| From 7a0153ee15575a4d07b5da8c96b79e0b0fd41a12 Mon Sep 17 00:00:00 2001 |
| From: Jiri Olsa <jolsa@redhat.com> |
| Date: Mon, 6 Feb 2012 18:54:06 -0200 |
| Subject: perf tools: Fix perf stack to non executable on x86_64 |
| |
| From: Jiri Olsa <jolsa@redhat.com> |
| |
| commit 7a0153ee15575a4d07b5da8c96b79e0b0fd41a12 upstream. |
| |
| By adding following objects: |
| bench/mem-memcpy-x86-64-asm.o |
| the x86_64 perf binary ended up with executable stack. |
| |
| The reason was that above object are assembler sourced and is missing the |
| GNU-stack note section. In such case the linker assumes that the final binary |
| should not be restricted at all and mark the stack as RWX. |
| |
| Adding section ".note.GNU-stack" definition to mentioned object, with all |
| flags disabled, thus omiting this object from linker stack flags decision. |
| |
| Problem introduced in: |
| |
| $ git describe ea7872b |
| v2.6.37-rc2-19-gea7872b |
| |
| Reported-at: https://bugzilla.redhat.com/show_bug.cgi?id=783570 |
| Reported-by: Clark Williams <williams@redhat.com> |
| Acked-by: Eric Dumazet <eric.dumazet@gmail.com> |
| Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> |
| Cc: Ingo Molnar <mingo@elte.hu> |
| Cc: Paul Mackerras <paulus@samba.org> |
| Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> |
| Link: http://lkml.kernel.org/r/1328100848-5630-1-git-send-email-jolsa@redhat.com |
| Signed-off-by: Jiri Olsa <jolsa@redhat.com> |
| [ committer note: Backported fix to perf/urgent (3.3-rc2+) ] |
| Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| tools/perf/bench/mem-memcpy-x86-64-asm.S | 6 ++++++ |
| 1 file changed, 6 insertions(+) |
| |
| --- a/tools/perf/bench/mem-memcpy-x86-64-asm.S |
| +++ b/tools/perf/bench/mem-memcpy-x86-64-asm.S |
| @@ -1,2 +1,8 @@ |
| |
| #include "../../../arch/x86/lib/memcpy_64.S" |
| +/* |
| + * We need to provide note.GNU-stack section, saying that we want |
| + * NOT executable stack. Otherwise the final linking will assume that |
| + * the ELF stack should not be restricted at all and set it RWX. |
| + */ |
| +.section .note.GNU-stack,"",@progbits |
