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s390/idle: fix accounting with machine checks
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commit 454efcf 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: 0b0ed65 ("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>
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svens-s390 authored and gregkh committed Dec 30, 2020
1 parent d5d2154 commit 24d9a8e
Showing 1 changed file with 6 additions and 6 deletions.
12 changes: 6 additions & 6 deletions arch/s390/kernel/entry.S
Expand Up @@ -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)
Expand Down Expand Up @@ -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

Expand Down Expand Up @@ -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
Expand Down Expand Up @@ -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
Expand Down Expand Up @@ -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)
Expand Down

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