kexec-tools/kexec-tools-2.0.4-makedumpfile-cache-Reuse-entry-in-pending-list.patch
arthur d43f2a8502 fix sadump format phys_base calculating error
Description of Problem:

  This is a REGRESSION issue.

  At fedora makedumpfile has been updated toward v1.5.4. Unfortunately,
  this version fails calculating phys_base on sadump format and then
  fails converting vmcore.

  x86_64 kernel is relocatable kernel and there can be a gap between
  the physical address statically assigned to kernel data and texts
  and the address that is really assigned to each object corresponding
  to the kernel symbols. The gap is phys_base. makedump calculates the
  phys_base in an ad-hoc way that comparing the addresses of some of
  occurrences of "Linux kernel" strings in certain range of vmcore.

Resolution:
  Fix patch has already been posted in upstream. so just back port.
  The commit ID are:
  commit e23dc0a1aa5fa7a4429f72ff1c2fe87a87291065
  commit 92563d7a7a5175ef78c4a94ee269b1b455331b4c

Signed-off-by: arthur <zzou@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
2013-10-29 13:28:26 +08:00

121 lines
4.4 KiB
Diff

From e23dc0a1aa5fa7a4429f72ff1c2fe87a87291065 Mon Sep 17 00:00:00 2001
From: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Date: Tue, 17 Sep 2013 15:29:38 +0900
Subject: [PATCH] [PATCH 2/2] cache: Reuse entry in pending list.
Currently, sadump_virt_phys_base() fails to calculate phys_base as
below:
$ /pub/repos/makedumpfile/makedumpfile -f -p -d 31 -x /pub3/vmcores/comparevmcore_data/vmlinux-2.6.18-363.el5 /pub3/vmcores/comparevmcore_data/vmcore-2.6.18-363.el5-sadump /pub3/vmcores/comparevmcore_data/vmcore-pd31
Switched running mode from cyclic to non-cyclic,
because the cyclic mode doesn't support sadump format.
readmem: type_addr: 1, addr:296020, size:13
readmem: type_addr: 1, addr:ffffffffff296020, size:13
readmem: type_addr: 1, addr:ffffffffff396020, size:13
readmem: type_addr: 1, addr:ffffffffff496020, size:13
readmem: type_addr: 1, addr:ffffffffff596020, size:13
readmem: type_addr: 1, addr:ffffffffff696020, size:13
readmem: type_addr: 1, addr:ffffffffff796020, size:13
readmem: type_addr: 1, addr:ffffffffff896020, size:13
readmem: type_addr: 1, addr:ffffffffff996020, size:13
readmem: type_addr: 1, addr:ffffffffffa96020, size:13
readmem: type_addr: 1, addr:ffffffffffb96020, size:13
readmem: type_addr: 1, addr:ffffffffffc96020, size:13
readmem: type_addr: 1, addr:ffffffffffd96020, size:13
readmem: type_addr: 1, addr:ffffffffffe96020, size:13
readmem: type_addr: 1, addr:fffffffffff96020, size:13
readmem: type_addr: 1, addr:96020, size:13
readmem: type_addr: 1, addr:196020, size:13
readmem: type_addr: 1, addr:296020, size:13
readmem: type_addr: 1, addr:396020, size:13
readmem: type_addr: 1, addr:496020, size:13
readmem: type_addr: 1, addr:596020, size:13
readmem: type_addr: 1, addr:696020, size:13
readmem: type_addr: 1, addr:796020, size:13
readmem: type_addr: 1, addr:896020, size:13
readmem: type_addr: 1, addr:996020, size:13
readmem: type_addr: 1, addr:a96020, size:13
readmem: type_addr: 1, addr:b96020, size:13
readmem: type_addr: 1, addr:c96020, size:13
readmem: type_addr: 1, addr:d96020, size:13
readmem: type_addr: 1, addr:e96020, size:13
readmem: type_addr: 1, addr:f96020, size:13
readmem: type_addr: 1, addr:1096020, size:13
readmem: type_addr: 1, addr:1196020, size:13
readmem: type_addr: 1, addr:1296020, size:13
readmem: type_addr: 0, addr:ffffffff8045e260, size:32
cpu_online_mask_init: Can't read cpu_online_mask memory.
makedumpfile Failed.
By git bisect, I found this bug is caused by the following commit:
commit 0aff0e5174d0708bf1bfb039ab863e1fea8a1029
Author: Petr Tesarik <ptesarik@suse.cz>
Date: Wed Oct 31 16:12:47 2012 +0900
[PATCH] keep dumpfile pages in a cache.
Then, I found this bug happens in the following senario.
If one of the readpage_xxx() methods fails reading 8 pages in a row, 8
entries in pool are fully contained in pending list. Then,
cache_alloc() returns NULL and this continues forever in the
execution. In other words, there's assumption in cache_alloc() that if
pool is fully used, they are fully in used list, not in pending list
at all. However, the buggy path here breaks the assumption. This patch
changes cache_alloc() so that it first tries to reuse enty in pending
list if exists.
In fact, I found this bug in ad-hoc phys_base calculation performed in
sadump_virt_phys_base(). However, I fixed cache side since this bug
can occur in general on every vmcore format. Crash dump can contain
broken data in any part of vmcore and so requested physical address to
read can be broken likewise.
Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
---
cache.c | 25 +++++++++++++------------
1 file changed, 13 insertions(+), 12 deletions(-)
diff --git a/makedumpfile-1.5.4/cache.c b/makedumpfile-1.5.4/cache.c
index dad8d80..0dd957c 100644
--- a/makedumpfile-1.5.4/cache.c
+++ b/makedumpfile-1.5.4/cache.c
@@ -103,19 +103,20 @@ cache_alloc(unsigned long long paddr)
{
struct cache_entry *entry = NULL;
- if (avail)
+ if (avail) {
entry = &pool[--avail];
-
- if (!entry) {
- if (used.tail) {
- entry = used.tail;
- remove_entry(&used, entry);
- } else
- return NULL;
- }
-
- entry->paddr = paddr;
- add_entry(&pending, entry);
+ entry->paddr = paddr;
+ add_entry(&pending, entry);
+ } else if (pending.tail) {
+ entry = pending.tail;
+ entry->paddr = paddr;
+ } else if (used.tail) {
+ entry = used.tail;
+ remove_entry(&used, entry);
+ entry->paddr = paddr;
+ add_entry(&pending, entry);
+ } else
+ return NULL;
return entry->bufptr;
}
--
1.8.3.1