[src/trunk]: src/tests/lib/libc/sys Enable traceme_vfork_raise2 ...

[kamil <kamil%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/2e3880f458df
branches:  trunk
changeset: 319149:2e3880f458df
user:      kamil <kamil%NetBSD.org@localhost>
date:      Sat May 19 05:07:42 2018 +0000

description:
Enable traceme_vfork_raise2 in ATF ptrace(2) tests

raise(SIGSTOP) is now handled correctly by the kernel, in a child that
vfork(2)ed and called PT_TRACE_ME.

Implement a helper process emitting SIGKILL to a stopped child of a
vfork(2)ed process.

Sponsored by <The NetBSD Foundation>

diffstat:

 tests/lib/libc/sys/t_ptrace_wait.c |  56 +++++++++++++++++++++++++++++++++----
 1 files changed, 50 insertions(+), 6 deletions(-)

diffs (110 lines):

diff -r 6af8624d10ed -r 2e3880f458df tests/lib/libc/sys/t_ptrace_wait.c
--- a/tests/lib/libc/sys/t_ptrace_wait.c        Sat May 19 05:04:09 2018 +0000
+++ b/tests/lib/libc/sys/t_ptrace_wait.c        Sat May 19 05:07:42 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: t_ptrace_wait.c,v 1.45 2018/05/16 03:52:35 kamil Exp $ */
+/*     $NetBSD: t_ptrace_wait.c,v 1.46 2018/05/19 05:07:42 kamil Exp $ */
 
 /*-
  * Copyright (c) 2016 The NetBSD Foundation, Inc.
@@ -27,7 +27,7 @@
  */
 
 #include <sys/cdefs.h>
-__RCSID("$NetBSD: t_ptrace_wait.c,v 1.45 2018/05/16 03:52:35 kamil Exp $");
+__RCSID("$NetBSD: t_ptrace_wait.c,v 1.46 2018/05/19 05:07:42 kamil Exp $");
 
 #include <sys/param.h>
 #include <sys/types.h>
@@ -429,13 +429,54 @@
 static void
 traceme_vfork_raise(int sigval)
 {
-       const int exitval = 5;
-       pid_t child, wpid;
+       const int exitval = 5, exitval_watcher = 10;
+       pid_t child, parent, watcher, wpid;
+       int rv;
 #if defined(TWAIT_HAVE_STATUS)
        int status;
        int expect_core = (sigval == SIGABRT) ? 1 : 0;
 #endif
 
+       /*
+        * Spawn a dedicated thread to watch for a stopped child and emit
+        * the SIGKILL signal to it.
+        *
+        * vfork(2) might clobber watcher, this means that it's safer and
+        * simpler to reparent this process to initproc and forget about it.
+        */
+       if (sigval == SIGSTOP) {
+               parent = getpid();
+
+               watcher = fork();
+               ATF_REQUIRE(watcher != 1);
+               if (watcher == 0) {
+                       /* Double fork(2) trick to reparent to initproc */
+                       watcher = fork();
+                       FORKEE_ASSERT_NEQ(watcher, -1);
+                       if (watcher != 0)
+                               _exit(exitval_watcher);
+
+                       child = await_stopped_child(parent);
+
+                       errno = 0;
+                       rv = kill(child, SIGKILL);
+                       FORKEE_ASSERT_EQ(rv, 0);
+                       FORKEE_ASSERT_EQ(errno, 0);
+
+                       /* This exit value will be collected by initproc */
+                       _exit(0);
+               }
+               DPRINTF("Before calling %s() for the child\n", TWAIT_FNAME);
+               TWAIT_REQUIRE_SUCCESS(wpid = TWAIT_GENERIC(watcher, &status, 0),
+                                     watcher);
+
+               validate_status_exited(status, exitval_watcher);
+
+               DPRINTF("Before calling %s() for the child\n", TWAIT_FNAME);
+               TWAIT_REQUIRE_FAILURE(ECHILD, wpid = TWAIT_GENERIC(watcher,
+                                                                  &status, 0));
+       }
+
        DPRINTF("Before forking process PID=%d\n", getpid());
        SYSCALL_REQUIRE((child = vfork()) != -1);
        if (child == 0) {
@@ -446,6 +487,7 @@
                FORKEE_ASSERT(raise(sigval) == 0);
 
                switch (sigval) {
+               case SIGSTOP:
                case SIGKILL:
                case SIGABRT:
                case SIGHUP:
@@ -468,6 +510,8 @@
                validate_status_signaled(status, sigval, expect_core);
                break;
        case SIGSTOP:
+               validate_status_signaled(status, SIGKILL, 0);
+               break;
        case SIGCONT:
                validate_status_exited(status, exitval);
                break;
@@ -497,7 +541,7 @@
 }
 
 TRACEME_VFORK_RAISE(traceme_vfork_raise1, SIGKILL) /* non-maskable */
-// TRACEME_VFORK_RAISE(traceme_vfork_raise2, SIGSTOP) /* non-maskable */ // TODO
+TRACEME_VFORK_RAISE(traceme_vfork_raise2, SIGSTOP) /* non-maskable */
 TRACEME_VFORK_RAISE(traceme_vfork_raise3, SIGABRT) /* regular abort trap */
 TRACEME_VFORK_RAISE(traceme_vfork_raise4, SIGHUP)  /* hangup */
 TRACEME_VFORK_RAISE(traceme_vfork_raise5, SIGCONT) /* continued? */
@@ -7071,7 +7115,7 @@
        ATF_TP_ADD_TC(tp, traceme_pid1_parent);
 
        ATF_TP_ADD_TC(tp, traceme_vfork_raise1);
-//     ATF_TP_ADD_TC(tp, traceme_vfork_raise2); // not yet
+       ATF_TP_ADD_TC(tp, traceme_vfork_raise2);
        ATF_TP_ADD_TC(tp, traceme_vfork_raise3);
        ATF_TP_ADD_TC(tp, traceme_vfork_raise4);
        ATF_TP_ADD_TC(tp, traceme_vfork_raise5);