2:dead:beef:cafe"
+
+readonly IP4_SLL="169.254.0.1"
+readonly IP4_DLL="169.254.0.2"
+readonly IP4_NET="169.254.0.0"
+
+cleanup()
+{
+	ip netns del ${NS_SRC}
+	ip netns del ${NS_FWD}
+	ip netns del ${NS_DST}
+}
+
+trap cleanup EXIT
+
+set -e
+
+ip netns add "${NS_SRC}"
+ip netns add "${NS_FWD}"
+ip netns add "${NS_DST}"
+
+ip link add veth_src type veth peer name veth_src_fwd
+ip link add veth_dst type veth peer name veth_dst_fwd
+
+ip link set veth_src netns ${NS_SRC}
+ip link set veth_src_fwd netns ${NS_FWD}
+
+ip link set veth_dst netns ${NS_DST}
+ip link set veth_dst_fwd netns ${NS_FWD}
+
+ip -netns ${NS_SRC} addr add ${IP4_SRC}/32 dev veth_src
+ip -netns ${NS_DST} addr add ${IP4_DST}/32 dev veth_dst
+
+# The fwd netns automatically get a v6 LL address / routes, but also needs v4
+# one in order to start ARP probing. IP4_NET route is added to the endpoints
+# so that the ARP processing will reply.
+
+ip -netns ${NS_FWD} addr add ${IP4_SLL}/32 dev veth_src_fwd
+ip -netns ${NS_FWD} addr add ${IP4_DLL}/32 dev veth_dst_fwd
+
+ip -netns ${NS_SRC} addr add ${IP6_SRC}/128 dev veth_src nodad
+ip -netns ${NS_DST} addr add ${IP6_DST}/128 dev veth_dst nodad
+
+ip -netns ${NS_SRC} link set dev veth_src up
+ip -netns ${NS_FWD} link set dev veth_src_fwd up
+
+ip -netns ${NS_DST} link set dev veth_dst up
+ip -netns ${NS_FWD} link set dev veth_dst_fwd up
+
+ip -netns ${NS_SRC} route add ${IP4_DST}/32 dev veth_src scope global
+ip -netns ${NS_SRC} route add ${IP4_NET}/16 dev veth_src scope global
+ip -netns ${NS_FWD} route add ${IP4_SRC}/32 dev veth_src_fwd scope global
+
+ip -netns ${NS_SRC} route add ${IP6_DST}/128 dev veth_src scope global
+ip -netns ${NS_FWD} route add ${IP6_SRC}/128 dev veth_src_fwd scope global
+
+ip -netns ${NS_DST} route add ${IP4_SRC}/32 dev veth_dst scope global
+ip -netns ${NS_DST} route add ${IP4_NET}/16 dev veth_dst scope global
+ip -netns ${NS_FWD} route add ${IP4_DST}/32 dev veth_dst_fwd scope global
+
+ip -netns ${NS_DST} route add ${IP6_SRC}/128 dev veth_dst scope global
+ip -netns ${NS_FWD} route add ${IP6_DST}/128 dev veth_dst_fwd scope global
+
+fmac_src=$(ip netns exec ${NS_FWD} cat /sys/class/net/veth_src_fwd/address)
+fmac_dst=$(ip netns exec ${NS_FWD} cat /sys/class/net/veth_dst_fwd/address)
+
+ip -netns ${NS_SRC} neigh add ${IP4_DST} dev veth_src lladdr $fmac_src
+ip -netns ${NS_DST} neigh add ${IP4_SRC} dev veth_dst lladdr $fmac_dst
+
+ip -netns ${NS_SRC} neigh add ${IP6_DST} dev veth_src lladdr $fmac_src
+ip -netns ${NS_DST} neigh add ${IP6_SRC} dev veth_dst lladdr $fmac_dst
+
+veth_dst=$(ip netns exec ${NS_FWD} cat /sys/class/net/veth_dst_fwd/ifindex | awk '{printf "%08x\n", $1}')
+veth_src=$(ip netns exec ${NS_FWD} cat /sys/class/net/veth_src_fwd/ifindex | awk '{printf "%08x\n", $1}')
+
+xxd -p < test_tc_neigh.o   | sed "s/eeddddee/$veth_src/g" | xxd -r -p > test_tc_neigh.x.o
+xxd -p < test_tc_neigh.x.o | sed "s/eeffffee/$veth_dst/g" | xxd -r -p > test_tc_neigh.y.o
+
+ip netns exec ${NS_FWD} tc qdisc add dev veth_src_fwd clsact
+ip netns exec ${NS_FWD} tc filter add dev veth_src_fwd ingress bpf da obj test_tc_neigh.y.o sec src_ingress
+ip netns exec ${NS_FWD} tc filter add dev veth_src_fwd egress  bpf da obj test_tc_neigh.y.o sec chk_neigh
+
+ip netns exec ${NS_FWD} tc qdisc add dev veth_dst_fwd clsact
+ip netns exec ${NS_FWD} tc filter add dev veth_dst_fwd ingress bpf da obj test_tc_neigh.y.o sec dst_ingress
+ip netns exec ${NS_FWD} tc filter add dev veth_dst_fwd egress  bpf da obj test_tc_neigh.y.o sec chk_neigh
+
+rm -f test_tc_neigh.x.o test_tc_neigh.y.o
+
+ip netns exec ${NS_DST} bash -c "nc -4 -l -p 9004 &"
+ip netns exec ${NS_DST} bash -c "nc -6 -l -p 9006 &"
+
+set +e
+
+TEST="TCPv4 connectivity test"
+ip netns exec ${NS_SRC} bash -c "timeout ${TIMEOUT} dd if=/dev/zero bs=1000 count=100 > /dev/tcp/${IP4_DST}/9004"
+if [ $? -ne 0 ]; then
+	echo -e "${TEST}: ${RED}FAIL${NC}"
+	exit 1
+fi
+echo -e "${TEST}: ${GREEN}PASS${NC}"
+
+TEST="TCPv6 connectivity test"
+ip netns exec ${NS_SRC} bash -c "timeout ${TIMEOUT} dd if=/dev/zero bs=1000 count=100 > /dev/tcp/${IP6_DST}/9006"
+if [ $? -ne 0 ]; then
+	echo -e "${TEST}: ${RED}FAIL${NC}"
+	exit 1
+fi
+echo -e "${TEST}: ${GREEN}PASS${NC}"
+
+TEST="ICMPv4 connectivity test"
+ip netns exec ${NS_SRC} ping  $PING_ARG ${IP4_DST}
+if [ $? -ne 0 ]; then
+	echo -e "${TEST}: ${RED}FAIL${NC}"
+	exit 1
+fi
+echo -e "${TEST}: ${GREEN}PASS${NC}"
+
+TEST="ICMPv6 connectivity test"
+ip netns exec ${NS_SRC} ping6 $PING_ARG ${IP6_DST}
+if [ $? -ne 0 ]; then
+	echo -e "${TEST}: ${RED}FAIL${NC}"
+	exit 1
+fi
+echo -e "${TEST}: ${GREEN}PASS${NC}"
diff --git a/tools/testing/selftests/bpf/verifier/and.c b/tools/testing/selftests/bpf/verifier/and.c
index d781bc86e100..ca8fdb1b3f01 100644
--- a/tools/testing/selftests/bpf/verifier/and.c
+++ b/tools/testing/selftests/bpf/verifier/and.c
@@ -48,3 +48,19 @@
 	.result = REJECT,
 	.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
 },
+{
+	"check known subreg with unknown reg",
+	.insns = {
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_get_prandom_u32),
+	BPF_ALU64_IMM(BPF_LSH, BPF_REG_0, 32),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 1),
+	BPF_ALU64_IMM(BPF_AND, BPF_REG_0, 0xFFFF1234),
+	/* Upper bits are unknown but AND above masks out 1 zero'ing lower bits */
+	BPF_JMP32_IMM(BPF_JLT, BPF_REG_0, 1, 1),
+	BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_1, 512),
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+	.retval = 0
+},
diff --git a/tools/testing/selftests/bpf/verifier/ref_tracking.c b/tools/testing/selftests/bpf/verifier/ref_tracking.c
index 056e0273bf12..006b5bd99c08 100644
--- a/tools/testing/selftests/bpf/verifier/ref_tracking.c
+++ b/tools/testing/selftests/bpf/verifier/ref_tracking.c
@@ -854,3 +854,50 @@
 	.errstr = "Unreleased reference",
 	.result = REJECT,
 },
+{
+	"reference tracking: bpf_sk_release(btf_tcp_sock)",
+	.insns = {
+	BPF_SK_LOOKUP(sk_lookup_tcp),
+	BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+	BPF_EXIT_INSN(),
+	BPF_MOV64_REG(BPF_REG_6, BPF_REG_0),
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+	BPF_EMIT_CALL(BPF_FUNC_skc_to_tcp_sock),
+	BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 3),
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
+	BPF_EMIT_CALL(BPF_FUNC_sk_release),
+	BPF_EXIT_INSN(),
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+	BPF_EMIT_CALL(BPF_FUNC_sk_release),
+	BPF_EXIT_INSN(),
+	},
+	.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+	.result = ACCEPT,
+	.result_unpriv = REJECT,
+	.errstr_unpriv = "unknown func",
+},
+{
+	"reference tracking: use ptr from bpf_skc_to_tcp_sock() after release",
+	.insns = {
+	BPF_SK_LOOKUP(sk_lookup_tcp),
+	BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+	BPF_EXIT_INSN(),
+	BPF_MOV64_REG(BPF_REG_6, BPF_REG_0),
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+	BPF_EMIT_CALL(BPF_FUNC_skc_to_tcp_sock),
+	BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 3),
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
+	BPF_EMIT_CALL(BPF_FUNC_sk_release),
+	BPF_EXIT_INSN(),
+	BPF_MOV64_REG(BPF_REG_7, BPF_REG_0),
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
+	BPF_EMIT_CALL(BPF_FUNC_sk_release),
+	BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_7, 0),
+	BPF_EXIT_INSN(),
+	},
+	.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+	.result = REJECT,
+	.errstr = "invalid mem access",
+	.result_unpriv = REJECT,
+	.errstr_unpriv = "unknown func",
+},