[src/trunk]: src/sys/uvm Avoid overflow if a very large number of pages are s...

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

details:   https://anonhg.NetBSD.org/src/rev/f0245e3197e2
branches:  trunk
changeset: 1009968:f0245e3197e2
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Sat May 09 22:00:48 2020 +0000

description:
Avoid overflow if a very large number of pages are swapped at once.

Unlikely, but let's make sure we don't hit this ever.

diffstat:

 sys/uvm/uvm_swap.c |  9 +++++----
 1 files changed, 5 insertions(+), 4 deletions(-)

diffs (37 lines):

diff -r a475e95fbd47 -r f0245e3197e2 sys/uvm/uvm_swap.c
--- a/sys/uvm/uvm_swap.c        Sat May 09 21:50:39 2020 +0000
+++ b/sys/uvm/uvm_swap.c        Sat May 09 22:00:48 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: uvm_swap.c,v 1.187 2020/05/09 21:50:39 riastradh Exp $ */
+/*     $NetBSD: uvm_swap.c,v 1.188 2020/05/09 22:00:48 riastradh Exp $ */
 
 /*
  * Copyright (c) 1995, 1996, 1997, 2009 Matthew R. Green
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uvm_swap.c,v 1.187 2020/05/09 21:50:39 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uvm_swap.c,v 1.188 2020/05/09 22:00:48 riastradh Exp $");
 
 #include "opt_uvmhist.h"
 #include "opt_compat_netbsd.h"
@@ -1872,7 +1872,7 @@
                                s -= sdp->swd_drumoffset;
                                KASSERT(s < sdp->swd_drumsize);
                                uvm_swap_encrypt(sdp,
-                                   (void *)(kva + i*PAGE_SIZE), s);
+                                   (void *)(kva + (vsize_t)i*PAGE_SIZE), s);
                                setbit(sdp->swd_encmap, s);
                        }
                } else {
@@ -1967,7 +1967,8 @@
                        KASSERT(s < sdp->swd_drumsize);
                        if (isclr(sdp->swd_encmap, s))
                                continue;
-                       uvm_swap_decrypt(sdp, (void *)(kva + i*PAGE_SIZE), s);
+                       uvm_swap_decrypt(sdp,
+                           (void *)(kva + (vsize_t)i*PAGE_SIZE), s);
                }
        } while (0);