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authorLi Zhong <zhong@linux.vnet.ibm.com>2012-01-07 21:54:52 +0400
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2012-01-11 05:50:26 +0400
commitebb7f616abf6ee11603e6b63aa6c5f84c80a17d0 (patch)
tree8912e1ebd7d665286e7bc28ec30688517835da87 /arch/powerpc
parenta5ccfee05a439b803640e94584056204501db31c (diff)
downloadlinux-ebb7f616abf6ee11603e6b63aa6c5f84c80a17d0.tar.xz
powerpc: Fix unpaired __trace_hcall_entry and __trace_hcall_exit
Unpaired calling of __trace_hcall_entry and __trace_hcall_exit could cause incorrect preempt count. And it might happen as the global variable hcall_tracepoint_refcount is checked separately before calling them. Instead, store the value that was used on entry in the stack frame and retreive it from there after the call Reported-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/platforms/pseries/hvCall.S3
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/powerpc/platforms/pseries/hvCall.S b/arch/powerpc/platforms/pseries/hvCall.S
index fd05fdee576a..3ce73d0052b1 100644
--- a/arch/powerpc/platforms/pseries/hvCall.S
+++ b/arch/powerpc/platforms/pseries/hvCall.S
@@ -36,6 +36,7 @@ BEGIN_FTR_SECTION; \
b 1f; \
END_FTR_SECTION(0, 1); \
ld r12,hcall_tracepoint_refcount@toc(r2); \
+ std r12,32(r1); \
cmpdi r12,0; \
beq+ 1f; \
mflr r0; \
@@ -74,7 +75,7 @@ END_FTR_SECTION(0, 1); \
BEGIN_FTR_SECTION; \
b 1f; \
END_FTR_SECTION(0, 1); \
- ld r12,hcall_tracepoint_refcount@toc(r2); \
+ ld r12,32(r1); \
cmpdi r12,0; \
beq+ 1f; \
mflr r0; \