From mboxrd@z Thu Jan 1 00:00:00 1970 From: Richard Henderson Date: Wed, 05 Dec 2001 03:00:48 +0000 Subject: [Linux-ia64] alpha bug in signal handling Message-Id: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org On Tue, Dec 04, 2001 at 06:15:50PM -0800, David Mosberger wrote: > Oh, sorry, I was referring to teh *other* problem... ;-) > > What I meant is that the check for re-scheduling > (current->need_resched) and signal deliverify (current->sigpending) > needs to be done with interrupts turned off, and the interrupts need > to be left off until user space is reached. Otherwise, you could get > an interrupt which would wake up a higher priority task or post a > signal between the check and the return to user space. > > I didn't see this interrupt disabling in the Alpha version of entry.S, > but I have to admit my Alpha assembly is getting quite rusty. Oh, yes, I see. This should fix it. r~ --- arch/alpha/kernel/entry.S.orig Tue Dec 4 18:40:53 2001 +++ arch/alpha/kernel/entry.S Tue Dec 4 18:46:33 2001 @@ -580,6 +580,10 @@ and $0,8,$0 beq $0,restore_all ret_from_reschedule: + /* Turn off interrupts so that resched and signal delivery + checks are done atomically. */ + addq $31,7,$16 + call_pal PAL_swpipl ldq $2,TASK_NEED_RESCHED($8) lda $4,init_task_union bne $2,reschedule