From mboxrd@z Thu Jan  1 00:00:00 1970
From: Yoann Padioleau <pad@fb.com>
To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net>
Date: Thu,  5 Jun 2014 00:56:22 +0000
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Subject: [9fans] minor kernel bug
Topicbox-Message-UUID: f52bd9c4-ead8-11e9-9d60-3106f5b1d025

Hi,

Here is a patch for tasklock.c:

int
lock(Lock *l)
{
	int i;
	ulong pc;

	pc =3D getcallerpc(&l);

	lockstats.locks++;
	if(up)
		inccnt(&up->nlocks);	/* prevent being scheded */
	if(tas(&l->key) =3D=3D 0){
		if(up)
			up->lastlock =3D l;
		l->pc =3D pc;
		l->p =3D up;
		l->isilock =3D 0;
+            	l->m =3D MACHP(m->machno);
...
		return 0;
	}

we do that in ilock() and canlock() so it's a bug I think to not do it also=
 in lock().
The field is only used in iprintcanlock which use canlock(), not lock(), so=
 this
if fine, but for consistency it would be better to also do it in lock() no?