diff options
Diffstat (limited to 'sysdeps/pthread/sem_open.c')
| -rw-r--r-- | sysdeps/pthread/sem_open.c | 34 |
1 files changed, 19 insertions, 15 deletions
diff --git a/sysdeps/pthread/sem_open.c b/sysdeps/pthread/sem_open.c index b0b722121d..d666414f32 100644 --- a/sysdeps/pthread/sem_open.c +++ b/sysdeps/pthread/sem_open.c @@ -62,8 +62,9 @@ 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) +check_add_mapping (const char *name, int fd, sem_t *existing) { + size_t namelen = strlen (name); sem_t *result = SEM_FAILED; /* Get the information about the file. */ @@ -150,8 +151,12 @@ sem_open (const char *name, int oflag, ...) return SEM_FAILED; } - /* Create the name of the final file in local variable SHM_NAME. */ - SHM_GET_NAME (EINVAL, SEM_FAILED, SEM_SHM_PREFIX); + struct shmdir_name dirname; + if (__shm_get_name (&dirname, name, true) != 0) + { + __set_errno (EINVAL); + return SEM_FAILED; + } /* Disable asynchronous cancellation. */ #ifdef __libc_ptf_call @@ -164,7 +169,7 @@ sem_open (const char *name, int oflag, ...) if ((oflag & O_CREAT) == 0 || (oflag & O_EXCL) == 0) { try_again: - fd = __libc_open (shm_name, + fd = __libc_open (dirname.name, (oflag & ~(O_CREAT|O_ACCMODE)) | O_NOFOLLOW | O_RDWR); if (fd == -1) @@ -178,13 +183,12 @@ sem_open (const char *name, int oflag, ...) else /* Check whether we already have this semaphore mapped and create one if necessary. */ - result = check_add_mapping (name, namelen, fd, SEM_FAILED); + result = check_add_mapping (name, 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; @@ -217,16 +221,11 @@ sem_open (const char *name, int oflag, ...) 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); - + char tmpfname[] = SHMDIR "sem.XXXXXX"; 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 @@ -244,7 +243,12 @@ sem_open (const char *name, int oflag, ...) if (errno == EEXIST) { if (++retries < NRETRIES) - continue; + { + /* Restore the six placeholder bytes before the + null terminator before the next attempt. */ + memcpy (tmpfname + sizeof (tmpfname) - 7, "XXXXXX", 6); + continue; + } __set_errno (EAGAIN); } @@ -265,7 +269,7 @@ sem_open (const char *name, int oflag, ...) fd, 0)) != MAP_FAILED) { /* Create the file. Don't overwrite an existing file. */ - if (link (tmpfname, shm_name) != 0) + if (link (tmpfname, dirname.name) != 0) { /* Undo the mapping. */ (void) munmap (result, sizeof (sem_t)); @@ -290,7 +294,7 @@ sem_open (const char *name, int oflag, ...) /* 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); + result = check_add_mapping (name, fd, result); } /* Now remove the temporary name. This should never fail. If |