perf x86: Fix perf to use non-executable stack, again
authorMathias Krause <minipli@googlemail.com>
Sun, 27 Apr 2014 16:51:05 +0000 (18:51 +0200)
committerJiri Olsa <jolsa@kernel.org>
Wed, 30 Apr 2014 15:02:30 +0000 (17:02 +0200)
commit6392b4ebdc1acfbed605d68c437ff5597d0a8d95
tree5a14df4426377d88702769dbb1859fbce076b4ab
parent603940b6b8b1347ec13a628165c00194ebc17ed2
perf x86: Fix perf to use non-executable stack, again

arch/x86/tests/regs_load.S is missing the linker note about the stack
requirements, therefore making the linker fall back to an executable
stack. As this object gets linked against the final perf binary, it'll
needlessly end up with an executable stack. Fix this by adding the
appropriate linker note.

Also add a global linker flag to prevent future regressions, as
suggested by Jiri. This way perf won't get an executable stack even if
we fail to add the .GNU-stack linker note to future assembler files.
Though, doing so might create regressions the other way around, when
(statically) linking against libraries needing an executable stack.
But, apparently, regressing in that direction is wanted as it is an
indicator of poor code quality -- or just missing linker notes.

Fixes: 3c8b06f981 ("perf tests x86: Introduce perf_regs_load function")

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1398617466-22749-1-git-send-email-minipli@googlemail.com
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
tools/perf/arch/x86/tests/regs_load.S
tools/perf/config/Makefile