X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=libinterfork%2Finterfork.c;h=746bbf58992bf2cb8deb9d469170d66698e3026b;hb=18126790113844366f69043308aac2a8ae511e7d;hp=a8db252fe0154fdf3567a5b9db0061e48ade850c;hpb=99b72dc0657875cee4a10bf4c855e99a1b1d1f9c;p=ust.git

diff --git a/libinterfork/interfork.c b/libinterfork/interfork.c
index a8db252..746bbf5 100644
--- a/libinterfork/interfork.c
+++ b/libinterfork/interfork.c
@@ -19,10 +19,19 @@
 #include <dlfcn.h>
 #include <unistd.h>
 #include <stdio.h>
+#include <signal.h>
+#include <ust/ust.h>
+#include <sched.h>
+#include <stdarg.h>
+#include <ust/tracectl.h>
+#include "usterr.h"
+
+struct user_desc;
 
 pid_t fork(void)
 {
 	static pid_t (*plibc_func)(void) = NULL;
+	ust_fork_info_t fork_info;
 
 	pid_t retval;
 
@@ -30,14 +39,105 @@ pid_t fork(void)
 		plibc_func = dlsym(RTLD_NEXT, "fork");
 		if(plibc_func == NULL) {
 			fprintf(stderr, "libcwrap: unable to find fork\n");
-			return NULL;
+			return -1;
 		}
 	}
 
+	ust_before_fork(&fork_info);
+
+	/* Do the real fork */
 	retval = plibc_func();
 
-	if(retval == 0)
-		ust_fork();
+	if(retval == 0) {
+		/* child */
+		ust_after_fork_child(&fork_info);
+	}
+	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 {
+	int (*fn)(void *);
+	void *arg;
+	ust_fork_info_t *fork_info;
+};
+
+static int clone_fn(void *arg)
+{
+	struct interfork_clone_info *info = (struct interfork_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 */
+	pid_t *ptid;
+	struct user_desc *tls;
+	pid_t *ctid;
+
+	int retval;
+
+	va_list ap;
+
+	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, "libinterfork: unable to find clone\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 };
+
+		ust_before_fork(&info.fork_info);
+
+		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;
 }