Re: __kernel_vsyscall () hangs in SIGCHLD handler

From: Ulrich Drepper
Date: Wed Sep 26 2007 - 13:03:45 EST

On 9/26/07, John Z. Bohach <jzb2@xxxxxxxxxxxxx> wrote:
> Is there some reason that syslog() sleeps in __kernel_vsyscall() when
> invoked from a signal handler?

Only very few functions are allowed to be called from signal handlers.
This is clearly spelled out in the POSIX spec. Section XSH 2.4.3
lists the allowed functions. syslog of course is not on it.
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