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

Pull networking updates from David Miller:
 "Another merge window, another pull full of stuff:

   1) Support alternative names for network devices, from Jiri Pirko.

   2) Introduce per-netns netdev notifiers, also from Jiri Pirko.

   3) Support MSG_PEEK in vsock/virtio, from Matias Ezequiel Vara
      Larsen.

   4) Allow compiling out the TLS TOE code, from Jakub Kicinski.

   5) Add several new tracepoints to the kTLS code, also from Jakub.

   6) Support set channels ethtool callback in ena driver, from Sameeh
      Jubran.

   7) New SCTP events SCTP_ADDR_ADDED, SCTP_ADDR_REMOVED,
      SCTP_ADDR_MADE_PRIM, and SCTP_SEND_FAILED_EVENT. From Xin Long.

   8) Add XDP support to mvneta driver, from Lorenzo Bianconi.

   9) Lots of netfilter hw offload fixes, cleanups and enhancements,
      from Pablo Neira Ayuso.

  10) PTP support for aquantia chips, from Egor Pomozov.

  11) Add UDP segmentation offload support to igb, ixgbe, and i40e. From
      Josh Hunt.

  12) Add smart nagle to tipc, from Jon Maloy.

  13) Support L2 field rewrite by TC offloads in bnxt_en, from Venkat
      Duvvuru.

  14) Add a flow mask cache to OVS, from Tonghao Zhang.

  15) Add XDP support to ice driver, from Maciej Fijalkowski.

  16) Add AF_XDP support to ice driver, from Krzysztof Kazimierczak.

  17) Support UDP GSO offload in atlantic driver, from Igor Russkikh.

  18) Support it in stmmac driver too, from Jose Abreu.

  19) Support TIPC encryption and auth, from Tuong Lien.

  20) Introduce BPF trampolines, from Alexei Starovoitov.

  21) Make page_pool API more numa friendly, from Saeed Mahameed.

  22) Introduce route hints to ipv4 and ipv6, from Paolo Abeni.

  23) Add UDP segmentation offload to cxgb4, Rahul Lakkireddy"

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1857 commits)
  libbpf: Fix usage of u32 in userspace code
  mm: Implement no-MMU variant of vmalloc_user_node_flags
  slip: Fix use-after-free Read in slip_open
  net: dsa: sja1105: fix sja1105_parse_rgmii_delays()
  macvlan: schedule bc_work even if error
  enetc: add support Credit Based Shaper(CBS) for hardware offload
  net: phy: add helpers phy_(un)lock_mdio_bus
  mdio_bus: don't use managed reset-controller
  ax88179_178a: add ethtool_op_get_ts_info()
  mlxsw: spectrum_router: Fix use of uninitialized adjacency index
  mlxsw: spectrum_router: After underlay moves, demote conflicting tunnels
  bpf: Simplify __bpf_arch_text_poke poke type handling
  bpf: Introduce BPF_TRACE_x helper for the tracing tests
  bpf: Add bpf_jit_blinding_enabled for !CONFIG_BPF_JIT
  bpf, testing: Add various tail call test cases
  bpf, x86: Emit patchable direct jump as tail call
  bpf: Constant map key tracking for prog array pokes
  bpf: Add poke dependency tracking for prog array maps
  bpf: Add initial poke descriptor table for jit images
  bpf: Move owner type, jited info into array auxiliary data
  ...

1 files changed, 775 insertions, 21 deletions

diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 29c7c06c6bd6..40efde5eedcb 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -2,6 +2,8 @@
 /* Copyright (c) 2018 Facebook */
 
 #include <uapi/linux/btf.h>
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/bpf_perf_event.h>
 #include <uapi/linux/types.h>
 #include <linux/seq_file.h>
 #include <linux/compiler.h>
@@ -16,6 +18,9 @@
 #include <linux/sort.h>
 #include <linux/bpf_verifier.h>
 #include <linux/btf.h>
+#include <linux/skmsg.h>
+#include <linux/perf_event.h>
+#include <net/sock.h>
 
 /* BTF (BPF Type Format) is the meta data format which describes
  * the data types of BPF program/map.  Hence, it basically focus
@@ -336,16 +341,6 @@ static bool btf_type_is_fwd(const struct btf_type *t)
 	return BTF_INFO_KIND(t->info) == BTF_KIND_FWD;
 }
 
-static bool btf_type_is_func(const struct btf_type *t)
-{
-	return BTF_INFO_KIND(t->info) == BTF_KIND_FUNC;
-}
-
-static bool btf_type_is_func_proto(const struct btf_type *t)
-{
-	return BTF_INFO_KIND(t->info) == BTF_KIND_FUNC_PROTO;
-}
-
 static bool btf_type_nosize(const struct btf_type *t)
 {
 	return btf_type_is_void(t) || btf_type_is_fwd(t) ||
@@ -377,16 +372,6 @@ static bool btf_type_is_array(const struct btf_type *t)
 	return BTF_INFO_KIND(t->info) == BTF_KIND_ARRAY;
 }
 
-static bool btf_type_is_ptr(const struct btf_type *t)
-{
-	return BTF_INFO_KIND(t->info) == BTF_KIND_PTR;
-}
-
-static bool btf_type_is_int(const struct btf_type *t)
-{
-	return BTF_INFO_KIND(t->info) == BTF_KIND_INT;
-}
-
 static bool btf_type_is_var(const struct btf_type *t)
 {
 	return BTF_INFO_KIND(t->info) == BTF_KIND_VAR;
@@ -698,6 +683,13 @@ __printf(4, 5) static void __btf_verifier_log_type(struct btf_verifier_env *env,
 	if (!bpf_verifier_log_needed(log))
 		return;
 
+	/* btf verifier prints all types it is processing via
+	 * btf_verifier_log_type(..., fmt = NULL).
+	 * Skip those prints for in-kernel BTF verification.
+	 */
+	if (log->level == BPF_LOG_KERNEL && !fmt)
+		return;
+
 	__btf_verifier_log(log, "[%u] %s %s%s",
 			   env->log_type_id,
 			   btf_kind_str[kind],
@@ -735,6 +727,8 @@ static void btf_verifier_log_member(struct btf_verifier_env *env,
 	if (!bpf_verifier_log_needed(log))
 		return;
 
+	if (log->level == BPF_LOG_KERNEL && !fmt)
+		return;
 	/* The CHECK_META phase already did a btf dump.
 	 *
 	 * If member is logged again, it must hit an error in
@@ -777,6 +771,8 @@ static void btf_verifier_log_vsi(struct btf_verifier_env *env,
 
 	if (!bpf_verifier_log_needed(log))
 		return;
+	if (log->level == BPF_LOG_KERNEL && !fmt)
+		return;
 	if (env->phase != CHECK_META)
 		btf_verifier_log_type(env, datasec_type, NULL);
 
@@ -802,6 +798,8 @@ static void btf_verifier_log_hdr(struct btf_verifier_env *env,
 	if (!bpf_verifier_log_needed(log))
 		return;
 
+	if (log->level == BPF_LOG_KERNEL)
+		return;
 	hdr = &btf->hdr;
 	__btf_verifier_log(log, "magic: 0x%x\n", hdr->magic);
 	__btf_verifier_log(log, "version: %u\n", hdr->version);
@@ -1043,6 +1041,82 @@ static const struct resolve_vertex *env_stack_peak(struct btf_verifier_env *env)
 	return env->top_stack ? &env->stack[env->top_stack - 1] : NULL;
 }
 
+/* Resolve the size of a passed-in "type"
+ *
+ * type: is an array (e.g. u32 array[x][y])
+ * return type: type "u32[x][y]", i.e. BTF_KIND_ARRAY,
+ * *type_size: (x * y * sizeof(u32)).  Hence, *type_size always
+ *             corresponds to the return type.
+ * *elem_type: u32
+ * *total_nelems: (x * y).  Hence, individual elem size is
+ *                (*type_size / *total_nelems)
+ *
+ * type: is not an array (e.g. const struct X)
+ * return type: type "struct X"
+ * *type_size: sizeof(struct X)
+ * *elem_type: same as return type ("struct X")
+ * *total_nelems: 1
+ */
+static const struct btf_type *
+btf_resolve_size(const struct btf *btf, const struct btf_type *type,
+		 u32 *type_size, const struct btf_type **elem_type,
+		 u32 *total_nelems)
+{
+	const struct btf_type *array_type = NULL;
+	const struct btf_array *array;
+	u32 i, size, nelems = 1;
+
+	for (i = 0; i < MAX_RESOLVE_DEPTH; i++) {
+		switch (BTF_INFO_KIND(type->info)) {
+		/* type->size can be used */
+		case BTF_KIND_INT:
+		case BTF_KIND_STRUCT:
+		case BTF_KIND_UNION:
+		case BTF_KIND_ENUM:
+			size = type->size;
+			goto resolved;
+
+		case BTF_KIND_PTR:
+			size = sizeof(void *);
+			goto resolved;
+
+		/* Modifiers */
+		case BTF_KIND_TYPEDEF:
+		case BTF_KIND_VOLATILE:
+		case BTF_KIND_CONST:
+		case BTF_KIND_RESTRICT:
+			type = btf_type_by_id(btf, type->type);
+			break;
+
+		case BTF_KIND_ARRAY:
+			if (!array_type)
+				array_type = type;
+			array = btf_type_array(type);
+			if (nelems && array->nelems > U32_MAX / nelems)
+				return ERR_PTR(-EINVAL);
+			nelems *= array->nelems;
+			type = btf_type_by_id(btf, array->type);
+			break;
+
+		/* type without size */
+		default:
+			return ERR_PTR(-EINVAL);
+		}
+	}
+
+	return ERR_PTR(-EINVAL);
+
+resolved:
+	if (nelems && size > U32_MAX / nelems)
+		return ERR_PTR(-EINVAL);
+
+	*type_size = nelems * size;
+	*total_nelems = nelems;
+	*elem_type = type;
+
+	return array_type ? : type;
+}
+
 /* The input param "type_id" must point to a needs_resolve type */
 static const struct btf_type *btf_type_id_resolve(const struct btf *btf,
 						  u32 *type_id)
@@ -2405,7 +2479,8 @@ static s32 btf_enum_check_meta(struct btf_verifier_env *env,
 			return -EINVAL;
 		}
 
-
+		if (env->log.level == BPF_LOG_KERNEL)
+			continue;
 		btf_verifier_log(env, "\t%s val=%d\n",
 				 __btf_name_by_offset(btf, enums[i].name_off),
 				 enums[i].val);
@@ -3367,6 +3442,685 @@ errout:
 	return ERR_PTR(err);
 }
 
+extern char __weak _binary__btf_vmlinux_bin_start[];
+extern char __weak _binary__btf_vmlinux_bin_end[];
+extern struct btf *btf_vmlinux;
+
+#define BPF_MAP_TYPE(_id, _ops)
+static union {
+	struct bpf_ctx_convert {
+#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
+	prog_ctx_type _id##_prog; \
+	kern_ctx_type _id##_kern;
+#include <linux/bpf_types.h>
+#undef BPF_PROG_TYPE
+	} *__t;
+	/* 't' is written once under lock. Read many times. */
+	const struct btf_type *t;
+} bpf_ctx_convert;
+enum {
+#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
+	__ctx_convert##_id,
+#include <linux/bpf_types.h>
+#undef BPF_PROG_TYPE
+};
+static u8 bpf_ctx_convert_map[] = {
+#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
+	[_id] = __ctx_convert##_id,
+#include <linux/bpf_types.h>
+#undef BPF_PROG_TYPE
+};
+#undef BPF_MAP_TYPE
+
+static const struct btf_member *
+btf_get_prog_ctx_type(struct bpf_verifier_log *log, struct btf *btf,
+		      const struct btf_type *t, enum bpf_prog_type prog_type)
+{
+	const struct btf_type *conv_struct;
+	const struct btf_type *ctx_struct;
+	const struct btf_member *ctx_type;
+	const char *tname, *ctx_tname;
+
+	conv_struct = bpf_ctx_convert.t;
+	if (!conv_struct) {
+		bpf_log(log, "btf_vmlinux is malformed\n");
+		return NULL;
+	}
+	t = btf_type_by_id(btf, t->type);
+	while (btf_type_is_modifier(t))
+		t = btf_type_by_id(btf, t->type);
+	if (!btf_type_is_struct(t)) {
+		/* Only pointer to struct is supported for now.
+		 * That means that BPF_PROG_TYPE_TRACEPOINT with BTF
+		 * is not supported yet.
+		 * BPF_PROG_TYPE_RAW_TRACEPOINT is fine.
+		 */
+		bpf_log(log, "BPF program ctx type is not a struct\n");
+		return NULL;
+	}
+	tname = btf_name_by_offset(btf, t->name_off);
+	if (!tname) {
+		bpf_log(log, "BPF program ctx struct doesn't have a name\n");
+		return NULL;
+	}
+	/* prog_type is valid bpf program type. No need for bounds check. */
+	ctx_type = btf_type_member(conv_struct) + bpf_ctx_convert_map[prog_type] * 2;
+	/* ctx_struct is a pointer to prog_ctx_type in vmlinux.
+	 * Like 'struct __sk_buff'
+	 */
+	ctx_struct = btf_type_by_id(btf_vmlinux, ctx_type->type);
+	if (!ctx_struct)
+		/* should not happen */
+		return NULL;
+	ctx_tname = btf_name_by_offset(btf_vmlinux, ctx_struct->name_off);
+	if (!ctx_tname) {
+		/* should not happen */
+		bpf_log(log, "Please fix kernel include/linux/bpf_types.h\n");
+		return NULL;
+	}
+	/* only compare that prog's ctx type name is the same as
+	 * kernel expects. No need to compare field by field.
+	 * It's ok for bpf prog to do:
+	 * struct __sk_buff {};
+	 * int socket_filter_bpf_prog(struct __sk_buff *skb)
+	 * { // no fields of skb are ever used }
+	 */
+	if (strcmp(ctx_tname, tname))
+		return NULL;
+	return ctx_type;
+}
+
+static int btf_translate_to_vmlinux(struct bpf_verifier_log *log,
+				     struct btf *btf,
+				     const struct btf_type *t,
+				     enum bpf_prog_type prog_type)
+{
+	const struct btf_member *prog_ctx_type, *kern_ctx_type;
+
+	prog_ctx_type = btf_get_prog_ctx_type(log, btf, t, prog_type);
+	if (!prog_ctx_type)
+		return -ENOENT;
+	kern_ctx_type = prog_ctx_type + 1;
+	return kern_ctx_type->type;
+}
+
+struct btf *btf_parse_vmlinux(void)
+{
+	struct btf_verifier_env *env = NULL;
+	struct bpf_verifier_log *log;
+	struct btf *btf = NULL;
+	int err, i;
+
+	env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN);
+	if (!env)
+		return ERR_PTR(-ENOMEM);
+
+	log = &env->log;
+	log->level = BPF_LOG_KERNEL;
+
+	btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN);
+	if (!btf) {
+		err = -ENOMEM;
+		goto errout;
+	}
+	env->btf = btf;
+
+	btf->data = _binary__btf_vmlinux_bin_start;
+	btf->data_size = _binary__btf_vmlinux_bin_end -
+		_binary__btf_vmlinux_bin_start;
+
+	err = btf_parse_hdr(env);
+	if (err)
+		goto errout;
+
+	btf->nohdr_data = btf->data + btf->hdr.hdr_len;
+
+	err = btf_parse_str_sec(env);
+	if (err)
+		goto errout;
+
+	err = btf_check_all_metas(env);
+	if (err)
+		goto errout;
+
+	/* find struct bpf_ctx_convert for type checking later */
+	for (i = 1; i <= btf->nr_types; i++) {
+		const struct btf_type *t;
+		const char *tname;
+
+		t = btf_type_by_id(btf, i);
+		if (!__btf_type_is_struct(t))
+			continue;
+		tname = __btf_name_by_offset(btf, t->name_off);
+		if (!strcmp(tname, "bpf_ctx_convert")) {
+			/* btf_parse_vmlinux() runs under bpf_verifier_lock */
+			bpf_ctx_convert.t = t;
+			break;
+		}
+	}
+	if (i > btf->nr_types) {
+		err = -ENOENT;
+		goto errout;
+	}
+
+	btf_verifier_env_free(env);
+	refcount_set(&btf->refcnt, 1);
+	return btf;
+
+errout:
+	btf_verifier_env_free(env);
+	if (btf) {
+		kvfree(btf->types);
+		kfree(btf);
+	}
+	return ERR_PTR(err);
+}
+
+struct btf *bpf_prog_get_target_btf(const struct bpf_prog *prog)
+{
+	struct bpf_prog *tgt_prog = prog->aux->linked_prog;
+
+	if (tgt_prog) {
+		return tgt_prog->aux->btf;
+	} else {
+		return btf_vmlinux;
+	}
+}
+
+bool btf_ctx_access(int off, int size, enum bpf_access_type type,
+		    const struct bpf_prog *prog,
+		    struct bpf_insn_access_aux *info)
+{
+	const struct btf_type *t = prog->aux->attach_func_proto;
+	struct bpf_prog *tgt_prog = prog->aux->linked_prog;
+	struct btf *btf = bpf_prog_get_target_btf(prog);
+	const char *tname = prog->aux->attach_func_name;
+	struct bpf_verifier_log *log = info->log;
+	const struct btf_param *args;
+	u32 nr_args, arg;
+	int ret;
+
+	if (off % 8) {
+		bpf_log(log, "func '%s' offset %d is not multiple of 8\n",
+			tname, off);
+		return false;
+	}
+	arg = off / 8;
+	args = (const struct btf_param *)(t + 1);
+	/* if (t == NULL) Fall back to default BPF prog with 5 u64 arguments */
+	nr_args = t ? btf_type_vlen(t) : 5;
+	if (prog->aux->attach_btf_trace) {
+		/* skip first 'void *__data' argument in btf_trace_##name typedef */
+		args++;
+		nr_args--;
+	}
+
+	if (prog->expected_attach_type == BPF_TRACE_FEXIT &&
+	    arg == nr_args) {
+		if (!t)
+			/* Default prog with 5 args. 6th arg is retval. */
+			return true;
+		/* function return type */
+		t = btf_type_by_id(btf, t->type);
+	} else if (arg >= nr_args) {
+		bpf_log(log, "func '%s' doesn't have %d-th argument\n",
+			tname, arg + 1);
+		return false;
+	} else {
+		if (!t)
+			/* Default prog with 5 args */
+			return true;
+		t = btf_type_by_id(btf, args[arg].type);
+	}
+	/* skip modifiers */
+	while (btf_type_is_modifier(t))
+		t = btf_type_by_id(btf, t->type);
+	if (btf_type_is_int(t))
+		/* accessing a scalar */
+		return true;
+	if (!btf_type_is_ptr(t)) {
+		bpf_log(log,
+			"func '%s' arg%d '%s' has type %s. Only pointer access is allowed\n",
+			tname, arg,
+			__btf_name_by_offset(btf, t->name_off),
+			btf_kind_str[BTF_INFO_KIND(t->info)]);
+		return false;
+	}
+	if (t->type == 0)
+		/* This is a pointer to void.
+		 * It is the same as scalar from the verifier safety pov.
+		 * No further pointer walking is allowed.
+		 */
+		return true;
+
+	/* this is a pointer to another type */
+	info->reg_type = PTR_TO_BTF_ID;
+	info->btf_id = t->type;
+
+	if (tgt_prog) {
+		ret = btf_translate_to_vmlinux(log, btf, t, tgt_prog->type);
+		if (ret > 0) {
+			info->btf_id = ret;
+			return true;
+		} else {
+			return false;
+		}
+	}
+	t = btf_type_by_id(btf, t->type);
+	/* skip modifiers */
+	while (btf_type_is_modifier(t))
+		t = btf_type_by_id(btf, t->type);
+	if (!btf_type_is_struct(t)) {
+		bpf_log(log,
+			"func '%s' arg%d type %s is not a struct\n",
+			tname, arg, btf_kind_str[BTF_INFO_KIND(t->info)]);
+		return false;
+	}
+	bpf_log(log, "func '%s' arg%d has btf_id %d type %s '%s'\n",
+		tname, arg, info->btf_id, btf_kind_str[BTF_INFO_KIND(t->info)],
+		__btf_name_by_offset(btf, t->name_off));
+	return true;
+}
+
+int btf_struct_access(struct bpf_verifier_log *log,
+		      const struct btf_type *t, int off, int size,
+		      enum bpf_access_type atype,
+		      u32 *next_btf_id)
+{
+	u32 i, moff, mtrue_end, msize = 0, total_nelems = 0;
+	const struct btf_type *mtype, *elem_type = NULL;
+	const struct btf_member *member;
+	const char *tname, *mname;
+
+again:
+	tname = __btf_name_by_offset(btf_vmlinux, t->name_off);
+	if (!btf_type_is_struct(t)) {
+		bpf_log(log, "Type '%s' is not a struct", tname);
+		return -EINVAL;
+	}
+
+	for_each_member(i, t, member) {
+		if (btf_member_bitfield_size(t, member))
+			/* bitfields are not supported yet */
+			continue;
+
+		/* offset of the field in bytes */
+		moff = btf_member_bit_offset(t, member) / 8;
+		if (off + size <= moff)
+			/* won't find anything, field is already too far */
+			break;
+		/* In case of "off" is pointing to holes of a struct */
+		if (off < moff)
+			continue;
+
+		/* type of the field */
+		mtype = btf_type_by_id(btf_vmlinux, member->type);
+		mname = __btf_name_by_offset(btf_vmlinux, member->name_off);
+
+		mtype = btf_resolve_size(btf_vmlinux, mtype, &msize,
+					 &elem_type, &total_nelems);
+		if (IS_ERR(mtype)) {
+			bpf_log(log, "field %s doesn't have size\n", mname);
+			return -EFAULT;
+		}
+
+		mtrue_end = moff + msize;
+		if (off >= mtrue_end)
+			/* no overlap with member, keep iterating */
+			continue;
+
+		if (btf_type_is_array(mtype)) {
+			u32 elem_idx;
+
+			/* btf_resolve_size() above helps to
+			 * linearize a multi-dimensional array.
+			 *
+			 * The logic here is treating an array
+			 * in a struct as the following way:
+			 *
+			 * struct outer {
+			 *	struct inner array[2][2];
+			 * };
+			 *
+			 * looks like:
+			 *
+			 * struct outer {
+			 *	struct inner array_elem0;
+			 *	struct inner array_elem1;
+			 *	struct inner array_elem2;
+			 *	struct inner array_elem3;
+			 * };
+			 *
+			 * When accessing outer->array[1][0], it moves
+			 * moff to "array_elem2", set mtype to
+			 * "struct inner", and msize also becomes
+			 * sizeof(struct inner).  Then most of the
+			 * remaining logic will fall through without
+			 * caring the current member is an array or
+			 * not.
+			 *
+			 * Unlike mtype/msize/moff, mtrue_end does not
+			 * change.  The naming difference ("_true") tells
+			 * that it is not always corresponding to
+			 * the current mtype/msize/moff.
+			 * It is the true end of the current
+			 * member (i.e. array in this case).  That
+			 * will allow an int array to be accessed like
+			 * a scratch space,
+			 * i.e. allow access beyond the size of
+			 *      the array's element as long as it is
+			 *      within the mtrue_end boundary.
+			 */
+
+			/* skip empty array */
+			if (moff == mtrue_end)
+				continue;
+
+			msize /= total_nelems;
+			elem_idx = (off - moff) / msize;
+			moff += elem_idx * msize;
+			mtype = elem_type;
+		}
+
+		/* the 'off' we're looking for is either equal to start
+		 * of this field or inside of this struct
+		 */
+		if (btf_type_is_struct(mtype)) {
+			/* our field must be inside that union or struct */
+			t = mtype;
+
+			/* adjust offset we're looking for */
+			off -= moff;
+			goto again;
+		}
+
+		if (btf_type_is_ptr(mtype)) {
+			const struct btf_type *stype;
+
+			if (msize != size || off != moff) {
+				bpf_log(log,
+					"cannot access ptr member %s with moff %u in struct %s with off %u size %u\n",
+					mname, moff, tname, off, size);
+				return -EACCES;
+			}
+
+			stype = btf_type_by_id(btf_vmlinux, mtype->type);
+			/* skip modifiers */
+			while (btf_type_is_modifier(stype))
+				stype = btf_type_by_id(btf_vmlinux, stype->type);
+			if (btf_type_is_struct(stype)) {
+				*next_btf_id = mtype->type;
+				return PTR_TO_BTF_ID;
+			}
+		}
+
+		/* Allow more flexible access within an int as long as
+		 * it is within mtrue_end.
+		 * Since mtrue_end could be the end of an array,
+		 * that also allows using an array of int as a scratch
+		 * space. e.g. skb->cb[].
+		 */
+		if (off + size > mtrue_end) {
+			bpf_log(log,
+				"access beyond the end of member %s (mend:%u) in struct %s with off %u size %u\n",
+				mname, mtrue_end, tname, off, size);
+			return -EACCES;
+		}
+
+		return SCALAR_VALUE;
+	}
+	bpf_log(log, "struct %s doesn't have field at offset %d\n", tname, off);
+	return -EINVAL;
+}
+
+static int __btf_resolve_helper_id(struct bpf_verifier_log *log, void *fn,
+				   int arg)
+{
+	char fnname[KSYM_SYMBOL_LEN + 4] = "btf_";
+	const struct btf_param *args;
+	const struct btf_type *t;
+	const char *tname, *sym;
+	u32 btf_id, i;
+
+	if (IS_ERR(btf_vmlinux)) {
+		bpf_log(log, "btf_vmlinux is malformed\n");
+		return -EINVAL;
+	}
+
+	sym = kallsyms_lookup((long)fn, NULL, NULL, NULL, fnname + 4);
+	if (!sym) {
+		bpf_log(log, "kernel doesn't have kallsyms\n");
+		return -EFAULT;
+	}
+
+	for (i = 1; i <= btf_vmlinux->nr_types; i++) {
+		t = btf_type_by_id(btf_vmlinux, i);
+		if (BTF_INFO_KIND(t->info) != BTF_KIND_TYPEDEF)
+			continue;
+		tname = __btf_name_by_offset(btf_vmlinux, t->name_off);
+		if (!strcmp(tname, fnname))
+			break;
+	}
+	if (i > btf_vmlinux->nr_types) {
+		bpf_log(log, "helper %s type is not found\n", fnname);
+		return -ENOENT;
+	}
+
+	t = btf_type_by_id(btf_vmlinux, t->type);
+	if (!btf_type_is_ptr(t))
+		return -EFAULT;
+	t = btf_type_by_id(btf_vmlinux, t->type);
+	if (!btf_type_is_func_proto(t))
+		return -EFAULT;
+
+	args = (const struct btf_param *)(t + 1);
+	if (arg >= btf_type_vlen(t)) {
+		bpf_log(log, "bpf helper %s doesn't have %d-th argument\n",
+			fnname, arg);
+		return -EINVAL;
+	}
+
+	t = btf_type_by_id(btf_vmlinux, args[arg].type);
+	if (!btf_type_is_ptr(t) || !t->type) {
+		/* anything but the pointer to struct is a helper config bug */
+		bpf_log(log, "ARG_PTR_TO_BTF is misconfigured\n");
+		return -EFAULT;
+	}
+	btf_id = t->type;
+	t = btf_type_by_id(btf_vmlinux, t->type);
+	/* skip modifiers */
+	while (btf_type_is_modifier(t)) {
+		btf_id = t->type;
+		t = btf_type_by_id(btf_vmlinux, t->type);
+	}
+	if (!btf_type_is_struct(t)) {
+		bpf_log(log, "ARG_PTR_TO_BTF is not a struct\n");
+		return -EFAULT;
+	}
+	bpf_log(log, "helper %s arg%d has btf_id %d struct %s\n", fnname + 4,
+		arg, btf_id, __btf_name_by_offset(btf_vmlinux, t->name_off));
+	return btf_id;
+}
+
+int btf_resolve_helper_id(struct bpf_verifier_log *log,
+			  const struct bpf_func_proto *fn, int arg)
+{
+	int *btf_id = &fn->btf_id[arg];
+	int ret;
+
+	if (fn->arg_type[arg] != ARG_PTR_TO_BTF_ID)
+		return -EINVAL;
+
+	ret = READ_ONCE(*btf_id);
+	if (ret)
+		return ret;
+	/* ok to race the search. The result is the same */
+	ret = __btf_resolve_helper_id(log, fn->func, arg);
+	if (!ret) {
+		/* Function argument cannot be type 'void' */
+		bpf_log(log, "BTF resolution bug\n");
+		return -EFAULT;
+	}
+	WRITE_ONCE(*btf_id, ret);
+	return ret;
+}
+
+static int __get_type_size(struct btf *btf, u32 btf_id,
+			   const struct btf_type **bad_type)
+{
+	const struct btf_type *t;
+
+	if (!btf_id)
+		/* void */
+		return 0;
+	t = btf_type_by_id(btf, btf_id);
+	while (t && btf_type_is_modifier(t))
+		t = btf_type_by_id(btf, t->type);
+	if (!t)
+		return -EINVAL;
+	if (btf_type_is_ptr(t))
+		/* kernel size of pointer. Not BPF's size of pointer*/
+		return sizeof(void *);
+	if (btf_type_is_int(t) || btf_type_is_enum(t))
+		return t->size;
+	*bad_type = t;
+	return -EINVAL;
+}
+
+int btf_distill_func_proto(struct bpf_verifier_log *log,
+			   struct btf *btf,
+			   const struct btf_type *func,
+			   const char *tname,
+			   struct btf_func_model *m)
+{
+	const struct btf_param *args;
+	const struct btf_type *t;
+	u32 i, nargs;
+	int ret;
+
+	if (!func) {
+		/* BTF function prototype doesn't match the verifier types.
+		 * Fall back to 5 u64 args.
+		 */
+		for (i = 0; i < 5; i++)
+			m->arg_size[i] = 8;
+		m->ret_size = 8;
+		m->nr_args = 5;
+		return 0;
+	}
+	args = (const struct btf_param *)(func + 1);
+	nargs = btf_type_vlen(func);
+	if (nargs >= MAX_BPF_FUNC_ARGS) {
+		bpf_log(log,
+			"The function %s has %d arguments. Too many.\n",
+			tname, nargs);
+		return -EINVAL;
+	}
+	ret = __get_type_size(btf, func->type, &t);
+	if (ret < 0) {
+		bpf_log(log,
+			"The function %s return type %s is unsupported.\n",
+			tname, btf_kind_str[BTF_INFO_KIND(t->info)]);
+		return -EINVAL;
+	}
+	m->ret_size = ret;
+
+	for (i = 0; i < nargs; i++) {
+		ret = __get_type_size(btf, args[i].type, &t);
+		if (ret < 0) {
+			bpf_log(log,
+				"The function %s arg%d type %s is unsupported.\n",
+				tname, i, btf_kind_str[BTF_INFO_KIND(t->info)]);
+			return -EINVAL;
+		}
+		m->arg_size[i] = ret;
+	}
+	m->nr_args = nargs;
+	return 0;
+}
+
+int btf_check_func_arg_match(struct bpf_verifier_env *env, int subprog)
+{
+	struct bpf_verifier_state *st = env->cur_state;
+	struct bpf_func_state *func = st->frame[st->curframe];
+	struct bpf_reg_state *reg = func->regs;
+	struct bpf_verifier_log *log = &env->log;
+	struct bpf_prog *prog = env->prog;
+	struct btf *btf = prog->aux->btf;
+	const struct btf_param *args;
+	const struct btf_type *t;
+	u32 i, nargs, btf_id;
+	const char *tname;
+
+	if (!prog->aux->func_info)
+		return 0;
+
+	btf_id = prog->aux->func_info[subprog].type_id;
+	if (!btf_id)
+		return 0;
+
+	if (prog->aux->func_info_aux[subprog].unreliable)
+		return 0;
+
+	t = btf_type_by_id(btf, btf_id);
+	if (!t || !btf_type_is_func(t)) {
+		bpf_log(log, "BTF of subprog %d doesn't point to KIND_FUNC\n",
+			subprog);
+		return -EINVAL;
+	}
+	tname = btf_name_by_offset(btf, t->name_off);
+
+	t = btf_type_by_id(btf, t->type);
+	if (!t || !btf_type_is_func_proto(t)) {
+		bpf_log(log, "Invalid type of func %s\n", tname);
+		return -EINVAL;
+	}
+	args = (const struct btf_param *)(t + 1);
+	nargs = btf_type_vlen(t);
+	if (nargs > 5) {
+		bpf_log(log, "Function %s has %d > 5 args\n", tname, nargs);
+		goto out;
+	}
+	/* check that BTF function arguments match actual types that the
+	 * verifier sees.
+	 */
+	for (i = 0; i < nargs; i++) {
+		t = btf_type_by_id(btf, args[i].type);
+		while (btf_type_is_modifier(t))
+			t = btf_type_by_id(btf, t->type);
+		if (btf_type_is_int(t) || btf_type_is_enum(t)) {
+			if (reg[i + 1].type == SCALAR_VALUE)
+				continue;
+			bpf_log(log, "R%d is not a scalar\n", i + 1);
+			goto out;
+		}
+		if (btf_type_is_ptr(t)) {
+			if (reg[i + 1].type == SCALAR_VALUE) {
+				bpf_log(log, "R%d is not a pointer\n", i + 1);
+				goto out;
+			}
+			/* If program is passing PTR_TO_CTX into subprogram
+			 * check that BTF type matches.
+			 */
+			if (reg[i + 1].type == PTR_TO_CTX &&
+			    !btf_get_prog_ctx_type(log, btf, t, prog->type))
+				goto out;
+			/* All other pointers are ok */
+			continue;
+		}
+		bpf_log(log, "Unrecognized argument type %s\n",
+			btf_kind_str[BTF_INFO_KIND(t->info)]);
+		goto out;
+	}
+	return 0;
+out:
+	/* LLVM optimizations can remove arguments from static functions. */
+	bpf_log(log,
+		"Type info disagrees with actual arguments due to compiler optimizations\n");
+	prog->aux->func_info_aux[subprog].unreliable = true;
+	return 0;
+}
+
 void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj,
 		       struct seq_file *m)
 {