git: 8cc85a87510a - stable/15 - diff: prefer posix_spawn over pdfork/execl

The branch stable/15 has been updated by bapt:

URL: https://cgit.FreeBSD.org/src/commit/?id=8cc85a87510a56afee49a3f5d153ab0328b676d7

commit 8cc85a87510a56afee49a3f5d153ab0328b676d7
Author:     Baptiste Daroussin <bapt@FreeBSD.org>
AuthorDate: 2026-03-25 10:22:02 +0000
Commit:     Baptiste Daroussin <bapt@FreeBSD.org>
CommitDate: 2026-04-06 16:51:46 +0000

    diff: prefer posix_spawn over pdfork/execl
    
    MFC After:              1 week
    Reviewed by:            kib
    Differential Revision:  https://reviews.freebsd.org/D56076
    
    (cherry picked from commit 6d8b2ac449f34423be9d56492022421db61d920e)
---
 usr.bin/diff/pr.c | 62 ++++++++++++++++++++++++++++++++++---------------------
 1 file changed, 39 insertions(+), 23 deletions(-)

diff --git a/usr.bin/diff/pr.c b/usr.bin/diff/pr.c
index 189e6b34649e..51cf2c765283 100644
--- a/usr.bin/diff/pr.c
+++ b/usr.bin/diff/pr.c
@@ -29,8 +29,10 @@
 
 #include <err.h>
 #include <errno.h>
+#include <fcntl.h>
 #include <paths.h>
 #include <signal.h>
+#include <spawn.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
@@ -41,6 +43,8 @@
 
 #define _PATH_PR "/usr/bin/pr"
 
+extern char **environ;
+
 struct pr *
 start_pr(char *file1, char *file2)
 {
@@ -48,6 +52,9 @@ start_pr(char *file1, char *file2)
 	pid_t pid;
 	char *header;
 	struct pr *pr;
+	posix_spawn_file_actions_t fa;
+	posix_spawnattr_t sa;
+	int error;
 
 	pr = xcalloc(1, sizeof(*pr));
 
@@ -56,32 +63,41 @@ start_pr(char *file1, char *file2)
 	fflush(stdout);
 	if (pipe(pfd) == -1)
 		err(2, "pipe");
-	switch ((pid = pdfork(&pr->procd, PD_CLOEXEC))) {
-	case -1:
-		err(2, "No more processes");
-	case 0:
-		/* child */
-		if (pfd[0] != STDIN_FILENO) {
-			dup2(pfd[0], STDIN_FILENO);
-			close(pfd[0]);
+
+	if ((error = posix_spawnattr_init(&sa)) != 0)
+		errc(2, error, "posix_spawnattr_init");
+	if ((error = posix_spawn_file_actions_init(&fa)) != 0)
+		errc(2, error, "posix_spawn_file_actions_init");
+
+	posix_spawnattr_setprocdescp_np(&sa, &pr->procd, 0);
+
+	if (pfd[0] != STDIN_FILENO) {
+		posix_spawn_file_actions_adddup2(&fa, pfd[0], STDIN_FILENO);
+		posix_spawn_file_actions_addclose(&fa, pfd[0]);
+	}
+	posix_spawn_file_actions_addclose(&fa, pfd[1]);
+
+	char *argv[] = { __DECONST(char *, _PATH_PR),
+	    __DECONST(char *, "-h"), header, NULL };
+	error = posix_spawn(&pid, _PATH_PR, &fa, &sa, argv, environ);
+	if (error != 0)
+		errc(2, error, "could not spawn pr");
+
+	posix_spawn_file_actions_destroy(&fa);
+	posix_spawnattr_destroy(&sa);
+
+	/* parent */
+	if (pfd[1] == STDOUT_FILENO) {
+		pr->ostdout = STDOUT_FILENO;
+	} else {
+		if ((pr->ostdout = dup(STDOUT_FILENO)) < 0 ||
+		    dup2(pfd[1], STDOUT_FILENO) < 0) {
+			err(2, "stdout");
 		}
 		close(pfd[1]);
-		execl(_PATH_PR, _PATH_PR, "-h", header, (char *)0);
-		_exit(127);
-	default:
-		/* parent */
-		if (pfd[1] == STDOUT_FILENO) {
-			pr->ostdout = STDOUT_FILENO;
-		} else {
-			if ((pr->ostdout = dup(STDOUT_FILENO)) < 0 ||
-			    dup2(pfd[1], STDOUT_FILENO) < 0) {
-				err(2, "stdout");
-			}
-			close(pfd[1]);
-		}
-		close(pfd[0]);
-		free(header);
 	}
+	close(pfd[0]);
+	free(header);
 	return (pr);
 }