Skip site navigation (1)Skip section navigation (2) 
Date:      Wed, 20 May 2026 14:35:36 +0000
From:      Mark Johnston <markj@FreeBSD.org>
To:        src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org
Cc:        Zishun Yi <zis@FreeBSD.org>
Subject:   git: b36fd09a834b - main - amd64/vmparam: Fix KASAN shadow map size in comment
Message-ID:  <6a0dc6b8.3de79.1a5e52c4@gitrepo.freebsd.org>
index | next in thread | raw e-mail 

The branch main has been updated by markj:

URL: https://cgit.FreeBSD.org/src/commit/?id=b36fd09a834be586fbc1630294e17554e1f76175

commit b36fd09a834be586fbc1630294e17554e1f76175
Author:     Zishun Yi <zis@FreeBSD.org>
AuthorDate: 2026-05-20 14:34:08 +0000
Commit:     Mark Johnston <markj@FreeBSD.org>
CommitDate: 2026-05-20 14:35:15 +0000

    amd64/vmparam: Fix KASAN shadow map size in comment
    
    The address range 0xfffff78000000000 - 0xfffff7bfffffffff spans exactly 256GB
    (0x4000000000 bytes), not 512GB.
    
    For a 2TB kernel map, based on the KASAN 1:8 shadow map ratio, the required
    shadow map size is indeed 256GB. The current comment incorrectly states 512GB,
    which can be misleading and cause confusion.
    
    Reviewed by:    markj
    MFC after:      1 week
    Differential Revision:  https://reviews.freebsd.org/D57129
---
 sys/amd64/include/vmparam.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sys/amd64/include/vmparam.h b/sys/amd64/include/vmparam.h
index 2914a204b2ef..1825c431f9f7 100644
--- a/sys/amd64/include/vmparam.h
+++ b/sys/amd64/include/vmparam.h
@@ -171,7 +171,7 @@
  * 0xffff808000000000 - 0xffff847fffffffff   large map (can be tuned up)
  * 0xffff848000000000 - 0xfffff77fffffffff   unused (large map extends there)
  * 0xfffff60000000000 - 0xfffff7ffffffffff   2TB KMSAN origin map, optional
- * 0xfffff78000000000 - 0xfffff7bfffffffff   512GB KASAN shadow map, optional
+ * 0xfffff78000000000 - 0xfffff7bfffffffff   256GB KASAN shadow map, optional
  * 0xfffff80000000000 - 0xfffffbffffffffff   4TB direct map
  * 0xfffffc0000000000 - 0xfffffdffffffffff   2TB KMSAN shadow map, optional
  * 0xfffffe0000000000 - 0xffffffffffffffff   2TB kernel map
@@ -185,7 +185,7 @@
  * 0xff41000000000000 - 0xffff7fffffffffff   unused
  * 0xffff800000000000 - 0xfffff5ffffffffff   unused (start of kernel pml4 entry)
  * 0xfffff60000000000 - 0xfffff7ffffffffff   2TB KMSAN origin map, optional
- * 0xfffff78000000000 - 0xfffff7bfffffffff   512GB KASAN shadow map, optional
+ * 0xfffff78000000000 - 0xfffff7bfffffffff   256GB KASAN shadow map, optional
  * 0xfffff80000000000 - 0xfffffbffffffffff   4TB unused
  * 0xfffffc0000000000 - 0xfffffdffffffffff   2TB KMSAN shadow map, optional
  * 0xfffffe0000000000 - 0xffffffffffffffff   2TB kernel map
home | help

Want to link to this message? Use this
URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?6a0dc6b8.3de79.1a5e52c4>