diff mbox series

[1/9] objtool: do not assume order of parent/child functions

Message ID 20200415210452.27436-2-kristen@linux.intel.com (mailing list archive)
State New, archived
Headers show
Series Function Granular Kernel Address Space Layout Randomization | expand

Commit Message

Kristen Carlson Accardi April 15, 2020, 9:04 p.m. UTC 
If a .cold function is examined prior to it's parent, the link
to the parent/child function can be overwritten when the parent
is examined. Only update pfunc and cfunc if they were previously
nil to prevent this from happening.

Signed-off-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
---
 tools/objtool/elf.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

Comments

Josh Poimboeuf April 22, 2020, 10:17 p.m. UTC | #1 
On Wed, Apr 15, 2020 at 02:04:43PM -0700, Kristen Carlson Accardi wrote:
> If a .cold function is examined prior to it's parent, the link
> to the parent/child function can be overwritten when the parent
> is examined. Only update pfunc and cfunc if they were previously
> nil to prevent this from happening.
> 
> Signed-off-by: Kristen Carlson Accardi <kristen@linux.intel.com>
> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>

Hi Kristen,

I grabbed this one and it will be merged into the -tip tree soon.
Thanks!
diff mbox series

Patch

diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index 09ddc8f1def3..2aa40f344392 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -408,7 +408,13 @@  static int read_symbols(struct elf *elf)
 			size_t pnamelen;
 			if (sym->type != STT_FUNC)
 				continue;
-			sym->pfunc = sym->cfunc = sym;
+
+			if (sym->pfunc == NULL)
+				sym->pfunc = sym;
+
+			if (sym->cfunc == NULL)
+				sym->cfunc = sym;
+
 			coldstr = strstr(sym->name, ".cold");
 			if (!coldstr)
 				continue;