-/*
- * Copyright (C) 2009 Pierre-Marc Fournier
- * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
- * This 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; version 2.1 of
- * the License.
- *
- * This 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 this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-#define _GNU_SOURCE
-#include <dlfcn.h>
-#include <unistd.h>
-#include <stdio.h>
-#include <signal.h>
-#include <sched.h>
-#include <stdarg.h>
-#include "usterr.h"
-
-#include <lttng/ust.h>
-
-pid_t fork(void)
-{
- static pid_t (*plibc_func)(void) = NULL;
- sigset_t sigset;
- pid_t retval;
-
- if (plibc_func == NULL) {
- plibc_func = dlsym(RTLD_NEXT, "fork");
- if (plibc_func == NULL) {
- fprintf(stderr, "libustfork: unable to find \"fork\" symbol\n");
- errno = ENOSYS;
- return -1;
- }
- }
-
- ust_before_fork(&sigset);
- /* Do the real fork */
- retval = plibc_func();
- if (retval == 0) {
- /* child */
- ust_after_fork_child(&sigset);
- } else {
- ust_after_fork_parent(&sigset);
- }
- return retval;
-}
-
-#ifdef __linux__
-
-struct user_desc;
-
-struct ustfork_clone_info {
- int (*fn)(void *);
- void *arg;
- sigset_t sigset;
-};
-
-static int clone_fn(void *arg)
-{
- struct ustfork_clone_info *info = (struct ustfork_clone_info *) arg;
-
- /* clone is now done and we are in child */
- ust_after_fork_child(&info->sigset);
- return info->fn(info->arg);
-}
-
-int clone(int (*fn)(void *), void *child_stack, int flags, void *arg, ...)
-{
- static int (*plibc_func)(int (*fn)(void *), void *child_stack,
- int flags, void *arg, pid_t *ptid,
- struct user_desc *tls, pid_t *ctid) = NULL;
- /* var args */
- pid_t *ptid;
- struct user_desc *tls;
- pid_t *ctid;
- /* end of var args */
- va_list ap;
- int retval;
-
- va_start(ap, arg);
- ptid = va_arg(ap, pid_t *);
- tls = va_arg(ap, struct user_desc *);
- ctid = va_arg(ap, pid_t *);
- va_end(ap);
-
- if (plibc_func == NULL) {
- plibc_func = dlsym(RTLD_NEXT, "clone");
- if (plibc_func == NULL) {
- fprintf(stderr, "libustfork: unable to find \"clone\" symbol.\n");
- errno = ENOSYS;
- return -1;
- }
- }
-
- if (flags & CLONE_VM) {
- /*
- * Creating a thread, no need to intervene, just pass on
- * the arguments.
- */
- retval = plibc_func(fn, child_stack, flags, arg, ptid,
- tls, ctid);
- } else {
- /* Creating a real process, we need to intervene. */
- struct ustfork_clone_info info = { fn = fn, arg = arg };
-
- ust_before_fork(&info.sigset);
- retval = plibc_func(clone_fn, child_stack, flags, &info,
- ptid, tls, ctid);
- /* The child doesn't get here. */
- ust_after_fork_parent(&info.sigset);
- }
- return retval;
-}
-
-#elif defined (__FreeBSD__)
-
-pid_t rfork(int flags)
-{
- static pid_t (*plibc_func)(void) = NULL;
- sigset_t sigset;
- pid_t retval;
-
- if (plibc_func == NULL) {
- plibc_func = dlsym(RTLD_NEXT, "rfork");
- if (plibc_func == NULL) {
- fprintf(stderr, "libustfork: unable to find \"rfork\" symbol\n");
- errno = ENOSYS;
- return -1;
- }
- }
-
- ust_before_fork(&sigset);
- /* Do the real rfork */
- retval = plibc_func();
- if (retval == 0) {
- /* child */
- ust_after_fork_child(&sigset);
- } else {
- ust_after_fork_parent(&sigset);
- }
- return retval;
-}
-
-/*
- * On BSD, no need to override vfork, because it runs in the context of
- * the parent, with parent waiting until execve or exit is executed in
- * the child.
- */
-
-#else
-#warning "Unknown OS. You might want to ensure that fork/clone/vfork/fork handling is complete."
-#endif