/* shm_open -- open a POSIX shared memory object. Generic POSIX file version.
- Copyright (C) 2001-2014 Free Software Foundation, Inc.
+ Copyright (C) 2001-2019 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
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
- <http://www.gnu.org/licenses/>. */
+ <https://www.gnu.org/licenses/>. */
#include <unistd.h>
#if ! _POSIX_MAPPED_FILES
-#include <rt/shm_open.c>
+
+# include <rt/shm_open.c>
#else
-#include <errno.h>
-#include <sys/mman.h>
-#include <fcntl.h>
-#include <string.h>
-#include <stdlib.h>
-#include <paths.h>
+# include <fcntl.h>
+# include <pthread.h>
+# include <shm-directory.h>
-#define SHMDIR (_PATH_DEV "shm/")
/* Open shared memory object. */
int
shm_open (const char *name, int oflag, mode_t mode)
{
- size_t namelen;
- char *fname;
- int fd;
-
- /* Construct the filename. */
- while (name[0] == '/')
- ++name;
-
- if (name[0] == '\0')
- {
- /* The name "/" is not supported. */
- __set_errno (EINVAL);
- return -1;
- }
-
- namelen = strlen (name);
- fname = (char *) __alloca (sizeof SHMDIR - 1 + namelen + 1);
- __mempcpy (__mempcpy (fname, SHMDIR, sizeof SHMDIR - 1),
- name, namelen + 1);
-
- fd = open (name, oflag, mode);
- if (fd != -1)
- {
- /* We got a descriptor. Now set the FD_CLOEXEC bit. */
- int flags = fcntl (fd, F_GETFD, 0);
-
- if (__builtin_expect (flags, 0) != -1)
- {
- flags |= FD_CLOEXEC;
- flags = fcntl (fd, F_SETFD, flags);
- }
-
- if (flags == -1)
- {
- /* Something went wrong. We cannot return the descriptor. */
- int save_errno = errno;
- close (fd);
- fd = -1;
- __set_errno (save_errno);
- }
- }
+ SHM_GET_NAME (EINVAL, -1, "");
+
+ oflag |= O_NOFOLLOW | O_CLOEXEC;
+
+ /* Disable asynchronous cancellation. */
+ int state;
+ pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, &state);
+
+ int fd = open (shm_name, oflag, mode);
+ if (fd == -1 && __glibc_unlikely (errno == EISDIR))
+ /* It might be better to fold this error with EINVAL since
+ directory names are just another example for unsuitable shared
+ object names and the standard does not mention EISDIR. */
+ __set_errno (EINVAL);
+
+ pthread_setcancelstate (state, NULL);
return fd;
}
-#endif
+#endif /* _POSIX_MAPPED_FILES */