The branch main has been updated by kib:

URL: 
https://cgit.FreeBSD.org/src/commit/?id=d0f67f97579f7b2febf29264b1874a95056dec06
commit d0f67f97579f7b2febf29264b1874a95056dec06
Author:     Konstantin Belousov <k...@freebsd.org>
AuthorDate: 2023-05-07 18:37:42 +0000
Commit:     Konstantin Belousov <k...@freebsd.org>
CommitDate: 2023-05-09 15:30:07 +0000

    smp_topo(): make it idempotent
    
    If more than one call to the function occurs, it currently allocates the
    same amount from the group[] array, eventually leading to the memory
    corruption.
    
    Noted and reviewed by:  markj
    Sponsored by:   The FreeBSD Foundation
    MFC after:      1 week
    Differential revision:  https://reviews.freebsd.org/D39981
---
 sys/kern/subr_smp.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/sys/kern/subr_smp.c b/sys/kern/subr_smp.c
index df82d948afb0..5a9aeb5ab04a 100644
--- a/sys/kern/subr_smp.c
+++ b/sys/kern/subr_smp.c
@@ -645,7 +645,14 @@ struct cpu_group *
 smp_topo(void)
 {
        char cpusetbuf[CPUSETBUFSIZ], cpusetbuf2[CPUSETBUFSIZ];
-       struct cpu_group *top;
+       static struct cpu_group *top = NULL;
+
+       /*
+        * The first call to smp_topo() is guaranteed to occur
+        * during the kernel boot while we are still single-threaded.
+        */
+       if (top != NULL)
+               return (top);
 
        /*
         * Check for a fake topology request for debugging purposes.

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