4.9-stable review patch. If anyone has any objections, please let me know.
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From: Dan Williams dan.j.williams@intel.com
commit eb6174f6d1be16b19cfa43dac296bfed003ce1a6 upstream.
The nospec.h header expects the per-architecture header file <asm/barrier.h> to optionally define array_index_mask_nospec(). Include that dependency to prevent inadvertent fallback to the default array_index_mask_nospec() implementation.
The default implementation may not provide a full mitigation on architectures that perform data value speculation.
Reported-by: Christian Borntraeger borntraeger@de.ibm.com Signed-off-by: Dan Williams dan.j.williams@intel.com Cc: Andy Lutomirski luto@kernel.org Cc: Arjan van de Ven arjan@linux.intel.com Cc: Borislav Petkov bp@alien8.de Cc: Dave Hansen dave.hansen@linux.intel.com Cc: David Woodhouse dwmw2@infradead.org Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: Josh Poimboeuf jpoimboe@redhat.com Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Peter Zijlstra peterz@infradead.org Cc: Thomas Gleixner tglx@linutronix.de Cc: Will Deacon will.deacon@arm.com Cc: linux-arch@vger.kernel.org Link: http://lkml.kernel.org/r/151881605404.17395.1341935530792574707.stgit@dwilli... Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- include/linux/nospec.h | 1 + 1 file changed, 1 insertion(+)
--- a/include/linux/nospec.h +++ b/include/linux/nospec.h @@ -5,6 +5,7 @@
#ifndef _LINUX_NOSPEC_H #define _LINUX_NOSPEC_H +#include <asm/barrier.h>
/** * array_index_mask_nospec() - generate a ~0 mask when index < size, 0 otherwise