diff options
| author | Oliver O'Halloran <oohall@gmail.com> | 2017-07-06 18:46:43 +1000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-07-27 15:06:05 -0700 |
| commit | b8c6a93837f0527a5cb4505cf90c83cc1538610e (patch) | |
| tree | 1841244be89f7ded51e0339953a07471c5ea9f3f /arch | |
| parent | 79afeb379cf496cad4cb0aefb8ed4f9670a74f18 (diff) | |
powerpc/asm: Mark cr0 as clobbered in mftb()
commit 2400fd822f467cb4c886c879d8ad99feac9cf319 upstream.
The workaround for the CELL timebase bug does not correctly mark cr0 as
being clobbered. This means GCC doesn't know that the asm block changes cr0 and
might leave the result of an unrelated comparison in cr0 across the block, which
we then trash, leading to basically random behaviour.
Fixes: 859deea949c3 ("[POWERPC] Cell timebase bug workaround")
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
[mpe: Tweak change log and flag for stable]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/include/asm/reg.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h index 627d129d7fcb..ca372bbc0ffe 100644 --- a/arch/powerpc/include/asm/reg.h +++ b/arch/powerpc/include/asm/reg.h @@ -1236,7 +1236,7 @@ static inline unsigned long mfvtb (void) " .llong 0\n" \ ".previous" \ : "=r" (rval) \ - : "i" (CPU_FTR_CELL_TB_BUG), "i" (SPRN_TBRL)); \ + : "i" (CPU_FTR_CELL_TB_BUG), "i" (SPRN_TBRL) : "cr0"); \ rval;}) #else #define mftb() ({unsigned long rval; \ |