Re: [patch 03/18] Dont leak NT bit into next task

From: Jan Engelhardt
Date: Wed Feb 21 2007 - 12:14:46 EST



On Feb 21 2007 11:00, Giuseppe Bilotta wrote:
>On Wednesday 21 February 2007 02:49, Greg KH wrote:
>
>> /* frame pointer must be last for get_wchan */
>> -#define SAVE_CONTEXT "pushq %%rbp ; movq %%rsi,%%rbp\n\t"
>> -#define RESTORE_CONTEXT "movq %%rbp,%%rsi ; popq %%rbp\n\t"
>> +#define SAVE_CONTEXT "pushf ; pushq %%rbp ; movq %%rsi,%%rbp\n\t"
>> +#define RESTORE_CONTEXT "movq %%rbp,%%rsi ; popq %%rbp ; popf\t"
>
>No idea if this is a problem or not, but you forgot a \n after popf.

It is on the edge. RESTORE_CONTEXT will not be passed any
arguments, so it is the only thing in a single line, and hence
the implicit \n of the source file applies after \t.
But yes, it may be dangerous. Better is an explicit \n or semicolon
after popf.


Jan
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