From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934489AbXKPO2u (ORCPT ); Fri, 16 Nov 2007 09:28:50 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933199AbXKPOZl (ORCPT ); Fri, 16 Nov 2007 09:25:41 -0500 Received: from mtagate1.de.ibm.com ([195.212.29.150]:24024 "EHLO mtagate1.de.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760196AbXKPOZ3 (ORCPT ); Fri, 16 Nov 2007 09:25:29 -0500 Message-Id: <20071116142527.043274700@de.ibm.com> References: <20071116142441.484714036@de.ibm.com> User-Agent: quilt/0.46-1 Date: Fri, 16 Nov 2007 15:24:47 +0100 From: Martin Schwidefsky To: linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org Cc: Heiko Carstens , Martin Schwidefsky Subject: [patch 06/10] Fix kernel preemption. Content-Disposition: inline; filename=006-preemption.diff Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org From: Heiko Carstens 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 -urpN linux-2.6/arch/s390/kernel/entry64.S linux-2.6-patched/arch/s390/kernel/entry64.S --- linux-2.6/arch/s390/kernel/entry64.S 2007-11-16 14:27:41.000000000 +0100 +++ linux-2.6-patched/arch/s390/kernel/entry64.S 2007-11-16 14:27:42.000000000 +0100 @@ -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 diff -urpN linux-2.6/arch/s390/kernel/entry.S linux-2.6-patched/arch/s390/kernel/entry.S --- linux-2.6/arch/s390/kernel/entry.S 2007-11-16 14:27:41.000000000 +0100 +++ linux-2.6-patched/arch/s390/kernel/entry.S 2007-11-16 14:27:42.000000000 +0100 @@ -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 -- blue skies, Martin. "Reality continues to ruin my life." - Calvin.