From b8e7a54cd06b0b0174029ef3a7f5a1415a2c28f2 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Tue, 20 Nov 2007 11:13:35 +0100 Subject: [PATCH] [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 Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/entry.S | 15 +++++---------- arch/s390/kernel/entry64.S | 12 ++---------- 2 files changed, 7 insertions(+), 20 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 diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S index e15c80efdd0..a3e47b893f0 100644 --- a/arch/s390/kernel/entry64.S +++ b/arch/s390/kernel/entry64.S @@ -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 -- 2.11.4.GIT