[PATCH 06/24] bpf tools: Iterate over ELF sections to collect information
From: Arnaldo Carvalho de Melo
Date: Fri Aug 07 2015 - 10:56:47 EST
From: Wang Nan <wangnan0@xxxxxxxxxx>
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 <wangnan0@xxxxxxxxxx>
Acked-by: Alexei Starovoitov <ast@xxxxxxxxxxxx>
Cc: Brendan Gregg <brendan.d.gregg@xxxxxxxxx>
Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: He Kuang <hekuang@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Kaixu Xia <xiakaixu@xxxxxxxxxx>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Zefan Li <lizefan@xxxxxxxxxx>
Cc: pi3orama@xxxxxxx
Link: http://lkml.kernel.org/r/1435716878-189507-9-git-send-email-wangnan0@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
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 15b3e82b22f6..d8d6eb580188 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;
--
2.1.0
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