Remove the assert which outlived its usefulness, and, by default,

disable compilation of the code which made it possible to call
stop_all_proc() from usermode at all.

Move the comment to the preamble of stop_all_proc() and reword it to
give overview of the function intent.

proc0 has P_HADTHREADS flag set due to kthread_add(), but no
P_KTHREAD, which triggered the assert, which does not serve a purpose
now.

Reported by:	Oliver Pinter
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks

1 files changed, 7 insertions, 12 deletions

diff --git a/sys/kern/kern_proc.c b/sys/kern/kern_proc.c
index a4f8576..729d7f0 100644
--- a/sys/kern/kern_proc.c
+++ b/sys/kern/kern_proc.c
@@ -2983,6 +2983,12 @@ static SYSCTL_NODE(_kern_proc, KERN_PROC_SIGTRAMP, sigtramp, CTLFLAG_RD |
 
 int allproc_gen;
 
+/*
+ * stop_all_proc() purpose is to stop all process which have usermode,
+ * except current process for obvious reasons.  This makes it somewhat
+ * unreliable when invoked from multithreaded process.  The service
+ * must not be user-callable anyway.
+ */
 void
 stop_all_proc(void)
 {
@@ -2991,17 +2997,6 @@ stop_all_proc(void)
 	bool restart, seen_stopped, seen_exiting, stopped_some;
 
 	cp = curproc;
-	/*
-	 * stop_all_proc() assumes that all process which have
-	 * usermode must be stopped, except current process, for
-	 * obvious reasons.  Since other threads in the process
-	 * establishing global stop could unstop something, disable
-	 * calls from multithreaded processes as precaution.  The
-	 * service must not be user-callable anyway.
-	 */
-	KASSERT((cp->p_flag & P_HADTHREADS) == 0 ||
-	    (cp->p_flag & P_KTHREAD) != 0, ("mt stop_all_proc"));
-
 allproc_loop:
 	sx_xlock(&allproc_lock);
 	gen = allproc_gen;
@@ -3088,7 +3083,7 @@ resume_all_proc(void)
 	sx_xunlock(&allproc_lock);
 }
 
-#define	TOTAL_STOP_DEBUG	1
+/* #define	TOTAL_STOP_DEBUG	1 */
 #ifdef TOTAL_STOP_DEBUG
 volatile static int ap_resume;
 #include <sys/mount.h>