Commit 454efcf8 authored by Sven Schnelle's avatar Sven Schnelle Committed by Heiko Carstens
Browse files

s390/idle: fix accounting with machine checks 



When a machine check interrupt is triggered during idle, the code
is using the async timer/clock for idle time calculation. It should use
the machine check enter timer/clock which is passed to the macro.

Fixes: 0b0ed657 ("s390: remove critical section cleanup from entry.S")
Cc: <stable@vger.kernel.org> # 5.8
Reviewed-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarSven Schnelle <svens@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
parent e259b3fa

arch/s390/kernel/entry.S

+6 −6
Original line number Diff line number Diff line
@@ -116,7 +116,7 @@ _LPP_OFFSET = __LC_LPP 
#endif

	.endm



	.macro	SWITCH_ASYNC savearea,timer

	.macro	SWITCH_ASYNC savearea,timer,clock

	tmhh	%r8,0x0001		# interrupting from user ?

	jnz	4f

#if IS_ENABLED(CONFIG_KVM)
@@ -149,8 +149,8 @@ _LPP_OFFSET = __LC_LPP 
	la	%r4,8(%r4)

	brct	%r1,1b



2:	mvc	__CLOCK_IDLE_EXIT(8,%r2), __LC_INT_CLOCK

	mvc	__TIMER_IDLE_EXIT(8,%r2), __LC_ASYNC_ENTER_TIMER

2:	mvc	__CLOCK_IDLE_EXIT(8,%r2), \clock

	mvc	__TIMER_IDLE_EXIT(8,%r2), \timer

	# account system time going idle

	ni	__LC_CPU_FLAGS+7,255-_CIF_ENABLED_WAIT
@@ -757,7 +757,7 @@ ENTRY(io_int_handler) 
	stmg	%r8,%r15,__LC_SAVE_AREA_ASYNC

	lg	%r12,__LC_CURRENT

	lmg	%r8,%r9,__LC_IO_OLD_PSW

	SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_ENTER_TIMER

	SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_ENTER_TIMER,__LC_INT_CLOCK

	stmg	%r0,%r7,__PT_R0(%r11)

	# clear user controlled registers to prevent speculative use

	xgr	%r0,%r0
@@ -952,7 +952,7 @@ ENTRY(ext_int_handler) 
	stmg	%r8,%r15,__LC_SAVE_AREA_ASYNC

	lg	%r12,__LC_CURRENT

	lmg	%r8,%r9,__LC_EXT_OLD_PSW

	SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_ENTER_TIMER

	SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_ENTER_TIMER,__LC_INT_CLOCK

	stmg	%r0,%r7,__PT_R0(%r11)

	# clear user controlled registers to prevent speculative use

	xgr	%r0,%r0
@@ -1183,7 +1183,7 @@ ENTRY(mcck_int_handler) 
	TSTMSK	__LC_MCCK_CODE,MCCK_CODE_PSW_IA_VALID

	jno	.Lmcck_panic

4:	ssm	__LC_PGM_NEW_PSW	# turn dat on, keep irqs off

	SWITCH_ASYNC __LC_GPREGS_SAVE_AREA+64,__LC_MCCK_ENTER_TIMER

	SWITCH_ASYNC __LC_GPREGS_SAVE_AREA+64,__LC_MCCK_ENTER_TIMER,__LC_MCCK_CLOCK

.Lmcck_skip:

	lghi	%r14,__LC_GPREGS_SAVE_AREA+64

	stmg	%r0,%r7,__PT_R0(%r11)