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authorGravatar Ismael Luceno <ismael.luceno@gmail.com>2012-03-05 06:43:49 -0200
committerGravatar Mike Frysinger <vapier@gentoo.org>2012-03-25 01:45:23 -0400
commit0dcf66744f533e160232072bd03273ca1c448879 (patch)
tree3658f9d75614bede75cfd49e00da4e73da2e8436 /librt
parentd1bc0c9915e3b1db796f4466de6167c0a0f0f108 (diff)
downloaduClibc-0dcf66744f533e160232072bd03273ca1c448879.tar.gz
uClibc-0dcf66744f533e160232072bd03273ca1c448879.tar.bz2
librt: add posix_spawn support
Signed-off-by: Ismael Luceno <ismael.luceno@gmail.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Diffstat (limited to 'librt')
-rw-r--r--librt/Makefile.in8
-rw-r--r--librt/spawn.c259
-rw-r--r--librt/spawn_faction_addclose.c51
-rw-r--r--librt/spawn_faction_adddup2.c52
-rw-r--r--librt/spawn_faction_addopen.c55
-rw-r--r--librt/spawn_faction_init.c42
-rw-r--r--librt/spawn_int.h26
7 files changed, 493 insertions, 0 deletions
diff --git a/librt/Makefile.in b/librt/Makefile.in
index 909afd884..857efb517 100644
--- a/librt/Makefile.in
+++ b/librt/Makefile.in
@@ -33,6 +33,14 @@ else
librt_filter_SRC += clock_nanosleep.c clock_getcpuclockid.c clock_gettime.c
librt_SSRC :=
endif
+
+librt_filter_SRC += $(if $(UCLIBC_HAS_ADVANCED_REALTIME),, \
+ spawn.c \
+ spawn_faction_addclose.c \
+ spawn_faction_adddup2.c \
+ spawn_faction_addopen.c \
+ spawn_faction_init.c)
+
librt_SRC := $(filter-out $(librt_filter_SRC),$(librt_SRC))
librt_OBJ := $(patsubst %.c,$(librt_OUT)/%.o,$(librt_SRC))
diff --git a/librt/spawn.c b/librt/spawn.c
new file mode 100644
index 000000000..b5935a1b4
--- /dev/null
+++ b/librt/spawn.c
@@ -0,0 +1,259 @@
+/* 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 <alloca.h>
+#include <unistd.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <fcntl.h>
+
+#include <sys/resource.h>
+#include <not-cancel.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
+
+/* Execute file actions.
+ * Returns true on error.
+ */
+inline static bool execute_file_actions(const posix_spawn_file_actions_t *fa)
+{
+ struct rlimit64 fdlimit;
+ bool have_fdlimit = false;
+
+ for (int cnt = 0; cnt < fa->__used; ++cnt) {
+ struct __spawn_action *action = &fa->__actions[cnt];
+
+ switch (action->tag) {
+ case spawn_do_close:
+ if (close_not_cancel(action->action.close_action.fd) != 0) {
+ if (!have_fdlimit) {
+ getrlimit64(RLIMIT_NOFILE, &fdlimit);
+ have_fdlimit = true;
+ }
+
+ /* Only signal errors for file descriptors out of range. */
+ if (0 > action->action.close_action.fd
+ || action->action.close_action.fd >= fdlimit.rlim_cur)
+ /* Signal the error. */
+ return true;
+ }
+ break;
+
+ case spawn_do_open:;
+ int new_fd = open_not_cancel(action->action.open_action.path,
+ action->action.open_action.oflag
+ | O_LARGEFILE,
+ action->action.open_action.mode);
+
+ if (new_fd == -1)
+ return true;
+
+ /* Make sure the desired file descriptor is used. */
+ if (new_fd != action->action.open_action.fd) {
+ if (dup2(new_fd, action->action.open_action.fd)
+ != action->action.open_action.fd)
+ return true;
+
+ if (close_not_cancel(new_fd) != 0)
+ return true;
+ }
+ break;
+
+ case spawn_do_dup2:
+ if (dup2(action->action.dup2_action.fd,
+ action->action.dup2_action.newfd)
+ != action->action.dup2_action.newfd)
+ return true;
+ break;
+ }
+ }
+
+ return false;
+}
+
+#define DANGEROUS (POSIX_SPAWN_SETSIGMASK \
+ | POSIX_SPAWN_SETSIGDEF \
+ | POSIX_SPAWN_SETSCHEDPARAM \
+ | POSIX_SPAWN_SETSCHEDULER \
+ | POSIX_SPAWN_SETPGROUP \
+ | POSIX_SPAWN_RESETIDS)
+inline static bool is_vfork_safe(short int flags)
+{
+ return ((flags & POSIX_SPAWN_USEVFORK) || !(flags & DANGEROUS));
+}
+
+
+/* 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[], const char *path)
+{
+ short int flags = attrp ? attrp->__flags : 0;
+
+ pid_t new_pid;
+ if (is_vfork_safe(flags) && !fa)
+ new_pid = vfork();
+ else
+ new_pid = fork();
+
+ if (new_pid) {
+ if (new_pid < 0)
+ return errno;
+
+ if (pid)
+ *pid = new_pid;
+
+ return 0;
+ }
+
+ if (flags & POSIX_SPAWN_SETSIGMASK) {
+ if (sigprocmask(SIG_SETMASK, &attrp->__ss, NULL) != 0)
+ goto error;
+ }
+
+ if (flags & POSIX_SPAWN_SETSIGDEF) {
+ /* We have to iterate over all signals. This could possibly be
+ done better but it requires system specific solutions since
+ the sigset_t data type can be very different on different
+ architectures. */
+ struct sigaction sa;
+
+ memset(&sa, 0, sizeof(sa));
+ sa.sa_handler = SIG_DFL;
+
+ for (int sig = 1; sig <= _NSIG; ++sig) {
+ if (sigismember(&attrp->__sd, sig)) {
+ if (sigaction(sig, &sa, NULL) != 0)
+ goto error;
+ }
+ }
+ }
+
+ if (flags & POSIX_SPAWN_SETSCHEDULER) {
+ if (sched_setscheduler(0, attrp->__policy, &attrp->__sp) == -1)
+ goto error;
+ } else if (flags & POSIX_SPAWN_SETSCHEDPARAM) {
+ if (sched_setparam(0, &attrp->__sp) == -1)
+ goto error;
+ }
+
+ if (flags & POSIX_SPAWN_SETPGROUP) {
+ if (setpgid(0, attrp->__pgrp) != 0)
+ goto error;
+ }
+
+ if (flags & POSIX_SPAWN_RESETIDS) {
+ if (seteuid(getuid()) || setegid(getgid()))
+ goto error;
+ }
+
+ if (fa && execute_file_actions(fa))
+ goto error;
+
+ if (!path || strchr(file, '/')) {
+ execve(file, argv, envp);
+ goto error;
+ }
+
+
+ char *name;
+ {
+ size_t filelen = strlen(file) + 1;
+ size_t pathlen = strlen(path) + 1;
+ name = alloca(pathlen + filelen);
+
+ /* Copy the file name at the top. */
+ name = (char *) memcpy(name + pathlen, file, filelen);
+
+ /* And add the slash. */
+ *--name = '/';
+ }
+
+ char *p;
+ do {
+ char *startp;
+ p = strchrnul(path, ':');
+
+ /* Two adjacent colons, or a colon at the beginning or the end
+ of `PATH' means to search the current directory. */
+ if (p == path)
+ startp = name + 1;
+ else
+ startp = (char *) memcpy(name - (p - path), path, p - path);
+
+ execve(startp, argv, envp);
+
+ switch (errno) {
+ case EACCES:
+ case ENOENT:
+ case ESTALE:
+ case ENOTDIR:
+ /* Those errors indicate the file is missing or not
+ executable by us, in which case we want to just try
+ the next path directory. */
+ break;
+ default:
+ /* Some other error means we found an executable file,
+ but something went wrong executing it; return the
+ error to our caller. */
+ goto error;
+ }
+
+ path = p;
+ } while (*p++ != '\0');
+
+error:
+ _exit(SPAWN_ERROR);
+}
+
+/* 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, NULL);
+}
+
+/* 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[])
+{
+ const char *path = getenv("PATH");
+
+ if (!path)
+ path = ":/bin:/usr/bin";
+
+ return __spawni(pid, file, fa, attrp, argv, envp, path);
+}
diff --git a/librt/spawn_faction_addclose.c b/librt/spawn_faction_addclose.c
new file mode 100644
index 000000000..b418f962f
--- /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 000000000..6d7331326
--- /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 000000000..285ca715e
--- /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 000000000..fb398a566
--- /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 000000000..89c88dba9
--- /dev/null
+++ b/librt/spawn_int.h
@@ -0,0 +1,26 @@
+/* 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;
+};
+
+int __posix_spawn_file_actions_realloc(posix_spawn_file_actions_t *fa);