git: 98af94cae78a - main - sysconf(3): add _SC_UEXTERR_LEN, the max length of the extended error string

The branch main has been updated by kib:

URL: https://cgit.FreeBSD.org/src/commit/?id=98af94cae78a01a62d1094e4f255f50af2e1269a

commit 98af94cae78a01a62d1094e4f255f50af2e1269a
Author:     Konstantin Belousov <kib@FreeBSD.org>
AuthorDate: 2025-05-24 11:10:48 +0000
Commit:     Konstantin Belousov <kib@FreeBSD.org>
CommitDate: 2025-05-31 19:52:42 +0000

    sysconf(3): add _SC_UEXTERR_LEN, the max length of the extended error string
    
    Reviewed by:    brooks
    Sponsored by:   The FreeBSD Foundation
    MFC after:      2 weeks
    Differential revision:  https://reviews.freebsd.org/D50483
---
 include/unistd.h       | 1 +
 lib/libc/gen/sysconf.c | 3 +++
 sys/sys/exterrvar.h    | 2 ++
 3 files changed, 6 insertions(+)

diff --git a/include/unistd.h b/include/unistd.h
index 8574b2ba9915..33dd983eb11a 100644
--- a/include/unistd.h
+++ b/include/unistd.h
@@ -292,6 +292,7 @@ typedef	__useconds_t	useconds_t;
 #define	_SC_NPROCESSORS_CONF	57
 #define	_SC_NPROCESSORS_ONLN	58
 #define	_SC_CPUSET_SIZE		122
+#define	_SC_UEXTERR_MAXLEN	123 /* user */
 #endif
 
 /* Extensions found in Solaris and Linux. */
diff --git a/lib/libc/gen/sysconf.c b/lib/libc/gen/sysconf.c
index 6a838ddd58d8..d20b70590fb6 100644
--- a/lib/libc/gen/sysconf.c
+++ b/lib/libc/gen/sysconf.c
@@ -34,6 +34,7 @@
 
 #include "namespace.h"
 #include <sys/param.h>
+#include <sys/exterrvar.h>
 #include <sys/time.h>
 #include <sys/sysctl.h>
 #include <sys/resource.h>
@@ -602,6 +603,8 @@ yesno:
 			return (-1);
 		return ((long)value);
 #endif
+	case _SC_UEXTERR_MAXLEN:
+		return (UEXTERROR_MAXLEN);
 
 	default:
 		errno = EINVAL;
diff --git a/sys/sys/exterrvar.h b/sys/sys/exterrvar.h
index 5afcd82b136a..6eb08d63aa48 100644
--- a/sys/sys/exterrvar.h
+++ b/sys/sys/exterrvar.h
@@ -26,6 +26,8 @@ struct uexterror {
 	char msg[128];
 };
 
+#define	UEXTERROR_MAXLEN	256
+
 #define	UEXTERROR_VER		0x10010001
 
 #define	EXTERRCTL_ENABLE	1