Subject: [PATCH 1/3] elf_symtab: Add support for SHN_XINDEX index to elf_section_by_name

From: Jiri Olsa <[email-masked]>
Date: Thu, 21 Jan 2021 21:22:01 +0100

In case the elf's header e_shstrndx contains SHN_XINDEX,
we need to call elf_getshdrstrndx to get the proper
string table index.

Signed-off-by: Jiri Olsa <[email-masked]>
---
 dutil.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/dutil.c b/dutil.c
index 7b667647420f..9e0fdca3ae04 100644
--- a/dutil.c
+++ b/dutil.c
@@ -179,13 +179,17 @@ Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
 {
 	Elf_Scn *sec = NULL;
 	size_t cnt = 1;
+	size_t str_idx;
+
+	if (elf_getshdrstrndx(elf, &str_idx))
+		return NULL;
 
 	while ((sec = elf_nextscn(elf, sec)) != NULL) {
 		char *str;
 
 		gelf_getshdr(sec, shp);
-		str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name);
-		if (!strcmp(name, str)) {
+		str = elf_strptr(elf, str_idx, shp->sh_name);
+		if (str && !strcmp(name, str)) {
 			if (index)
 				*index = cnt;
 			break;
-- 
2.27.0