diff options
| author | Andy Lutomirski <luto@kernel.org> | 2015-07-15 10:29:34 -0700 |
|---|---|---|
| committer | Sasha Levin <sasha.levin@oracle.com> | 2015-09-27 12:18:52 -0400 |
| commit | 20c593d25ee47f0fc56a292d5ea1684ccb1ca4ef (patch) | |
| tree | da403ab0532cc6344d90499b49bf506b9c37616e | |
| parent | b1dc7a725e553dc0cc11facb9e2aba60255cd01f (diff) | |
x86/nmi/64: Remove asm code that saves CR2
[ Upstream commit 0e181bb58143cb4a2e8f01c281b0816cd0e4798e ]
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>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
| -rw-r--r-- | arch/x86/kernel/entry_64.S | 18 |
1 files changed, 0 insertions, 18 deletions
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index e36d9815ef56..c33d25b33a4e 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -1629,29 +1629,11 @@ 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: |