From e89cef136a8b56eef1acf702591fd3039fc3385d Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 1 Feb 2012 13:54:08 +0100 Subject: [PATCH] perf tool: Fix perf stack to non executable on x86_64 By adding following objects: bench/mem-memset-x86-64-asm.o bench/mem-memcpy-x86-64-asm.o the x86_64 perf binary ended up with executable stack. The reason was that above objects are assembler sourced and are 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 objects, with all flags disabled, thus omiting those objects from linker stack flags decision. Reported-at: https://bugzilla.redhat.com/show_bug.cgi?id=783570 Reported-by: Clark Williams Acked-by: Eric Dumazet Cc: Corey Ashford Cc: Ingo Molnar Cc: Paul Mackerras Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1328100848-5630-1-git-send-email-jolsa@redhat.com Signed-off-by: Jiri Olsa [ committer note: Remaining bits after what was already added to perf/urgent ] Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/bench/mem-memset-x86-64-asm.S | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/tools/perf/bench/mem-memset-x86-64-asm.S b/tools/perf/bench/mem-memset-x86-64-asm.S index cb92170..9e5af89 100644 --- a/tools/perf/bench/mem-memset-x86-64-asm.S +++ b/tools/perf/bench/mem-memset-x86-64-asm.S @@ -4,3 +4,10 @@ #define Lmemset_c globl memset_c; memset_c #define Lmemset_c_e globl memset_c_e; memset_c_e #include "../../../arch/x86/lib/memset_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 -- 2.7.4