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authorHeiko Carstens <heiko.carstens@de.ibm.com>2007-11-20 11:13:35 +0100
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2007-11-20 11:13:46 +0100
commitb8e7a54cd06b0b0174029ef3a7f5a1415a2c28f2 (patch)
treee42beedde089c3aabe9df1537ad687f2756a69ac /arch/s390/kernel/entry.S
parent37e3a6ac5a30468021a2f366e497d455bbcb5d21 (diff)
[S390] Fix kernel preemption.
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>
Diffstat (limited to 'arch/s390/kernel/entry.S')
-rw-r--r--arch/s390/kernel/entry.S15
1 files changed, 5 insertions, 10 deletions
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index 764d56177cb..b2b2edc40eb 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -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