From 749cd2ca7893702f762de9d9852a39973eb044a0 Mon Sep 17 00:00:00 2001 From: Samuel Thibault Date: Sun, 13 Dec 2020 15:20:32 +0000 Subject: htl: Get sem_open/sem_close/sem_unlink support [BZ #25524] This just moves the existing nptl implementation to reuse as it is in htl. --- nptl/sem_open.c | 320 -------------------------------------------------------- 1 file changed, 320 deletions(-) delete mode 100644 nptl/sem_open.c (limited to 'nptl/sem_open.c') diff --git a/nptl/sem_open.c b/nptl/sem_open.c deleted file mode 100644 index 634bdf7..0000000 --- a/nptl/sem_open.c +++ /dev/null @@ -1,320 +0,0 @@ -/* Copyright (C) 2002-2020 Free Software Foundation, Inc. - This file is part of the GNU C Library. - Contributed by Ulrich Drepper , 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 - . */ - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include "semaphoreP.h" -#include -#include -#include - -/* 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 (__fstat64 (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; -} -- cgit v1.1