From 97c6de49a991d4e0f412fd3e8c1ffe42a6c8fb3b Mon Sep 17 00:00:00 2001 From: Helge Deller Date: Mon, 24 Oct 2016 21:55:58 +0200 Subject: [PATCH] parisc: Re-enable interrupts early Since kernel 3.9 we re-enable interrupts quite late due to commit 2d1b2f1194a ("parisc: only re-enable interrupts if we need to schedule or deliver signals when returning to userspace"). At that time the parisc kernel had no dedicated IRQ stack, and this commit prevented kernel stack overflows. But since commit 175219a9c31 ("parisc: implement irq stacks") we now have an IRQ stack, so we may be safe now. And when CONFIG_DEBUG_STACKOVERFLOW=y is enabled, we can even check at runtime for overflows. Signed-off-by: Helge Deller --- arch/parisc/kernel/entry.S | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) diff --git a/arch/parisc/kernel/entry.S b/arch/parisc/kernel/entry.S index 4fcff2dcc9c30..ad4cb1613c57a 100644 --- a/arch/parisc/kernel/entry.S +++ b/arch/parisc/kernel/entry.S @@ -878,6 +878,9 @@ ENTRY_CFI(syscall_exit_rfi) STREG %r19,PT_SR7(%r16) intr_return: + /* NOTE: Need to enable interrupts incase we schedule. */ + ssm PSW_SM_I, %r0 + /* check for reschedule */ mfctl %cr30,%r1 LDREG TI_FLAGS(%r1),%r19 /* sched.h: TIF_NEED_RESCHED */ @@ -904,11 +907,6 @@ intr_check_sig: LDREG PT_IASQ1(%r16), %r20 cmpib,COND(=),n 0,%r20,intr_restore /* backward */ - /* NOTE: We need to enable interrupts if we have to deliver - * signals. We used to do this earlier but it caused kernel - * stack overflows. */ - ssm PSW_SM_I, %r0 - copy %r0, %r25 /* long in_syscall = 0 */ #ifdef CONFIG_64BIT ldo -16(%r30),%r29 /* Reference param save area */ @@ -960,10 +958,6 @@ intr_do_resched: cmpib,COND(=) 0, %r20, intr_do_preempt nop - /* NOTE: We need to enable interrupts if we schedule. We used - * to do this earlier but it caused kernel stack overflows. */ - ssm PSW_SM_I, %r0 - #ifdef CONFIG_64BIT ldo -16(%r30),%r29 /* Reference param save area */ #endif -- 2.39.5