mirror of
https://github.com/classilla/tenfourfox.git
synced 2024-06-12 01:29:43 +00:00
266 lines
8.1 KiB
Python
266 lines
8.1 KiB
Python
#!/usr/bin/python
|
|
|
|
# This Source Code Form is subject to the terms of the Mozilla Public
|
|
# License, v. 2.0. If a copy of the MPL was not distributed with this
|
|
# file, You can obtain one at http://mozilla.org/MPL/2.0/.
|
|
|
|
# From a scan mode DMD log, extract some information about a
|
|
# particular block, such as its allocation stack or which other blocks
|
|
# contain pointers to it. This can be useful when investigating leaks
|
|
# caused by unknown references to refcounted objects.
|
|
|
|
import json
|
|
import gzip
|
|
import sys
|
|
import argparse
|
|
import re
|
|
|
|
|
|
# The DMD output version this script handles.
|
|
outputVersion = 4
|
|
|
|
# If --ignore-alloc-fns is specified, stack frames containing functions that
|
|
# match these strings will be removed from the *start* of stack traces. (Once
|
|
# we hit a non-matching frame, any subsequent frames won't be removed even if
|
|
# they do match.)
|
|
allocatorFns = [
|
|
'malloc (',
|
|
'replace_malloc',
|
|
'replace_calloc',
|
|
'replace_realloc',
|
|
'replace_memalign',
|
|
'replace_posix_memalign',
|
|
'malloc_zone_malloc',
|
|
'moz_xmalloc',
|
|
'moz_xcalloc',
|
|
'moz_xrealloc',
|
|
'operator new(',
|
|
'operator new[](',
|
|
'g_malloc',
|
|
'g_slice_alloc',
|
|
'callocCanGC',
|
|
'reallocCanGC',
|
|
'vpx_malloc',
|
|
'vpx_calloc',
|
|
'vpx_realloc',
|
|
'vpx_memalign',
|
|
'js_malloc',
|
|
'js_calloc',
|
|
'js_realloc',
|
|
'pod_malloc',
|
|
'pod_calloc',
|
|
'pod_realloc',
|
|
'nsTArrayInfallibleAllocator::Malloc',
|
|
# This one necessary to fully filter some sequences of allocation functions
|
|
# that happen in practice. Note that ??? entries that follow non-allocation
|
|
# functions won't be stripped, as explained above.
|
|
'???',
|
|
]
|
|
|
|
####
|
|
|
|
# Command line arguments
|
|
|
|
def range_1_24(string):
|
|
value = int(string)
|
|
if value < 1 or value > 24:
|
|
msg = '{:s} is not in the range 1..24'.format(string)
|
|
raise argparse.ArgumentTypeError(msg)
|
|
return value
|
|
|
|
parser = argparse.ArgumentParser(description='Analyze the heap graph to find out things about an object. \
|
|
By default this prints out information about blocks that point to the given block.')
|
|
|
|
parser.add_argument('dmd_log_file_name',
|
|
help='clamped DMD log file name')
|
|
|
|
parser.add_argument('block',
|
|
help='address of the block of interest')
|
|
|
|
parser.add_argument('--info', dest='info', action='store_true',
|
|
default=False,
|
|
help='Print out information about the block.')
|
|
|
|
parser.add_argument('-sfl', '--max-stack-frame-length', type=int,
|
|
default=150,
|
|
help='Maximum number of characters to print from each stack frame')
|
|
|
|
parser.add_argument('-a', '--ignore-alloc-fns', action='store_true',
|
|
help='ignore allocation functions at the start of traces')
|
|
|
|
parser.add_argument('-f', '--max-frames', type=range_1_24,
|
|
help='maximum number of frames to consider in each trace')
|
|
|
|
parser.add_argument('-c', '--chain-reports', action='store_true',
|
|
help='if only one block is found to hold onto the object, report the next one, too')
|
|
|
|
|
|
####
|
|
|
|
|
|
class BlockData:
|
|
def __init__(self, json_block):
|
|
self.addr = json_block['addr']
|
|
|
|
if 'contents' in json_block:
|
|
contents = json_block['contents']
|
|
else:
|
|
contents = []
|
|
self.contents = []
|
|
for c in contents:
|
|
self.contents.append(int(c, 16))
|
|
|
|
self.req_size = json_block['req']
|
|
|
|
self.alloc_stack = json_block['alloc']
|
|
|
|
|
|
def print_trace_segment(args, stacks, block):
|
|
(traceTable, frameTable) = stacks
|
|
|
|
for l in traceTable[block.alloc_stack]:
|
|
# The 5: is to remove the bogus leading "#00: " from the stack frame.
|
|
print ' ', frameTable[l][5:args.max_stack_frame_length]
|
|
|
|
|
|
def show_referrers(args, blocks, stacks, block):
|
|
visited = set([])
|
|
|
|
anyFound = False
|
|
|
|
while True:
|
|
referrers = {}
|
|
|
|
for b, data in blocks.iteritems():
|
|
which_edge = 0
|
|
for e in data.contents:
|
|
if e == block:
|
|
# 8 is the number of bytes per word on a 64-bit system.
|
|
# XXX This means that this output will be wrong for logs from 32-bit systems!
|
|
referrers.setdefault(b, []).append(8 * which_edge)
|
|
anyFound = True
|
|
which_edge += 1
|
|
|
|
for r in referrers:
|
|
sys.stdout.write('0x{} size = {} bytes'.format(blocks[r].addr, blocks[r].req_size))
|
|
plural = 's' if len(referrers[r]) > 1 else ''
|
|
sys.stdout.write(' at byte offset' + plural + ' ' + (', '.join(str(x) for x in referrers[r])))
|
|
print
|
|
print_trace_segment(args, stacks, blocks[r])
|
|
print
|
|
|
|
if args.chain_reports:
|
|
if len(referrers) == 0:
|
|
sys.stdout.write('Found no more referrers.\n')
|
|
break
|
|
if len(referrers) > 1:
|
|
sys.stdout.write('Found too many referrers.\n')
|
|
break
|
|
|
|
sys.stdout.write('Chaining to next referrer.\n\n')
|
|
for r in referrers:
|
|
block = r
|
|
if block in visited:
|
|
sys.stdout.write('Found a loop.\n')
|
|
break
|
|
visited.add(block)
|
|
else:
|
|
break
|
|
|
|
if not anyFound:
|
|
print 'No referrers found.'
|
|
|
|
|
|
def show_block_info(args, blocks, stacks, block):
|
|
b = blocks[block]
|
|
sys.stdout.write('block: 0x{}\n'.format(b.addr))
|
|
sys.stdout.write('requested size: {} bytes\n'.format(b.req_size))
|
|
sys.stdout.write('\n')
|
|
sys.stdout.write('block contents: ')
|
|
for c in b.contents:
|
|
v = '0' if c == 0 else blocks[c].addr
|
|
sys.stdout.write('0x{} '.format(v))
|
|
sys.stdout.write('\n\n')
|
|
sys.stdout.write('allocation stack:\n')
|
|
print_trace_segment(args, stacks, b)
|
|
return
|
|
|
|
|
|
def cleanupTraceTable(args, frameTable, traceTable):
|
|
# Remove allocation functions at the start of traces.
|
|
if args.ignore_alloc_fns:
|
|
# Build a regexp that matches every function in allocatorFns.
|
|
escapedAllocatorFns = map(re.escape, allocatorFns)
|
|
fn_re = re.compile('|'.join(escapedAllocatorFns))
|
|
|
|
# Remove allocator fns from each stack trace.
|
|
for traceKey, frameKeys in traceTable.items():
|
|
numSkippedFrames = 0
|
|
for frameKey in frameKeys:
|
|
frameDesc = frameTable[frameKey]
|
|
if re.search(fn_re, frameDesc):
|
|
numSkippedFrames += 1
|
|
else:
|
|
break
|
|
if numSkippedFrames > 0:
|
|
traceTable[traceKey] = frameKeys[numSkippedFrames:]
|
|
|
|
# Trim the number of frames.
|
|
for traceKey, frameKeys in traceTable.items():
|
|
if len(frameKeys) > args.max_frames:
|
|
traceTable[traceKey] = frameKeys[:args.max_frames]
|
|
|
|
|
|
def loadGraph(options):
|
|
# Handle gzipped input if necessary.
|
|
isZipped = options.dmd_log_file_name.endswith('.gz')
|
|
opener = gzip.open if isZipped else open
|
|
|
|
with opener(options.dmd_log_file_name, 'rb') as f:
|
|
j = json.load(f)
|
|
|
|
if j['version'] != outputVersion:
|
|
raise Exception("'version' property isn't '{:d}'".format(outputVersion))
|
|
|
|
invocation = j['invocation']
|
|
sampleBelowSize = invocation['sampleBelowSize']
|
|
heapIsSampled = sampleBelowSize > 1
|
|
if heapIsSampled:
|
|
raise Exception("Heap analysis is not going to work with sampled blocks.")
|
|
|
|
block_list = j['blockList']
|
|
blocks = {}
|
|
|
|
for json_block in block_list:
|
|
blocks[int(json_block['addr'], 16)] = BlockData(json_block)
|
|
|
|
traceTable = j['traceTable']
|
|
frameTable = j['frameTable']
|
|
|
|
cleanupTraceTable(options, frameTable, traceTable)
|
|
|
|
return (blocks, (traceTable, frameTable))
|
|
|
|
|
|
def analyzeLogs():
|
|
options = parser.parse_args()
|
|
|
|
(blocks, stacks) = loadGraph(options)
|
|
|
|
block = int(options.block, 16)
|
|
|
|
if not block in blocks:
|
|
print 'Object', block, 'not found in traces.'
|
|
print 'It could still be the target of some nodes.'
|
|
return
|
|
|
|
if options.info:
|
|
show_block_info(options, blocks, stacks, block)
|
|
return
|
|
|
|
show_referrers(options, blocks, stacks, block)
|
|
|
|
|
|
if __name__ == "__main__":
|
|
analyzeLogs()
|