[src/trunk]: src/sys/kern Need to keep track of the requested size, when real...

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

details:   https://anonhg.NetBSD.org/src/rev/50c3f652192c
branches:  trunk
changeset: 834629:50c3f652192c
user:      maxv <maxv%NetBSD.org@localhost>
date:      Tue Aug 21 07:56:53 2018 +0000

description:
Need to keep track of the requested size, when realloc is used under kASan.
Maybe we could use mh_rqsz by default.

diffstat:

 sys/kern/kern_malloc.c |  16 +++++++++++++---
 1 files changed, 13 insertions(+), 3 deletions(-)

diffs (52 lines):

diff -r 3ef0a5238100 -r 50c3f652192c sys/kern/kern_malloc.c
--- a/sys/kern/kern_malloc.c    Tue Aug 21 06:49:21 2018 +0000
+++ b/sys/kern/kern_malloc.c    Tue Aug 21 07:56:53 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_malloc.c,v 1.149 2018/08/21 01:25:57 pgoyette Exp $       */
+/*     $NetBSD: kern_malloc.c,v 1.150 2018/08/21 07:56:53 maxv Exp $   */
 
 /*
  * Copyright (c) 1987, 1991, 1993
@@ -70,7 +70,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_malloc.c,v 1.149 2018/08/21 01:25:57 pgoyette Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_malloc.c,v 1.150 2018/08/21 07:56:53 maxv Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_kasan.h"
@@ -101,7 +101,10 @@
  * Header contains total size, including the header itself.
  */
 struct malloc_header {
-       size_t          mh_size;
+       size_t mh_size;
+#ifdef KASAN
+       size_t mh_rqsz;
+#endif
 } __aligned(ALIGNBYTES + 1);
 
 void *
@@ -139,6 +142,9 @@
        }
        mh = (void *)((char *)p + hdroffset);
        mh->mh_size = allocsize - hdroffset;
+#ifdef KASAN
+       mh->mh_rqsz = origsize;
+#endif
        mh++;
 
 #ifdef KASAN
@@ -195,7 +201,11 @@
        mh = curaddr;
        mh--;
 
+#ifdef KASAN
+       cursize = mh->mh_rqsz;
+#else
        cursize = mh->mh_size - sizeof(struct malloc_header);
+#endif
 
        /*
         * If we already actually have as much as they want, we're done.