[04/28] perf tools: Fix perf stack to non executable on x86_64
From: Greg KH <gregkh@linuxfoundation.org>
Date: 2012-02-17 01:00:24
Also in:
lkml
3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jiri Olsa <redacted> 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 <redacted> Acked-by: Eric Dumazet <redacted> Cc: Corey Ashford <redacted> Cc: Ingo Molnar <redacted> Cc: Paul Mackerras <redacted> Cc: Peter Zijlstra <redacted> Link: http://lkml.kernel.org/r/1328100848-5630-1-git-send-email-jolsa@redhat.com Signed-off-by: Jiri Olsa <redacted> [ committer note: Backported fix to perf/urgent (3.3-rc2+) ] Signed-off-by: Arnaldo Carvalho de Melo <redacted> 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