xen: x86_32: do not enable iterrupts when returning from exception in interrupt context
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 CC: stable@kernel.org Signed-off-by:Igor Mammedov <imammedo@redhat.com> Acked-by:
Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by:
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
parent
d312ae87
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