git: fafba5672b1a - stable/15 - sysctl: don't loop when EAGAIN is returned

The branch stable/15 has been updated by tuexen:

URL: https://cgit.FreeBSD.org/src/commit/?id=fafba5672b1ac028807c0378b92c8427396a2f35

commit fafba5672b1ac028807c0378b92c8427396a2f35
Author:     Michael Tuexen <tuexen@FreeBSD.org>
AuthorDate: 2026-10-08 13:05:11 +0000
Commit:     Michael Tuexen <tuexen@FreeBSD.org>
CommitDate: 2026-10-23 18:10:03 +0000

    sysctl: don't loop when EAGAIN is returned
    
    When userland_sysctl() experiences EAGAIN, don't loop internally but
    leave retrying to the caller.
    Looping was a problem in case of using tcpsso(8) to switch a TCP stack
    where the acceptance check of the new TCP stack results in EAGAIN.
    
    Reviewed by:            kib, glebius
    Sponsored by:           Netflix, Inc.
    Differential Revision:  https://reviews.freebsd.org/D60444
    
    (cherry picked from commit d39b12e9030b20410cecbcbb0c22847d7f8b5471)
---
 sys/kern/kern_sysctl.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/sys/kern/kern_sysctl.c b/sys/kern/kern_sysctl.c
index b5449af5d32e..fa79f11f440b 100644
--- a/sys/kern/kern_sysctl.c
+++ b/sys/kern/kern_sysctl.c
@@ -2580,14 +2580,9 @@ userland_sysctl(struct thread *td, int *name, u_int namelen, void *old,
 	}
 	CURVNET_SET(TD_TO_VNET(td));
 
-	for (;;) {
-		req.oldidx = 0;
-		req.newidx = 0;
-		error = sysctl_root(0, name, namelen, &req);
-		if (error != EAGAIN)
-			break;
-		kern_yield(PRI_USER);
-	}
+	req.oldidx = 0;
+	req.newidx = 0;
+	error = sysctl_root(0, name, namelen, &req);
 
 	CURVNET_RESTORE();