From cdbee3839cd91a4577425c43cf064b9523926159 Mon Sep 17 00:00:00 2001 From: Andrey Ignatov Date: Wed, 18 Dec 2019 23:44:36 -0800 Subject: libbpf: Introduce bpf_prog_attach_xattr Introduce a new bpf_prog_attach_xattr function that, in addition to program fd, target fd and attach type, accepts an extendable struct bpf_prog_attach_opts. bpf_prog_attach_opts relies on DECLARE_LIBBPF_OPTS macro to maintain backward and forward compatibility and has the following "optional" attach attributes: * existing attach_flags, since it's not required when attaching in NONE mode. Even though it's quite often used in MULTI and OVERRIDE mode it seems to be a good idea to reduce number of arguments to bpf_prog_attach_xattr; * newly introduced attribute of BPF_PROG_ATTACH command: replace_prog_fd that is fd of previously attached cgroup-bpf program to replace if BPF_F_REPLACE flag is used. The new function is named to be consistent with other xattr-functions (bpf_prog_test_run_xattr, bpf_create_map_xattr, bpf_load_program_xattr). The struct bpf_prog_attach_opts is supposed to be used with DECLARE_LIBBPF_OPTS macro. Signed-off-by: Andrey Ignatov Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/bd6e0732303eb14e4b79cb128268d9e9ad6db208.1576741281.git.rdna@fb.com --- tools/lib/bpf/bpf.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) (limited to 'tools/lib/bpf/bpf.c') diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 98596e15390f..a787d53699c8 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -466,14 +466,29 @@ int bpf_obj_get(const char *pathname) int bpf_prog_attach(int prog_fd, int target_fd, enum bpf_attach_type type, unsigned int flags) +{ + DECLARE_LIBBPF_OPTS(bpf_prog_attach_opts, opts, + .flags = flags, + ); + + return bpf_prog_attach_xattr(prog_fd, target_fd, type, &opts); +} + +int bpf_prog_attach_xattr(int prog_fd, int target_fd, + enum bpf_attach_type type, + const struct bpf_prog_attach_opts *opts) { union bpf_attr attr; + if (!OPTS_VALID(opts, bpf_prog_attach_opts)) + return -EINVAL; + memset(&attr, 0, sizeof(attr)); attr.target_fd = target_fd; attr.attach_bpf_fd = prog_fd; attr.attach_type = type; - attr.attach_flags = flags; + attr.attach_flags = OPTS_GET(opts, flags, 0); + attr.replace_bpf_fd = OPTS_GET(opts, replace_prog_fd, 0); return sys_bpf(BPF_PROG_ATTACH, &attr, sizeof(attr)); } -- cgit From 590a0088825016ca7ec53f1aef7e84e1211778d8 Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Wed, 8 Jan 2020 16:35:14 -0800 Subject: bpf: libbpf: Add STRUCT_OPS support This patch adds BPF STRUCT_OPS support to libbpf. The only sec_name convention is SEC(".struct_ops") to identify the struct_ops implemented in BPF, e.g. To implement a tcp_congestion_ops: SEC(".struct_ops") struct tcp_congestion_ops dctcp = { .init = (void *)dctcp_init, /* <-- a bpf_prog */ /* ... some more func prts ... */ .name = "bpf_dctcp", }; Each struct_ops is defined as a global variable under SEC(".struct_ops") as above. libbpf creates a map for each variable and the variable name is the map's name. Multiple struct_ops is supported under SEC(".struct_ops"). In the bpf_object__open phase, libbpf will look for the SEC(".struct_ops") section and find out what is the btf-type the struct_ops is implementing. Note that the btf-type here is referring to a type in the bpf_prog.o's btf. A "struct bpf_map" is added by bpf_object__add_map() as other maps do. It will then collect (through SHT_REL) where are the bpf progs that the func ptrs are referring to. No btf_vmlinux is needed in the open phase. In the bpf_object__load phase, the map-fields, which depend on the btf_vmlinux, are initialized (in bpf_map__init_kern_struct_ops()). It will also set the prog->type, prog->attach_btf_id, and prog->expected_attach_type. Thus, the prog's properties do not rely on its section name. [ Currently, the bpf_prog's btf-type ==> btf_vmlinux's btf-type matching process is as simple as: member-name match + btf-kind match + size match. If these matching conditions fail, libbpf will reject. The current targeting support is "struct tcp_congestion_ops" which most of its members are function pointers. The member ordering of the bpf_prog's btf-type can be different from the btf_vmlinux's btf-type. ] Then, all obj->maps are created as usual (in bpf_object__create_maps()). Once the maps are created and prog's properties are all set, the libbpf will proceed to load all the progs. bpf_map__attach_struct_ops() is added to register a struct_ops map to a kernel subsystem. Signed-off-by: Martin KaFai Lau Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200109003514.3856730-1-kafai@fb.com --- tools/lib/bpf/bpf.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'tools/lib/bpf/bpf.c') diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index a787d53699c8..b0ecbe9ef2d4 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -95,7 +95,11 @@ int bpf_create_map_xattr(const struct bpf_create_map_attr *create_attr) attr.btf_key_type_id = create_attr->btf_key_type_id; attr.btf_value_type_id = create_attr->btf_value_type_id; attr.map_ifindex = create_attr->map_ifindex; - attr.inner_map_fd = create_attr->inner_map_fd; + if (attr.map_type == BPF_MAP_TYPE_STRUCT_OPS) + attr.btf_vmlinux_value_type_id = + create_attr->btf_vmlinux_value_type_id; + else + attr.inner_map_fd = create_attr->inner_map_fd; return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr)); } @@ -228,7 +232,9 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, memset(&attr, 0, sizeof(attr)); attr.prog_type = load_attr->prog_type; attr.expected_attach_type = load_attr->expected_attach_type; - if (attr.prog_type == BPF_PROG_TYPE_TRACING) { + if (attr.prog_type == BPF_PROG_TYPE_STRUCT_OPS) { + attr.attach_btf_id = load_attr->attach_btf_id; + } else if (attr.prog_type == BPF_PROG_TYPE_TRACING) { attr.attach_btf_id = load_attr->attach_btf_id; attr.attach_prog_fd = load_attr->attach_prog_fd; } else { -- cgit From 1d1a3bcffe360a56fd8cc287ed74d4c3066daf42 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Fri, 10 Jan 2020 10:19:16 -0800 Subject: libbpf: Poison kernel-only integer types It's been a recurring issue with types like u32 slipping into libbpf source code accidentally. This is not detected during builds inside kernel source tree, but becomes a compilation error in libbpf's Github repo. Libbpf is supposed to use only __{s,u}{8,16,32,64} typedefs, so poison {s,u}{8,16,32,64} explicitly in every .c file. Doing that in a bit more centralized way, e.g., inside libbpf_internal.h breaks selftests, which are both using kernel u32 and libbpf_internal.h. This patch also fixes a new u32 occurence in libbpf.c, added recently. Fixes: 590a00888250 ("bpf: libbpf: Add STRUCT_OPS support") Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/bpf/20200110181916.271446-1-andriin@fb.com --- tools/lib/bpf/bpf.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'tools/lib/bpf/bpf.c') diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index b0ecbe9ef2d4..500afe478e94 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -32,6 +32,9 @@ #include "libbpf.h" #include "libbpf_internal.h" +/* make sure libbpf doesn't use kernel-only integer typedefs */ +#pragma GCC poison u8 u16 u32 u64 s8 s16 s32 s64 + /* * When building perf, unistd.h is overridden. __NR_bpf is * required to be defined explicitly. -- cgit From 2ab3d86ea1859d1a4b830ce3551cba725620593a Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Wed, 15 Jan 2020 10:43:06 -0800 Subject: libbpf: Add libbpf support to batch ops Added four libbpf API functions to support map batch operations: . int bpf_map_delete_batch( ... ) . int bpf_map_lookup_batch( ... ) . int bpf_map_lookup_and_delete_batch( ... ) . int bpf_map_update_batch( ... ) Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200115184308.162644-8-brianvv@google.com --- tools/lib/bpf/bpf.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 58 insertions(+) (limited to 'tools/lib/bpf/bpf.c') diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 500afe478e94..317727d61214 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -452,6 +452,64 @@ int bpf_map_freeze(int fd) return sys_bpf(BPF_MAP_FREEZE, &attr, sizeof(attr)); } +static int bpf_map_batch_common(int cmd, int fd, void *in_batch, + void *out_batch, void *keys, void *values, + __u32 *count, + const struct bpf_map_batch_opts *opts) +{ + union bpf_attr attr = {}; + int ret; + + if (!OPTS_VALID(opts, bpf_map_batch_opts)) + return -EINVAL; + + memset(&attr, 0, sizeof(attr)); + attr.batch.map_fd = fd; + attr.batch.in_batch = ptr_to_u64(in_batch); + attr.batch.out_batch = ptr_to_u64(out_batch); + attr.batch.keys = ptr_to_u64(keys); + attr.batch.values = ptr_to_u64(values); + attr.batch.count = *count; + attr.batch.elem_flags = OPTS_GET(opts, elem_flags, 0); + attr.batch.flags = OPTS_GET(opts, flags, 0); + + ret = sys_bpf(cmd, &attr, sizeof(attr)); + *count = attr.batch.count; + + return ret; +} + +int bpf_map_delete_batch(int fd, void *keys, __u32 *count, + const struct bpf_map_batch_opts *opts) +{ + return bpf_map_batch_common(BPF_MAP_DELETE_BATCH, fd, NULL, + NULL, keys, NULL, count, opts); +} + +int bpf_map_lookup_batch(int fd, void *in_batch, void *out_batch, void *keys, + void *values, __u32 *count, + const struct bpf_map_batch_opts *opts) +{ + return bpf_map_batch_common(BPF_MAP_LOOKUP_BATCH, fd, in_batch, + out_batch, keys, values, count, opts); +} + +int bpf_map_lookup_and_delete_batch(int fd, void *in_batch, void *out_batch, + void *keys, void *values, __u32 *count, + const struct bpf_map_batch_opts *opts) +{ + return bpf_map_batch_common(BPF_MAP_LOOKUP_AND_DELETE_BATCH, + fd, in_batch, out_batch, keys, values, + count, opts); +} + +int bpf_map_update_batch(int fd, void *keys, void *values, __u32 *count, + const struct bpf_map_batch_opts *opts) +{ + return bpf_map_batch_common(BPF_MAP_UPDATE_BATCH, fd, NULL, NULL, + keys, values, count, opts); +} + int bpf_obj_pin(int fd, const char *pathname) { union bpf_attr attr; -- cgit From 858e284f0ec18bff2620d9a6afe764dc683f8ba1 Mon Sep 17 00:00:00 2001 From: Brian Vazquez Date: Wed, 15 Jan 2020 20:59:18 -0800 Subject: libbpf: Fix unneeded extra initialization in bpf_map_batch_common bpf_attr doesn't required to be declared with '= {}' as memset is used in the code. Fixes: 2ab3d86ea1859 ("libbpf: Add libbpf support to batch ops") Reported-by: Andrii Nakryiko Signed-off-by: Brian Vazquez Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20200116045918.75597-1-brianvv@google.com --- tools/lib/bpf/bpf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'tools/lib/bpf/bpf.c') diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 317727d61214..ed42b006533c 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -457,7 +457,7 @@ static int bpf_map_batch_common(int cmd, int fd, void *in_batch, __u32 *count, const struct bpf_map_batch_opts *opts) { - union bpf_attr attr = {}; + union bpf_attr attr; int ret; if (!OPTS_VALID(opts, bpf_map_batch_opts)) -- cgit From 2db6eab18b9778d55f48c804f8efebd7097e7958 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Mon, 20 Jan 2020 16:53:47 -0800 Subject: libbpf: Add support for program extensions MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add minimal support for program extensions. bpf_object_open_opts() needs to be called with attach_prog_fd = target_prog_fd and BPF program extension needs to have in .c file section definition like SEC("freplace/func_to_be_replaced"). libbpf will search for "func_to_be_replaced" in the target_prog_fd's BTF and will pass it in attach_btf_id to the kernel. This approach works for tests, but more compex use case may need to request function name (and attach_btf_id that kernel sees) to be more dynamic. Such API will be added in future patches. Signed-off-by: Alexei Starovoitov Signed-off-by: Daniel Borkmann Acked-by: John Fastabend Acked-by: Andrii Nakryiko Acked-by: Toke Høiland-Jørgensen Link: https://lore.kernel.org/bpf/20200121005348.2769920-3-ast@kernel.org --- tools/lib/bpf/bpf.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'tools/lib/bpf/bpf.c') diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index ed42b006533c..c6dafe563176 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -237,7 +237,8 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, attr.expected_attach_type = load_attr->expected_attach_type; if (attr.prog_type == BPF_PROG_TYPE_STRUCT_OPS) { attr.attach_btf_id = load_attr->attach_btf_id; - } else if (attr.prog_type == BPF_PROG_TYPE_TRACING) { + } else if (attr.prog_type == BPF_PROG_TYPE_TRACING || + attr.prog_type == BPF_PROG_TYPE_EXT) { attr.attach_btf_id = load_attr->attach_btf_id; attr.attach_prog_fd = load_attr->attach_prog_fd; } else { -- cgit