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

Release crash-7.3.0-2

Resolves: rhbz#1954913

Signed-off-by: Lianbo Jiang <lijiang@redhat.com>

0001-Fix-for-kmem-s-S-option-on-Linux-5.7-and-later-kerne.patch

@@ -0,0 +1,58 @@
+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
+

crash.spec

@@ -4,7 +4,7 @@
 Summary: Kernel analysis utility for live systems, netdump, diskdump, kdump, LKCD or mcore dumpfiles
 Name: crash
 Version: 7.3.0
-Release: 1%{?dist}
+Release: 2%{?dist}
 License: GPLv3
 Source0: https://github.com/crash-utility/crash/archive/crash-%{version}.tar.gz
 Source1: http://ftp.gnu.org/gnu/gdb/gdb-7.6.tar.gz
@@ -18,6 +18,7 @@ Requires: binutils
 Provides: bundled(libiberty)
 Provides: bundled(gdb) = 7.6
 Patch0: lzo_snappy.patch
+Patch1: 0001-Fix-for-kmem-s-S-option-on-Linux-5.7-and-later-kerne.patch
 
 %description
 The core analysis suite is a self-contained tool that can be used to
@@ -38,6 +39,7 @@ offered by Mission Critical Linux, or the LKCD kernel patch.
 %prep
 %setup -n %{name}-%{version} -q
 %patch0 -p1 -b lzo_snappy.patch
+%patch1 -p1
 
 %build
 # This package has an internal copy of GDB which has broken configure code for
@@ -69,6 +71,9 @@ cp -p defs.h %{buildroot}%{_includedir}/crash
 %{_includedir}/*
 
 %changelog
+* Fri Jun 11 2021 Lianbo Jiang <lijiang@redhat.com> - 7.3.0-2
+- Fix for "kmem -s|-S" option on Linux 5.7 and later kernels
+
 * Mon May 10 2021 Lianbo Jiang <lijiang@redhat.com> - 7.3.0-1
 - Rebase to upstream 7.3.0