For very large ELF objects (with many sections), we could
get special value SHN_XINDEX (65535) for elf object's string
table index - e_shstrndx.
In such case we need to call elf_getshdrstrndx to get the
proper string table index.
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
---
tools/lib/bpf/btf.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 3c3f2bc6c652..4fe987846bc0 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -863,6 +863,7 @@ static struct btf *btf_parse_elf(const char *path, struct btf *base_btf,
Elf_Scn *scn = NULL;
Elf *elf = NULL;
GElf_Ehdr ehdr;
+ size_t shstrndx;
if (elf_version(EV_CURRENT) == EV_NONE) {
pr_warn("failed to init libelf for %s\n", path);
@@ -887,7 +888,16 @@ static struct btf *btf_parse_elf(const char *path, struct btf *base_btf,
pr_warn("failed to get EHDR from %s\n", path);
goto done;
}
- if (!elf_rawdata(elf_getscn(elf, ehdr.e_shstrndx), NULL)) {
+
+ /*
+ * Get string table index from extended section index
+ * table if needed.
+ */
+ shstrndx = ehdr.e_shstrndx;
+ if (shstrndx == SHN_XINDEX && elf_getshdrstrndx(elf, &shstrndx))
+ goto done;
+
+ if (!elf_rawdata(elf_getscn(elf, shstrndx), NULL)) {
pr_warn("failed to get e_shstrndx from %s\n", path);
goto done;
}
@@ -902,7 +912,7 @@ static struct btf *btf_parse_elf(const char *path, struct btf *base_btf,
idx, path);
goto done;
}
- name = elf_strptr(elf, ehdr.e_shstrndx, sh.sh_name);
+ name = elf_strptr(elf, shstrndx, sh.sh_name);
if (!name) {
pr_warn("failed to get section(%d) name from %s\n",
idx, path);
--
2.27.0
