From 296036653ae8b1367ec9d06d65377c2e2371b153 Mon Sep 17 00:00:00 2001 From: Wang Nan Date: Wed, 1 Jul 2015 02:13:56 +0000 Subject: [PATCH] bpf tools: Iterate over ELF sections to collect information bpf_obj_elf_collect() is introduced to iterate over each elf sections to collection information in eBPF object files. This function will futher enhanced to collect license, kernel version, programs, configs and map information. Signed-off-by: Wang Nan Acked-by: 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/1435716878-189507-9-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/lib/bpf/libbpf.c | 53 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 15b3e82..d8d6eb5 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -220,6 +220,57 @@ mismatch: return -EINVAL; } +static int bpf_object__elf_collect(struct bpf_object *obj) +{ + Elf *elf = obj->efile.elf; + GElf_Ehdr *ep = &obj->efile.ehdr; + Elf_Scn *scn = NULL; + int idx = 0, err = 0; + + /* Elf is corrupted/truncated, avoid calling elf_strptr. */ + if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL)) { + pr_warning("failed to get e_shstrndx from %s\n", + obj->path); + return -EINVAL; + } + + while ((scn = elf_nextscn(elf, scn)) != NULL) { + char *name; + GElf_Shdr sh; + Elf_Data *data; + + idx++; + if (gelf_getshdr(scn, &sh) != &sh) { + pr_warning("failed to get section header from %s\n", + obj->path); + err = -EINVAL; + goto out; + } + + name = elf_strptr(elf, ep->e_shstrndx, sh.sh_name); + if (!name) { + pr_warning("failed to get section name from %s\n", + obj->path); + err = -EINVAL; + goto out; + } + + data = elf_getdata(scn, 0); + if (!data) { + pr_warning("failed to get section data from %s(%s)\n", + name, obj->path); + err = -EINVAL; + goto out; + } + pr_debug("section %s, size %ld, link %d, flags %lx, type=%d\n", + name, (unsigned long)data->d_size, + (int)sh.sh_link, (unsigned long)sh.sh_flags, + (int)sh.sh_type); + } +out: + return err; +} + static struct bpf_object * __bpf_object__open(const char *path, void *obj_buf, size_t obj_buf_sz) { @@ -238,6 +289,8 @@ __bpf_object__open(const char *path, void *obj_buf, size_t obj_buf_sz) goto out; if (bpf_object__check_endianness(obj)) goto out; + if (bpf_object__elf_collect(obj)) + goto out; bpf_object__elf_finish(obj); return obj; -- 2.7.4