From acf860ae7c53cc8b0c5d372c218332aac3eeba4f Mon Sep 17 00:00:00 2001 From: Wang Nan Date: Thu, 27 Aug 2015 02:30:55 +0000 Subject: [PATCH] bpf tools: New API to get name from a BPF object Before this patch there's no way to connect a loaded bpf object to its source file. However, during applying perf's '--filter' to BPF object, without this connection makes things harder, because perf loads all programs together, but '--filter' setting is for each object. The API of bpf_object__open_buffer() is changed to allow passing a name. Fortunately, at this time there's only one user of it (perf test LLVM), so we change it together. Signed-off-by: Wang Nan Cc: Alexei Starovoitov Cc: Brendan Gregg Cc: Daniel Borkmann Cc: David Ahern Cc: He Kuang Cc: Jiri Olsa Cc: Kaixu Xia Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1440742821-44548-2-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/lib/bpf/libbpf.c | 25 ++++++++++++++++++++++--- tools/lib/bpf/libbpf.h | 4 +++- tools/perf/tests/llvm.c | 2 +- 3 files changed, 26 insertions(+), 5 deletions(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 4fa4bc4505f5..4252fc22f78f 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -880,15 +880,26 @@ struct bpf_object *bpf_object__open(const char *path) } struct bpf_object *bpf_object__open_buffer(void *obj_buf, - size_t obj_buf_sz) + size_t obj_buf_sz, + const char *name) { + char tmp_name[64]; + /* param validation */ if (!obj_buf || obj_buf_sz <= 0) return NULL; - pr_debug("loading object from buffer\n"); + if (!name) { + snprintf(tmp_name, sizeof(tmp_name), "%lx-%lx", + (unsigned long)obj_buf, + (unsigned long)obj_buf_sz); + tmp_name[sizeof(tmp_name) - 1] = '\0'; + name = tmp_name; + } + pr_debug("loading object '%s' from buffer\n", + name); - return __bpf_object__open("[buffer]", obj_buf, obj_buf_sz); + return __bpf_object__open(name, obj_buf, obj_buf_sz); } int bpf_object__unload(struct bpf_object *obj) @@ -975,6 +986,14 @@ bpf_object__next(struct bpf_object *prev) return next; } +const char * +bpf_object__get_name(struct bpf_object *obj) +{ + if (!obj) + return NULL; + return obj->path; +} + struct bpf_program * bpf_program__next(struct bpf_program *prev, struct bpf_object *obj) { diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index ea8adc206b62..f16170c95ffd 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -28,12 +28,14 @@ struct bpf_object; struct bpf_object *bpf_object__open(const char *path); struct bpf_object *bpf_object__open_buffer(void *obj_buf, - size_t obj_buf_sz); + size_t obj_buf_sz, + const char *name); void bpf_object__close(struct bpf_object *object); /* Load/unload object into/from kernel */ int bpf_object__load(struct bpf_object *obj); int bpf_object__unload(struct bpf_object *obj); +const char *bpf_object__get_name(struct bpf_object *obj); struct bpf_object *bpf_object__next(struct bpf_object *prev); #define bpf_object__for_each_safe(pos, tmp) \ diff --git a/tools/perf/tests/llvm.c b/tools/perf/tests/llvm.c index a337356fd979..52d55971f66f 100644 --- a/tools/perf/tests/llvm.c +++ b/tools/perf/tests/llvm.c @@ -26,7 +26,7 @@ static int test__bpf_parsing(void *obj_buf, size_t obj_buf_sz) { struct bpf_object *obj; - obj = bpf_object__open_buffer(obj_buf, obj_buf_sz); + obj = bpf_object__open_buffer(obj_buf, obj_buf_sz, NULL); if (!obj) return -1; bpf_object__close(obj); -- 2.20.1