git: 40c6cb628a12 - stable/14 - kern_proc_kqueues_out(): maxlen == -1 means there is no maxlen

From: Konstantin Belousov <kib_at_FreeBSD.org>
Date: Mon, 07 Apr 2025 01:29:15 UTC
The branch stable/14 has been updated by kib:

URL: https://cgit.FreeBSD.org/src/commit/?id=40c6cb628a122b32986bdadb8ddf70f1a4455c92

commit 40c6cb628a122b32986bdadb8ddf70f1a4455c92
Author:     Konstantin Belousov <kib@FreeBSD.org>
AuthorDate: 2025-03-24 04:29:15 +0000
Commit:     Konstantin Belousov <kib@FreeBSD.org>
CommitDate: 2025-04-07 01:28:22 +0000

    kern_proc_kqueues_out(): maxlen == -1 means there is no maxlen
    
    (cherry picked from commit c18a16ebcf5bf0bad19be10f58d9f42cbc079057)
---
 sys/kern/kern_event.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/sys/kern/kern_event.c b/sys/kern/kern_event.c
index e891cb7c094a..eb77a5064113 100644
--- a/sys/kern/kern_event.c
+++ b/sys/kern/kern_event.c
@@ -2974,13 +2974,21 @@ kern_proc_kqueues_out(struct proc *p, struct sbuf *sb, size_t maxlen,
     bool compat32)
 {
 	struct sbuf *s, sm;
+	size_t sb_len;
 	int error;
 
-	s = sbuf_new(&sm, NULL, maxlen, SBUF_FIXEDLEN);
+	if (maxlen == -1 || maxlen == 0)
+		sb_len = 128;
+	else
+		sb_len = maxlen;
+	s = sbuf_new(&sm, NULL, sb_len, maxlen == -1 ? SBUF_AUTOEXTEND :
+	    SBUF_FIXEDLEN);
 	error = kern_proc_kqueues_out1(curthread, p, s, compat32);
 	sbuf_finish(s);
-	if (error == 0)
-		sbuf_bcat(sb, sbuf_data(s), MIN(sbuf_len(s), maxlen));
+	if (error == 0) {
+		sbuf_bcat(sb, sbuf_data(s), MIN(sbuf_len(s), maxlen == -1 ?
+		    SIZE_T_MAX : maxlen));
+	}
 	sbuf_delete(s);
 	return (error);
 }