glibc/hurd/hurdfchdir.c
Samuel Thibault c3b287be74 hurd: handle EINTR during critical sections
During critical sections, signal handling is deferred and thus RPCs return
EINTR, even if SA_RESTART is set. We thus have to restart the whole critical
section in that case.

This also adds HURD_CRITICAL_UNLOCK in the cases where one wants to
break the section in the middle.
2021-03-23 22:40:10 +00:00

63 lines
1.7 KiB
C

/* Change a port cell to a directory in an open file descriptor.
Copyright (C) 1999-2021 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 <errno.h>
#include <unistd.h>
#include <hurd.h>
#include <hurd/port.h>
#include <hurd/fd.h>
#include <fcntl.h>
int
_hurd_change_directory_port_from_fd (struct hurd_port *portcell, int fd)
{
int ret;
struct hurd_fd *d = _hurd_fd_get (fd);
if (!d)
return __hurd_fail (EBADF);
retry:
HURD_CRITICAL_BEGIN;
ret = HURD_PORT_USE (&d->port,
({
int ret;
/* We look up "." to force ENOTDIR if it's not a
directory and EACCES if we don't have search
permission. */
file_t dir = __file_name_lookup_under (port, ".",
O_NOTRANS, 0);
if (dir == MACH_PORT_NULL)
ret = -1;
else
{
_hurd_port_set (portcell, dir);
ret = 0;
}
ret;
}));
HURD_CRITICAL_END;
if (ret == -1 && errno == EINTR)
/* Got a signal while inside an RPC of the critical section, retry again */
goto retry;
return ret;
}