From e89cef136a8b56eef1acf702591fd3039fc3385d Mon Sep 17 00:00:00 2001
From: Jiri Olsa <jolsa@redhat.com>
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 <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: Remaining bits after what was already added to perf/urgent ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 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 cb9217063776..9e5af89ed13a 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
-- 
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