glibc/sysdeps/mach/hurd/seteuid.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

72 lines
2.0 KiB
C

/* Copyright (C) 1993-2021 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 <sys/types.h>
#include <hurd/id.h>
#include <string.h>
/* Set the effective user ID of the calling process to UID. */
int
seteuid (uid_t uid)
{
auth_t newauth;
error_t err;
retry:
HURD_CRITICAL_BEGIN;
__mutex_lock (&_hurd_id.lock);
err = _hurd_check_ids ();
if (!err)
{
/* Make a new auth handle which has EUID as the first element in the
list of effective uids. */
if (_hurd_id.gen.nuids > 0)
{
_hurd_id.gen.uids[0] = uid;
_hurd_id.valid = 0;
}
err = __USEPORT (AUTH, __auth_makeauth
(port, NULL, MACH_MSG_TYPE_COPY_SEND, 0,
_hurd_id.gen.nuids ? _hurd_id.gen.uids : &uid,
_hurd_id.gen.nuids ?: 1,
_hurd_id.aux.uids, _hurd_id.aux.nuids,
_hurd_id.gen.gids, _hurd_id.gen.ngids,
_hurd_id.aux.gids, _hurd_id.aux.ngids,
&newauth));
}
__mutex_unlock (&_hurd_id.lock);
HURD_CRITICAL_END;
if (err == EINTR)
/* Got a signal while inside an RPC of the critical section, retry again */
goto retry;
if (err)
return __hurd_fail (err);
/* Install the new handle and reauthenticate everything. */
err = __setauth (newauth);
__mach_port_deallocate (__mach_task_self (), newauth);
return err;
}
libc_hidden_def (seteuid)