glibc/posix/spawn_int.h

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/* Internal definitions for posix_spawn functionality.
Copyright (C) 2000-2024 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
Prefer https to http for gnu.org and fsf.org URLs Also, change sources.redhat.com to sourceware.org. This patch was automatically generated by running the following shell script, which uses GNU sed, and which avoids modifying files imported from upstream: sed -ri ' s,(http|ftp)(://(.*\.)?(gnu|fsf|sourceware)\.org($|[^.]|\.[^a-z])),https\2,g s,(http|ftp)(://(.*\.)?)sources\.redhat\.com($|[^.]|\.[^a-z]),https\2sourceware.org\4,g ' \ $(find $(git ls-files) -prune -type f \ ! -name '*.po' \ ! -name 'ChangeLog*' \ ! -path COPYING ! -path COPYING.LIB \ ! -path manual/fdl-1.3.texi ! -path manual/lgpl-2.1.texi \ ! -path manual/texinfo.tex ! -path scripts/config.guess \ ! -path scripts/config.sub ! -path scripts/install-sh \ ! -path scripts/mkinstalldirs ! -path scripts/move-if-change \ ! -path INSTALL ! -path locale/programs/charmap-kw.h \ ! -path po/libc.pot ! -path sysdeps/gnu/errlist.c \ ! '(' -name configure \ -execdir test -f configure.ac -o -f configure.in ';' ')' \ ! '(' -name preconfigure \ -execdir test -f preconfigure.ac ';' ')' \ -print) and then by running 'make dist-prepare' to regenerate files built from the altered files, and then executing the following to cleanup: chmod a+x sysdeps/unix/sysv/linux/riscv/configure # Omit irrelevant whitespace and comment-only changes, # perhaps from a slightly-different Autoconf version. git checkout -f \ sysdeps/csky/configure \ sysdeps/hppa/configure \ sysdeps/riscv/configure \ sysdeps/unix/sysv/linux/csky/configure # Omit changes that caused a pre-commit check to fail like this: # remote: *** error: sysdeps/powerpc/powerpc64/ppc-mcount.S: trailing lines git checkout -f \ sysdeps/powerpc/powerpc64/ppc-mcount.S \ sysdeps/unix/sysv/linux/s390/s390-64/syscall.S # Omit change that caused a pre-commit check to fail like this: # remote: *** error: sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S: last line does not end in newline git checkout -f sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S
2019-09-07 05:40:42 +00:00
<https://www.gnu.org/licenses/>. */
#ifndef _SPAWN_INT_H
#define _SPAWN_INT_H
#include <spawn.h>
posix: Add posix_spawn_file_actions_addclosefrom_np This patch adds a way to close a range of file descriptors on posix_spawn as a new file action. The API is similar to the one provided by Solaris 11 [1], where the file action causes the all open file descriptors greater than or equal to input on to be closed when the new process is spawned. The function posix_spawn_file_actions_addclosefrom_np is safe to be implemented by iterating over /proc/self/fd, since the Linux spawni.c helper process does not use CLONE_FILES, so its has own file descriptor table and any failure (in /proc operation) aborts the process creation and returns an error to the caller. I am aware that this file action might be redundant to the current approach of POSIX in promoting O_CLOEXEC in more interfaces. However O_CLOEXEC is still not the default and for some specific usages, the caller needs to close all possible file descriptors to avoid them leaking. Some examples are CPython (discussed in BZ#10353) and OpenJDK jspawnhelper [2] (where OpenJDK spawns a helper process to exactly closes all file descriptors). Most likely any environment which calls functions that might open file descriptor under the hood and aim to use posix_spawn might face the same requirement. Checked on x86_64-linux-gnu and i686-linux-gnu on kernel 5.11 and 4.15. [1] https://docs.oracle.com/cd/E36784_01/html/E36874/posix-spawn-file-actions-addclosefrom-np-3c.html [2] https://github.com/openjdk/jdk/blob/master/src/java.base/unix/native/libjava/childproc.c#L82
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#include <spawn_int_def.h>
#include <stdbool.h>
Update. 2000-04-15 Ulrich Drepper <drepper@redhat.com> * posix/Makefile (headers): Add spawn.h. (distribute): Add spawn_int.h. (routines): Add spawn_faction_init, spawn_faction_destroy, spawn_faction_addclose, spawn_faction_addopen, spawn_faction_adddup2, spawnattr_init, spawnattr_destroy, spawnattr_getdefault, spawnattr_setdefault, spawnattr_getflags, spawnattr_setflags, spawnattr_getpgroup, spawnattr_setpgroup, spawn, spawnp, and spawni. * posix/Versions [libc] (GLIBC_2.2): Add posix_spawn_file_actions_init, posix_spawn_file_actions_destroy, posix_spawn_file_actions_addclose, posix_spawn_file_actions_addopen, posix_spawn_file_actions_adddup2, posix_spawnattr_init, posix_spawnattr_destroy, posix_spawnattr_getdefault, posix_spawnattr_setdefault, posix_spawnattr_getflags, posix_spawnattr_setflags, posix_spawnattr_getpgroup, posix_spawnattr_setpgroup, posix_spawn, and posix_spawnp. * posix/spawn.c: New file. * posix/spawn.h: New file. * posix/spawn_faction_addclose.c: New file. * posix/spawn_faction_adddup2.c: New file. * posix/spawn_faction_addopen.c: New file. * posix/spawn_faction_destroy.c: New file. * posix/spawn_faction_init.c: New file. * posix/spawn_int.h: New file. * posix/spawnattr_destroy.c: New file. * posix/spawnattr_getdefault.c: New file. * posix/spawnattr_getflags.c: New file. * posix/spawnattr_getpgroup.c: New file. * posix/spawnattr_getschedparam.c: New file. * posix/spawnattr_getschedpolicy.c: New file. * posix/spawnattr_getsigmask.c: New file. * posix/spawnattr_init.c: New file. * posix/spawnattr_setdefault.c: New file. * posix/spawnattr_setflags.c: New file. * posix/spawnattr_setpgroup.c: New file. * posix/spawnattr_setschedparam.c: New file. * posix/spawnattr_setschedpolicy.c: New file. * posix/spawnattr_setsigmask.c: New file. * posix/spawni.c: New file. * posix/spawnp.c: New file. * sysdeps/mach/hurd/bits/posix_opt.h: Add _POSIX_SPAWN. * sysdeps/unix/sysv/linux/bits/posix_opt.h: Likewise.
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/* Data structure to contain the action information. */
struct __spawn_action
{
enum
{
spawn_do_close,
spawn_do_dup2,
spawn_do_open,
spawn_do_chdir,
spawn_do_fchdir,
posix: Add posix_spawn_file_actions_addclosefrom_np This patch adds a way to close a range of file descriptors on posix_spawn as a new file action. The API is similar to the one provided by Solaris 11 [1], where the file action causes the all open file descriptors greater than or equal to input on to be closed when the new process is spawned. The function posix_spawn_file_actions_addclosefrom_np is safe to be implemented by iterating over /proc/self/fd, since the Linux spawni.c helper process does not use CLONE_FILES, so its has own file descriptor table and any failure (in /proc operation) aborts the process creation and returns an error to the caller. I am aware that this file action might be redundant to the current approach of POSIX in promoting O_CLOEXEC in more interfaces. However O_CLOEXEC is still not the default and for some specific usages, the caller needs to close all possible file descriptors to avoid them leaking. Some examples are CPython (discussed in BZ#10353) and OpenJDK jspawnhelper [2] (where OpenJDK spawns a helper process to exactly closes all file descriptors). Most likely any environment which calls functions that might open file descriptor under the hood and aim to use posix_spawn might face the same requirement. Checked on x86_64-linux-gnu and i686-linux-gnu on kernel 5.11 and 4.15. [1] https://docs.oracle.com/cd/E36784_01/html/E36874/posix-spawn-file-actions-addclosefrom-np-3c.html [2] https://github.com/openjdk/jdk/blob/master/src/java.base/unix/native/libjava/childproc.c#L82
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spawn_do_closefrom,
spawn_do_tcsetpgrp
Update. 2000-04-15 Ulrich Drepper <drepper@redhat.com> * posix/Makefile (headers): Add spawn.h. (distribute): Add spawn_int.h. (routines): Add spawn_faction_init, spawn_faction_destroy, spawn_faction_addclose, spawn_faction_addopen, spawn_faction_adddup2, spawnattr_init, spawnattr_destroy, spawnattr_getdefault, spawnattr_setdefault, spawnattr_getflags, spawnattr_setflags, spawnattr_getpgroup, spawnattr_setpgroup, spawn, spawnp, and spawni. * posix/Versions [libc] (GLIBC_2.2): Add posix_spawn_file_actions_init, posix_spawn_file_actions_destroy, posix_spawn_file_actions_addclose, posix_spawn_file_actions_addopen, posix_spawn_file_actions_adddup2, posix_spawnattr_init, posix_spawnattr_destroy, posix_spawnattr_getdefault, posix_spawnattr_setdefault, posix_spawnattr_getflags, posix_spawnattr_setflags, posix_spawnattr_getpgroup, posix_spawnattr_setpgroup, posix_spawn, and posix_spawnp. * posix/spawn.c: New file. * posix/spawn.h: New file. * posix/spawn_faction_addclose.c: New file. * posix/spawn_faction_adddup2.c: New file. * posix/spawn_faction_addopen.c: New file. * posix/spawn_faction_destroy.c: New file. * posix/spawn_faction_init.c: New file. * posix/spawn_int.h: New file. * posix/spawnattr_destroy.c: New file. * posix/spawnattr_getdefault.c: New file. * posix/spawnattr_getflags.c: New file. * posix/spawnattr_getpgroup.c: New file. * posix/spawnattr_getschedparam.c: New file. * posix/spawnattr_getschedpolicy.c: New file. * posix/spawnattr_getsigmask.c: New file. * posix/spawnattr_init.c: New file. * posix/spawnattr_setdefault.c: New file. * posix/spawnattr_setflags.c: New file. * posix/spawnattr_setpgroup.c: New file. * posix/spawnattr_setschedparam.c: New file. * posix/spawnattr_setschedpolicy.c: New file. * posix/spawnattr_setsigmask.c: New file. * posix/spawni.c: New file. * posix/spawnp.c: New file. * sysdeps/mach/hurd/bits/posix_opt.h: Add _POSIX_SPAWN. * sysdeps/unix/sysv/linux/bits/posix_opt.h: Likewise.
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} tag;
union
{
struct
{
int fd;
} close_action;
struct
{
int fd;
int newfd;
} dup2_action;
struct
{
int fd;
char *path;
Update. 2000-04-15 Ulrich Drepper <drepper@redhat.com> * posix/Makefile (headers): Add spawn.h. (distribute): Add spawn_int.h. (routines): Add spawn_faction_init, spawn_faction_destroy, spawn_faction_addclose, spawn_faction_addopen, spawn_faction_adddup2, spawnattr_init, spawnattr_destroy, spawnattr_getdefault, spawnattr_setdefault, spawnattr_getflags, spawnattr_setflags, spawnattr_getpgroup, spawnattr_setpgroup, spawn, spawnp, and spawni. * posix/Versions [libc] (GLIBC_2.2): Add posix_spawn_file_actions_init, posix_spawn_file_actions_destroy, posix_spawn_file_actions_addclose, posix_spawn_file_actions_addopen, posix_spawn_file_actions_adddup2, posix_spawnattr_init, posix_spawnattr_destroy, posix_spawnattr_getdefault, posix_spawnattr_setdefault, posix_spawnattr_getflags, posix_spawnattr_setflags, posix_spawnattr_getpgroup, posix_spawnattr_setpgroup, posix_spawn, and posix_spawnp. * posix/spawn.c: New file. * posix/spawn.h: New file. * posix/spawn_faction_addclose.c: New file. * posix/spawn_faction_adddup2.c: New file. * posix/spawn_faction_addopen.c: New file. * posix/spawn_faction_destroy.c: New file. * posix/spawn_faction_init.c: New file. * posix/spawn_int.h: New file. * posix/spawnattr_destroy.c: New file. * posix/spawnattr_getdefault.c: New file. * posix/spawnattr_getflags.c: New file. * posix/spawnattr_getpgroup.c: New file. * posix/spawnattr_getschedparam.c: New file. * posix/spawnattr_getschedpolicy.c: New file. * posix/spawnattr_getsigmask.c: New file. * posix/spawnattr_init.c: New file. * posix/spawnattr_setdefault.c: New file. * posix/spawnattr_setflags.c: New file. * posix/spawnattr_setpgroup.c: New file. * posix/spawnattr_setschedparam.c: New file. * posix/spawnattr_setschedpolicy.c: New file. * posix/spawnattr_setsigmask.c: New file. * posix/spawni.c: New file. * posix/spawnp.c: New file. * sysdeps/mach/hurd/bits/posix_opt.h: Add _POSIX_SPAWN. * sysdeps/unix/sysv/linux/bits/posix_opt.h: Likewise.
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int oflag;
mode_t mode;
} open_action;
struct
{
char *path;
} chdir_action;
struct
{
int fd;
} fchdir_action;
posix: Add posix_spawn_file_actions_addclosefrom_np This patch adds a way to close a range of file descriptors on posix_spawn as a new file action. The API is similar to the one provided by Solaris 11 [1], where the file action causes the all open file descriptors greater than or equal to input on to be closed when the new process is spawned. The function posix_spawn_file_actions_addclosefrom_np is safe to be implemented by iterating over /proc/self/fd, since the Linux spawni.c helper process does not use CLONE_FILES, so its has own file descriptor table and any failure (in /proc operation) aborts the process creation and returns an error to the caller. I am aware that this file action might be redundant to the current approach of POSIX in promoting O_CLOEXEC in more interfaces. However O_CLOEXEC is still not the default and for some specific usages, the caller needs to close all possible file descriptors to avoid them leaking. Some examples are CPython (discussed in BZ#10353) and OpenJDK jspawnhelper [2] (where OpenJDK spawns a helper process to exactly closes all file descriptors). Most likely any environment which calls functions that might open file descriptor under the hood and aim to use posix_spawn might face the same requirement. Checked on x86_64-linux-gnu and i686-linux-gnu on kernel 5.11 and 4.15. [1] https://docs.oracle.com/cd/E36784_01/html/E36874/posix-spawn-file-actions-addclosefrom-np-3c.html [2] https://github.com/openjdk/jdk/blob/master/src/java.base/unix/native/libjava/childproc.c#L82
2021-03-10 15:26:33 +00:00
struct
{
int from;
} closefrom_action;
struct
{
int fd;
} setpgrp_action;
Update. 2000-04-15 Ulrich Drepper <drepper@redhat.com> * posix/Makefile (headers): Add spawn.h. (distribute): Add spawn_int.h. (routines): Add spawn_faction_init, spawn_faction_destroy, spawn_faction_addclose, spawn_faction_addopen, spawn_faction_adddup2, spawnattr_init, spawnattr_destroy, spawnattr_getdefault, spawnattr_setdefault, spawnattr_getflags, spawnattr_setflags, spawnattr_getpgroup, spawnattr_setpgroup, spawn, spawnp, and spawni. * posix/Versions [libc] (GLIBC_2.2): Add posix_spawn_file_actions_init, posix_spawn_file_actions_destroy, posix_spawn_file_actions_addclose, posix_spawn_file_actions_addopen, posix_spawn_file_actions_adddup2, posix_spawnattr_init, posix_spawnattr_destroy, posix_spawnattr_getdefault, posix_spawnattr_setdefault, posix_spawnattr_getflags, posix_spawnattr_setflags, posix_spawnattr_getpgroup, posix_spawnattr_setpgroup, posix_spawn, and posix_spawnp. * posix/spawn.c: New file. * posix/spawn.h: New file. * posix/spawn_faction_addclose.c: New file. * posix/spawn_faction_adddup2.c: New file. * posix/spawn_faction_addopen.c: New file. * posix/spawn_faction_destroy.c: New file. * posix/spawn_faction_init.c: New file. * posix/spawn_int.h: New file. * posix/spawnattr_destroy.c: New file. * posix/spawnattr_getdefault.c: New file. * posix/spawnattr_getflags.c: New file. * posix/spawnattr_getpgroup.c: New file. * posix/spawnattr_getschedparam.c: New file. * posix/spawnattr_getschedpolicy.c: New file. * posix/spawnattr_getsigmask.c: New file. * posix/spawnattr_init.c: New file. * posix/spawnattr_setdefault.c: New file. * posix/spawnattr_setflags.c: New file. * posix/spawnattr_setpgroup.c: New file. * posix/spawnattr_setschedparam.c: New file. * posix/spawnattr_setschedpolicy.c: New file. * posix/spawnattr_setsigmask.c: New file. * posix/spawni.c: New file. * posix/spawnp.c: New file. * sysdeps/mach/hurd/bits/posix_opt.h: Add _POSIX_SPAWN. * sysdeps/unix/sysv/linux/bits/posix_opt.h: Likewise.
2000-04-15 16:51:16 +00:00
} action;
};
#define SPAWN_XFLAGS_USE_PATH 0x1
#define SPAWN_XFLAGS_TRY_SHELL 0x2
posix: Add pidfd_spawn and pidfd_spawnp (BZ 30349) Returning a pidfd allows a process to keep a race-free handle for a child process, otherwise, the caller will need to either use pidfd_open (which still might be subject to TOCTOU) or keep the old racy interface base on pid_t. To correct use pifd_spawn, the kernel must support not only returning the pidfd with clone/clone3 but also waitid (P_PIDFD) (added on Linux 5.4). If kernel does not support the waitid, pidfd return ENOSYS. It avoids the need to racy workarounds, such as reading the procfs fdinfo to get the pid to use along with other wait interfaces. These interfaces are similar to the posix_spawn and posix_spawnp, with the only difference being it returns a process file descriptor (int) instead of a process ID (pid_t). Their prototypes are: int pidfd_spawn (int *restrict pidfd, const char *restrict file, const posix_spawn_file_actions_t *restrict facts, const posix_spawnattr_t *restrict attrp, char *const argv[restrict], char *const envp[restrict]) int pidfd_spawnp (int *restrict pidfd, const char *restrict path, const posix_spawn_file_actions_t *restrict facts, const posix_spawnattr_t *restrict attrp, char *const argv[restrict_arr], char *const envp[restrict_arr]); A new symbol is used instead of a posix_spawn extension to avoid possible issues with language bindings that might track the return argument lifetime. Although on Linux pid_t and int are interchangeable, POSIX only states that pid_t should be a signed integer. Both symbols reuse the posix_spawn posix_spawn_file_actions_t and posix_spawnattr_t, to void rehash posix_spawn API or add a new one. It also means that both interfaces support the same attribute and file actions, and a new flag or file action on posix_spawn is also added automatically for pidfd_spawn. Also, using posix_spawn plumbing allows the reusing of most of the current testing with some changes: - waitid is used instead of waitpid since it is a more generic interface. - tst-posix_spawn-setsid.c is adapted to take into consideration that the caller can check for session id directly. The test now spawns itself and writes the session id as a file instead. - tst-spawn3.c need to know where pidfd_spawn is used so it keeps an extra file description unused. Checked on x86_64-linux-gnu on Linux 4.15 (no CLONE_PIDFD or waitid support), Linux 5.4 (full support), and Linux 6.2. Reviewed-by: Florian Weimer <fweimer@redhat.com>
2023-08-24 16:42:18 +00:00
#define SPAWN_XFLAGS_RET_PIDFD 0x4
Update. 2000-04-15 Ulrich Drepper <drepper@redhat.com> * posix/Makefile (headers): Add spawn.h. (distribute): Add spawn_int.h. (routines): Add spawn_faction_init, spawn_faction_destroy, spawn_faction_addclose, spawn_faction_addopen, spawn_faction_adddup2, spawnattr_init, spawnattr_destroy, spawnattr_getdefault, spawnattr_setdefault, spawnattr_getflags, spawnattr_setflags, spawnattr_getpgroup, spawnattr_setpgroup, spawn, spawnp, and spawni. * posix/Versions [libc] (GLIBC_2.2): Add posix_spawn_file_actions_init, posix_spawn_file_actions_destroy, posix_spawn_file_actions_addclose, posix_spawn_file_actions_addopen, posix_spawn_file_actions_adddup2, posix_spawnattr_init, posix_spawnattr_destroy, posix_spawnattr_getdefault, posix_spawnattr_setdefault, posix_spawnattr_getflags, posix_spawnattr_setflags, posix_spawnattr_getpgroup, posix_spawnattr_setpgroup, posix_spawn, and posix_spawnp. * posix/spawn.c: New file. * posix/spawn.h: New file. * posix/spawn_faction_addclose.c: New file. * posix/spawn_faction_adddup2.c: New file. * posix/spawn_faction_addopen.c: New file. * posix/spawn_faction_destroy.c: New file. * posix/spawn_faction_init.c: New file. * posix/spawn_int.h: New file. * posix/spawnattr_destroy.c: New file. * posix/spawnattr_getdefault.c: New file. * posix/spawnattr_getflags.c: New file. * posix/spawnattr_getpgroup.c: New file. * posix/spawnattr_getschedparam.c: New file. * posix/spawnattr_getschedpolicy.c: New file. * posix/spawnattr_getsigmask.c: New file. * posix/spawnattr_init.c: New file. * posix/spawnattr_setdefault.c: New file. * posix/spawnattr_setflags.c: New file. * posix/spawnattr_setpgroup.c: New file. * posix/spawnattr_setschedparam.c: New file. * posix/spawnattr_setschedpolicy.c: New file. * posix/spawnattr_setsigmask.c: New file. * posix/spawni.c: New file. * posix/spawnp.c: New file. * sysdeps/mach/hurd/bits/posix_opt.h: Add _POSIX_SPAWN. * sysdeps/unix/sysv/linux/bits/posix_opt.h: Likewise.
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extern int __posix_spawn_file_actions_realloc (posix_spawn_file_actions_t *
file_actions)
attribute_hidden;
Update. 2000-04-15 Ulrich Drepper <drepper@redhat.com> * posix/Makefile (headers): Add spawn.h. (distribute): Add spawn_int.h. (routines): Add spawn_faction_init, spawn_faction_destroy, spawn_faction_addclose, spawn_faction_addopen, spawn_faction_adddup2, spawnattr_init, spawnattr_destroy, spawnattr_getdefault, spawnattr_setdefault, spawnattr_getflags, spawnattr_setflags, spawnattr_getpgroup, spawnattr_setpgroup, spawn, spawnp, and spawni. * posix/Versions [libc] (GLIBC_2.2): Add posix_spawn_file_actions_init, posix_spawn_file_actions_destroy, posix_spawn_file_actions_addclose, posix_spawn_file_actions_addopen, posix_spawn_file_actions_adddup2, posix_spawnattr_init, posix_spawnattr_destroy, posix_spawnattr_getdefault, posix_spawnattr_setdefault, posix_spawnattr_getflags, posix_spawnattr_setflags, posix_spawnattr_getpgroup, posix_spawnattr_setpgroup, posix_spawn, and posix_spawnp. * posix/spawn.c: New file. * posix/spawn.h: New file. * posix/spawn_faction_addclose.c: New file. * posix/spawn_faction_adddup2.c: New file. * posix/spawn_faction_addopen.c: New file. * posix/spawn_faction_destroy.c: New file. * posix/spawn_faction_init.c: New file. * posix/spawn_int.h: New file. * posix/spawnattr_destroy.c: New file. * posix/spawnattr_getdefault.c: New file. * posix/spawnattr_getflags.c: New file. * posix/spawnattr_getpgroup.c: New file. * posix/spawnattr_getschedparam.c: New file. * posix/spawnattr_getschedpolicy.c: New file. * posix/spawnattr_getsigmask.c: New file. * posix/spawnattr_init.c: New file. * posix/spawnattr_setdefault.c: New file. * posix/spawnattr_setflags.c: New file. * posix/spawnattr_setpgroup.c: New file. * posix/spawnattr_setschedparam.c: New file. * posix/spawnattr_setschedpolicy.c: New file. * posix/spawnattr_setsigmask.c: New file. * posix/spawni.c: New file. * posix/spawnp.c: New file. * sysdeps/mach/hurd/bits/posix_opt.h: Add _POSIX_SPAWN. * sysdeps/unix/sysv/linux/bits/posix_opt.h: Likewise.
2000-04-15 16:51:16 +00:00
posix: Add pidfd_spawn and pidfd_spawnp (BZ 30349) Returning a pidfd allows a process to keep a race-free handle for a child process, otherwise, the caller will need to either use pidfd_open (which still might be subject to TOCTOU) or keep the old racy interface base on pid_t. To correct use pifd_spawn, the kernel must support not only returning the pidfd with clone/clone3 but also waitid (P_PIDFD) (added on Linux 5.4). If kernel does not support the waitid, pidfd return ENOSYS. It avoids the need to racy workarounds, such as reading the procfs fdinfo to get the pid to use along with other wait interfaces. These interfaces are similar to the posix_spawn and posix_spawnp, with the only difference being it returns a process file descriptor (int) instead of a process ID (pid_t). Their prototypes are: int pidfd_spawn (int *restrict pidfd, const char *restrict file, const posix_spawn_file_actions_t *restrict facts, const posix_spawnattr_t *restrict attrp, char *const argv[restrict], char *const envp[restrict]) int pidfd_spawnp (int *restrict pidfd, const char *restrict path, const posix_spawn_file_actions_t *restrict facts, const posix_spawnattr_t *restrict attrp, char *const argv[restrict_arr], char *const envp[restrict_arr]); A new symbol is used instead of a posix_spawn extension to avoid possible issues with language bindings that might track the return argument lifetime. Although on Linux pid_t and int are interchangeable, POSIX only states that pid_t should be a signed integer. Both symbols reuse the posix_spawn posix_spawn_file_actions_t and posix_spawnattr_t, to void rehash posix_spawn API or add a new one. It also means that both interfaces support the same attribute and file actions, and a new flag or file action on posix_spawn is also added automatically for pidfd_spawn. Also, using posix_spawn plumbing allows the reusing of most of the current testing with some changes: - waitid is used instead of waitpid since it is a more generic interface. - tst-posix_spawn-setsid.c is adapted to take into consideration that the caller can check for session id directly. The test now spawns itself and writes the session id as a file instead. - tst-spawn3.c need to know where pidfd_spawn is used so it keeps an extra file description unused. Checked on x86_64-linux-gnu on Linux 4.15 (no CLONE_PIDFD or waitid support), Linux 5.4 (full support), and Linux 6.2. Reviewed-by: Florian Weimer <fweimer@redhat.com>
2023-08-24 16:42:18 +00:00
extern int __spawni (int *pid, const char *path,
Update. 2000-04-15 Ulrich Drepper <drepper@redhat.com> * posix/Makefile (headers): Add spawn.h. (distribute): Add spawn_int.h. (routines): Add spawn_faction_init, spawn_faction_destroy, spawn_faction_addclose, spawn_faction_addopen, spawn_faction_adddup2, spawnattr_init, spawnattr_destroy, spawnattr_getdefault, spawnattr_setdefault, spawnattr_getflags, spawnattr_setflags, spawnattr_getpgroup, spawnattr_setpgroup, spawn, spawnp, and spawni. * posix/Versions [libc] (GLIBC_2.2): Add posix_spawn_file_actions_init, posix_spawn_file_actions_destroy, posix_spawn_file_actions_addclose, posix_spawn_file_actions_addopen, posix_spawn_file_actions_adddup2, posix_spawnattr_init, posix_spawnattr_destroy, posix_spawnattr_getdefault, posix_spawnattr_setdefault, posix_spawnattr_getflags, posix_spawnattr_setflags, posix_spawnattr_getpgroup, posix_spawnattr_setpgroup, posix_spawn, and posix_spawnp. * posix/spawn.c: New file. * posix/spawn.h: New file. * posix/spawn_faction_addclose.c: New file. * posix/spawn_faction_adddup2.c: New file. * posix/spawn_faction_addopen.c: New file. * posix/spawn_faction_destroy.c: New file. * posix/spawn_faction_init.c: New file. * posix/spawn_int.h: New file. * posix/spawnattr_destroy.c: New file. * posix/spawnattr_getdefault.c: New file. * posix/spawnattr_getflags.c: New file. * posix/spawnattr_getpgroup.c: New file. * posix/spawnattr_getschedparam.c: New file. * posix/spawnattr_getschedpolicy.c: New file. * posix/spawnattr_getsigmask.c: New file. * posix/spawnattr_init.c: New file. * posix/spawnattr_setdefault.c: New file. * posix/spawnattr_setflags.c: New file. * posix/spawnattr_setpgroup.c: New file. * posix/spawnattr_setschedparam.c: New file. * posix/spawnattr_setschedpolicy.c: New file. * posix/spawnattr_setsigmask.c: New file. * posix/spawni.c: New file. * posix/spawnp.c: New file. * sysdeps/mach/hurd/bits/posix_opt.h: Add _POSIX_SPAWN. * sysdeps/unix/sysv/linux/bits/posix_opt.h: Likewise.
2000-04-15 16:51:16 +00:00
const posix_spawn_file_actions_t *file_actions,
const posix_spawnattr_t *attrp, char *const argv[],
char *const envp[], int xflags) attribute_hidden;
/* Return true if FD falls into the range valid for file descriptors.
The check in this form is mandated by POSIX. */
bool __spawn_valid_fd (int fd) attribute_hidden;
#endif /* _SPAWN_INT_H */