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| author | Li Zhong <zhong@linux.vnet.ibm.com> | 2012-01-07 17:54:52 +0000 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2012-01-11 12:50:26 +1100 |
| commit | ebb7f616abf6ee11603e6b63aa6c5f84c80a17d0 (patch) | |
| tree | 8912e1ebd7d665286e7bc28ec30688517835da87 /arch/powerpc | |
| parent | a5ccfee05a439b803640e94584056204501db31c (diff) | |
| download | linux-ebb7f616abf6ee11603e6b63aa6c5f84c80a17d0.tar.gz linux-ebb7f616abf6ee11603e6b63aa6c5f84c80a17d0.tar.bz2 linux-ebb7f616abf6ee11603e6b63aa6c5f84c80a17d0.zip | |
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.S | 3 |
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; \ |