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Linux: Move mq_notify from librt to libc

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The symbol was moved using scripts/move-symbol-to-libc.py.

An explicit call from fork into the mq_notify implementation replaces
the previous use of pthread_atfork.

Reviewed-by: Adhemerva Zanella  <adhemerval.zanella@linaro.org>
This commit is contained in:
Florian Weimer
2021-06-25 10:42:52 +02:00
parent f66d9abca7
commit 2da5f22fff
68 changed files with 101 additions and 68 deletions
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59
sysdeps/unix/sysv/linux/mq_notify.c
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@ -29,7 +29,7 @@
#include <sys/socket.h>
#include <not-cancel.h>
#include <pthreadP.h>
#include <shlib-compat.h>
/* Defined in the kernel headers: */
#define NOTIFY_COOKIE_LEN 32 /* Length of the cookie used. */
@ -75,7 +75,7 @@ change_sigmask (int how, sigset_t *oss)
{
sigset_t ss;
sigfillset (&ss);
return pthread_sigmask (how, &ss, oss);
return __pthread_sigmask (how, &ss, oss);
}
@ -93,7 +93,7 @@ notification_function (void *arg)
(void) __pthread_barrier_wait (&notify_barrier);
/* Make the thread detached. */
(void) pthread_detach (pthread_self ());
__pthread_detach (__pthread_self ());
/* The parent thread has all signals blocked. This is probably a
bit surprising for this thread. So we unblock all of them. */
@ -125,9 +125,8 @@ helper_thread (void *arg)
/* Just create the thread as instructed. There is no way to
report a problem with creating a thread. */
pthread_t th;
if (__builtin_expect (pthread_create (&th, data.attr,
notification_function, &data)
== 0, 0))
if (__pthread_create (&th, data.attr, notification_function, &data)
== 0)
/* Since we passed a pointer to DATA to the new thread we have
to wait until it is done with it. */
(void) __pthread_barrier_wait (&notify_barrier);
@ -135,7 +134,7 @@ helper_thread (void *arg)
else if (data.raw[NOTIFY_COOKIE_LEN - 1] == NOTIFY_REMOVED)
{
/* The only state we keep is the copy of the thread attributes. */
pthread_attr_destroy (data.attr);
__pthread_attr_destroy (data.attr);
free (data.attr);
}
}
@ -143,8 +142,8 @@ helper_thread (void *arg)
}
static void
reset_once (void)
void
__mq_notify_fork_subprocess (void)
{
once = PTHREAD_ONCE_INIT;
}
@ -167,15 +166,14 @@ init_mq_netlink (void)
int err = 1;
/* Initialize the barrier. */
if (__builtin_expect (__pthread_barrier_init (&notify_barrier, NULL, 2) == 0,
0))
if (__pthread_barrier_init (&notify_barrier, NULL, 2) == 0)
{
/* Create the helper thread. */
pthread_attr_t attr;
(void) pthread_attr_init (&attr);
(void) pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
__pthread_attr_init (&attr);
__pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
/* We do not need much stack space, the bare minimum will be enough. */
(void) pthread_attr_setstacksize (&attr, __pthread_get_minstack (&attr));
__pthread_attr_setstacksize (&attr, __pthread_get_minstack (&attr));
/* Temporarily block all signals so that the newly created
thread inherits the mask. */
@ -183,29 +181,13 @@ init_mq_netlink (void)
int have_no_oss = change_sigmask (SIG_BLOCK, &oss);
pthread_t th;
err = pthread_create (&th, &attr, helper_thread, NULL);
err = __pthread_create (&th, &attr, helper_thread, NULL);
/* Reset the signal mask. */
if (!have_no_oss)
pthread_sigmask (SIG_SETMASK, &oss, NULL);
__pthread_sigmask (SIG_SETMASK, &oss, NULL);
(void) pthread_attr_destroy (&attr);
if (err == 0)
{
static int added_atfork;
if (added_atfork == 0
&& pthread_atfork (NULL, NULL, reset_once) != 0)
{
/* The child thread will call recv() which is a
cancellation point. */
(void) pthread_cancel (th);
err = 1;
}
else
added_atfork = 1;
}
__pthread_attr_destroy (&attr);
}
if (err != 0)
@ -219,7 +201,7 @@ init_mq_netlink (void)
/* Register notification upon message arrival to an empty message queue
MQDES. */
int
mq_notify (mqd_t mqdes, const struct sigevent *notification)
__mq_notify (mqd_t mqdes, const struct sigevent *notification)
{
/* Make sure the type is correctly defined. */
assert (sizeof (union notify_data) == NOTIFY_COOKIE_LEN);
@ -235,7 +217,7 @@ mq_notify (mqd_t mqdes, const struct sigevent *notification)
response. */
/* Initialize only once. */
pthread_once (&once, init_mq_netlink);
__pthread_once (&once, init_mq_netlink);
/* If we cannot create the netlink socket we cannot provide
SIGEV_THREAD support. */
@ -280,9 +262,14 @@ mq_notify (mqd_t mqdes, const struct sigevent *notification)
/* If it failed, free the allocated memory. */
if (retval != 0 && data.attr != NULL)
{
pthread_attr_destroy (data.attr);
__pthread_attr_destroy (data.attr);
free (data.attr);
}
return retval;
}
versioned_symbol (libc, __mq_notify, mq_notify, GLIBC_2_34);
libc_hidden_ver (__mq_notify, mq_notify)
#if OTHER_SHLIB_COMPAT (librt, GLIBC_2_3_4, GLIBC_2_34)
compat_symbol (librt, __mq_notify, mq_notify, GLIBC_2_3_4);
#endif