From e90598bb77482a8a32bf02b83da35fc6f55432e5 Mon Sep 17 00:00:00 2001
From: Laura Abbott <lauraa@codeaurora.org>
Date: Fri, 24 Jan 2014 17:03:08 -0800
Subject: [PATCH] linux-ramdump-parser-v2: Improve slabinfo robustness
Sometimes the slabinfo data structures may be corrupt because of software
error or when the ramdumps were collected. Detect this bettter to
avoid looping forever or going out of bounds.
Change-Id: I5b0202048d61b937355d7e3d2b2b18f629529657
---
linux-ramdump-parser-v2/parsers/slabinfo.py | 17 ++++++++++++++---
1 file changed, 14 insertions(+), 3 deletions(-)
diff --git a/linux-ramdump-parser-v2/parsers/slabinfo.py b/linux-ramdump-parser-v2/parsers/slabinfo.py
index 40d7f22..5d739af 100644
--- a/linux-ramdump-parser-v2/parsers/slabinfo.py
+++ b/linux-ramdump-parser-v2/parsers/slabinfo.py
@@ -1,4 +1,4 @@
-# Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
+# Copyright (c) 2012-2014, The Linux Foundation. All rights reserved.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 and
@@ -11,7 +11,7 @@
import re
-from mm import page_address
+from mm import page_address, pfn_to_page
from print_out import print_out_str
from parser_util import register_parser, RamParser
@@ -39,13 +39,15 @@ class Slabinfo(RamParser):
freelist = self.ramdump.read_word(page + freelist_offset)
p = freelist
addr = page_address(self.ramdump, page)
+ seen = []
if addr is None:
return
- while p != 0 and p is not None:
+ while p != 0 and p is not None and p not in seen:
idx = self.slab_index(self.ramdump, p, addr, slab)
if idx >= len(bitarray) or idx < 0:
return
bitarray[idx] = 1
+ seen.append(p)
p = self.get_free_pointer(self.ramdump, slab, p)
def get_track(self, ramdump, slab, obj, track_type):
@@ -136,15 +138,24 @@ class Slabinfo(RamParser):
def print_slab_page_info(self, ramdump, slab, slab_node, start, out_file):
page = self.ramdump.read_word(start)
+ seen = []
if page == 0:
return
slab_lru_offset = self.ramdump.field_offset('struct page', 'lru')
page_flags_offset = self.ramdump.field_offset('struct page', 'flags')
slab_node_offset = self.ramdump.field_offset(
'struct kmem_cache', 'size')
+ max_pfn_addr = self.ramdump.addr_lookup('max_pfn')
+ max_pfn = self.ramdump.read_word(max_pfn_addr)
+ max_page = pfn_to_page(ramdump, max_pfn)
while page != start:
if page is None:
return
+ if page in seen:
+ return
+ if page > max_page:
+ return
+ seen.append(page)
page = page - slab_lru_offset
page_flags = self.ramdump.read_word(page + page_flags_offset)
page_addr = page_address(self.ramdump, page)
--
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