From: Hydro Flask <hydroflask@yqxmail.com>
To: musl@lists.openwall.com
Subject: [musl] Potential deadlock in pthread_kill()
Date: Mon, 29 Jun 2020 21:19:08 -0700 [thread overview]
Message-ID: <0217b8838100175725993b0ed0114ee7@thelig.ht> (raw)
Hello all,
Noticed something while reading some code today. pthread_kill() is
specified by POSIX to be async signal safe but I noticed that in musl's
implementation if a signal occurs while the "killlock" is held and the
signal handler calls pthread_kill() on the same target thread, a
deadlock will occur. Is this intentional?
int pthread_kill(pthread_t t, int sig)
{
int r;
LOCK(t->killlock);
r = t->tid ? -__syscall(SYS_tkill, t->tid, sig)
: (sig+0U >= _NSIG ? EINVAL : 0);
UNLOCK(t->killlock);
return r;
}
Thank you for your attention.
Hydro
next reply other threads:[~2020-06-30 4:19 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-30 4:19 Hydro Flask [this message]
2020-06-30 4:43 ` Rich Felker
2020-06-30 6:19 ` Hydro Flask
2020-06-30 9:26 ` Rich Felker
2020-06-30 14:58 ` Markus Wichmann
2020-06-30 16:28 ` Hydro Flask
2020-06-30 19:28 ` Dmitry Samersoff
2020-06-30 19:54 ` Rich Felker
2020-06-30 21:00 ` Hydro Flask
2020-07-06 22:00 ` Rich Felker
2020-07-06 22:14 ` Hydro Flask
2020-07-06 22:22 ` Rich Felker
2020-07-06 22:37 ` Hydro Flask
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