Commit-ID: 36f1a77b3aa57c5c2eb1ae2d67d07c4350a78345 Gitweb: http://git.kernel.org/tip/36f1a77b3aa57c5c2eb1ae2d67d07c4350a78345 Author: Andy Lutomirski <luto@xxxxxxxxxx> AuthorDate: Wed, 15 Jul 2015 10:29:40 -0700 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Fri, 17 Jul 2015 12:50:13 +0200 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@xxxxxxxxxx> Reviewed-by: Steven Rostedt <rostedt@xxxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- arch/x86/entry/entry_64.S | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 0fb5252..5422bd2 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 -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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