devproc: fix proccrlmemio bugs

dont kill the calling process when demand load fails if fixfault()
is called from devproc. this happens when you delete the binary
of a running process and try to debug the process accessing uncached
pages thru /proc/$pid/mem file.

fixes to procctlmemio():

- fix missed unlock as txt2data() can error
- make sure the segment isnt freed by taking a reference (under p->seglock)
- access the page with segment locked (see comment)
- get rid of the segment stealer lock

other stuff:

- move txt2data() and data2txt() to segment.c
- add procpagecount() function
- make return type mcounseg() to ulong

1 files changed, 0 insertions, 5 deletions

diff --git a/sys/src/9/port/swap.c b/sys/src/9/port/swap.c
index ff2694f25..355c37f5f 100644
--- a/sys/src/9/port/swap.c
+++ b/sys/src/9/port/swap.c
@@ -222,11 +222,6 @@ pageout(Proc *p, Segment *s)
 	if(!canqlock(s))	/* We cannot afford to wait, we will surely deadlock */
 		return;
 
-	if(s->steal) {		/* Protected by /dev/proc */
-		qunlock(s);
-		return;
-	}
-
 	if(!canflush(p, s)) {	/* Able to invalidate all tlbs with references */
 		qunlock(s);
 		putseg(s);