Change the vm_ooffset_t type to unsigned.

The type represents byte offset in the vm_object_t data space, which
does not span negative offsets in FreeBSD VM.  The change matches byte
offset signess with the unsignedness of the vm_pindex_t which
represents the type of the page indexes in the objects.

This allows to remove the UOFF_TO_IDX() macro which was used when we
have to forcibly interpret the type as unsigned anyway.  Also it fixes
a lot of implicit bugs in the device drivers d_mmap methods.

Reviewed by:	alc, markj (previous version)
Tested by:	pho
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation

1 files changed, 2 insertions, 9 deletions

diff --git a/sys/vm/vm_object.h b/sys/vm/vm_object.h
index fb1fa1f365ca..89aea522374e 100644
--- a/sys/vm/vm_object.h
+++ b/sys/vm/vm_object.h
@@ -196,20 +196,13 @@ struct vm_object {
 /*
  * Helpers to perform conversion between vm_object page indexes and offsets.
  * IDX_TO_OFF() converts an index into an offset.
- * OFF_TO_IDX() converts an offset into an index.  Since offsets are signed
- *   by default, the sign propagation in OFF_TO_IDX(), when applied to
- *   negative offsets, is intentional and returns a vm_object page index
- *   that cannot be created by a userspace mapping.
- * UOFF_TO_IDX() treats the offset as an unsigned value and converts it
- *   into an index accordingly.  Use it only when the full range of offset
- *   values are allowed.  Currently, this only applies to device mappings.
+ * OFF_TO_IDX() converts an offset into an index.
  * OBJ_MAX_SIZE specifies the maximum page index corresponding to the
  *   maximum unsigned offset.
  */
 #define	IDX_TO_OFF(idx) (((vm_ooffset_t)(idx)) << PAGE_SHIFT)
 #define	OFF_TO_IDX(off) ((vm_pindex_t)(((vm_ooffset_t)(off)) >> PAGE_SHIFT))
-#define	UOFF_TO_IDX(off) (((vm_pindex_t)(off)) >> PAGE_SHIFT)
-#define	OBJ_MAX_SIZE	(UOFF_TO_IDX(UINT64_MAX) + 1)
+#define	OBJ_MAX_SIZE	(OFF_TO_IDX(UINT64_MAX) + 1)
 
 #ifdef	_KERNEL