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| author | Steven Rostedt <rostedt@goodmis.org> | 2010-12-22 16:42:56 +0000 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2011-01-21 14:08:33 +1100 |
| commit | 06ca2188eccbd7932636ac5bde2837297800480e (patch) | |
| tree | 6eecdd819e8a96f04eda7fab9d85b04af9bdb06d /arch/powerpc/kernel/entry_32.S | |
| parent | 3cb5f1a3e58c0bd70d47d9907cc5c65192281dee (diff) | |
| download | linux-06ca2188eccbd7932636ac5bde2837297800480e.tar.bz2 | |
powerpc/ppc32/tracing: Add stack frame to calls of trace_hardirqs_on/off
32-bit variant of the previous patch for 64-bit:
<<
When an interrupt occurs in userspace, we can call trace_hardirqs_on/off()
With one level stack. But if we have irqsoff tracing enabled,
it checks both CALLER_ADDR0 and CALLER_ADDR1. The second call
goes two stack frames up. If this is from user space, then there may
not exist a second stack....
>>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/kernel/entry_32.S')
| -rw-r--r-- | arch/powerpc/kernel/entry_32.S | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index c22dc1ec1c94..56212bc0ab08 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -880,7 +880,18 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_47x) */ andi. r10,r9,MSR_EE beq 1f + /* + * Since the ftrace irqsoff latency trace checks CALLER_ADDR1, + * which is the stack frame here, we need to force a stack frame + * in case we came from user space. + */ + stwu r1,-32(r1) + mflr r0 + stw r0,4(r1) + stwu r1,-32(r1) bl trace_hardirqs_on + lwz r1,0(r1) + lwz r1,0(r1) lwz r9,_MSR(r1) 1: #endif /* CONFIG_TRACE_IRQFLAGS */ |