Repository navigation
Expand file tree
/
Copy pathmemleak.py
More file actions
Latest commit
executable file
·267 lines (234 loc) · 9.55 KB
/
Copy pathmemleak.py
File metadata and controls
executable file
·267 lines (234 loc) · 9.55 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
#!/usr/bin/env python
#
# memleak Trace and display outstanding allocations to detect
# memory leaks in user-mode processes and the kernel.
#
# USAGE: memleak [-h] [-p PID] [-t] [-a] [-o OLDER] [-c COMMAND]
# [-s SAMPLE_RATE] [-d STACK_DEPTH] [-T TOP] [-z MIN_SIZE]
# [-Z MAX_SIZE]
# [interval] [count]
#
# Licensed under the Apache License, Version 2.0 (the "License")
# Copyright (C) 2016 Sasha Goldshtein.
from bcc import BPF
from time import sleep
from datetime import datetime
import argparse
import subprocess
import os
class Allocation(object):
def __init__(self, stack, size):
self.stack = stack
self.count = 1
self.size = size
def update(self, size):
self.count += 1
self.size += size
def run_command_get_output(command):
p = subprocess.Popen(command.split(),
stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
return iter(p.stdout.readline, b'')
def run_command_get_pid(command):
p = subprocess.Popen(command.split())
return p.pid
examples = """
EXAMPLES:
./memleak -p $(pidof allocs)
Trace allocations and display a summary of "leaked" (outstanding)
allocations every 5 seconds
./memleak -p $(pidof allocs) -t
Trace allocations and display each individual call to malloc/free
./memleak -ap $(pidof allocs) 10
Trace allocations and display allocated addresses, sizes, and stacks
every 10 seconds for outstanding allocations
./memleak -c "./allocs"
Run the specified command and trace its allocations
./memleak
Trace allocations in kernel mode and display a summary of outstanding
allocations every 5 seconds
./memleak -o 60000
Trace allocations in kernel mode and display a summary of outstanding
allocations that are at least one minute (60 seconds) old
./memleak -s 5
Trace roughly every 5th allocation, to reduce overhead
"""
description = """
Trace outstanding memory allocations that weren't freed.
Supports both user-mode allocations made with malloc/free and kernel-mode
allocations made with kmalloc/kfree.
"""
parser = argparse.ArgumentParser(description=description,
formatter_class=argparse.RawDescriptionHelpFormatter,
epilog=examples)
parser.add_argument("-p", "--pid", type=int, default=-1,
help="the PID to trace; if not specified, trace kernel allocs")
parser.add_argument("-t", "--trace", action="store_true",
help="print trace messages for each alloc/free call")
parser.add_argument("interval", nargs="?", default=5, type=int,
help="interval in seconds to print outstanding allocations")
parser.add_argument("count", nargs="?", type=int,
help="number of times t
8000
o print the report before exiting")
parser.add_argument("-a", "--show-allocs", default=False, action="store_true",
help="show allocation addresses and sizes as well as call stacks")
parser.add_argument("-o", "--older", default=500, type=int,
help="prune allocations younger than this age in milliseconds")
parser.add_argument("-c", "--command",
help="execute and trace the specified command")
parser.add_argument("-s", "--sample-rate", default=1, type=int,
help="sample every N-th allocation to decrease the overhead")
parser.add_argument("-T", "--top", type=int, default=10,
help="display only this many top allocating stacks (by size)")
parser.add_argument("-z", "--min-size", type=int,
help="capture only allocations larger than this size")
parser.add_argument("-Z", "--max-size", type=int,
help="capture only allocations smaller than this size")
parser.add_argument("-O", "--obj", type=str, default="c",
help="attach to malloc & free in the specified object")
args = parser.parse_args()
pid = args.pid
command = args.command
kernel_trace = (pid == -1 and command is None)
trace_all = args.trace
interval = args.interval
min_age_ns = 1e6 * args.older
sample_every_n = args.sample_rate
num_prints = args.count
top_stacks = args.top
min_size = args.min_size
max_size = args.max_size
obj = args.obj
if min_size is not None and max_size is not None and min_size > max_size:
print("min_size (-z) can't be greater than max_size (-Z)")
exit(1)
if command is not None:
print("Executing '%s' and tracing the resulting process." % command)
pid = run_command_get_pid(command)
bpf_source = """
#include <uapi/linux/ptrace.h>
struct alloc_info_t {
u64 size;
u64 timestamp_ns;
int stack_id;
};
BPF_HASH(sizes, u64);
BPF_HASH(allocs, u64, struct alloc_info_t);
BPF_STACK_TRACE(stack_traces, 1024)
int alloc_enter(struct pt_regs *ctx, size_t size)
{
SIZE_FILTER
if (SAMPLE_EVERY_N > 1) {
u64 ts = bpf_ktime_get_ns();
if (ts % SAMPLE_EVERY_N != 0)
return 0;
}
u64 pid = bpf_get_current_pid_tgid();
u64 size64 = size;
sizes.update(&pid, &size64);
if (SHOULD_PRINT)
bpf_trace_printk("alloc entered, size = %u\\n", size);
return 0;
}
int alloc_exit(struct pt_regs *ctx)
{
u64 address = PT_REGS_RC(ctx);
u64 pid = bpf_get_current_pid_tgid();
u64* size64 = sizes.lookup(&pid);
struct alloc_info_t info = {0};
if (size64 == 0)
return 0; // missed alloc entry
info.size = *size64;
sizes.delete(&pid);
info.timestamp_ns = bpf_ktime_get_ns();
info.stack_id = stack_traces.get_stackid(ctx, STACK_FLAGS);
allocs.update(&address, &info);
if (SHOULD_PRINT) {
bpf_trace_printk("alloc exited, size = %lu, result = %lx\\n",
info.size, address);
}
return 0;
}
int free_enter(struct pt_regs *ctx, void *address)
{
u64 addr = (u64)address;
struct alloc_info_t *info = allocs.lookup(&addr);
if (info == 0)
return 0;
allocs.delete(&addr);
if (SHOULD_PRINT) {
bpf_trace_printk("free entered, address = %lx, size = %lu\\n",
address, info->size);
}
return 0;
}
"""
bpf_source = bpf_source.replace("SHOULD_PRINT", "1" if trace_all else "0")
bpf_source = bpf_source.replace("SAMPLE_EVERY_N", str(sample_every_n))
size_filter = ""
if min_size is not None and max_size is not None:
size_filter = "if (size < %d || size > %d) return 0;" % \
(min_size, max_size)
elif min_size is not None:
size_filter = "if (size < %d) return 0;" % min_size
elif max_size is not None:
size_filter = "if (size > %d) return 0;" % max_size
bpf_source = bpf_source.replace("SIZE_FILTER", size_filter)
stack_flags = "BPF_F_REUSE_STACKID"
if not kernel_trace:
stack_flags += "|BPF_F_USER_STACK"
bpf_source = bpf_source.replace("STACK_FLAGS", stack_flags)
bpf_program = BPF(text=bpf_source)
if not kernel_trace:
print("Attaching to malloc and free in pid %d, Ctrl+C to quit." % pid)
bpf_program.attach_uprobe(name=obj, sym="malloc",
fn_name="alloc_enter", pid=pid)
bpf_program.attach_uretprobe(name=obj, sym="malloc",
fn_name="alloc_exit", pid=pid)
bpf_program.attach_uprobe(name=obj, sym="free",
fn_name="free_enter", pid=pid)
else:
print("Attaching to kmalloc and kfree, Ctrl+C to quit.")
bpf_program.attach_kprobe(event="__kmalloc", fn_name="alloc_enter")
bpf_program.attach_kretprobe(event="__kmalloc", fn_name="alloc_exit")
bpf_program.attach_kprobe(event="kfree", fn_name="free_enter")
def print_outstanding():
print("[%s] Top %d stacks with outstanding allocations:" %
(datetime.now().strftime("%H:%M:%S"), top_stacks))
alloc_info = {}
allocs = bpf_program["allocs"]
stack_traces = bpf_program["stack_traces"]
for address, info in sorted(allocs.items(), key=lambda a: a[1].size):
if BPF.monotonic_time() - min_age_ns < info.timestamp_ns:
continue
if info.stack_id < 0:
continue
if info.stack_id in alloc_info:
alloc_info[info.stack_id].update(info.size)
else:
stack = list(stack_traces.walk(info.stack_id))
combined = []
for addr in stack:
combined.append(bpf_program.sym(addr, pid,
show_module=True, show_offset=True))
alloc_info[info.stack_id] = Allocation(combined,
info.size)
if args.show_allocs:
print("\taddr = %x size = %s" %
(address.value, info.size))
to_show = sorted(alloc_info.values(),
key=lambda a: a.size)[-top_stacks:]
for alloc in to_show:
print("\t%d bytes in %d allocations from stack\n\t\t%s" %
(alloc.size, alloc.count, "\n\t\t".join(alloc.stack)))
count_so_far = 0
while True:
if trace_all:
print(bpf_program.trace_fields())
else:
try:
sleep(interval)
except KeyboardInterrupt:
exit()
print_outstanding()
count_so_far += 1
if num_prints is not None and count_so_far >= num_prints:
exit()