[PATCH 4.14 03/89] objtool: Fix seg fault with clang-compiled objects

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Simon Ser <contact@xxxxxxxxxxx>

commit ce90aaf5cde4ce057b297bb6c955caf16ef00ee6 upstream.

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>
Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 tools/objtool/orc_gen.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/tools/objtool/orc_gen.c
+++ b/tools/objtool/orc_gen.c
@@ -165,6 +165,8 @@ int create_orc_sections(struct objtool_f
 
 	/* 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)