[PATCH 2/4] x86, fpu: run device not available trap with interrupts enabled
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From: Avi Kivity on 13 Jun 2010 11:10 In order to allow a task's fpu state to fully float, we may need to bring it back from another processor. To do that, we need interrupts to be enabled so we can fire off an IPI to that processor. May break 80386/7 combos with FERR# wired through the interrupt controller. Signed-off-by: Avi Kivity <avi(a)redhat.com> --- arch/x86/kernel/traps.c | 13 +++++-------- 1 files changed, 5 insertions(+), 8 deletions(-) diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 142d70c..c7d67cb 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -740,7 +740,6 @@ asmlinkage void math_state_restore(void) struct task_struct *tsk = thread->task; if (!tsk_used_math(tsk)) { - local_irq_enable(); /* * does a slab alloc which can sleep */ @@ -751,7 +750,6 @@ asmlinkage void math_state_restore(void) do_group_exit(SIGKILL); return; } - local_irq_disable(); } clts(); /* Allow maths ops (or we recurse) */ @@ -774,21 +772,20 @@ void math_emulate(struct math_emu_info *info) dotraplinkage void __kprobes do_device_not_available(struct pt_regs *regs, long error_code) { + preempt_disable(); + local_irq_enable(); #ifdef CONFIG_X86_32 if (read_cr0() & X86_CR0_EM) { struct math_emu_info info = { }; - conditional_sti(regs); - info.regs = regs; math_emulate(&info); - } else { - math_state_restore(); /* interrupts still off */ - conditional_sti(regs); - } + } else + math_state_restore(); #else math_state_restore(); #endif + preempt_enable(); } #ifdef CONFIG_X86_32 -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |