X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=liblttng-ust-fork%2Fustfork.c;h=71c4b86c1189ff7f89e1f7edba541c5d69d98df5;hb=1b8aad8ae2ae63030ad16cef203cf283459583c8;hp=8fade56e84c5413bd30c679d7f3fd5c30b4e3c70;hpb=a2adb105d815cfbcf9bf8f870f2f72f79a319138;p=lttng-ust.git

diff --git a/liblttng-ust-fork/ustfork.c b/liblttng-ust-fork/ustfork.c
index 8fade56e..71c4b86c 100644
--- a/liblttng-ust-fork/ustfork.c
+++ b/liblttng-ust-fork/ustfork.c
@@ -1,6 +1,6 @@
 /*
  * 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
@@ -18,13 +18,13 @@
  */
 
 #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>
 
@@ -33,11 +33,13 @@ pid_t fork(void)
 	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, "fork");
 		if (plibc_func == NULL) {
 			fprintf(stderr, "libustfork: unable to find \"fork\" symbol\n");
+			errno = ENOSYS;
 			return -1;
 		}
 	}
@@ -45,12 +47,45 @@ pid_t fork(void)
 	ust_before_fork(&sigset);
 	/* Do the real fork */
 	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;
+}
+
+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 {
+		/* on error in the parent */
+		ust_after_fork_parent(&sigset);
+	}
+	errno = saved_errno;
 	return retval;
 }
 
@@ -85,6 +120,7 @@ int clone(int (*fn)(void *), void *child_stack, int flags, void *arg, ...)
 	/* end of var args */
 	va_list ap;
 	int retval;
+	int saved_errno;
 
 	va_start(ap, arg);
 	ptid = va_arg(ap, pid_t *);
@@ -96,6 +132,7 @@ int clone(int (*fn)(void *), void *child_stack, int flags, void *arg, ...)
 		plibc_func = dlsym(RTLD_NEXT, "clone");
 		if (plibc_func == NULL) {
 			fprintf(stderr, "libustfork: unable to find \"clone\" symbol.\n");
+			errno = ENOSYS;
 			return -1;
 		}
 	}
@@ -107,16 +144,19 @@ int clone(int (*fn)(void *), void *child_stack, int flags, void *arg, ...)
 		 */
 		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.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.sigset);
 	}
+	errno = saved_errno;
 	return retval;
 }
 
@@ -127,11 +167,13 @@ 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;
 		}
 	}
@@ -139,12 +181,14 @@ pid_t rfork(int flags)
 	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;
 }