From: Andi Kleen <a...@linux.intel.com>
copy_xregs_to_kernel checks if the alternatives have been already
patched.
This WARN_ON is always executed in every context switch.
All the other checks in fpu internal.h are WARN_ON_FPU, but
this one is plain WARN_ON. I assume it was forgotten to switch it.
So switch it to WARN_ON_FPU too to avoid some unnecessary code
in the context switch, and a potentially expensive cache line miss for the
global variable.
(or could be removed since if it hasn't triggered by now it probably never will)
Signed-off-by: Andi Kleen <a...@linux.intel.com>
---
arch/x86/include/asm/fpu/internal.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/fpu/internal.h
b/arch/x86/include/asm/fpu/internal.h
index d4a684997497..ec0c542a91ab 100644
--- a/arch/x86/include/asm/fpu/internal.h
+++ b/arch/x86/include/asm/fpu/internal.h
@@ -340,7 +340,7 @@ static inline void copy_xregs_to_kernel(struct xregs_state
*xstate)
u32 hmask = mask >> 32;
int err;
- WARN_ON(!alternatives_patched);
+ WARN_ON_FPU(!alternatives_patched);
XSTATE_XSAVE(xstate, lmask, hmask, err);
--
2.9.3
