/*
* Copyright (C) 2009 Pierre-Marc Fournier
- * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ * 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
*/
#define _GNU_SOURCE
-#include <dlfcn.h>
+#include <lttng/ust-dlfcn.h>
#include <unistd.h>
#include <stdio.h>
#include <signal.h>
#include <sched.h>
#include <stdarg.h>
-#include "usterr.h"
+#include <errno.h>
#include <lttng/ust.h>
-struct user_desc;
-
pid_t fork(void)
{
static pid_t (*plibc_func)(void) = NULL;
- ust_fork_info_t fork_info;
+ sigset_t sigset;
pid_t retval;
+ int saved_errno;
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(&fork_info);
+ ust_before_fork(&sigset);
/* Do the real fork */
retval = plibc_func();
+ saved_errno = errno;
if (retval == 0) {
/* child */
- ust_after_fork_child(&fork_info);
+ ust_after_fork_child(&sigset);
+ } else {
+ ust_after_fork_parent(&sigset);
+ }
+ errno = saved_errno;
+ return retval;
+}
+
+int daemon(int nochdir, int noclose)
+{
+ static int (*plibc_func)(int nochdir, int noclose) = NULL;
+ sigset_t sigset;
+ int retval;
+ int saved_errno;
+
+ if (plibc_func == NULL) {
+ plibc_func = dlsym(RTLD_NEXT, "daemon");
+ if (plibc_func == NULL) {
+ fprintf(stderr, "libustfork: unable to find \"daemon\" symbol\n");
+ errno = ENOSYS;
+ return -1;
+ }
+ }
+
+ ust_before_fork(&sigset);
+ /* Do the real daemon call */
+ retval = plibc_func(nochdir, noclose);
+ saved_errno = errno;
+ if (retval == 0) {
+ /* child, parent called _exit() directly */
+ ust_after_fork_child(&sigset);
} else {
- ust_after_fork_parent(&fork_info);
+ /* on error in the parent */
+ ust_after_fork_parent(&sigset);
}
+ errno = saved_errno;
return retval;
}
+#ifdef __linux__
+
+struct user_desc;
+
struct ustfork_clone_info {
int (*fn)(void *);
void *arg;
- ust_fork_info_t fork_info;
+ 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->fork_info);
+ ust_after_fork_child(&info->sigset);
return info->fn(info->arg);
}
/* end of var args */
va_list ap;
int retval;
+ int saved_errno;
va_start(ap, arg);
ptid = va_arg(ap, pid_t *);
plibc_func = dlsym(RTLD_NEXT, "clone");
if (plibc_func == NULL) {
fprintf(stderr, "libustfork: unable to find \"clone\" symbol.\n");
+ errno = ENOSYS;
return -1;
}
}
*/
retval = plibc_func(fn, child_stack, flags, arg, ptid,
tls, ctid);
+ saved_errno = errno;
} else {
/* Creating a real process, we need to intervene. */
- struct ustfork_clone_info info = { fn: fn, arg: arg };
+ struct ustfork_clone_info info = { .fn = fn, .arg = arg };
- ust_before_fork(&info.fork_info);
+ ust_before_fork(&info.sigset);
retval = plibc_func(clone_fn, child_stack, flags, &info,
ptid, tls, ctid);
+ saved_errno = errno;
/* The child doesn't get here. */
- ust_after_fork_parent(&info.fork_info);
+ ust_after_fork_parent(&info.sigset);
+ }
+ errno = saved_errno;
+ return retval;
+}
+
+int setns(int fd, int nstype)
+{
+ static int (*plibc_func)(int fd, int nstype) = NULL;
+ int retval;
+ int saved_errno;
+
+ if (plibc_func == NULL) {
+ plibc_func = dlsym(RTLD_NEXT, "setns");
+ if (plibc_func == NULL) {
+ fprintf(stderr, "libustfork: unable to find \"setns\" symbol\n");
+ errno = ENOSYS;
+ return -1;
+ }
}
+
+ /* Do the real setns */
+ retval = plibc_func(fd, nstype);
+ saved_errno = errno;
+
+ ust_after_setns();
+
+ errno = saved_errno;
return retval;
}
+
+int unshare(int flags)
+{
+ static int (*plibc_func)(int flags) = NULL;
+ int retval;
+ int saved_errno;
+
+ if (plibc_func == NULL) {
+ plibc_func = dlsym(RTLD_NEXT, "unshare");
+ if (plibc_func == NULL) {
+ fprintf(stderr, "libustfork: unable to find \"unshare\" symbol\n");
+ errno = ENOSYS;
+ return -1;
+ }
+ }
+
+ /* Do the real setns */
+ retval = plibc_func(flags);
+ saved_errno = errno;
+
+ ust_after_unshare();
+
+ errno = saved_errno;
+ return retval;
+}
+
+#elif defined (__FreeBSD__)
+
+pid_t rfork(int flags)
+{
+ static pid_t (*plibc_func)(void) = NULL;
+ sigset_t sigset;
+ pid_t retval;
+ int saved_errno;
+
+ 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();
+ saved_errno = errno;
+ if (retval == 0) {
+ /* child */
+ ust_after_fork_child(&sigset);
+ } else {
+ ust_after_fork_parent(&sigset);
+ }
+ errno = saved_errno;
+ 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
projects / lttng-ust.git / blobdiff