From de0851f7cf3e76ad75abe1eb7c5281591d87a56a Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Fri, 22 Oct 1993 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1993-10-22

---
 carrera/trap.c | 11 +++++++++++
 pc/trap.c      | 10 ++++++++++
 port/cache.c   |  1 +
 port/devproc.c |  4 +---
 port/portfns.h |  1 +
 power/trap.c   | 11 +++++++++++
 6 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/carrera/trap.c b/carrera/trap.c
index 1c7a1e159e6757615d260bf1c552ef5bc90acafb..84250fb056d2da4dbffd3225166ea8bd9d2d2431 100644
--- a/carrera/trap.c
+++ b/carrera/trap.c
@@ -681,3 +681,14 @@ setregisters(Ureg *xp, char *pureg, char *uva, int n)
 	memmove(pureg, uva, n);
 	xp->status = status;
 }
+
+/* Give enough context in the ureg to produce a kernel stack for
+ * a sleeping process
+ */
+void
+setkernur(Ureg *xp, Proc *p)
+{
+	xp->pc = p->sched.pc;
+	xp->sp = p->sched.sp;
+	xp->r31 = (ulong)sched;
+}
diff --git a/pc/trap.c b/pc/trap.c
index ddbc73e940ce145952f72cbe4ce05443ab4e8282..aeb8d43e6ee17ab89b90a709da658d3ebc769c87 100644
--- a/pc/trap.c
+++ b/pc/trap.c
@@ -591,3 +591,13 @@ setregisters(Ureg *xp, char *pureg, char *uva, int n)
 	xp->cs = cs;
 	xp->ss = ss;
 }
+
+/* Give enough context in the ureg to produce a kernel stack for
+ * a sleeping process
+ */
+void
+setkernur(Ureg *xp, Proc *p)
+{
+	xp->pc = p->sched.pc;
+	xp->sp = p->sched.sp;
+}
diff --git a/port/cache.c b/port/cache.c
index d3dc9f7a4e160adc3144810e213676f00727c858..fb65b3a36c8f75d3300f160f9a85e38c6b880ddf 100644
--- a/port/cache.c
+++ b/port/cache.c
@@ -555,6 +555,7 @@ cwrite(Chan* c, uchar *buf, int len, ulong offset)
 			m->list = e;
 		else
 			p->next = e;
+
 		if(tail != 0)
 			tail->next = f;
 	}
diff --git a/port/devproc.c b/port/devproc.c
index 33a52def7f1fc362c922c869ae9c3e9e60e81b31..93b0ed1a74e3dce2241c97962dd70ceed39667a4 100644
--- a/port/devproc.c
+++ b/port/devproc.c
@@ -350,9 +350,7 @@ procread(Chan *c, void *va, long n, ulong offset)
 
 	case Qkregs:
 		memset(&kur, 0, sizeof(Ureg));
-		kur.pc = p->sched.pc;
-		kur.sp = p->sched.sp;
-		kur.r31 = (ulong)sched;
+		setkernur(&kur, p);
 		rptr = (uchar*)&kur;
 		rsize = sizeof(Ureg);
 		goto regread;
diff --git a/port/portfns.h b/port/portfns.h
index 7ac65db57d346da3d465ec2364c58b6b39842d94..beea71666ee8463da8d3a8744190c14c8b2830a7 100644
--- a/port/portfns.h
+++ b/port/portfns.h
@@ -230,6 +230,7 @@ long		seconds(void);
 ulong		segattach(Proc*, ulong, char *, ulong, ulong);
 void		segpage(Segment*, Page*);
 int		setcolor(ulong, ulong, ulong, ulong);
+void		setkernur(Ureg*, Proc*);
 int		setlabel(Label*);
 void		setregisters(Ureg*, char*, char*, int);
 void		setswapchan(Chan*);
diff --git a/power/trap.c b/power/trap.c
index f2a8d668d49f30642bc63ec0794fc0139164b54d..2a06c77877356cb452b37f60f0fd2a2bb284dbee 100644
--- a/power/trap.c
+++ b/power/trap.c
@@ -647,3 +647,14 @@ setregisters(Ureg *xp, char *pureg, char *uva, int n)
 	memmove(pureg, uva, n);
 	xp->status = status;
 }
+
+/* Give enough context in the ureg to produce a kernel stack for
+ * a sleeping process
+ */
+void
+setkernur(Ureg *xp, Proc *p)
+{
+	xp->pc = p->sched.pc;
+	xp->sp = p->sched.sp;
+	xp->r31 = (ulong)sched;
+}