Fix 'kmem -s|-S' option on Linux 5.7 and later kernels

This commit is contained in:
huskarTang 2022-12-29 11:47:25 +08:00
parent 5e1c30fc74
commit bd3bd6b94d
2 changed files with 68 additions and 1 deletions

View File

@ -0,0 +1,63 @@
From b43fc52b01897346f6e0977fecb3b056f41753f8 Mon Sep 17 00:00:00 2001
From: huskarTang <tanly6@chinatelecom.cn>
Date: Thu, 29 Dec 2022 11:32:59 +0800
Subject: [PATCH] Fix for 'kmem -s|-S' option on Linux 5.7 and later kernels
Linux 5.7 and later kernels that contain kernel commit 1ad53d9fa3f6
("slub: improve bit diffusion for freelist ptr obfuscation") changed
the calculation formula in the freelist_ptr(), which added a swab()
call to mix bits a little more. When kernel is configured with the
"CONFIG_SLAB_FREELIST_HARDENED=y", without the patch, the "kmem -s|-S"
options display wrong statistics and state whether slab objects are
in use or free and can print the following errors:
crash> kmem -s
CACHE OBJSIZE ALLOCATED TOTAL SLABS SSIZE NAME
87201e00 528 0 0 0 8k xfs_dqtrx
87201f00 496 0 0 0 8k xfs_dquot
kmem: xfs_buf: slab: 37202e6e900 invalid freepointer: b844bab900001d70
kmem: xfs_buf: slab: 3720250fd80 invalid freepointer: b8603f9400001370
...
---
memory.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/memory.c b/memory.c
index 8c6bbe4..f3862c2 100644
--- a/memory.c
+++ b/memory.c
@@ -16,10 +16,14 @@
* GNU General Public License for more details.
*/
+#define _LARGEFILE64_SOURCE 1 /* stat64() */
#include "defs.h"
#include <sys/mman.h>
#include <ctype.h>
#include <netinet/in.h>
+#include "makedumpfile.h"
+#include <byteswap.h>
+
struct meminfo { /* general purpose memory information structure */
ulong cache; /* used by the various memory searching/dumping */
@@ -19336,10 +19340,14 @@ count_free_objects(struct meminfo *si, ulong freelist)
static ulong
freelist_ptr(struct meminfo *si, ulong ptr, ulong ptr_addr)
{
- if (VALID_MEMBER(kmem_cache_random))
+ if (VALID_MEMBER(kmem_cache_random)) {
/* CONFIG_SLAB_FREELIST_HARDENED */
+
+ if (THIS_KERNEL_VERSION >= LINUX(5,7,0))
+ if (sizeof(long) == 8)
+ ptr_addr = bswap_64(ptr_addr);
return (ptr ^ si->random ^ ptr_addr);
- else
+ } else
return ptr;
}
--
2.7.4

View File

@ -1,6 +1,6 @@
Name: crash Name: crash
Version: 7.3.0 Version: 7.3.0
Release: 9 Release: 10
Summary: Linux kernel crash utility. Summary: Linux kernel crash utility.
License: GPLv3 License: GPLv3
URL: https://crash-utility.github.io URL: https://crash-utility.github.io
@ -19,6 +19,7 @@ Patch8: 0007-crash-7.3.0-sw.patch
%endif %endif
Patch9: 0008-arm64-fix-backtraces-of-KASAN-kernel-dumpfile-truncated.patch Patch9: 0008-arm64-fix-backtraces-of-KASAN-kernel-dumpfile-truncated.patch
Patch10: 0009-Add-lowercase-tcr_el1_t1sz.patch Patch10: 0009-Add-lowercase-tcr_el1_t1sz.patch
Patch11: 0010-Fix-kmem-option-on-Linux-5.7-and-later.patch
BuildRequires: ncurses-devel zlib-devel lzo-devel snappy-devel BuildRequires: ncurses-devel zlib-devel lzo-devel snappy-devel
@ -85,6 +86,9 @@ install -D -m 0644 defs.h %{buildroot}%{_includedir}/%{name}/defs.h
%{_mandir}/man8/crash.8* %{_mandir}/man8/crash.8*
%changelog %changelog
* Thu Dec 29 2022 huskartang <tanly6@chinatelecom.cn> - 7.3.0-10
- Fix "kmem -s|-S" option on Linux 5.7 and later kernels
* Thu Dec 29 2022 huskartang <tanly6@chinatelecom.cn> - 7.3.0-9 * Thu Dec 29 2022 huskartang <tanly6@chinatelecom.cn> - 7.3.0-9
- Add lowercase tcr_el1_t1sz - Add lowercase tcr_el1_t1sz