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[S390] Fix kernel preemption.

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When returning from IRQ handling and TIF_NEED_RESCHED is set we must
call preempt_schedule_irq() instead of schedule().
Otherwise the BKL might be unlocked in schedule() and therfore
everything that relies on the BKL is broken.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Heiko Carstens 2007-11-20 11:13:35 +01:00 committed by Martin Schwidefsky
parent 37e3a6ac5a
commit b8e7a54cd0
2 changed files with 7 additions and 20 deletions
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15
arch/s390/kernel/entry.S
View File

@ -640,15 +640,9 @@ io_preempt:
io_resume_loop:
tm __TI_flags+3(%r9),_TIF_NEED_RESCHED
bno BASED(io_restore)
mvc __TI_precount(4,%r9),BASED(.Lc_pactive)
TRACE_IRQS_ON
stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
l %r1,BASED(.Lschedule)
basr %r14,%r1 # call schedule
stnsm __SF_EMPTY(%r15),0xfc # disable I/O and ext. interrupts
TRACE_IRQS_OFF
xc __TI_precount(4,%r9),__TI_precount(%r9)
b BASED(io_resume_loop)
l %r1,BASED(.Lpreempt_schedule_irq)
la %r14,BASED(io_resume_loop)
br %r1 # call schedule
#endif
#
@ -1062,7 +1056,6 @@ cleanup_io_leave_insn:
.align 4
.Lc_spsize: .long SP_SIZE
.Lc_overhead: .long STACK_FRAME_OVERHEAD
.Lc_pactive: .long PREEMPT_ACTIVE
.Lnr_syscalls: .long NR_syscalls
.L0x018: .short 0x018
.L0x020: .short 0x020
@ -1086,6 +1079,8 @@ cleanup_io_leave_insn:
.Lexecve_tail: .long execve_tail
.Ljump_table: .long pgm_check_table
.Lschedule: .long schedule
.Lpreempt_schedule_irq:
.long preempt_schedule_irq
.Ltrace: .long syscall_trace
.Lschedtail: .long schedule_tail
.Lsysc_table: .long sys_call_table

12
arch/s390/kernel/entry64.S
View File

@ -623,15 +623,8 @@ io_preempt:
io_resume_loop:
tm __TI_flags+7(%r9),_TIF_NEED_RESCHED
jno io_restore
larl %r1,.Lc_pactive
mvc __TI_precount(4,%r9),0(%r1)
TRACE_IRQS_ON
stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
brasl %r14,schedule # call schedule
stnsm __SF_EMPTY(%r15),0xfc # disable I/O and ext. interrupts
TRACE_IRQS_OFF
xc __TI_precount(4,%r9),__TI_precount(%r9)
j io_resume_loop
larl %r14,io_resume_loop
jg preempt_schedule_irq
#endif
#
@ -1029,7 +1022,6 @@ cleanup_io_leave_insn:
*/
.align 4
.Lconst:
.Lc_pactive: .long PREEMPT_ACTIVE
.Lnr_syscalls: .long NR_syscalls
.L0x0130: .short 0x130
.L0x0140: .short 0x140