59 lines
2.0 KiB
Diff
59 lines
2.0 KiB
Diff
From 647a5c33e1c94054d7b63168cd6c12901591cb77 Mon Sep 17 00:00:00 2001
|
|
From: Lianbo Jiang <lijiang@redhat.com>
|
|
Date: Thu, 27 May 2021 18:02:11 +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
|
|
...
|
|
|
|
Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
|
|
---
|
|
memory.c | 9 +++++++--
|
|
1 file changed, 7 insertions(+), 2 deletions(-)
|
|
|
|
diff --git a/memory.c b/memory.c
|
|
index 8c6bbe409922..a3cf8a86728d 100644
|
|
--- a/memory.c
|
|
+++ b/memory.c
|
|
@@ -20,6 +20,7 @@
|
|
#include <sys/mman.h>
|
|
#include <ctype.h>
|
|
#include <netinet/in.h>
|
|
+#include <byteswap.h>
|
|
|
|
struct meminfo { /* general purpose memory information structure */
|
|
ulong cache; /* used by the various memory searching/dumping */
|
|
@@ -19336,10 +19337,14 @@ 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))
|
|
+ ptr_addr = (sizeof(long) == 8) ? bswap_64(ptr_addr)
|
|
+ : bswap_32(ptr_addr);
|
|
return (ptr ^ si->random ^ ptr_addr);
|
|
- else
|
|
+ } else
|
|
return ptr;
|
|
}
|
|
|
|
--
|
|
2.30.2
|
|
|