[tip:core/urgent] objtool: Fix seg fault with clang-compiled objects

[tip-bot for Simon Ser]

Commit-ID:  ce90aaf5cde4ce057b297bb6c955caf16ef00ee6
Gitweb:     https://git.kernel.org/tip/ce90aaf5cde4ce057b297bb6c955caf16ef00ee6
Author:     Simon Ser <contact@xxxxxxxxxxx>
AuthorDate: Sat, 30 Dec 2017 14:43:32 -0600
Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Sat, 30 Dec 2017 22:04:17 +0100

objtool: Fix seg fault with clang-compiled objects

Fix a seg fault which happens when an input file provided to 'objtool
orc generate' doesn't have a '.shstrtab' section (for instance, object
files produced by clang don't have this section).

Signed-off-by: Simon Ser <contact@xxxxxxxxxxx>
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/c0f2231683e9bed40fac1f13ce2c33b8389854bc.1514666459.git.jpoimboe@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 tools/objtool/orc_gen.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/objtool/orc_gen.c b/tools/objtool/orc_gen.c
index e5ca314..e61fe70 100644
--- a/tools/objtool/orc_gen.c
+++ b/tools/objtool/orc_gen.c
@@ -165,6 +165,8 @@ int create_orc_sections(struct objtool_file *file)
 
 	/* create .orc_unwind_ip and .rela.orc_unwind_ip sections */
 	sec = elf_create_section(file->elf, ".orc_unwind_ip", sizeof(int), idx);
+	if (!sec)
+		return -1;
 
 	ip_relasec = elf_create_rela_section(file->elf, sec);
 	if (!ip_relasec)