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    SubjectRe: [RFC] de-asmify the x86-64 system call slowpath
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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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