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| author | Igor Mammedov <[email protected]> | 2011-09-01 11:46:55 +0000 |
|---|---|---|
| committer | Konrad Rzeszutek Wilk <[email protected]> | 2011-09-01 16:54:42 +0000 |
| commit | d198d499148a0c64a41b3aba9e7dd43772832b91 (patch) | |
| tree | ddc0bf46ac10d84db5d06dceb44c21770692f596 /lib/dynamic_debug.c | |
| parent | xen: use maximum reservation to limit amount of usable RAM (diff) | |
| download | kernel-d198d499148a0c64a41b3aba9e7dd43772832b91.tar.gz kernel-d198d499148a0c64a41b3aba9e7dd43772832b91.zip | |
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: [email protected]
Signed-off-by: Igor Mammedov <[email protected]>
Acked-by: Jeremy Fitzhardinge <[email protected]>
Signed-off-by: Konrad Rzeszutek Wilk <[email protected]>
Diffstat (limited to 'lib/dynamic_debug.c')
0 files changed, 0 insertions, 0 deletions