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| author | Heiko Carstens <heiko.carstens@de.ibm.com> | 2008-11-14 18:18:05 +0100 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2008-11-14 18:18:53 +0100 |
| commit | 50bec4ce5d36ebf96189dcc54e20c7fce4bf61bf (patch) | |
| tree | 5f04e012e882ed15f9c7f1f45b0e9a27dd2656f5 /arch/s390/kernel/entry64.S | |
| parent | 632448f65001c4935ed0d3bb362017d773da2eca (diff) | |
| download | blackbird-op-linux-50bec4ce5d36ebf96189dcc54e20c7fce4bf61bf.tar.gz blackbird-op-linux-50bec4ce5d36ebf96189dcc54e20c7fce4bf61bf.zip | |
[S390] ftrace: fix kernel stack backchain walking
With CONFIG_IRQSOFF_TRACER the trace_hardirqs_off() function includes
a call to __builtin_return_address(1). But we calltrace_hardirqs_off()
from early entry code. There we have just a single stack frame.
So this results in a kernel stack backchain walk that would walk beyond
the kernel stack. Following the NULL terminated backchain this results
in a lowcore read access.
To fix this we simply call trace_hardirqs_off_caller() and pass the
current instruction pointer.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/kernel/entry64.S')
| -rw-r--r-- | arch/s390/kernel/entry64.S | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S index d7ce150453f2..41aca06682aa 100644 --- a/arch/s390/kernel/entry64.S +++ b/arch/s390/kernel/entry64.S @@ -61,19 +61,22 @@ _TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \ #ifdef CONFIG_TRACE_IRQFLAGS .macro TRACE_IRQS_ON - brasl %r14,trace_hardirqs_on + basr %r2,%r0 + brasl %r14,trace_hardirqs_on_caller .endm .macro TRACE_IRQS_OFF - brasl %r14,trace_hardirqs_off + basr %r2,%r0 + brasl %r14,trace_hardirqs_off_caller .endm .macro TRACE_IRQS_CHECK + basr %r2,%r0 tm SP_PSW(%r15),0x03 # irqs enabled? jz 0f - brasl %r14,trace_hardirqs_on + brasl %r14,trace_hardirqs_on_caller j 1f -0: brasl %r14,trace_hardirqs_off +0: brasl %r14,trace_hardirqs_off_caller 1: .endm #else |
