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RFE: Implementing posix_spawnattr_setfchdir() in glibc
- From: Michal Hlavinka <mhlavink at redhat dot com>
- To: libc-alpha at sourceware dot org
- Date: Mon, 05 Nov 2012 16:11:57 +0100
- Subject: RFE: Implementing posix_spawnattr_setfchdir() in glibc
- References: <50914F19.9070307@redhat.com>
Hi,
I'm forwarding a request I got - if glibc could implement new attribute.
Do you think it'd be possible to add such attribute?
Thanks,
Michal
-------- Original Message --------
Subject: Implementing posix_spawnattr_setfchdir() in Linux glibc
Michal, I need again your help. Apple
OSX and Solaris are going to implement a new attribute for
posix_spawn(), posix_spawnattr_setfchdir() and
posix_spawnattr_getfchdir(), to set and get the new current directory
for the new child process, Default value is AT_FDCWD, which means the
value is inherited from the global cwd.
I asked why there is no chdir() version, the rationale is that this
adds an extra set of failure modes, which can be prevented by forcing
every one to do a openat(AT_FDCWD, ".", O_SEARCH), in which case it is
guaranteed that at least the directory exists (Linux will have to use
O_PATH instead of O_SEARCH).
My question is, can you help me with getting this implemented in
glibc, please? I have attached the Apple OSX header one of the
engineers (Sebastian Feld) send to me, for reference.
Olga
/*
* Copyright (c) 2006, 2012 Apple Inc. All rights reserved.
*
* @APPLE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this
* file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_LICENSE_HEADER_END@
*/
#ifndef _SPAWN_H_
#define _SPAWN_H_
/*
* [SPN] Support for _POSIX_SPAWN
*/
#include <sys/cdefs.h>
#include <_types.h>
#include <sys/spawn.h> /* shared types */
/*
* [SPN] Inclusion of the <spawn.h> header may make visible symbols defined
* in the <sched.h>, <signal.h>, and <sys/types.h> headers.
*/
#ifndef _PID_T
typedef __darwin_pid_t pid_t;
#define _PID_T
#endif
#ifndef _SIGSET_T
#define _SIGSET_T
typedef __darwin_sigset_t sigset_t;
#endif
#ifndef _MODE_T
typedef __darwin_mode_t mode_t;
#define _MODE_T
#endif
/*
* Opaque types for use with posix_spawn() family functions. Internals are
* not defined, and should not be accessed directly. Types are defined as
* mandated by POSIX.
*/
typedef void *posix_spawnattr_t;
typedef void *posix_spawn_file_actions_t;
__BEGIN_DECLS
/*
* gcc under c99 mode won't compile "[ __restrict]" by itself. As a workaround,
* a dummy argument name is added.
*/
int posix_spawn(pid_t * __restrict, const char * __restrict,
const posix_spawn_file_actions_t *,
const posix_spawnattr_t * __restrict,
char *const __argv[ __restrict],
char *const __envp[ __restrict]);
int posix_spawnp(pid_t * __restrict, const char * __restrict,
const posix_spawn_file_actions_t *,
const posix_spawnattr_t * __restrict,
char *const __argv[ __restrict],
char *const __envp[ __restrict]);
int posix_spawn_file_actions_addclose(posix_spawn_file_actions_t *, int);
int posix_spawn_file_actions_adddup2(posix_spawn_file_actions_t *, int,
int);
int posix_spawn_file_actions_addopen(
posix_spawn_file_actions_t * __restrict, int,
const char * __restrict, int, mode_t);
int posix_spawn_file_actions_destroy(posix_spawn_file_actions_t *);
int posix_spawn_file_actions_init(posix_spawn_file_actions_t *);
int posix_spawnattr_destroy(posix_spawnattr_t *);
int posix_spawnattr_getsigdefault(const posix_spawnattr_t * __restrict,
sigset_t * __restrict);
int posix_spawnattr_getflags(const posix_spawnattr_t * __restrict,
short * __restrict);
int posix_spawnattr_getpgroup(const posix_spawnattr_t * __restrict,
pid_t * __restrict);
int posix_spawnattr_getsigmask(const posix_spawnattr_t * __restrict,
sigset_t * __restrict);
int posix_spawnattr_init(posix_spawnattr_t *);
int posix_spawnattr_setsigdefault(posix_spawnattr_t * __restrict,
const sigset_t * __restrict);
int posix_spawnattr_setflags(posix_spawnattr_t *, short);
int posix_spawnattr_setpgroup(posix_spawnattr_t *, pid_t);
int posix_spawnattr_setsigmask(posix_spawnattr_t * __restrict,
const sigset_t * __restrict);
#if 0 /* _POSIX_PRIORITY_SCHEDULING [PS] : not supported */
int posix_spawnattr_setschedparam(posix_spawnattr_t * __restrict,
const struct sched_param * __restrict);
int posix_spawnattr_setschedpolicy(posix_spawnattr_t *, int);
int posix_spawnattr_getschedparam(const posix_spawnattr_t * __restrict,
struct sched_param * __restrict);
int posix_spawnattr_getschedpolicy(const posix_spawnattr_t * __restrict,
int * __restrict);
#endif /* 0 */
__END_DECLS
#if !defined(_POSIX_C_SOURCE) || defined(_DARWIN_C_SOURCE)
/*
* Darwin-specific extensions below
*/
#include <mach/exception_types.h>
#include <mach/machine.h>
#include <mach/port.h>
#ifndef _SIZE_T
typedef __darwin_size_t size_t;
#define _SIZE_T
#endif
__BEGIN_DECLS
int posix_spawnattr_getbinpref_np(const posix_spawnattr_t * __restrict,
size_t, cpu_type_t *__restrict, size_t *__restrict);
int posix_spawnattr_getfchdir(const posix_spawnattr_t * __restrict,
int * __restrict);
int posix_spawnattr_setauditsessionport_np(posix_spawnattr_t *__restrict,
mach_port_t);
int posix_spawnattr_setbinpref_np(posix_spawnattr_t * __restrict,
size_t, cpu_type_t *__restrict, size_t *__restrict);
int posix_spawnattr_setfchdir(posix_spawnattr_t *, int);
int posix_spawnattr_setexceptionports_np(posix_spawnattr_t *__restrict,
exception_mask_t, mach_port_t,
exception_behavior_t, thread_state_flavor_t);
int posix_spawnattr_setspecialport_np(posix_spawnattr_t *__restrict,
mach_port_t, int);
__END_DECLS
#endif /* (!_POSIX_C_SOURCE || _DARWIN_C_SOURCE) */
#endif /* _SPAWN_H_ */