[S390] fix single stepped svcs with TRACE_IRQFLAGS=y (21ec7f6d) · Commits · 戴 / test

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. Cc: stable@kernel.org Signed-off-by:

Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/kernel/entry.S

+1 −0

Original line number	Diff line number	Diff line
		@@ -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)

arch/s390/kernel/entry64.S

+1 −0

Original line number	Diff line number	Diff line
		@@ -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

Admin message