Commit ac11aba3 authored by Andy Lutomirski's avatar Andy Lutomirski Committed by Luis Henriques

x86/nmi/64: Remove asm code that saves CR2

commit 0e181bb5 upstream.

Now that do_nmi saves CR2, we don't need to save it in asm.
Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
Reviewed-by: default avatarSteven Rostedt <rostedt@goodmis.org>
Acked-by: default avatarBorislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
[bwh: Backported to 4.0: adjust filename, context]
Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
[ luis: backported to 3.16: used Ben's backport to 4.0 ]
Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
parent 58e0d2a4
...@@ -1636,29 +1636,11 @@ end_repeat_nmi: ...@@ -1636,29 +1636,11 @@ end_repeat_nmi:
call save_paranoid call save_paranoid
DEFAULT_FRAME 0 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 */ /* paranoidentry do_nmi, 0; without TRACE_IRQS_OFF */
movq %rsp,%rdi movq %rsp,%rdi
movq $-1,%rsi movq $-1,%rsi
call do_nmi 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? */ testl %ebx,%ebx /* swapgs needed? */
jnz nmi_restore jnz nmi_restore
nmi_swapgs: nmi_swapgs:
......
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