glibc/sysdeps/mach/hurd/geteuid.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

61 lines
1.6 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 <hurd/id.h>
/* Get the effective user ID of the calling process. */
uid_t
__geteuid (void)
{
error_t err;
uid_t euid;
retry:
HURD_CRITICAL_BEGIN;
__mutex_lock (&_hurd_id.lock);
if (err = _hurd_check_ids ())
{
errno = err;
euid = -1;
}
else if (_hurd_id.gen.nuids >= 1)
euid = _hurd_id.gen.uids[0];
else if (_hurd_id.aux.nuids >= 1)
/* We have no effective uids. Return the real uid. */
euid = _hurd_id.aux.uids[0];
else
{
/* We do not even have a real uid. */
errno = EGRATUITOUS;
euid = -1;
}
__mutex_unlock (&_hurd_id.lock);
HURD_CRITICAL_END;
if (euid == -1 && errno == EINTR)
/* Got a signal while inside an RPC of the critical section, retry again */
goto retry;
return euid;
}
weak_alias (__geteuid, geteuid)