[PATCH] librt: Add partial posix_spawn support

Ismael Luceno ismael.luceno at gmail.com
Thu Mar 1 03:40:02 UTC 2012


Signed-off-by: Ismael Luceno <ismael.luceno at gmail.com>
---
 include/spawn.h                |  266 ++++++++++++++++++++++++++++++++++++++++
 librt/spawn.c                  |   61 +++++++++
 librt/spawn_faction_addclose.c |   51 ++++++++
 librt/spawn_faction_adddup2.c  |   52 ++++++++
 librt/spawn_faction_addopen.c  |   55 ++++++++
 librt/spawn_faction_init.c     |   42 +++++++
 librt/spawn_int.h              |   29 +++++
 7 files changed, 556 insertions(+), 0 deletions(-)
 create mode 100644 include/spawn.h
 create mode 100644 librt/spawn.c
 create mode 100644 librt/spawn_faction_addclose.c
 create mode 100644 librt/spawn_faction_adddup2.c
 create mode 100644 librt/spawn_faction_addopen.c
 create mode 100644 librt/spawn_faction_init.c
 create mode 100644 librt/spawn_int.h

diff --git a/include/spawn.h b/include/spawn.h
new file mode 100644
index 0000000..8b07bb8
--- /dev/null
+++ b/include/spawn.h
@@ -0,0 +1,266 @@
+/* Definitions for POSIX spawn interface.
+   Copyright (C) 2000,2003,2004,2009,2011,2012 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
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef	_SPAWN_H
+#define	_SPAWN_H	1
+
+#include <errno.h>
+#include <string.h>
+#include <stdlib.h>
+
+#include <features.h>
+#include <sched.h>
+#define __need_sigset_t
+#include <signal.h>
+#include <sys/types.h>
+
+
+/* Data structure to contain attributes for thread creation.  */
+typedef struct {
+	short int __flags;
+	pid_t __pgrp;
+	sigset_t __sd;
+	sigset_t __ss;
+	struct sched_param __sp;
+	int __policy;
+	int __pad[16];
+} posix_spawnattr_t;
+
+
+/* Data structure to contain information about the actions to be
+   performed in the new process with respect to file descriptors.  */
+typedef struct {
+	int __allocated;
+	int __used;
+	struct __spawn_action *__actions;
+	int __pad[16];
+} posix_spawn_file_actions_t;
+
+
+/* Flags to be set in the `posix_spawnattr_t'.  */
+#define POSIX_SPAWN_RESETIDS		0x01
+#define POSIX_SPAWN_SETPGROUP		0x02
+#define POSIX_SPAWN_SETSIGDEF		0x04
+#define POSIX_SPAWN_SETSIGMASK		0x08
+#define POSIX_SPAWN_SETSCHEDPARAM	0x10
+#define POSIX_SPAWN_SETSCHEDULER	0x20
+#define POSIX_SPAWN_USEVFORK		0x40 /* GNU extension */
+
+
+#define __POSIX_SPAWN_MASK (POSIX_SPAWN_RESETIDS		\
+			    | POSIX_SPAWN_SETPGROUP		\
+			    | POSIX_SPAWN_SETSIGDEF		\
+			    | POSIX_SPAWN_SETSIGMASK		\
+			    | POSIX_SPAWN_SETSCHEDPARAM		\
+			    | POSIX_SPAWN_SETSCHEDULER		\
+			    | POSIX_SPAWN_USEVFORK)
+
+__BEGIN_DECLS
+
+/* Spawn a new process executing PATH with the attributes describes in *ATTRP.
+   Before running the process perform the actions described in FILE-ACTIONS.
+
+   This function is a possible cancellation point and therefore not
+   marked with __THROW. */
+int posix_spawn(pid_t * restrict pid, const char * restrict path,
+		const posix_spawn_file_actions_t * restrict file_actions,
+		const posix_spawnattr_t * restrict attrp,
+		char * const argv[restrict],
+		char * const envp[restrict]);
+
+/* Similar to `posix_spawn' but search for FILE in the PATH.
+
+   This function is a possible cancellation point and therefore not
+   marked with __THROW.  */
+int posix_spawnp(pid_t *pid, const char *file,
+		 const posix_spawn_file_actions_t *file_actions,
+		 const posix_spawnattr_t *attrp,
+		 char * const argv[], char * const envp[]);
+
+/* Initialize data structure with attributes for `spawn' to default values. */
+inline static int
+posix_spawnattr_init(posix_spawnattr_t *attr)
+{
+	memset(attr, 0, sizeof(*attr));
+	return 0;
+}
+
+/* Free resources associated with ATTR.  */
+inline static int
+posix_spawnattr_destroy(posix_spawnattr_t *attr)
+{
+	return 0;
+}
+
+/* Store signal mask for signals with default handling from ATTR in
+   SIGDEFAULT.  */
+inline static int
+posix_spawnattr_getsigdefault(const posix_spawnattr_t *attr,
+			      sigset_t *sigdefault)
+{
+	memcpy(sigdefault, &attr->__sd, sizeof(sigset_t));
+	return 0;
+}
+
+
+/* Set signal mask for signals with default handling in ATTR to SIGDEFAULT.  */
+inline static int
+posix_spawnattr_setsigdefault(posix_spawnattr_t *attr,
+			      const sigset_t *sigdefault)
+{
+	memcpy(&attr->__sd, sigdefault, sizeof(sigset_t));
+	return 0;
+}
+
+/* Store signal mask for the new process from ATTR in SIGMASK.  */
+inline static int
+posix_spawnattr_getsigmask(const posix_spawnattr_t *attr,
+			   sigset_t *sigmask)
+{
+	memcpy(sigmask, &attr->__ss, sizeof(sigset_t));
+	return 0;
+}
+
+
+/* Set signal mask for the new process in ATTR to SIGMASK.  */
+inline static int
+posix_spawnattr_setsigmask(posix_spawnattr_t *attr,
+			   const sigset_t *sigmask)
+{
+	memcpy(&attr->__ss, sigmask, sizeof(sigset_t));
+	return 0;
+}
+
+/* Get flag word from the attribute structure.  */
+inline static int
+posix_spawnattr_getflags(const posix_spawnattr_t *attr, short int *flags)
+{
+	*flags = attr->__flags;
+	return 0;
+}
+
+/* Store flags in the attribute structure.  */
+inline static int
+posix_spawnattr_setflags(posix_spawnattr_t *attr, short int flags)
+{
+	/* Check no invalid bits are set.  */
+	if (flags & ~__POSIX_SPAWN_MASK)
+		return EINVAL;
+
+	attr->__flags = flags;
+	return 0;
+}
+
+/* Get process group ID from the attribute structure.  */
+inline static int
+posix_spawnattr_getpgroup(const posix_spawnattr_t *attr, pid_t *pgroup)
+{
+	*pgroup = attr->__pgrp;
+	return 0;
+}
+
+/* Store process group ID in the attribute structure.  */
+inline static int
+posix_spawnattr_setpgroup(posix_spawnattr_t *attr, pid_t pgroup)
+{
+	attr->__pgrp = pgroup;
+	return 0;
+}
+
+/* Get scheduling policy from the attribute structure.  */
+inline static int
+posix_spawnattr_getschedpolicy(const posix_spawnattr_t *attr,
+			       int *schedpolicy)
+{
+	*schedpolicy = attr->__policy;
+	return 0;
+}
+
+/* Store scheduling policy in the attribute structure.  */
+inline static int
+posix_spawnattr_setschedpolicy(posix_spawnattr_t *attr, int schedpolicy)
+{
+	switch (schedpolicy) {
+	case SCHED_OTHER:
+	case SCHED_FIFO:
+	case SCHED_RR:
+		break;
+	default:
+		return EINVAL;
+	}
+
+	attr->__policy = schedpolicy;
+	return 0;
+}
+
+/* Get scheduling parameters from the attribute structure.  */
+static inline int
+posix_spawnattr_getschedparam(const posix_spawnattr_t *attr,
+			      struct sched_param *schedparam)
+{
+	memcpy(schedparam, &attr->__sp, sizeof(attr->__sp));
+	return 0;
+}
+
+/* Store scheduling parameters in the attribute structure.  */
+static inline int
+posix_spawnattr_setschedparam(posix_spawnattr_t *attr,
+			      const struct sched_param *schedparam)
+{
+	attr->__sp = *schedparam;
+	return 0;
+}
+
+/* Initialize data structure for file attribute for `spawn' call.  */
+inline static int
+posix_spawn_file_actions_init(posix_spawn_file_actions_t *file_actions)
+{
+	memset(file_actions, 0, sizeof(*file_actions));
+	return 0;
+}
+
+/* Free resources associated with FILE-ACTIONS.  */
+inline static int
+posix_spawn_file_actions_destroy(posix_spawn_file_actions_t *file_actions)
+{
+	free(file_actions->__actions);
+	return 0;
+}
+
+/* Add an action to FILE-ACTIONS which tells the implementation to call
+   `open' for the given file during the `spawn' call.  */
+int posix_spawn_file_actions_addopen(posix_spawn_file_actions_t * restrict
+				     file_actions, int fd,
+				     const char * restrict path,
+				     int oflag, mode_t mode)
+     __THROW;
+
+/* Add an action to FILE-ACTIONS which tells the implementation to call
+   `close' for the given file descriptor during the `spawn' call.  */
+int posix_spawn_file_actions_addclose(posix_spawn_file_actions_t *file_actions,
+				      int fd)
+     __THROW;
+
+/* Add an action to FILE-ACTIONS which tells the implementation to call
+   `dup2' for the given file descriptors during the `spawn' call.  */
+int posix_spawn_file_actions_adddup2(posix_spawn_file_actions_t *file_actions,
+				     int fd, int newfd) __THROW;
+
+__END_DECLS
+
+#endif /* spawn.h */
diff --git a/librt/spawn.c b/librt/spawn.c
new file mode 100644
index 0000000..4142765
--- /dev/null
+++ b/librt/spawn.c
@@ -0,0 +1,61 @@
+/* Copyright (C) 2000, 2011 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
+   <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <spawn.h>
+#include "spawn_int.h"
+
+/* The Unix standard contains a long explanation of the way to signal
+   an error after the fork() was successful.  Since no new wait status
+   was wanted there is no way to signal an error using one of the
+   available methods.  The committee chose to signal an error by a
+   normal program exit with the exit code 127.  */
+#define SPAWN_ERROR	127
+
+/* Spawn a new process executing PATH with the attributes describes in *ATTRP.
+   Before running the process perform the actions described in FILE-ACTIONS. */
+static int
+__spawni(pid_t *pid, const char *file,
+	 const posix_spawn_file_actions_t *fa,
+	 const posix_spawnattr_t *attrp, char *const argv[],
+	 char *const envp[], int xflags)
+{
+	__set_errno(ENOSYS);
+	return -1;
+}
+
+/* Spawn a new process executing PATH with the attributes describes in *ATTRP.
+   Before running the process perform the actions described in FILE-ACTIONS. */
+int posix_spawn (pid_t *pid, const char *path,
+	       const posix_spawn_file_actions_t *fa,
+	       const posix_spawnattr_t *attrp, char *const argv[],
+	       char *const envp[])
+{
+	return __spawni(pid, path, fa, attrp, argv, envp, 0);
+}
+
+/* Spawn a new process executing FILE with the attributes describes in *ATTRP.
+   Before running the process perform the actions described in FILE-ACTIONS. */
+int
+posix_spawnp(pid_t *pid, const char *file,
+	     const posix_spawn_file_actions_t *fa,
+	     const posix_spawnattr_t *attrp, char *const argv[],
+	     char *const envp[])
+{
+	return __spawni(pid, file, fa, attrp, argv, envp,
+			SPAWN_XFLAGS_USE_PATH);
+}
diff --git a/librt/spawn_faction_addclose.c b/librt/spawn_faction_addclose.c
new file mode 100644
index 0000000..b418f96
--- /dev/null
+++ b/librt/spawn_faction_addclose.c
@@ -0,0 +1,51 @@
+/* Copyright (C) 2000 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
+   <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <spawn.h>
+#include <unistd.h>
+
+#include "spawn_int.h"
+
+/* Add an action to FILE-ACTIONS which tells the implementation to call
+   `close' for the given file descriptor during the `spawn' call.  */
+int
+posix_spawn_file_actions_addclose(posix_spawn_file_actions_t *file_actions,
+				  int fd)
+{
+	int maxfd = sysconf(_SC_OPEN_MAX);
+	struct __spawn_action *rec;
+
+	/* Test for the validity of the file descriptor.  */
+	if (fd < 0 || fd >= maxfd)
+		return EBADF;
+
+	/* Allocate more memory if needed.  */
+	if (file_actions->__used == file_actions->__allocated
+	    && __posix_spawn_file_actions_realloc(file_actions) != 0)
+		/* This can only mean we ran out of memory.  */
+		return ENOMEM;
+
+	/* Add the new value.  */
+	rec = &file_actions->__actions[file_actions->__used];
+	rec->tag = spawn_do_close;
+	rec->action.open_action.fd = fd;
+
+	/* Account for the new entry.  */
+	++file_actions->__used;
+	return 0;
+}
diff --git a/librt/spawn_faction_adddup2.c b/librt/spawn_faction_adddup2.c
new file mode 100644
index 0000000..6d73313
--- /dev/null
+++ b/librt/spawn_faction_adddup2.c
@@ -0,0 +1,52 @@
+/* Copyright (C) 2000 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
+   <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <spawn.h>
+#include <unistd.h>
+
+#include "spawn_int.h"
+
+/* Add an action to FILE-ACTIONS which tells the implementation to call
+   `dup2' for the given file descriptors during the `spawn' call.  */
+int
+posix_spawn_file_actions_adddup2(posix_spawn_file_actions_t *file_actions,
+				 int fd, int newfd)
+{
+	int maxfd = sysconf(_SC_OPEN_MAX);
+	struct __spawn_action *rec;
+
+	/* Test for the validity of the file descriptor.  */
+	if (fd < 0 || newfd < 0 || fd >= maxfd || newfd >= maxfd)
+		return EBADF;
+
+	/* Allocate more memory if needed.  */
+	if (file_actions->__used == file_actions->__allocated
+	    && __posix_spawn_file_actions_realloc (file_actions) != 0)
+		/* This can only mean we ran out of memory.  */
+		return ENOMEM;
+
+	/* Add the new value.  */
+	rec = &file_actions->__actions[file_actions->__used];
+	rec->tag = spawn_do_dup2;
+	rec->action.dup2_action.fd = fd;
+	rec->action.dup2_action.newfd = newfd;
+
+	/* Account for the new entry.  */
+	++file_actions->__used;
+	return 0;
+}
diff --git a/librt/spawn_faction_addopen.c b/librt/spawn_faction_addopen.c
new file mode 100644
index 0000000..285ca71
--- /dev/null
+++ b/librt/spawn_faction_addopen.c
@@ -0,0 +1,55 @@
+/* Copyright (C) 2000 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
+   <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <spawn.h>
+#include <unistd.h>
+
+#include "spawn_int.h"
+
+/* Add an action to FILE-ACTIONS which tells the implementation to call
+   `open' for the given file during the `spawn' call.  */
+int
+posix_spawn_file_actions_addopen(posix_spawn_file_actions_t *file_actions,
+				 int fd, const char *path, int oflag,
+				 mode_t mode)
+{
+	int maxfd = sysconf(_SC_OPEN_MAX);
+	struct __spawn_action *rec;
+
+	/* Test for the validity of the file descriptor.  */
+	if (fd < 0 || fd >= maxfd)
+		return EBADF;
+
+	/* Allocate more memory if needed.  */
+	if (file_actions->__used == file_actions->__allocated
+	    && __posix_spawn_file_actions_realloc (file_actions) != 0)
+		/* This can only mean we ran out of memory.  */
+		return ENOMEM;
+
+	/* Add the new value.  */
+	rec = &file_actions->__actions[file_actions->__used];
+	rec->tag = spawn_do_open;
+	rec->action.open_action.fd = fd;
+	rec->action.open_action.path = path;
+	rec->action.open_action.oflag = oflag;
+	rec->action.open_action.mode = mode;
+
+	/* Account for the new entry.  */
+	++file_actions->__used;
+	return 0;
+}
diff --git a/librt/spawn_faction_init.c b/librt/spawn_faction_init.c
new file mode 100644
index 0000000..fb398a5
--- /dev/null
+++ b/librt/spawn_faction_init.c
@@ -0,0 +1,42 @@
+/* Copyright (C) 2000 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
+   <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <spawn.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "spawn_int.h"
+
+
+/* Function used to increase the size of the allocated array.  This
+   function is called from the `add'-functions.  */
+int
+__posix_spawn_file_actions_realloc(posix_spawn_file_actions_t *file_actions)
+{
+	int newalloc = file_actions->__allocated + 8;
+	void *newmem = realloc(file_actions->__actions,
+			       newalloc * sizeof(struct __spawn_action));
+
+	if (newmem == NULL)
+		/* Not enough memory.  */
+		return ENOMEM;
+
+	file_actions->__actions = (struct __spawn_action *)newmem;
+	file_actions->__allocated = newalloc;
+	return 0;
+}
diff --git a/librt/spawn_int.h b/librt/spawn_int.h
new file mode 100644
index 0000000..b37899b
--- /dev/null
+++ b/librt/spawn_int.h
@@ -0,0 +1,29 @@
+/* Data structure to contain the action information.  */
+struct __spawn_action {
+	enum {
+		spawn_do_close,
+		spawn_do_dup2,
+		spawn_do_open
+	} tag;
+
+	union {
+		struct {
+			int fd;
+		} close_action;
+		struct {
+			int fd;
+			int newfd;
+		} dup2_action;
+		struct {
+			int fd;
+			const char *path;
+			int oflag;
+			mode_t mode;
+		} open_action;
+	} action;
+};
+
+#define SPAWN_XFLAGS_USE_PATH	0x1
+#define SPAWN_XFLAGS_TRY_SHELL	0x2
+
+int __posix_spawn_file_actions_realloc(posix_spawn_file_actions_t *fa);
-- 
1.7.9.1



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