Messages in this thread | | | Date | Thu, 01 Sep 2011 09:46:56 -0700 | From | Jeremy Fitzhardinge <> | Subject | Re: [PATCH v2] xen: x86_32: do not enable iterrupts when returning from exception in interrupt context |
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On 09/01/2011 04:46 AM, Igor Mammedov wrote: > If vmalloc page_fault happens inside of interrupt handler with interrupts > disabled then on exit path from exception handler when there is no pending > interrupts, the following code (arch/x86/xen/xen-asm_32.S:112): > > cmpw $0x0001, XEN_vcpu_info_pending(%eax) > sete XEN_vcpu_info_mask(%eax) > > will enable interrupts even if they has been previously disabled according to > eflags from the bounce frame (arch/x86/xen/xen-asm_32.S:99) > > testb $X86_EFLAGS_IF>>8, 8+1+ESP_OFFSET(%esp) > setz XEN_vcpu_info_mask(%eax) > > Solution is in setting XEN_vcpu_info_mask only when it should be set > according to > cmpw $0x0001, XEN_vcpu_info_pending(%eax) > but not clearing it if there isn't any pending events. > > Reproducer for bug is attached to RHBZ 707552 > > Signed-off-by: Igor Mammedov <imammedo@redhat.com> > Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org>
One nit, this should be acked-by or reviewed-by, not signed-off-by, since the patch isn't passing through my hands.
J
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