Messages in this thread | | | Date | Fri, 28 Feb 2014 08:37:28 -0500 | From | Steven Rostedt <> | Subject | Re: perf_fuzzer compiled for x32 causes reboot |
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On Fri, 28 Feb 2014 12:11:11 +0100 Peter Zijlstra <peterz@infradead.org> wrote:
> On Thu, Feb 27, 2014 at 09:57:26PM -0500, Steven Rostedt wrote: > > @@ -512,8 +508,21 @@ static inline void nmi_nesting_postprocess(void) > > dotraplinkage notrace __kprobes void > > do_nmi(struct pt_regs *regs, long error_code) > > { > > + unsigned long cr2; > > + > > nmi_nesting_preprocess(regs); > > > > + /* > > + * 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. > > You might want to make that line go away :-) >
Gah! I noticed that before sending and deleted the line, recreated the patch and sent that out. The one step I forgot to do was to save the file after deleting it :-p
-- Steve
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