diff options
Diffstat (limited to 'sysdeps/mach/hurd/dup2.c')
| -rw-r--r-- | sysdeps/mach/hurd/dup2.c | 40 |
1 files changed, 30 insertions, 10 deletions
diff --git a/sysdeps/mach/hurd/dup2.c b/sysdeps/mach/hurd/dup2.c index f4ec623b05..c4b16698b8 100644 --- a/sysdeps/mach/hurd/dup2.c +++ b/sysdeps/mach/hurd/dup2.c @@ -58,8 +58,7 @@ DEFUN(__dup2, (fd, fd2), int fd AND int fd2) io_t ctty = _hurd_port_get (&d->ctty, &ctty_ulink); io_t port = _hurd_port_locked_get (&d->port, &ulink); /* Unlocks D. */ - __mutex_lock (&_hurd_dtable_lock); - if (fd2 < 0 || fd2 >= _hurd_dtablesize) + if (fd2 < 0) { errno = EBADF; fd2 = -1; @@ -67,16 +66,37 @@ DEFUN(__dup2, (fd, fd2), int fd AND int fd2) else { /* Get a hold of the destination descriptor. */ - struct hurd_fd *d2 = _hurd_dtable[fd2]; - if (d2 == NULL) + struct hurd_fd *d2; + + if (fd2 >= _hurd_dtablesize) + { + /* The table is not large enough to hold the destination + descriptor. Enlarge it as necessary to allocate this + descriptor. */ + __mutex_unlock (&_hurd_dtable_lock); + /* We still hold FD1's lock, but this is safe because + _hurd_alloc_fd will only examine the cells starting + at FD2. */ + d2 = _hurd_alloc_fd (NULL, fd2); + if (d2) + __spin_unlock (&d2->port.lock); + __mutex_lock (&_hurd_dtable_lock); + } + else { - /* Must allocate a new one. We don't initialize the port cells - with this call so that if it fails (out of memory), we will - not have already added user references for the ports, which we - would then have to deallocate. */ - d2 = _hurd_dtable[fd2] = _hurd_new_fd (MACH_PORT_NULL, - MACH_PORT_NULL); + d2 = _hurd_dtable[fd2]; + if (d2 == NULL) + { + /* Must allocate a new one. We don't initialize the port + cells with this call so that if it fails (out of + memory), we will not have already added user + references for the ports, which we would then have to + deallocate. */ + d2 = _hurd_dtable[fd2] = _hurd_new_fd (MACH_PORT_NULL, + MACH_PORT_NULL); + } } + if (d2 == NULL) { fd2 = -1; |