diff options
| author | Jeff Garzik <jeff@garzik.org> | 2012-07-25 15:58:48 -0400 |
|---|---|---|
| committer | Jeff Garzik <jgarzik@redhat.com> | 2012-07-25 15:58:48 -0400 |
| commit | 8407884dd9164ec18ed2afc00f56b87e36c51fcf (patch) | |
| tree | b6ea42c231d7d39f454de28a068d78ce11709770 /arch/x86/kernel/entry_64.S | |
| parent | dc7f71f486f4f5fa96f6dcf86833da020cde8a11 (diff) | |
| parent | bdc0077af574800d24318b6945cf2344e8dbb050 (diff) | |
Merge branch 'master' [vanilla Linus master] into libata-dev.git/upstream
Two bits were appended to the end of the bitfield
list in struct scsi_device. Resolve that conflict
by including both bits.
Conflicts:
include/scsi/scsi_device.h
Diffstat (limited to 'arch/x86/kernel/entry_64.S')
| -rw-r--r-- | arch/x86/kernel/entry_64.S | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index 7d65133b51b..111f6bbd8b3 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -1758,10 +1758,30 @@ end_repeat_nmi: */ call save_paranoid DEFAULT_FRAME 0 + + /* + * Save off the CR2 register. If we take a page fault in the NMI then + * it could corrupt the CR2 value. If the NMI preempts a page fault + * handler before it was able to read the CR2 register, and then the + * NMI itself takes a page fault, the page fault that was preempted + * will read the information from the NMI page fault and not the + * origin fault. Save it off and restore it if it changes. + * Use the r12 callee-saved register. + */ + movq %cr2, %r12 + /* paranoidentry do_nmi, 0; without TRACE_IRQS_OFF */ movq %rsp,%rdi movq $-1,%rsi call do_nmi + + /* Did the NMI take a page fault? Restore cr2 if it did */ + movq %cr2, %rcx + cmpq %rcx, %r12 + je 1f + movq %r12, %cr2 +1: + testl %ebx,%ebx /* swapgs needed? */ jnz nmi_restore nmi_swapgs: |