single_thread_clear() manipulates the same data structures as
single_thread_set() and, as such, doesn't need the KERNEL_LOCK().
However cursig() does need some sort of serialization to ensure that
per-process data structures like signals, flags and traced-signum stay
consistent. So the diff below move the assertion up in preparation for
more mp work.
ok?
Index: kern/kern_sig.c
===================================================================
RCS file: /cvs/src/sys/kern/kern_sig.c,v
retrieving revision 1.274
diff -u -p -r1.274 kern_sig.c
--- kern/kern_sig.c 4 Mar 2021 09:02:37 -0000 1.274
+++ kern/kern_sig.c 4 Mar 2021 09:35:47 -0000
@@ -1182,6 +1182,8 @@ cursig(struct proc *p)
int dolock = (p->p_flag & P_SINTR) == 0;
int s;
+ KERNEL_ASSERT_LOCKED();
+
sigpending = (p->p_siglist | pr->ps_siglist);
if (sigpending == 0)
return 0;
@@ -1225,11 +1227,7 @@ cursig(struct proc *p)
if (dolock)
SCHED_UNLOCK(s);
- if (dolock)
- KERNEL_LOCK();
single_thread_clear(p, 0);
- if (dolock)
- KERNEL_UNLOCK();
/*
* If we are no longer being traced, or the parent
@@ -2128,7 +2126,6 @@ single_thread_clear(struct proc *p, int
KASSERT(pr->ps_single == p);
KASSERT(curproc == p);
- KERNEL_ASSERT_LOCKED();
SCHED_LOCK(s);
pr->ps_single = NULL;
