Patchwork [50/52] x86/alternatives: Fix p6 nops on non-modular kernels

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Submitter Greg KH
Date Oct. 4, 2012, 9:21 p.m.
Message ID <20121004210641.663297238@linuxfoundation.org>
Download mbox | patch
Permalink /patch/189335/
State New
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Comments

Greg KH - Oct. 4, 2012, 9:21 p.m.
3.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Avi Kivity <avi@redhat.com>

commit cb09cad44f07044d9810f18f6f9a6a6f3771f979 upstream.

Probably a leftover from the early days of self-patching, p6nops
are marked __initconst_or_module, which causes them to be
discarded in a non-modular kernel.  If something later triggers
patching, it will overwrite kernel code with garbage.

Reported-by: Tomas Racek <tracek@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Cc: Michael Tokarev <mjt@tls.msk.ru>
Cc: Borislav Petkov <borislav.petkov@amd.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: qemu-devel@nongnu.org
Cc: Anthony Liguori <anthony@codemonkey.ws>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Alan Cox <alan@linux.intel.com>
Link: http://lkml.kernel.org/r/5034AE84.90708@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Ben Jencks <ben@bjencks.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/x86/kernel/alternative.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Patch

--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -160,7 +160,7 @@  static const unsigned char * const k7_no
 #endif
 
 #ifdef P6_NOP1
-static const unsigned char  __initconst_or_module p6nops[] =
+static const unsigned char p6nops[] =
 {
 	P6_NOP1,
 	P6_NOP2,