test/threaded_execve: make it also test a case when leader is not in syscall

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/test/threaded_execve.c b/test/threaded_execve.c
index 9cf3dae2ddec64c58b8ff42aa1d4a4150f14aaa6..628589a3059e1896bf308e18672eea3f972927ed 100644 (file)
--- a/test/threaded_execve.c
+++ b/test/threaded_execve.c
@@ -10,24 +10,24 @@
  *
  * # Should not be confused by traced execve-ing thread
  * # replacing traced leader:
- * [LEADER_EXIT=1] strace -oLOG -f ./threaded_execve
+ * strace -oLOG -f ./threaded_execve
  *
  * # Same, but different output mode. Output after execve
  * # should go into leader's LOG.<pid> file, not into execve'ed
  * # thread's log file:
- * [LEADER_EXIT=1] strace -oLOG -ff ./threaded_execve
+ * strace -oLOG -ff ./threaded_execve
  *
  * # Should not be confused by non-traced execve-ing thread
  * # replacing traced leader:
- * [LEADER_EXIT=1] strace -oLOG ./threaded_execve
- * ^^^^^^^^^^^^^^^^^^^^^
+ * strace -oLOG ./threaded_execve
+ * ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  * In Linux 3.2, non-traced execve-ing thread does not
  * become traced after execve, even though it has pid == leader's pid
  * after execve. And yet, strace's waitpid doesn't return ECHILD.
  *
  * # Run for NUM seconds, not just one second.
  * # Watch top to check for memory leaks in strace:
- * [LEADER_EXIT=1] strace -oLOG -f ./threaded_execve <NUM>
+ * strace -oLOG -f ./threaded_execve <NUM>
  *
  */
 #define NUM_THREADS 1
@@ -65,6 +65,7 @@ extern int __clone2(int (*fn) (void *), void *child_stack_base,
 #define syscall_exit(v) syscall(__NR_exit, (v));
 
 static char my_name[PATH_MAX];
+static int leader_final_action;
 
 static int
 thread1(void *unused)
@@ -77,18 +78,20 @@ thread1(void *unused)
 static int
 thread2(void *unused)
 {
+       char buf[64];
+       sprintf(buf, "%d", leader_final_action);
        write(1, "2", 1);
        usleep(20*1000);
        /* This fails with ENOENT if leader has exited by now! :) */
-       execl("/proc/self/exe", "exe", "exe", NULL);
+       execl("/proc/self/exe", "exe", "exe", buf, NULL);
        /* So fall back to resolved name */
-       execl(my_name, "exe", "exe", NULL);
+       execl(my_name, "exe", "exe", buf, NULL);
        for(;;) pause();
        return 0;
 }
 
 static void
-thread_leader(int die)
+thread_leader(void)
 {
        /* malloc gives sufficiently aligned buffer.
         * long buf[] does not! (on ia64).
@@ -111,27 +114,31 @@ thread_leader(int die)
                | 0        /* no signal to send on death */
                , NULL);
 
-       if (die) syscall_exit(42);
-       for(;;) pause();
+       /* Various states leader can be while other thread execve's: */
+       switch (leader_final_action % 3) {
+               case 0: syscall_exit(42); /* leader is dead */
+               case 1: for(;;) pause(); /* leader is in syscall */
+               default: for(;;) continue; /* leader is in userspace */
+       }
 }
 
 int
 main(int argc, char **argv)
 {
-       int die = getenv("LEADER_EXIT") != NULL;
-
        if (readlink("/proc/self/exe", my_name, sizeof(my_name)-1) <= 0)
                return 1;
 
        setbuf(stdout, NULL);
 
-       if (argv[1] && strcmp(argv[1], "exe") == 0)
-               thread_leader(die);
+       if (argv[1] && strcmp(argv[1], "exe") == 0) {
+               leader_final_action = atoi(argv[2]) + 1;
+               thread_leader();
+       }
 
        printf("%d: thread leader\n", getpid());
 
        alarm(argv[1] ? atoi(argv[1]) : 1);
-       thread_leader(die);
+       thread_leader();
 
         return 0;
 }