Messages in this thread Patch in this message | | | From | Arnaldo Carvalho de Melo <> | Subject | [PATCH 1/3] perf tools: Fix perf stack to non executable on x86_64 | Date | Mon, 6 Feb 2012 19:36:07 -0200 |
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From: Jiri Olsa <jolsa@redhat.com>
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> Cc: stable@kernel.org 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> --- tools/perf/bench/mem-memcpy-x86-64-asm.S | 6 ++++++ 1 files changed, 6 insertions(+), 0 deletions(-)
diff --git a/tools/perf/bench/mem-memcpy-x86-64-asm.S b/tools/perf/bench/mem-memcpy-x86-64-asm.S index a57b66e..185a96d 100644 --- 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 -- 1.7.9.rc2.1.g69204
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