[06/74] S390: fix single stepped svcs with TRACE_IRQFLAGS=y

[Greg KH]

2.6.32-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>

commit 21ec7f6dbf10492ce9a21718040677d3e68bd57d upstream.

If irq flags tracing is enabled the TRACE_IRQS_ON macros expands to
a function call which clobbers registers %r0-%r5. The macro is used
in the code path for single stepped system calls. The argument
registers %r2-%r6 need to be restored from the stack before the system
call function is called.

Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 arch/s390/kernel/entry.S   |    1 +
 arch/s390/kernel/entry64.S |    1 +
 2 files changed, 2 insertions(+)

--- a/arch/s390/kernel/entry64.S
+++ b/arch/s390/kernel/entry64.S
@@ -549,6 +549,7 @@ pgm_svcper:
 	mvc	__THREAD_per+__PER_access_id(1,%r8),__LC_PER_ACCESS_ID
 	oi	__TI_flags+7(%r9),_TIF_SINGLE_STEP # set TIF_SINGLE_STEP
 	TRACE_IRQS_ON
+	lmg	%r2,%r6,SP_R2(%r15)	# load svc arguments
 	stosm	__SF_EMPTY(%r15),0x03	# reenable interrupts
 	j	sysc_do_svc
 
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -571,6 +571,7 @@ pgm_svcper:
 	mvc	__THREAD_per+__PER_access_id(1,%r8),__LC_PER_ACCESS_ID
 	oi	__TI_flags+3(%r9),_TIF_SINGLE_STEP # set TIF_SINGLE_STEP
 	TRACE_IRQS_ON
+	lm	%r2,%r6,SP_R2(%r15)	# load svc arguments
 	stosm	__SF_EMPTY(%r15),0x03	# reenable interrupts
 	b	BASED(sysc_do_svc)
 


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