Messages in this thread | | | Date | Sun, 26 Jan 2014 20:32:09 -0800 | Subject | Re: [RFC] de-asmify the x86-64 system call slowpath | From | Linus Torvalds <> |
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On Sun, Jan 26, 2014 at 4:22 PM, Al Viro <viro@zeniv.linux.org.uk> wrote: > > Umm... Can't uprobe_notify_resume() modify regs as well?
Probably.
.. and on the other hand, we should actually be able to use 'sysret' for signal handling on x86-64, because while sysret destroys %rcx and doesn't allow for returning to odd modes, for calling a signal handler I don't think we really care..
> While we > are at it, when we start using the same thing on 32bit kernels, we'll > need to watch out for execve() - the reason why start_thread() sets > TIF_NOTIFY_RESUME is to force us away from sysexit path. IIRC, vm86 > is another thing to watch out for (same reasons).
Yes, the 32-bit code I didn't want to touch, partly because I no longer have a test-case. And it does end up having some more interesting cases.
Linus
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