X-Git-Url: http://git.archive.openwrt.org/?p=project%2Fprocd.git;a=blobdiff_plain;f=trace%2Ftrace.c;h=cad2d370996d1ad179658cd950f00e78be5a575b;hp=5941f90661204e50d615f293404c57e86f202485;hb=b5d53c6c683ee73b5d494b5d0750d1deca7b749f;hpb=11fa67184a3a26830223158345b1e7764bd33710

diff --git a/trace/trace.c b/trace/trace.c
index 5941f90..cad2d37 100644
--- a/trace/trace.c
+++ b/trace/trace.c
@@ -53,15 +53,19 @@
 } while (0)
 
 #define ERROR(fmt, ...) do { \
-	syslog(0, "utrace: "fmt, ## __VA_ARGS__); \
+	syslog(LOG_ERR, "utrace: "fmt, ## __VA_ARGS__); \
 	fprintf(stderr, "utrace: "fmt, ## __VA_ARGS__); \
 } while (0)
 
-static struct uloop_process tracer;
+struct tracee {
+	struct uloop_process proc;
+	int in_syscall;
+};
+
+static struct tracee tracer;
 static int *syscall_count;
 static struct blob_buf b;
 static int syscall_max;
-static int in_syscall;
 static int debug;
 
 static int max_syscall = ARRAY_SIZE(syscall_names);
@@ -77,6 +81,16 @@ static void set_syscall(const char *name, int val)
 		}
 }
 
+struct syscall {
+	int syscall;
+	int count;
+};
+
+static int cmp_count(const void *a, const void *b)
+{
+	return ((struct syscall*)b)->count - ((struct syscall*)a)->count;
+}
+
 static void print_syscalls(int policy, const char *json)
 {
 	void *c;
@@ -88,19 +102,29 @@ static void print_syscalls(int policy, const char *json)
 	set_syscall("exit_group", 1);
 	set_syscall("exit", 1);
 
+	struct syscall sorted[ARRAY_SIZE(syscall_names)];
+
+	for (i = 0; i < ARRAY_SIZE(syscall_names); i++) {
+		sorted[i].syscall = i;
+		sorted[i].count = syscall_count[i];
+	}
+
+	qsort(sorted, ARRAY_SIZE(syscall_names), sizeof(sorted[0]), cmp_count);
+
 	blob_buf_init(&b, 0);
 	c = blobmsg_open_array(&b, "whitelist");
 
 	for (i = 0; i < ARRAY_SIZE(syscall_names); i++) {
-		if (!syscall_count[i])
-			continue;
-		if (syscall_names[i]) {
+		int sc = sorted[i].syscall;
+		if (!sorted[i].count)
+			break;
+		if (syscall_names[sc]) {
 			if (debug)
 				printf("syscall %d (%s) was called %d times\n",
-					i, syscall_names[i], syscall_count[i]);
-			blobmsg_add_string(&b, NULL, syscall_names[i]);
+					sc, syscall_names[sc], sorted[i].count);
+			blobmsg_add_string(&b, NULL, syscall_names[sc]);
 		} else {
-			ERROR("no name found for syscall(%d)\n", i);
+			ERROR("no name found for syscall(%d)\n", sc);
 		}
 	}
 	blobmsg_close_array(&b, c);
@@ -123,25 +147,53 @@ static void print_syscalls(int policy, const char *json)
 
 static void tracer_cb(struct uloop_process *c, int ret)
 {
-	if (WIFSTOPPED(ret) && WSTOPSIG(ret) & 0x80) {
-		if (!in_syscall) {
-			int syscall = ptrace(PTRACE_PEEKUSER, c->pid, reg_syscall_nr);
-
-			if (syscall < syscall_max) {
-				syscall_count[syscall]++;
-				if (debug)
-					fprintf(stderr, "%s()\n", syscall_names[syscall]);
-			} else if (debug) {
-				fprintf(stderr, "syscal(%d)\n", syscall);
+	struct tracee *tracee = container_of(c, struct tracee, proc);
+	int inject_signal = 0;
+
+	if (WIFSTOPPED(ret)) {
+		if (WSTOPSIG(ret) & 0x80) {
+			if (!tracee->in_syscall) {
+				int syscall = ptrace(PTRACE_PEEKUSER, c->pid, reg_syscall_nr);
+
+				if (syscall < syscall_max) {
+					syscall_count[syscall]++;
+					if (debug)
+						fprintf(stderr, "%s()\n", syscall_names[syscall]);
+				} else if (debug) {
+					fprintf(stderr, "syscal(%d)\n", syscall);
+				}
 			}
+			tracee->in_syscall = !tracee->in_syscall;
+		} else if ((ret >> 8) == (SIGTRAP | (PTRACE_EVENT_FORK << 8)) ||
+			   (ret >> 8) == (SIGTRAP | (PTRACE_EVENT_VFORK << 8)) ||
+			   (ret >> 8) == (SIGTRAP | (PTRACE_EVENT_CLONE << 8))) {
+			struct tracee *child = calloc(1, sizeof(struct tracee));
+
+			ptrace(PTRACE_GETEVENTMSG, c->pid, 0, &child->proc.pid);
+			child->proc.cb = tracer_cb;
+			ptrace(PTRACE_SYSCALL, child->proc.pid, 0, 0);
+			uloop_process_add(&child->proc);
+			if (debug)
+				fprintf(stderr, "Tracing new child %d\n", child->proc.pid);
+		} else {
+			inject_signal = WSTOPSIG(ret);
+			if (debug)
+				fprintf(stderr, "Injecting signal %d into pid %d\n",
+					inject_signal, tracee->proc.pid);
+		}
+	} else if (WIFEXITED(ret) || (WIFSIGNALED(ret) && WTERMSIG(ret))) {
+		if (tracee == &tracer) {
+			uloop_end(); /* Main process exit */
+		} else {
+			if (debug)
+				fprintf(stderr, "Child %d exited\n", tracee->proc.pid);
+			free(tracee);
 		}
-		in_syscall = !in_syscall;
-	} else if (WIFEXITED(ret)) {
-		uloop_end();
 		return;
 	}
-	ptrace(PTRACE_SYSCALL, c->pid, 0, 0);
-	uloop_process_add(&tracer);
+
+	ptrace(PTRACE_SYSCALL, c->pid, 0, inject_signal);
+	uloop_process_add(c);
 }
 
 int main(int argc, char **argv, char **envp)
@@ -176,8 +228,8 @@ int main(int argc, char **argv, char **envp)
 	if (child == 0) {
 		char **_argv = calloc(argc + 1, sizeof(char *));
 		char **_envp;
-		char preload[] = "LD_PRELOAD=/lib/libpreload-trace.so";
-		int envc = 1;
+		char *preload = "LD_PRELOAD=/lib/libpreload-trace.so";
+		int envc = 0;
 		int ret;
 
 		memcpy(_argv, argv, argc * sizeof(char *));
@@ -185,12 +237,15 @@ int main(int argc, char **argv, char **envp)
 		while (envp[envc++])
 			;
 
-		_envp = calloc(envc, sizeof(char *));
-		memcpy(&_envp[1], _envp, envc * sizeof(char *));
-		*envp = preload;
+		_envp = calloc(envc + 1, sizeof(char *));
+		memcpy(&_envp[1], envp, envc * sizeof(char *));
+		*_envp = preload;
 
-		ret = execve(_argv[0], _argv, envp);
+		ret = execve(_argv[0], _argv, _envp);
 		ERROR("failed to exec %s: %s\n", _argv[0], strerror(errno));
+
+		free(_argv);
+		free(_envp);
 		return ret;
 	}
 
@@ -205,13 +260,17 @@ int main(int argc, char **argv, char **envp)
 		return -1;
 	}
 
-	ptrace(PTRACE_SETOPTIONS, child, 0, PTRACE_O_TRACESYSGOOD);
+	ptrace(PTRACE_SETOPTIONS, child, 0,
+	       PTRACE_O_TRACESYSGOOD |
+	       PTRACE_O_TRACEFORK |
+	       PTRACE_O_TRACEVFORK |
+	       PTRACE_O_TRACECLONE);
 	ptrace(PTRACE_SYSCALL, child, 0, 0);
 
 	uloop_init();
-	tracer.pid = child;
-	tracer.cb = tracer_cb;
-	uloop_process_add(&tracer);
+	tracer.proc.pid = child;
+	tracer.proc.cb = tracer_cb;
+	uloop_process_add(&tracer.proc);
 	uloop_run();
 	uloop_done();