path: root/arch
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authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2012-03-02 11:01:31 +1100
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2012-03-09 10:55:16 +1100
commit990118c84b3e90b2b5354b6e2acd961044d7fa12 (patch)
treec34310e6d49cffa38d242270e58f661dd90a575d /arch
parent7ac21cd465391802d931bd5e692302639383b8f5 (diff)
powerpc: Fix register clobbering when accumulating stolen time
When running under a hypervisor that supports stolen time accounting, we may call C code from the macro EXCEPTION_PROLOG_COMMON in the exception entry path, which clobbers CR0. However, the FPU and vector traps rely on CR0 indicating whether we are coming from userspace or kernel to decide what to do. So we need to restore that value after the C call Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch')
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h
index 368f72f7980..50f73aa2ba2 100644
--- a/arch/powerpc/include/asm/ppc_asm.h
+++ b/arch/powerpc/include/asm/ppc_asm.h
@@ -60,6 +60,8 @@ BEGIN_FW_FTR_SECTION; \
cmpd cr1,r11,r10; \
beq+ cr1,33f; \
bl .accumulate_stolen_time; \
+ ld r12,_MSR(r1); \
+ andi. r10,r12,MSR_PR; /* Restore cr0 (coming from user) */ \
33: \