Messages in this thread | | | Date | Wed, 08 Aug 2012 17:02:33 +0200 | From | Sebastian Andrzej Siewior <> | Subject | Re: [PATCH 2/5] x86/uprobes: implement x86 specific arch_uprobe_*_step |
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On 08/08/2012 04:53 PM, Oleg Nesterov wrote: >> Why? I tried 'lock popf' and I got invalid instruction. The same for >> 'rep popf'. > > int main(void) > { > asm volatile ("pushf; rep; popf"); > > return 0; > } >
Just tested and it works. Hmm.
> OK, probably nobody should do this (although the kernel should not > assume this imho), but > > asm volatile ("pushfw; popfw"); > > doesn't look bad and the code is > > 000000000040047c<main>: > 40047c: 55 push %rbp > 40047d: 48 89 e5 mov %rsp,%rbp > 400480: 66 9c pushfw > 400482: 66 9d popfw > 400484: b8 00 00 00 00 mov $0x0,%eax > 400489: c9 leaveq > 40048a: c3 retq
Yes, that one works as well.
> And in any case it would be better to re-use auprobe->fixups.
Okay.
> Oleg. >
Sebastian
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