[PATCH 01/22] objtool: use sh_info to find the base for .rela sections

Sami Tolvanen
2020-06-24T20:33:14Z

ELF doesn't require .rela section names to match the base section. Use
the section index in sh_info to find the section instead of looking it
up by name.

LLD, for example, generates a .rela section that doesn't match the base
section name when we merge sections in a linker script for a binary
compiled with -ffunction-sections.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
---
tools/objtool/elf.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index 84225679f96d..c1ba92abaa03 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -502,7 +502,7 @@ static int read_relas(struct elf *elf)
if (sec->sh.sh_type != SHT_RELA)
continue;

- sec->base = find_section_by_name(elf, sec->name + 5);
+ sec->base = find_section_by_index(elf, sec->sh.sh_info);
if (!sec->base) {
WARN("can't find base section for rela section %s",
sec->name);
--
2.27.0.212.ge8ba1cc988-goog