git: 86950cf9ffe8 - main - tests: Fix race condition in aslr_setuid, take 2

The branch main has been updated by des:

URL: https://cgit.FreeBSD.org/src/commit/?id=86950cf9ffe89b7978fca019019692b3ea492044

commit 86950cf9ffe89b7978fca019019692b3ea492044
Author:     Dag-Erling Smørgrav <des@FreeBSD.org>
AuthorDate: 2026-06-23 15:20:26 +0000
Commit:     Dag-Erling Smørgrav <des@FreeBSD.org>
CommitDate: 2026-06-23 15:20:38 +0000

    tests: Fix race condition in aslr_setuid, take 2
    
    Instead of a cloexec pipe, ingest ping's stdout and block until it has
    printed its initial summary, then close the pipe and return to the main
    test loop.  Run ping in quiet mode so it won't mind that stdout is gone.
    
    PR:             296116
    MFC after:      1 week
    Fixes:          080a4087014e ("tests: Fix race condition in aslr_setuid")
    Reviewed by:    markj
    Differential Revision:  https://reviews.freebsd.org/D57763
---
 tests/sys/kern/aslr.c | 18 ++++++++----------
 1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/tests/sys/kern/aslr.c b/tests/sys/kern/aslr.c
index 7d5282fc7cf3..966ea5c3b83a 100644
--- a/tests/sys/kern/aslr.c
+++ b/tests/sys/kern/aslr.c
@@ -29,23 +29,21 @@
 static pid_t
 spawn_ping(const atf_tc_t *tc)
 {
+	char line[64];
 	const char *user;
 	struct passwd *passwd;
 	pid_t child;
-	int arg, error, ctl[2];
-	char dummy;
+	int arg, error, io[2];
 
 	user = atf_tc_get_config_var(tc, "unprivileged_user");
 	passwd = getpwnam(user);
 	ATF_REQUIRE(passwd != NULL);
 
-	ATF_REQUIRE(pipe2(ctl, O_CLOEXEC) == 0);
+	ATF_REQUIRE(pipe2(io, O_CLOEXEC) == 0);
 	child = fork();
 	ATF_REQUIRE(child >= 0);
 	if (child == 0) {
-		if (close(ctl[0]) != 0 ||
-		    close(STDOUT_FILENO) != 0 ||
-		    open("/dev/null", O_WRONLY | O_APPEND) != STDOUT_FILENO ||
+		if (dup2(io[1], STDOUT_FILENO) != STDOUT_FILENO ||
 		    seteuid(passwd->pw_uid) != 0)
 			_exit(1);
 
@@ -54,12 +52,12 @@ spawn_ping(const atf_tc_t *tc)
 		if (error != 0)
 			_exit(2);
 
-		execl("/sbin/ping", "ping", "127.0.0.1", NULL);
+		execl("/sbin/ping", "ping", "-q", "127.0.0.1", NULL);
 		_exit(127);
 	}
-	ATF_REQUIRE(close(ctl[1]) == 0);
-	ATF_REQUIRE(read(ctl[0], &dummy, 1) == 0);
-	ATF_REQUIRE(close(ctl[0]) == 0);
+	ATF_REQUIRE(close(io[1]) == 0);
+	ATF_REQUIRE(read(io[0], line, sizeof(line)) > 0);
+	ATF_REQUIRE(close(io[0]) == 0);
 
 	return (child);
 }