[src/trunk]: src/sys/uvm Don't silently truncate the voff_t offset to vaddr_t...

[drochner <drochner%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/79eb7d3afe37
branches:  trunk
changeset: 486765:79eb7d3afe37
user:      drochner <drochner%NetBSD.org@localhost>
date:      Sun May 28 10:21:55 2000 +0000

description:
Don't silently truncate the voff_t offset to vaddr_t when passing it to
udv_attach. Pass the whole voff_t instead and do an explicite overflow
check before it is passed to the device's mmap handler (as "int", sadly).

diffstat:

 sys/uvm/uvm_device.c |  13 +++++++++++--
 sys/uvm/uvm_device.h |   4 ++--
 2 files changed, 13 insertions(+), 4 deletions(-)

diffs (52 lines):

diff -r d8001087fab3 -r 79eb7d3afe37 sys/uvm/uvm_device.c
--- a/sys/uvm/uvm_device.c      Sun May 28 09:59:48 2000 +0000
+++ b/sys/uvm/uvm_device.c      Sun May 28 10:21:55 2000 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: uvm_device.c,v 1.21 2000/04/03 07:35:24 chs Exp $      */
+/*     $NetBSD: uvm_device.c,v 1.22 2000/05/28 10:21:55 drochner Exp $ */
 
 /*
  *
@@ -131,7 +131,7 @@
 udv_attach(arg, accessprot, off, size)
        void *arg;
        vm_prot_t accessprot;
-       vaddr_t off;                    /* used only for access check */
+       voff_t off;                     /* used only for access check */
        vsize_t size;                   /* used only for access check */
 {
        dev_t device = *((dev_t *) arg);
@@ -152,6 +152,15 @@
                return(NULL);
 
        /*
+        * As long as the device d_mmap interface gets an "int"
+        * offset, we have to watch out not to overflow its
+        * numeric range. (assuming it will be interpreted as
+        * "unsigned")
+        */
+       if (((off + size - 1) & (u_int)-1) != off + size - 1)
+               return (0);
+
+       /*
         * Check that the specified range of the device allows the
         * desired protection.
         * 
diff -r d8001087fab3 -r 79eb7d3afe37 sys/uvm/uvm_device.h
--- a/sys/uvm/uvm_device.h      Sun May 28 09:59:48 2000 +0000
+++ b/sys/uvm/uvm_device.h      Sun May 28 10:21:55 2000 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: uvm_device.h,v 1.8 1999/06/21 17:25:11 thorpej Exp $   */
+/*     $NetBSD: uvm_device.h,v 1.9 2000/05/28 10:21:55 drochner Exp $  */
 
 /*
  *
@@ -69,7 +69,7 @@
  * prototypes
  */
 
-struct uvm_object *udv_attach __P((void *, vm_prot_t, vaddr_t, vsize_t));
+struct uvm_object *udv_attach __P((void *, vm_prot_t, voff_t, vsize_t));
 
 #endif /* _KERNEL */