pc64: fix segattach

the comment about Physseg.size being in pages is wrong,
change type to uintptr and correct the comment.

change the length parameter of segattach() and isoverlap()
to uintptr as well. segments can grow over 4GB in pc64 now
and globalsegattach() in devsegment calculates len argument
of isoverlap() by s->top - s->bot. note that the syscall
still takes 32bit ulong argument for the length!

check for integer overflow in segattach(), make sure segment
goes not beyond USTKTOP.

change PTEMAPMEM constant to uvlong as it is used to calculate
SEGMAXSIZE.

5 files changed, 11 insertions, 12 deletions

diff --git a/sys/src/9/bcm/main.c b/sys/src/9/bcm/main.c
index 3382bd397..2d74f083f 100644
--- a/sys/src/9/bcm/main.c
+++ b/sys/src/9/bcm/main.c
@@ -223,7 +223,7 @@ gpiomeminit(void)
 	seg.attr = SG_PHYSICAL;
 	seg.name = "gpio";
 	seg.pa = (VIRTIO+0x200000);
-	seg.size = 1;
+	seg.size = BY2PG;
 	addphysseg(&seg);
 }
 
diff --git a/sys/src/9/pc64/mem.h b/sys/src/9/pc64/mem.h
index d75e0f941..a641f8800 100644
--- a/sys/src/9/pc64/mem.h
+++ b/sys/src/9/pc64/mem.h
@@ -132,7 +132,7 @@
 /*
  *  virtual MMU
  */
-#define	PTEMAPMEM	(1024*1024)	
+#define	PTEMAPMEM	(1ull*MiB)	
 #define	PTEPERTAB	(PTEMAPMEM/BY2PG)
 #define	SEGMAPSIZE	65536
 #define	SSEGMAPSIZE	16
diff --git a/sys/src/9/port/portdat.h b/sys/src/9/port/portdat.h
index 062a6ac56..ee92c43c3 100644
--- a/sys/src/9/port/portdat.h
+++ b/sys/src/9/port/portdat.h
@@ -389,7 +389,7 @@ struct Physseg
 	ulong	attr;			/* Segment attributes */
 	char	*name;			/* Attach name */
 	uintptr	pa;			/* Physical address */
-	ulong	size;			/* Maximum segment size in pages */
+	uintptr	size;			/* Maximum segment size in bytes */
 	Page	*(*pgalloc)(Segment*, uintptr);	/* Allocation if we need it */
 	void	(*pgfree)(Page*);
 };
diff --git a/sys/src/9/port/portfns.h b/sys/src/9/port/portfns.h
index 5200be1e9..233dcaf9a 100644
--- a/sys/src/9/port/portfns.h
+++ b/sys/src/9/port/portfns.h
@@ -137,7 +137,7 @@ int		iprint(char*, ...);
 void		isdir(Chan*);
 int		iseve(void);
 int		islo(void);
-Segment*	isoverlap(Proc*, uintptr, int);
+Segment*	isoverlap(Proc*, uintptr, uintptr);
 int		ispages(void*);
 int		isphysseg(char*);
 void		ixsummary(void);
@@ -302,7 +302,7 @@ void		scheddump(void);
 void		schedinit(void);
 void		(*screenputs)(char*, int);
 long		seconds(void);
-uintptr		segattach(Proc*, ulong, char *, uintptr, ulong);
+uintptr		segattach(Proc*, ulong, char *, uintptr, uintptr);
 void		segclock(uintptr);
 void		segpage(Segment*, Page*);
 int		setcolor(ulong, ulong, ulong, ulong);
diff --git a/sys/src/9/port/segment.c b/sys/src/9/port/segment.c
index c73698b9e..735c876b4 100644
--- a/sys/src/9/port/segment.c
+++ b/sys/src/9/port/segment.c
@@ -558,7 +558,7 @@ out:
 }
 
 Segment*
-isoverlap(Proc *p, uintptr va, int len)
+isoverlap(Proc *p, uintptr va, uintptr len)
 {
 	int i;
 	Segment *ns;
@@ -621,7 +621,7 @@ isphysseg(char *name)
 }
 
 uintptr
-segattach(Proc *p, ulong attr, char *name, uintptr va, ulong len)
+segattach(Proc *p, ulong attr, char *name, uintptr va, uintptr len)
 {
 	int sno;
 	Segment *s, *os;
@@ -671,13 +671,12 @@ segattach(Proc *p, ulong attr, char *name, uintptr va, ulong len)
 				error(Enovmem);
 			va -= len;
 		}
-		va &= ~(BY2PG-1);
-	} else {
-		va &= ~(BY2PG-1);
-		if(va == 0 || va >= USTKTOP)
-			error(Ebadarg);
 	}
 
+	va &= ~(BY2PG-1);
+	if(va == 0 || (va+len) > USTKTOP || (va+len) < va)
+		error(Ebadarg);
+
 	if(isoverlap(p, va, len) != nil)
 		error(Esoverlap);