glibc/sysdeps/mach/hurd/getresuid.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
1.8 KiB
C

/* getresuid -- fetch real user ID, effective user ID, and saved-set user ID
Copyright (C) 2002-2021 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>
/* Fetch the real user ID, effective user ID, and saved-set user ID,
of the calling process. */
int
__getresuid (uid_t *ruid, uid_t *euid, uid_t *suid)
{
error_t err;
retry:
HURD_CRITICAL_BEGIN;
__mutex_lock (&_hurd_id.lock);
err = _hurd_check_ids ();
if (!err)
{
if (_hurd_id.aux.nuids < 1)
/* We do not even have a real UID. */
err = EGRATUITOUS;
else
{
uid_t real = _hurd_id.aux.uids[0];
*ruid = real;
*euid = _hurd_id.gen.nuids < 1 ? real : _hurd_id.gen.uids[0];
*suid = _hurd_id.aux.nuids < 2 ? real : _hurd_id.aux.uids[1];
}
}
__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;
return __hurd_fail (err);
}
libc_hidden_def (__getresuid)
weak_alias (__getresuid, getresuid)