[PATCH 5.10 554/717] s390/idle: fix accounting with machine checks

Greg Kroah-Hartman
2020-12-28T14:25:52Z

From: Sven Schnelle <svens@linux.ibm.com>

commit 454efcf82ea17d7efeb86ebaa20775a21ec87d27 upstream.

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: 0b0ed657fe00 ("s390: remove critical section cleanup from entry.S")
Cc: <stable@vger.kernel.org> # 5.8
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/s390/kernel/entry.S | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -110,7 +110,7 @@ _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)
@@ -143,8 +143,8 @@ _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

@@ -761,7 +761,7 @@ 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
@@ -961,7 +961,7 @@ 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)