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| author | Andy Lutomirski <luto@kernel.org> | 2015-07-15 10:29:40 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-07-17 12:50:13 +0200 |
| commit | 36f1a77b3aa57c5c2eb1ae2d67d07c4350a78345 (patch) | |
| tree | d948951c13d43bfd632922c8c17ca56add40431d | |
| parent | 23a781e987f05029c4a99a5c145be3efa6eda9f3 (diff) | |
| download | linux-36f1a77b3aa57c5c2eb1ae2d67d07c4350a78345.tar.gz | |
x86/nmi/64: Make the "NMI executing" variable more consistent
Currently, "NMI executing" is one the first time an outermost NMI hits repeat_nmi and zero thereafter. Change it to be zero each time for consistency. This is intended to help NMI handling fail harder if it's buggy. Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Borislav 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: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | arch/x86/entry/entry_64.S | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 0fb52526e452..5422bd20bdf4 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -1441,8 +1441,8 @@ first_nmi: /* Restore rdx. */ movq (%rsp), %rdx - /* Set "NMI executing" on the stack. */ - pushq $1 + /* Make room for "NMI executing". */ + pushq $0 /* Leave room for the "iret" frame */ subq $(5*8), %rsp @@ -1467,11 +1467,10 @@ repeat_nmi: * RSP is pointing to "outermost RIP". gsbase is unknown, but, if * we're repeating an NMI, gsbase has the same value that it had on * the first iteration. paranoid_entry will load the kernel - * gsbase if needed before we call do_nmi. - * - * Set "NMI executing" in case we came back here via IRET. + * gsbase if needed before we call do_nmi. "NMI executing" + * is zero. */ - movq $1, 10*8(%rsp) + movq $1, 10*8(%rsp) /* Set "NMI executing". */ /* * Copy the "outermost" frame to the "iret" frame. NMIs that nest |