Hi,

With witness and lock debug I have seen a crashes on 7.4.  Without
debug kernel the machine just hangs.

panic: acquiring blockable sleep lock with spinlock or critical section held (kernel_lock) &kernel_lock
Stopped at      db_enter+0x14:  popq    %rbp
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
  90996   9372   3189    0x100003          0    4  gzip
*274329  88028   3189         0x3          0    0  perl
 414521  64780   3189         0x3          0    2  perl
db_enter() at db_enter+0x14
panic(ffffffff820c8388) at panic+0xc3
witness_checkorder(ffffffff825dcb70,9,0) at witness_checkorder+0xb61
__mp_lock(ffffffff825dc968) at __mp_lock+0x63
intr_handler(ffff80002400f730,ffff800000320180) at intr_handler+0x48
Xintr_ioapic_edge21_untramp() at Xintr_ioapic_edge21_untramp+0x18f
pool_do_get(ffffffff82519e58,1,ffff80002400f8a4) at pool_do_get+0x7e
pool_get(ffffffff82519e58,1) at pool_get+0xa4
sys_ypconnect(ffff800024372aa0,ffff80002400fb40,ffff80002400fba0) at sys_ypconn
ect+0xa9
syscall(ffff80002400fc10) at syscall+0x3d4
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7345666e6710, count: 4

Pool namei_pool is initialized with IPL_NONE as filesystem always
runs with kernel lock.  So pool_get() also needs kernel lock in
sys_ypconnect().

ok?

bluhm

Index: kern/uipc_syscalls.c
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/sys/kern/uipc_syscalls.c,v
diff -u -p -r1.217 uipc_syscalls.c
--- kern/uipc_syscalls.c	3 Feb 2024 22:50:09 -0000	1.217
+++ kern/uipc_syscalls.c	27 Feb 2024 17:51:22 -0000
@@ -1560,12 +1560,12 @@ sys_ypconnect(struct proc *p, void *v, r
 
 	if (p->p_p->ps_flags & PS_CHROOT)
 		return EACCES;
+	KERNEL_LOCK();
 	name = pool_get(&namei_pool, PR_WAITOK);
 	snprintf(name, MAXPATHLEN, "/var/yp/binding/%s.2", domainname);
 	NDINIT(&nid, 0, NOFOLLOW|LOCKLEAF|KERNELPATH, UIO_SYSSPACE, name, p);
 	nid.ni_pledge = PLEDGE_RPATH;
 
-	KERNEL_LOCK();
 	error = namei(&nid);
 	pool_put(&namei_pool, name);
 	if (error)