[src/trunk]: src/tests/lib/libc/sys Fix race in fork_singalmasked

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

details:   https://anonhg.NetBSD.org/src/rev/74da75c62add
branches:  trunk
changeset: 971983:74da75c62add
user:      kamil <kamil%NetBSD.org@localhost>
date:      Mon May 11 20:58:48 2020 +0000

description:
Fix race in fork_singalmasked

ELF RTLD after rtld.c r. 1.204 introduced locking that wraps the fork
syscall. This locking changes signal mask of the calling process during
the forking process.

Instead of comparing old and new signal mask, just after the forking
operation, check whether the expected signal is still masked and in
another test whether it is still ignored.

diffstat:

 tests/lib/libc/sys/t_ptrace_fork_wait.h |  33 +++++++++++++++------------------
 1 files changed, 15 insertions(+), 18 deletions(-)

diffs (89 lines):

diff -r 94cf565fb71e -r 74da75c62add tests/lib/libc/sys/t_ptrace_fork_wait.h
--- a/tests/lib/libc/sys/t_ptrace_fork_wait.h   Mon May 11 19:36:39 2020 +0000
+++ b/tests/lib/libc/sys/t_ptrace_fork_wait.h   Mon May 11 20:58:48 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: t_ptrace_fork_wait.h,v 1.1 2020/05/04 22:34:22 kamil Exp $     */
+/*     $NetBSD: t_ptrace_fork_wait.h,v 1.2 2020/05/11 20:58:48 kamil Exp $     */
 
 /*-
  * Copyright (c) 2016, 2017, 2018, 2020 The NetBSD Foundation, Inc.
@@ -1318,11 +1318,8 @@
 
        FORKEE_ASSERT_EQ(sysctl(name, namelen, &kp, &len, NULL, 0), 0);
 
-       if (masked)
-               kp_sigmask = kp.p_sigmask;
-
-       if (ignored)
-               kp_sigignore = kp.p_sigignore;
+       kp_sigmask = kp.p_sigmask;
+       kp_sigignore = kp.p_sigignore;
 
        DPRINTF("Set 0%s%s%s%s in EVENT_MASK for the child %d\n",
            strcmp(fn, "spawn") == 0 ? "|PTRACE_POSIX_SPAWN" : "",
@@ -1368,8 +1365,8 @@
                            kp.p_sigmask.__bits[0], kp.p_sigmask.__bits[1],
                            kp.p_sigmask.__bits[2], kp.p_sigmask.__bits[3]);
 
-                       ATF_REQUIRE(!memcmp(&kp_sigmask, &kp.p_sigmask,
-                           sizeof(kp_sigmask)));
+                       ATF_REQUIRE(sigismember((sigset_t *)&kp.p_sigmask,
+                           SIGTRAP));
                }
 
                if (ignored) {
@@ -1385,8 +1382,8 @@
                            kp.p_sigignore.__bits[0], kp.p_sigignore.__bits[1],
                            kp.p_sigignore.__bits[2], kp.p_sigignore.__bits[3]);
 
-                       ATF_REQUIRE(!memcmp(&kp_sigignore, &kp.p_sigignore,
-                           sizeof(kp_sigignore)));
+                       ATF_REQUIRE(sigismember((sigset_t *)&kp.p_sigignore,
+                           SIGTRAP));
                }
 
                SYSCALL_REQUIRE(
@@ -1431,8 +1428,8 @@
                            kp.p_sigmask.__bits[0], kp.p_sigmask.__bits[1],
                            kp.p_sigmask.__bits[2], kp.p_sigmask.__bits[3]);
 
-                       ATF_REQUIRE(!memcmp(&kp_sigmask, &kp.p_sigmask,
-                           sizeof(kp_sigmask)));
+                       ATF_REQUIRE(sigismember((sigset_t *)&kp.p_sigmask,
+                           SIGTRAP));
                }
 
                if (ignored) {
@@ -1448,8 +1445,8 @@
                            kp.p_sigignore.__bits[0], kp.p_sigignore.__bits[1],
                            kp.p_sigignore.__bits[2], kp.p_sigignore.__bits[3]);
 
-                       ATF_REQUIRE(!memcmp(&kp_sigignore, &kp.p_sigignore,
-                           sizeof(kp_sigignore)));
+                       ATF_REQUIRE(sigismember((sigset_t *)&kp.p_sigignore,
+                           SIGTRAP));
                }
 
                SYSCALL_REQUIRE(
@@ -1510,8 +1507,8 @@
                            kp.p_sigmask.__bits[0], kp.p_sigmask.__bits[1],
                            kp.p_sigmask.__bits[2], kp.p_sigmask.__bits[3]);
 
-                       ATF_REQUIRE(!memcmp(&kp_sigmask, &kp.p_sigmask,
-                           sizeof(kp_sigmask)));
+                       ATF_REQUIRE(sigismember((sigset_t *)&kp.p_sigmask,
+                           SIGTRAP));
                }
 
                if (ignored) {
@@ -1527,8 +1524,8 @@
                            kp.p_sigignore.__bits[0], kp.p_sigignore.__bits[1],
                            kp.p_sigignore.__bits[2], kp.p_sigignore.__bits[3]);
 
-                       ATF_REQUIRE(!memcmp(&kp_sigignore, &kp.p_sigignore,
-                           sizeof(kp_sigignore)));
+                       ATF_REQUIRE(sigismember((sigset_t *)&kp.p_sigignore,
+                           SIGTRAP));
                }
 
                SYSCALL_REQUIRE(