Unlock KERN_MSGBUFSIZE and KERN_CONSBUFSIZE.

`msgbufp' and `consbufp' are immutable, such as `msg_magic' and
`msg_bufs'. initmsgbuf() and initconsbuf() which initialize this buffers
are called during kernel bootstrap, when concurrent sysctl(2) is
impossible, so they don't need to be reordered or use barriers.

ok bluhm

diff --git a/sys/kern/kern_sysctl.c b/sys/kern/kern_sysctl.c
index cc0d453..3ac262a 100644 (file)
--- a/sys/kern/kern_sysctl.c
+++ b/sys/kern/kern_sysctl.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: kern_sysctl.c,v 1.434 2024/08/06 12:36:54 mvs Exp $   */
+/*     $OpenBSD: kern_sysctl.c,v 1.435 2024/08/08 10:25:00 mvs Exp $   */
 /*     $NetBSD: kern_sysctl.c,v 1.17 1996/05/20 17:49:05 mrg Exp $     */
 
 /*-
@@ -533,6 +533,18 @@ kern_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp,
                return (sysctl_rdstruct(oldp, oldlenp, newp,
                    &mbs, sizeof(mbs)));
        }
+       case KERN_MSGBUFSIZE:
+       case KERN_CONSBUFSIZE: {
+               struct msgbuf *mp;
+               mp = (name[0] == KERN_MSGBUFSIZE) ? msgbufp : consbufp;
+               /*
+                * deal with cases where the message buffer has
+                * become corrupted.
+                */
+               if (!mp || mp->msg_magic != MSG_MAGIC)
+                       return (ENXIO);
+               return (sysctl_rdint(oldp, oldlenp, newp, mp->msg_bufs));
+       }
        case KERN_OSREV:
        case KERN_NFILES:
        case KERN_TTYCOUNT:
@@ -616,18 +628,6 @@ kern_sysctl_locked(int *name, u_int namelen, void *oldp, size_t *oldlenp,
                error =  sysctl_int(oldp, oldlenp, newp, newlen, &inthostid);
                hostid = inthostid;
                return (error);
-       case KERN_MSGBUFSIZE:
-       case KERN_CONSBUFSIZE: {
-               struct msgbuf *mp;
-               mp = (name[0] == KERN_MSGBUFSIZE) ? msgbufp : consbufp;
-               /*
-                * deal with cases where the message buffer has
-                * become corrupted.
-                */
-               if (!mp || mp->msg_magic != MSG_MAGIC)
-                       return (ENXIO);
-               return (sysctl_rdint(oldp, oldlenp, newp, mp->msg_bufs));
-       }
        case KERN_CONSBUF:
                if ((error = suser(p)))
                        return (error);
@@ -635,7 +635,10 @@ kern_sysctl_locked(int *name, u_int namelen, void *oldp, size_t *oldlenp,
        case KERN_MSGBUF: {
                struct msgbuf *mp;
                mp = (name[0] == KERN_MSGBUF) ? msgbufp : consbufp;
-               /* see note above */
+               /*
+                * deal with cases where the message buffer has
+                * become corrupted.
+                */
                if (!mp || mp->msg_magic != MSG_MAGIC)
                        return (ENXIO);
                return (sysctl_rdstruct(oldp, oldlenp, newp, mp,