X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=libustfork%2Fustfork.c;h=b16d41508423e61835383d195ed2059a70ea44ee;hb=e822f505be95ac8c30c7b535a7b48c05ed0c1293;hp=c88805f73165f9ddb4835e96d7300ee16c1314be;hpb=74d89c32c1f8928943e1ce7eae5d659d4fd601a9;p=lttng-ust.git

diff --git a/libustfork/ustfork.c b/libustfork/ustfork.c
index c88805f7..b16d4150 100644
--- a/libustfork/ustfork.c
+++ b/libustfork/ustfork.c
@@ -1,9 +1,11 @@
-/* Copyright (C) 2009  Pierre-Marc Fournier
+/*
+ * Copyright (C) 2009  Pierre-Marc Fournier
+ * Copyright (C) 2011  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; either
- * version 2.1 of the License, or (at your option) any later version.
+ * 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
@@ -22,64 +24,39 @@
 #include <signal.h>
 #include <sched.h>
 #include <stdarg.h>
-#include <ust/tracectl.h>
 #include "usterr.h"
 
+#include <ust/ust.h>
+
 struct user_desc;
 
 pid_t fork(void)
 {
 	static pid_t (*plibc_func)(void) = NULL;
 	ust_fork_info_t fork_info;
-
 	pid_t retval;
 
-	if(plibc_func == NULL) {
+	if (plibc_func == NULL) {
 		plibc_func = dlsym(RTLD_NEXT, "fork");
-		if(plibc_func == NULL) {
-			fprintf(stderr, "libcwrap: unable to find fork\n");
+		if (plibc_func == NULL) {
+			fprintf(stderr, "libustfork: unable to find \"fork\" symbol\n");
 			return -1;
 		}
 	}
 
 	ust_before_fork(&fork_info);
-
 	/* Do the real fork */
 	retval = plibc_func();
-
-	if(retval == 0) {
+	if (retval == 0) {
 		/* child */
 		ust_after_fork_child(&fork_info);
-	}
-	else {
+	} else {
 		ust_after_fork_parent(&fork_info);
 	}
-
 	return retval;
 }
 
-int execve(const char *filename, char *const argv[], char *const envp[])
-{
-	static int (*plibc_func)(const char *filename, char *const argv[], char *const envp[]) = NULL;
-
-	pid_t retval;
-
-	if(plibc_func == NULL) {
-		plibc_func = dlsym(RTLD_NEXT, "execve");
-		if(plibc_func == NULL) {
-			fprintf(stderr, "libinterfork: unable to find execve\n");
-			return -1;
-		}
-	}
-
-	ust_potential_exec();
-
-	retval = plibc_func(filename, argv, envp);
-
-	return retval;
-}
-
-struct interfork_clone_info {
+struct ustfork_clone_info {
 	int (*fn)(void *);
 	void *arg;
 	ust_fork_info_t fork_info;
@@ -87,26 +64,25 @@ struct interfork_clone_info {
 
 static int clone_fn(void *arg)
 {
-	struct interfork_clone_info *info = (struct interfork_clone_info *)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);
-
 	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;
-
-	/* varargs */
+	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;
-
-	int retval;
-
+	/* end of var args */
 	va_list ap;
+	int retval;
 
 	va_start(ap, arg);
 	ptid = va_arg(ap, pid_t *);
@@ -114,29 +90,30 @@ int clone(int (*fn)(void *), void *child_stack, int flags, void *arg, ...)
 	ctid = va_arg(ap, pid_t *);
 	va_end(ap);
 
-	if(plibc_func == NULL) {
+	if (plibc_func == NULL) {
 		plibc_func = dlsym(RTLD_NEXT, "clone");
-		if(plibc_func == NULL) {
-			fprintf(stderr, "libinterfork: unable to find clone\n");
+		if (plibc_func == NULL) {
+			fprintf(stderr, "libustfork: unable to find \"clone\" symbol.\n");
 			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 interfork_clone_info info = { fn: fn, arg: arg };
+	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.fork_info);
-
-		retval = plibc_func(clone_fn, child_stack, flags, &info, ptid, tls, ctid);
-
-		/* The child doesn't get here */
+		retval = plibc_func(clone_fn, child_stack, flags, &info,
+				ptid, tls, ctid);
+		/* The child doesn't get here. */
 		ust_after_fork_parent(&info.fork_info);
 	}
-
 	return retval;
 }