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    SubjectRe: ERESTARTSYS question.
    On Thu, 5 Apr 2001, Jani Monoses wrote:
    > On Thu, 5 Apr 2001, Bjorn Wesen wrote:
    > > ERESTARTSYS is a part of the api between the driver and the
    > > signal-handling code in the kernel. It does not reach user-space (provided
    > > of course that it's used appropriately in the drivers :)
    >
    > As an example sound/via82cxxx_audio.c returns ERESTARTSYS from
    > via_dsp_open() .I suppose this _does_ reach userland right?

    No; system calls do not exit directly to userland, they exit through the
    magic in entry.S (confusingly so :). If a signal is pending (which it is,
    if down_interruptible fails) the return is made through do_signal, which
    rewrites the return value and does the proper restarting.

    (down_interruptible means it can be interrupted by a signal, btw - bad
    drivers do sleep and semaphoring without _interruptible so if your HW is
    bad the process can get stuck irrecoverably in the kernel)

    /Bjorn

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