Messages in this thread | | | Date | Fri, 02 Sep 2011 10:18:23 +0200 | From | Igor Mammedov <> | 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 06:46 PM, Jeremy Fitzhardinge wrote: > 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
I'm new to this stuff, would you like me to re-post it? Next time will do it right.
------- Thanks, Igor
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