| |
|
 |
|
 |
|
|
|
| |
|
|
xen-devel
[Xen-devel] Re: [PATCH v2] xen: x86_32: do not enable iterrupts when ret
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@xxxxxxxxxx>
Signed-off-by: Jeremy Fitzhardinge<jeremy@xxxxxxxx>
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
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
|
|
|
| |
|
Home