Messages in this thread |  | | From | Andy Lutomirski <> | | Date | Mon, 27 Jul 2015 16:36:26 -0700 | | Subject | Re: ASM flags in general |
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On Mon, Jul 27, 2015 at 4:22 PM, H. Peter Anvin <hpa@zytor.com> wrote: > For that to work, gcc would have to know about the extable.
It could, I think:
asm goto ( "1: mov ...\n\t" _ASM_EXTABLE(1b, %l2) /* or whatever index it is */ : ... : ... : ... : efault);
return 0;
efault: return -EFAULT;
I think that wrmsr_safe could get this treatment with current GCC. put_user plausibly could, too, if we were willing to mark it volatile and accept that we're lying a little bit about the lack of an output constraint. get_user would need GCC to understand output constraints for real.
--Andy
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