diff options
author | Alexei Starovoitov <ast@kernel.org> | 2020-02-20 17:48:40 -0800 |
---|---|---|
committer | Alexei Starovoitov <ast@kernel.org> | 2020-02-20 17:51:40 -0800 |
commit | 2c3a368127e1b56b32e147971ab804176ff4c9f3 (patch) | |
tree | e4deb87a21fd976b52af9400335b73168437a9b9 /tools/lib/bpf | |
parent | 5327644614a18f5d0ff845844a4e9976210b3d8d (diff) | |
parent | 933ce62d68dee5465cb5f5b359ab0638c9f665b1 (diff) |
Merge branch 'set_attach_target'
Eelco Chaudron says:
====================
Currently when you want to attach a trace program to a bpf program
the section name needs to match the tracepoint/function semantics.
However the addition of the bpf_program__set_attach_target() API
allows you to specify the tracepoint/function dynamically.
The call flow would look something like this:
xdp_fd = bpf_prog_get_fd_by_id(id);
trace_obj = bpf_object__open_file("func.o", NULL);
prog = bpf_object__find_program_by_title(trace_obj,
"fentry/myfunc");
bpf_program__set_expected_attach_type(prog, BPF_TRACE_FENTRY);
bpf_program__set_attach_target(prog, xdp_fd,
"xdpfilt_blk_all");
bpf_object__load(trace_obj)
v1 -> v2: Remove requirement for attach type hint in API
v2 -> v3: Moved common warning to __find_vmlinux_btf_id, requested by Andrii
Updated the xdp_bpf2bpf test to use this new API
v3 -> v4: Split up patch, update libbpf.map version
v4 -> v5: Fix return code, and prog assignment in test case
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools/lib/bpf')
-rw-r--r-- | tools/lib/bpf/libbpf.c | 34 | ||||
-rw-r--r-- | tools/lib/bpf/libbpf.h | 4 | ||||
-rw-r--r-- | tools/lib/bpf/libbpf.map | 5 |
3 files changed, 39 insertions, 4 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 0eb10b6..8f0c436 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -4937,8 +4937,8 @@ int bpf_program__load(struct bpf_program *prog, char *license, __u32 kern_ver) { int err = 0, fd, i, btf_id; - if (prog->type == BPF_PROG_TYPE_TRACING || - prog->type == BPF_PROG_TYPE_EXT) { + if ((prog->type == BPF_PROG_TYPE_TRACING || + prog->type == BPF_PROG_TYPE_EXT) && !prog->attach_btf_id) { btf_id = libbpf_find_attach_btf_id(prog); if (btf_id <= 0) return btf_id; @@ -6581,6 +6581,9 @@ static inline int __find_vmlinux_btf_id(struct btf *btf, const char *name, else err = btf__find_by_name_kind(btf, name, BTF_KIND_FUNC); + if (err <= 0) + pr_warn("%s is not found in vmlinux BTF\n", name); + return err; } @@ -6653,8 +6656,6 @@ static int libbpf_find_attach_btf_id(struct bpf_program *prog) err = __find_vmlinux_btf_id(prog->obj->btf_vmlinux, name + section_defs[i].len, attach_type); - if (err <= 0) - pr_warn("%s is not found in vmlinux BTF\n", name); return err; } pr_warn("failed to identify btf_id based on ELF section name '%s'\n", name); @@ -8130,6 +8131,31 @@ void bpf_program__bpil_offs_to_addr(struct bpf_prog_info_linear *info_linear) } } +int bpf_program__set_attach_target(struct bpf_program *prog, + int attach_prog_fd, + const char *attach_func_name) +{ + int btf_id; + + if (!prog || attach_prog_fd < 0 || !attach_func_name) + return -EINVAL; + + if (attach_prog_fd) + btf_id = libbpf_find_prog_btf_id(attach_func_name, + attach_prog_fd); + else + btf_id = __find_vmlinux_btf_id(prog->obj->btf_vmlinux, + attach_func_name, + prog->expected_attach_type); + + if (btf_id < 0) + return btf_id; + + prog->attach_btf_id = btf_id; + prog->attach_prog_fd = attach_prog_fd; + return 0; +} + int parse_cpu_mask_str(const char *s, bool **mask, int *mask_sz) { int err = 0, n, len, start, end = -1; diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 3fe12c9..02fc58a 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -334,6 +334,10 @@ LIBBPF_API void bpf_program__set_expected_attach_type(struct bpf_program *prog, enum bpf_attach_type type); +LIBBPF_API int +bpf_program__set_attach_target(struct bpf_program *prog, int attach_prog_fd, + const char *attach_func_name); + LIBBPF_API bool bpf_program__is_socket_filter(const struct bpf_program *prog); LIBBPF_API bool bpf_program__is_tracepoint(const struct bpf_program *prog); LIBBPF_API bool bpf_program__is_raw_tracepoint(const struct bpf_program *prog); diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index b035122..7b014c8 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -235,3 +235,8 @@ LIBBPF_0.0.7 { btf__align_of; libbpf_find_kernel_btf; } LIBBPF_0.0.6; + +LIBBPF_0.0.8 { + global: + bpf_program__set_attach_target; +} LIBBPF_0.0.7; |