diff options
| author |   Andy Lutomirski <luto@kernel.org> | 2015-07-15 10:29:34 -0700 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2015-07-17 12:50:11 +0200 |
| commit | 0e181bb58143cb4a2e8f01c281b0816cd0e4798e (patch) | |
| tree | 14eb4bb8ddec0622dc8123f744f893d14b09cdb5 /arch | |
| parent | x86/nmi: Enable nested do_nmi() handling for 64-bit kernels (diff) | |
| download | linux-dev-0e181bb58143cb4a2e8f01c281b0816cd0e4798e.tar.xz linux-dev-0e181bb58143cb4a2e8f01c281b0816cd0e4798e.zip | |
x86/nmi/64: Remove asm code that saves CR2
Now that do_nmi saves CR2, we don't need to save it in asm.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/entry/entry_64.S | 17 |
1 files changed, 0 insertions, 17 deletions
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 3bb2c4302df1..062feb4eb478 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -1415,28 +1415,11 @@ end_repeat_nmi: */ call paranoid_entry - /* - * 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: |