pt-getschedparam pt-setschedparam pt-setschedprio \
pt-yield \
\
- sem-close sem-destroy sem-getvalue sem-init sem-open \
- sem-post sem-timedwait sem-trywait sem-unlink \
+ sem_close sem-destroy sem-getvalue sem-init sem_open \
+ sem-post sem-timedwait sem-trywait sem_unlink \
sem-wait sem-waitfast \
\
shm-directory \
--- /dev/null
+/* Copyright (C) 2002-2020 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <semaphore.h>
+#include "pt-internal.h"
+
+#define SEM_SHM_PREFIX "sem."
+
+/* Keeping track of currently used mappings. */
+struct inuse_sem
+{
+ dev_t dev;
+ ino_t ino;
+ int refcnt;
+ sem_t *sem;
+ char name[0];
+};
+
+
+/* The search tree for existing mappings. */
+extern void *__sem_mappings attribute_hidden;
+
+/* Lock to protect the search tree. */
+extern int __sem_mappings_lock attribute_hidden;
+
+
+/* Comparison function for search in tree with existing mappings. */
+extern int __sem_search (const void *a, const void *b) attribute_hidden;
+
+static inline void __new_sem_open_init (struct new_sem *sem, unsigned value)
+{
+ /* This always is a shared semaphore. */
+ *sem = (struct new_sem) __SEMAPHORE_INITIALIZER (1, value);
+}
+++ /dev/null
-/* Copyright (C) 2002-2020 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
- Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
-
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
-
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; if not, see
- <https://www.gnu.org/licenses/>. */
-
-#include <errno.h>
-#include <search.h>
-#include <sys/mman.h>
-#include "semaphoreP.h"
-
-struct walk_closure
-{
- sem_t *the_sem;
- struct inuse_sem *rec;
-};
-
-static void
-walker (const void *inodep, VISIT which, void *closure0)
-{
- struct walk_closure *closure = closure0;
- struct inuse_sem *nodep = *(struct inuse_sem **) inodep;
-
- if (nodep->sem == closure->the_sem)
- closure->rec = nodep;
-}
-
-
-int
-sem_close (sem_t *sem)
-{
- int result = 0;
-
- /* Get the lock. */
- lll_lock (__sem_mappings_lock, LLL_PRIVATE);
-
- /* Locate the entry for the mapping the caller provided. */
- struct inuse_sem *rec;
- {
- struct walk_closure closure = { .the_sem = sem, .rec = NULL };
- __twalk_r (__sem_mappings, walker, &closure);
- rec = closure.rec;
- }
- if (rec != NULL)
- {
- /* Check the reference counter. If it is going to be zero, free
- all the resources. */
- if (--rec->refcnt == 0)
- {
- /* Remove the record from the tree. */
- (void) __tdelete (rec, &__sem_mappings, __sem_search);
-
- result = munmap (rec->sem, sizeof (sem_t));
-
- free (rec);
- }
- }
- else
- {
- /* This is no valid semaphore. */
- result = -1;
- __set_errno (EINVAL);
- }
-
- /* Release the lock. */
- lll_unlock (__sem_mappings_lock, LLL_PRIVATE);
-
- return result;
-}
+++ /dev/null
-/* Copyright (C) 2002-2020 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
- Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
-
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
-
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; if not, see
- <https://www.gnu.org/licenses/>. */
-
-#include <errno.h>
-#include <fcntl.h>
-#include <pthread.h>
-#include <search.h>
-#include <semaphore.h>
-#include <stdarg.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-#include <sys/mman.h>
-#include <sys/stat.h>
-#include "semaphoreP.h"
-#include <shm-directory.h>
-#include <futex-internal.h>
-#include <libc-lock.h>
-
-/* Comparison function for search of existing mapping. */
-int
-attribute_hidden
-__sem_search (const void *a, const void *b)
-{
- const struct inuse_sem *as = (const struct inuse_sem *) a;
- const struct inuse_sem *bs = (const struct inuse_sem *) b;
-
- if (as->ino != bs->ino)
- /* Cannot return the difference the type is larger than int. */
- return as->ino < bs->ino ? -1 : (as->ino == bs->ino ? 0 : 1);
-
- if (as->dev != bs->dev)
- /* Cannot return the difference the type is larger than int. */
- return as->dev < bs->dev ? -1 : (as->dev == bs->dev ? 0 : 1);
-
- return strcmp (as->name, bs->name);
-}
-
-
-/* The search tree for existing mappings. */
-void *__sem_mappings attribute_hidden;
-
-/* Lock to protect the search tree. */
-int __sem_mappings_lock attribute_hidden = LLL_LOCK_INITIALIZER;
-
-
-/* Search for existing mapping and if possible add the one provided. */
-static sem_t *
-check_add_mapping (const char *name, size_t namelen, int fd, sem_t *existing)
-{
- sem_t *result = SEM_FAILED;
-
- /* Get the information about the file. */
- struct stat64 st;
- if (__fxstat64 (_STAT_VER, fd, &st) == 0)
- {
- /* Get the lock. */
- lll_lock (__sem_mappings_lock, LLL_PRIVATE);
-
- /* Search for an existing mapping given the information we have. */
- struct inuse_sem *fake;
- fake = (struct inuse_sem *) alloca (sizeof (*fake) + namelen);
- memcpy (fake->name, name, namelen);
- fake->dev = st.st_dev;
- fake->ino = st.st_ino;
-
- struct inuse_sem **foundp = __tfind (fake, &__sem_mappings,
- __sem_search);
- if (foundp != NULL)
- {
- /* There is already a mapping. Use it. */
- result = (*foundp)->sem;
- ++(*foundp)->refcnt;
- }
- else
- {
- /* We haven't found a mapping. Install ione. */
- struct inuse_sem *newp;
-
- newp = (struct inuse_sem *) malloc (sizeof (*newp) + namelen);
- if (newp != NULL)
- {
- /* If the caller hasn't provided any map it now. */
- if (existing == SEM_FAILED)
- existing = (sem_t *) mmap (NULL, sizeof (sem_t),
- PROT_READ | PROT_WRITE, MAP_SHARED,
- fd, 0);
-
- newp->dev = st.st_dev;
- newp->ino = st.st_ino;
- newp->refcnt = 1;
- newp->sem = existing;
- memcpy (newp->name, name, namelen);
-
- /* Insert the new value. */
- if (existing != MAP_FAILED
- && __tsearch (newp, &__sem_mappings, __sem_search) != NULL)
- /* Successful. */
- result = existing;
- else
- /* Something went wrong while inserting the new
- value. We fail completely. */
- free (newp);
- }
- }
-
- /* Release the lock. */
- lll_unlock (__sem_mappings_lock, LLL_PRIVATE);
- }
-
- if (result != existing && existing != SEM_FAILED && existing != MAP_FAILED)
- {
- /* Do not disturb errno. */
- int save = errno;
- munmap (existing, sizeof (sem_t));
- errno = save;
- }
-
- return result;
-}
-
-
-sem_t *
-sem_open (const char *name, int oflag, ...)
-{
- int fd;
- sem_t *result;
-
- /* Check that shared futexes are supported. */
- int err = futex_supports_pshared (PTHREAD_PROCESS_SHARED);
- if (err != 0)
- {
- __set_errno (err);
- return SEM_FAILED;
- }
-
- /* Create the name of the final file in local variable SHM_NAME. */
- SHM_GET_NAME (EINVAL, SEM_FAILED, SEM_SHM_PREFIX);
-
- /* Disable asynchronous cancellation. */
-#ifdef __libc_ptf_call
- int state;
- __libc_ptf_call (__pthread_setcancelstate,
- (PTHREAD_CANCEL_DISABLE, &state), 0);
-#endif
-
- /* If the semaphore object has to exist simply open it. */
- if ((oflag & O_CREAT) == 0 || (oflag & O_EXCL) == 0)
- {
- try_again:
- fd = __libc_open (shm_name,
- (oflag & ~(O_CREAT|O_ACCMODE)) | O_NOFOLLOW | O_RDWR);
-
- if (fd == -1)
- {
- /* If we are supposed to create the file try this next. */
- if ((oflag & O_CREAT) != 0 && errno == ENOENT)
- goto try_create;
-
- /* Return. errno is already set. */
- }
- else
- /* Check whether we already have this semaphore mapped and
- create one if necessary. */
- result = check_add_mapping (name, namelen, fd, SEM_FAILED);
- }
- else
- {
- /* We have to open a temporary file first since it must have the
- correct form before we can start using it. */
- char *tmpfname;
- mode_t mode;
- unsigned int value;
- va_list ap;
-
- try_create:
- va_start (ap, oflag);
-
- mode = va_arg (ap, mode_t);
- value = va_arg (ap, unsigned int);
-
- va_end (ap);
-
- if (value > SEM_VALUE_MAX)
- {
- __set_errno (EINVAL);
- result = SEM_FAILED;
- goto out;
- }
-
- /* Create the initial file content. */
- union
- {
- sem_t initsem;
- struct new_sem newsem;
- } sem;
-
- __new_sem_open_init (&sem.newsem, value);
-
- /* Initialize the remaining bytes as well. */
- memset ((char *) &sem.initsem + sizeof (struct new_sem), '\0',
- sizeof (sem_t) - sizeof (struct new_sem));
-
- tmpfname = __alloca (shm_dirlen + sizeof SEM_SHM_PREFIX + 6);
- char *xxxxxx = __mempcpy (tmpfname, shm_dir, shm_dirlen);
-
- int retries = 0;
-#define NRETRIES 50
- while (1)
- {
- /* Add the suffix for mktemp. */
- strcpy (xxxxxx, "XXXXXX");
-
- /* We really want to use mktemp here. We cannot use mkstemp
- since the file must be opened with a specific mode. The
- mode cannot later be set since then we cannot apply the
- file create mask. */
- if (__mktemp (tmpfname) == NULL)
- {
- result = SEM_FAILED;
- goto out;
- }
-
- /* Open the file. Make sure we do not overwrite anything. */
- fd = __libc_open (tmpfname, O_RDWR | O_CREAT | O_EXCL, mode);
- if (fd == -1)
- {
- if (errno == EEXIST)
- {
- if (++retries < NRETRIES)
- continue;
-
- __set_errno (EAGAIN);
- }
-
- result = SEM_FAILED;
- goto out;
- }
-
- /* We got a file. */
- break;
- }
-
- if (TEMP_FAILURE_RETRY (__libc_write (fd, &sem.initsem, sizeof (sem_t)))
- == sizeof (sem_t)
- /* Map the sem_t structure from the file. */
- && (result = (sem_t *) mmap (NULL, sizeof (sem_t),
- PROT_READ | PROT_WRITE, MAP_SHARED,
- fd, 0)) != MAP_FAILED)
- {
- /* Create the file. Don't overwrite an existing file. */
- if (link (tmpfname, shm_name) != 0)
- {
- /* Undo the mapping. */
- (void) munmap (result, sizeof (sem_t));
-
- /* Reinitialize 'result'. */
- result = SEM_FAILED;
-
- /* This failed. If O_EXCL is not set and the problem was
- that the file exists, try again. */
- if ((oflag & O_EXCL) == 0 && errno == EEXIST)
- {
- /* Remove the file. */
- (void) unlink (tmpfname);
-
- /* Close the file. */
- (void) __libc_close (fd);
-
- goto try_again;
- }
- }
- else
- /* Insert the mapping into the search tree. This also
- determines whether another thread sneaked by and already
- added such a mapping despite the fact that we created it. */
- result = check_add_mapping (name, namelen, fd, result);
- }
-
- /* Now remove the temporary name. This should never fail. If
- it fails we leak a file name. Better fix the kernel. */
- (void) unlink (tmpfname);
- }
-
- /* Map the mmap error to the error we need. */
- if (MAP_FAILED != (void *) SEM_FAILED && result == MAP_FAILED)
- result = SEM_FAILED;
-
- /* We don't need the file descriptor anymore. */
- if (fd != -1)
- {
- /* Do not disturb errno. */
- int save = errno;
- __libc_close (fd);
- errno = save;
- }
-
-out:
-#ifdef __libc_ptf_call
- __libc_ptf_call (__pthread_setcancelstate, (state, NULL), 0);
-#endif
-
- return result;
-}
+++ /dev/null
-/* Copyright (C) 2002-2020 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
- Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
-
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
-
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; if not, see
- <https://www.gnu.org/licenses/>. */
-
-#include <errno.h>
-#include <semaphore.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-#include "semaphoreP.h"
-#include <shm-directory.h>
-
-int
-sem_unlink (const char *name)
-{
- /* Construct the filename. */
- SHM_GET_NAME (ENOENT, -1, SEM_SHM_PREFIX);
-
- /* Now try removing it. */
- int ret = unlink (shm_name);
- if (ret < 0 && errno == EPERM)
- __set_errno (EACCES);
- return ret;
-}
+++ /dev/null
-/* Close a named semaphore. Generic version.
- Copyright (C) 2005-2020 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
-
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
-
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; if not, see
- <https://www.gnu.org/licenses/>. */
-
-#include <semaphore.h>
-#include <errno.h>
-
-#include <pt-internal.h>
-
-int
-__sem_close (sem_t *sem)
-{
- errno = EOPNOTSUPP;
- return -1;
-}
-
-strong_alias (__sem_close, sem_close);
+++ /dev/null
-/* Open a named semaphore. Generic version.
- Copyright (C) 2005-2020 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
-
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
-
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; if not, see
- <https://www.gnu.org/licenses/>. */
-
-#include <semaphore.h>
-#include <errno.h>
-
-#include <pt-internal.h>
-
-sem_t *
-__sem_open (const char *name, int open_flags, ...)
-{
- errno = EOPNOTSUPP;
- return SEM_FAILED;
-}
-
-strong_alias (__sem_open, sem_open);
+++ /dev/null
-/* Unlink a named semaphore. Generic version.
- Copyright (C) 2005-2020 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
-
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
-
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; if not, see
- <https://www.gnu.org/licenses/>. */
-
-#include <semaphore.h>
-#include <errno.h>
-
-#include <pt-internal.h>
-
-int
-__sem_unlink (const char *name)
-{
- errno = EOPNOTSUPP;
- return -1;
-}
-
-strong_alias (__sem_unlink, sem_unlink);
--- /dev/null
+/* Copyright (C) 2002-2020 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <errno.h>
+#include <search.h>
+#include <sys/mman.h>
+#include "semaphoreP.h"
+
+struct walk_closure
+{
+ sem_t *the_sem;
+ struct inuse_sem *rec;
+};
+
+static void
+walker (const void *inodep, VISIT which, void *closure0)
+{
+ struct walk_closure *closure = closure0;
+ struct inuse_sem *nodep = *(struct inuse_sem **) inodep;
+
+ if (nodep->sem == closure->the_sem)
+ closure->rec = nodep;
+}
+
+
+int
+sem_close (sem_t *sem)
+{
+ int result = 0;
+
+ /* Get the lock. */
+ lll_lock (__sem_mappings_lock, LLL_PRIVATE);
+
+ /* Locate the entry for the mapping the caller provided. */
+ struct inuse_sem *rec;
+ {
+ struct walk_closure closure = { .the_sem = sem, .rec = NULL };
+ __twalk_r (__sem_mappings, walker, &closure);
+ rec = closure.rec;
+ }
+ if (rec != NULL)
+ {
+ /* Check the reference counter. If it is going to be zero, free
+ all the resources. */
+ if (--rec->refcnt == 0)
+ {
+ /* Remove the record from the tree. */
+ (void) __tdelete (rec, &__sem_mappings, __sem_search);
+
+ result = munmap (rec->sem, sizeof (sem_t));
+
+ free (rec);
+ }
+ }
+ else
+ {
+ /* This is no valid semaphore. */
+ result = -1;
+ __set_errno (EINVAL);
+ }
+
+ /* Release the lock. */
+ lll_unlock (__sem_mappings_lock, LLL_PRIVATE);
+
+ return result;
+}
--- /dev/null
+/* Copyright (C) 2002-2020 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <pthread.h>
+#include <search.h>
+#include <semaphore.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include "semaphoreP.h"
+#include <shm-directory.h>
+#include <futex-internal.h>
+#include <libc-lock.h>
+
+/* Comparison function for search of existing mapping. */
+int
+attribute_hidden
+__sem_search (const void *a, const void *b)
+{
+ const struct inuse_sem *as = (const struct inuse_sem *) a;
+ const struct inuse_sem *bs = (const struct inuse_sem *) b;
+
+ if (as->ino != bs->ino)
+ /* Cannot return the difference the type is larger than int. */
+ return as->ino < bs->ino ? -1 : (as->ino == bs->ino ? 0 : 1);
+
+ if (as->dev != bs->dev)
+ /* Cannot return the difference the type is larger than int. */
+ return as->dev < bs->dev ? -1 : (as->dev == bs->dev ? 0 : 1);
+
+ return strcmp (as->name, bs->name);
+}
+
+
+/* The search tree for existing mappings. */
+void *__sem_mappings attribute_hidden;
+
+/* Lock to protect the search tree. */
+int __sem_mappings_lock attribute_hidden = LLL_LOCK_INITIALIZER;
+
+
+/* Search for existing mapping and if possible add the one provided. */
+static sem_t *
+check_add_mapping (const char *name, size_t namelen, int fd, sem_t *existing)
+{
+ sem_t *result = SEM_FAILED;
+
+ /* Get the information about the file. */
+ struct stat64 st;
+ if (__fxstat64 (_STAT_VER, fd, &st) == 0)
+ {
+ /* Get the lock. */
+ lll_lock (__sem_mappings_lock, LLL_PRIVATE);
+
+ /* Search for an existing mapping given the information we have. */
+ struct inuse_sem *fake;
+ fake = (struct inuse_sem *) alloca (sizeof (*fake) + namelen);
+ memcpy (fake->name, name, namelen);
+ fake->dev = st.st_dev;
+ fake->ino = st.st_ino;
+
+ struct inuse_sem **foundp = __tfind (fake, &__sem_mappings,
+ __sem_search);
+ if (foundp != NULL)
+ {
+ /* There is already a mapping. Use it. */
+ result = (*foundp)->sem;
+ ++(*foundp)->refcnt;
+ }
+ else
+ {
+ /* We haven't found a mapping. Install ione. */
+ struct inuse_sem *newp;
+
+ newp = (struct inuse_sem *) malloc (sizeof (*newp) + namelen);
+ if (newp != NULL)
+ {
+ /* If the caller hasn't provided any map it now. */
+ if (existing == SEM_FAILED)
+ existing = (sem_t *) mmap (NULL, sizeof (sem_t),
+ PROT_READ | PROT_WRITE, MAP_SHARED,
+ fd, 0);
+
+ newp->dev = st.st_dev;
+ newp->ino = st.st_ino;
+ newp->refcnt = 1;
+ newp->sem = existing;
+ memcpy (newp->name, name, namelen);
+
+ /* Insert the new value. */
+ if (existing != MAP_FAILED
+ && __tsearch (newp, &__sem_mappings, __sem_search) != NULL)
+ /* Successful. */
+ result = existing;
+ else
+ /* Something went wrong while inserting the new
+ value. We fail completely. */
+ free (newp);
+ }
+ }
+
+ /* Release the lock. */
+ lll_unlock (__sem_mappings_lock, LLL_PRIVATE);
+ }
+
+ if (result != existing && existing != SEM_FAILED && existing != MAP_FAILED)
+ {
+ /* Do not disturb errno. */
+ int save = errno;
+ munmap (existing, sizeof (sem_t));
+ errno = save;
+ }
+
+ return result;
+}
+
+
+sem_t *
+sem_open (const char *name, int oflag, ...)
+{
+ int fd;
+ sem_t *result;
+
+ /* Check that shared futexes are supported. */
+ int err = futex_supports_pshared (PTHREAD_PROCESS_SHARED);
+ if (err != 0)
+ {
+ __set_errno (err);
+ return SEM_FAILED;
+ }
+
+ /* Create the name of the final file in local variable SHM_NAME. */
+ SHM_GET_NAME (EINVAL, SEM_FAILED, SEM_SHM_PREFIX);
+
+ /* Disable asynchronous cancellation. */
+#ifdef __libc_ptf_call
+ int state;
+ __libc_ptf_call (__pthread_setcancelstate,
+ (PTHREAD_CANCEL_DISABLE, &state), 0);
+#endif
+
+ /* If the semaphore object has to exist simply open it. */
+ if ((oflag & O_CREAT) == 0 || (oflag & O_EXCL) == 0)
+ {
+ try_again:
+ fd = __libc_open (shm_name,
+ (oflag & ~(O_CREAT|O_ACCMODE)) | O_NOFOLLOW | O_RDWR);
+
+ if (fd == -1)
+ {
+ /* If we are supposed to create the file try this next. */
+ if ((oflag & O_CREAT) != 0 && errno == ENOENT)
+ goto try_create;
+
+ /* Return. errno is already set. */
+ }
+ else
+ /* Check whether we already have this semaphore mapped and
+ create one if necessary. */
+ result = check_add_mapping (name, namelen, fd, SEM_FAILED);
+ }
+ else
+ {
+ /* We have to open a temporary file first since it must have the
+ correct form before we can start using it. */
+ char *tmpfname;
+ mode_t mode;
+ unsigned int value;
+ va_list ap;
+
+ try_create:
+ va_start (ap, oflag);
+
+ mode = va_arg (ap, mode_t);
+ value = va_arg (ap, unsigned int);
+
+ va_end (ap);
+
+ if (value > SEM_VALUE_MAX)
+ {
+ __set_errno (EINVAL);
+ result = SEM_FAILED;
+ goto out;
+ }
+
+ /* Create the initial file content. */
+ union
+ {
+ sem_t initsem;
+ struct new_sem newsem;
+ } sem;
+
+ __new_sem_open_init (&sem.newsem, value);
+
+ /* Initialize the remaining bytes as well. */
+ memset ((char *) &sem.initsem + sizeof (struct new_sem), '\0',
+ sizeof (sem_t) - sizeof (struct new_sem));
+
+ tmpfname = __alloca (shm_dirlen + sizeof SEM_SHM_PREFIX + 6);
+ char *xxxxxx = __mempcpy (tmpfname, shm_dir, shm_dirlen);
+
+ int retries = 0;
+#define NRETRIES 50
+ while (1)
+ {
+ /* Add the suffix for mktemp. */
+ strcpy (xxxxxx, "XXXXXX");
+
+ /* We really want to use mktemp here. We cannot use mkstemp
+ since the file must be opened with a specific mode. The
+ mode cannot later be set since then we cannot apply the
+ file create mask. */
+ if (__mktemp (tmpfname) == NULL)
+ {
+ result = SEM_FAILED;
+ goto out;
+ }
+
+ /* Open the file. Make sure we do not overwrite anything. */
+ fd = __libc_open (tmpfname, O_RDWR | O_CREAT | O_EXCL, mode);
+ if (fd == -1)
+ {
+ if (errno == EEXIST)
+ {
+ if (++retries < NRETRIES)
+ continue;
+
+ __set_errno (EAGAIN);
+ }
+
+ result = SEM_FAILED;
+ goto out;
+ }
+
+ /* We got a file. */
+ break;
+ }
+
+ if (TEMP_FAILURE_RETRY (__libc_write (fd, &sem.initsem, sizeof (sem_t)))
+ == sizeof (sem_t)
+ /* Map the sem_t structure from the file. */
+ && (result = (sem_t *) mmap (NULL, sizeof (sem_t),
+ PROT_READ | PROT_WRITE, MAP_SHARED,
+ fd, 0)) != MAP_FAILED)
+ {
+ /* Create the file. Don't overwrite an existing file. */
+ if (link (tmpfname, shm_name) != 0)
+ {
+ /* Undo the mapping. */
+ (void) munmap (result, sizeof (sem_t));
+
+ /* Reinitialize 'result'. */
+ result = SEM_FAILED;
+
+ /* This failed. If O_EXCL is not set and the problem was
+ that the file exists, try again. */
+ if ((oflag & O_EXCL) == 0 && errno == EEXIST)
+ {
+ /* Remove the file. */
+ (void) unlink (tmpfname);
+
+ /* Close the file. */
+ (void) __libc_close (fd);
+
+ goto try_again;
+ }
+ }
+ else
+ /* Insert the mapping into the search tree. This also
+ determines whether another thread sneaked by and already
+ added such a mapping despite the fact that we created it. */
+ result = check_add_mapping (name, namelen, fd, result);
+ }
+
+ /* Now remove the temporary name. This should never fail. If
+ it fails we leak a file name. Better fix the kernel. */
+ (void) unlink (tmpfname);
+ }
+
+ /* Map the mmap error to the error we need. */
+ if (MAP_FAILED != (void *) SEM_FAILED && result == MAP_FAILED)
+ result = SEM_FAILED;
+
+ /* We don't need the file descriptor anymore. */
+ if (fd != -1)
+ {
+ /* Do not disturb errno. */
+ int save = errno;
+ __libc_close (fd);
+ errno = save;
+ }
+
+out:
+#ifdef __libc_ptf_call
+ __libc_ptf_call (__pthread_setcancelstate, (state, NULL), 0);
+#endif
+
+ return result;
+}
--- /dev/null
+/* Copyright (C) 2002-2020 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <errno.h>
+#include <semaphore.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include "semaphoreP.h"
+#include <shm-directory.h>
+
+int
+sem_unlink (const char *name)
+{
+ /* Construct the filename. */
+ SHM_GET_NAME (ENOENT, -1, SEM_SHM_PREFIX);
+
+ /* Now try removing it. */
+ int ret = unlink (shm_name);
+ if (ret < 0 && errno == EPERM)
+ __set_errno (EACCES);
+ return ret;
+}
projects / glibc.git / commitdiff