objtool: Fix seg fault with clang-compiled objects

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@emersion.fr>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/c0f2231683e9bed40fac1f13ce2c33b8389854bc.1514666459.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/tools/objtool/orc_gen.c b/tools/objtool/orc_gen.c
index e5ca314..e61fe70 100644 (file)
--- 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)