[src/trunk]: src/sys/kern Correctly align the size+redzone for KASAN, on amd6...

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

details:   https://anonhg.NetBSD.org/src/rev/70c3e3801946
branches:  trunk
changeset: 993427:70c3e3801946
user:      maxv <maxv%NetBSD.org@localhost>
date:      Mon Sep 10 13:11:05 2018 +0000

description:
Correctly align the size+redzone for KASAN, on amd64 it happens to be
always 8byte-aligned but on other architectures it may not be.

diffstat:

 sys/kern/subr_pool.c |  25 +++++++++++++++++++------
 1 files changed, 19 insertions(+), 6 deletions(-)

diffs (76 lines):

diff -r 7fe08b3bd187 -r 70c3e3801946 sys/kern/subr_pool.c
--- a/sys/kern/subr_pool.c      Mon Sep 10 11:05:12 2018 +0000
+++ b/sys/kern/subr_pool.c      Mon Sep 10 13:11:05 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: subr_pool.c,v 1.226 2018/08/25 05:56:24 maxv Exp $     */
+/*     $NetBSD: subr_pool.c,v 1.227 2018/09/10 13:11:05 maxv Exp $     */
 
 /*-
  * Copyright (c) 1997, 1999, 2000, 2002, 2007, 2008, 2010, 2014, 2015
@@ -33,7 +33,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_pool.c,v 1.226 2018/08/25 05:56:24 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_pool.c,v 1.227 2018/09/10 13:11:05 maxv Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_ddb.h"
@@ -2749,8 +2749,17 @@
 static void
 pool_redzone_init(struct pool *pp, size_t requested_size)
 {
+       size_t redzsz;
        size_t nsz;
 
+#ifdef KASAN
+       redzsz = requested_size;
+       kasan_add_redzone(&redzsz);
+       redzsz -= requested_size;
+#else
+       redzsz = POOL_REDZONE_SIZE;
+#endif
+
        if (pp->pr_roflags & PR_NOTOUCH) {
                pp->pr_reqsize = 0;
                pp->pr_redzone = false;
@@ -2761,7 +2770,7 @@
         * We may have extended the requested size earlier; check if
         * there's naturally space in the padding for a red zone.
         */
-       if (pp->pr_size - requested_size >= POOL_REDZONE_SIZE) {
+       if (pp->pr_size - requested_size >= redzsz) {
                pp->pr_reqsize = requested_size;
                pp->pr_redzone = true;
                return;
@@ -2771,7 +2780,7 @@
         * No space in the natural padding; check if we can extend a
         * bit the size of the pool.
         */
-       nsz = roundup(pp->pr_size + POOL_REDZONE_SIZE, pp->pr_align);
+       nsz = roundup(pp->pr_size + redzsz, pp->pr_align);
        if (nsz <= pp->pr_alloc->pa_pagesz) {
                /* Ok, we can */
                pp->pr_size = nsz;
@@ -2791,7 +2800,9 @@
        if (!pp->pr_redzone)
                return;
 #ifdef KASAN
-       kasan_alloc(p, pp->pr_reqsize, pp->pr_reqsize + POOL_REDZONE_SIZE);
+       size_t size_with_redzone = pp->pr_reqsize;
+       kasan_add_redzone(&size_with_redzone);
+       kasan_alloc(p, pp->pr_reqsize, size_with_redzone);
 #else
        uint8_t *cp, pat;
        const uint8_t *ep;
@@ -2820,7 +2831,9 @@
        if (!pp->pr_redzone)
                return;
 #ifdef KASAN
-       kasan_free(p, pp->pr_reqsize + POOL_REDZONE_SIZE);
+       size_t size_with_redzone = pp->pr_reqsize;
+       kasan_add_redzone(&size_with_redzone);
+       kasan_free(p, size_with_redzone);
 #else
        uint8_t *cp, pat, expected;
        const uint8_t *ep;