forked from iovisor/bcc
/
opensnoop_example.txt
144 lines (119 loc) · 5.96 KB
/
opensnoop_example.txt
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
Demonstrations of opensnoop, the Linux eBPF/bcc version.
opensnoop traces the open() syscall system-wide, and prints various details.
Example output:
# ./opensnoop
PID COMM FD ERR PATH
17326 <...> 7 0 /sys/kernel/debug/tracing/trace_pipe
1576 snmpd 9 0 /proc/net/dev
1576 snmpd 11 0 /proc/net/if_inet6
1576 snmpd 11 0 /proc/sys/net/ipv4/neigh/eth0/retrans_time_ms
1576 snmpd 11 0 /proc/sys/net/ipv6/neigh/eth0/retrans_time_ms
1576 snmpd 11 0 /proc/sys/net/ipv6/conf/eth0/forwarding
1576 snmpd 11 0 /proc/sys/net/ipv6/neigh/eth0/base_reachable_time_ms
1576 snmpd 11 0 /proc/sys/net/ipv4/neigh/lo/retrans_time_ms
1576 snmpd 11 0 /proc/sys/net/ipv6/neigh/lo/retrans_time_ms
1576 snmpd 11 0 /proc/sys/net/ipv6/conf/lo/forwarding
1576 snmpd 11 0 /proc/sys/net/ipv6/neigh/lo/base_reachable_time_ms
1576 snmpd 9 0 /proc/diskstats
1576 snmpd 9 0 /proc/stat
1576 snmpd 9 0 /proc/vmstat
1956 supervise 9 0 supervise/status.new
1956 supervise 9 0 supervise/status.new
17358 run 3 0 /etc/ld.so.cache
17358 run 3 0 /lib/x86_64-linux-gnu/libtinfo.so.5
17358 run 3 0 /lib/x86_64-linux-gnu/libdl.so.2
17358 run 3 0 /lib/x86_64-linux-gnu/libc.so.6
17358 run -1 6 /dev/tty
17358 run 3 0 /proc/meminfo
17358 run 3 0 /etc/nsswitch.conf
17358 run 3 0 /etc/ld.so.cache
17358 run 3 0 /lib/x86_64-linux-gnu/libnss_compat.so.2
17358 run 3 0 /lib/x86_64-linux-gnu/libnsl.so.1
17358 run 3 0 /etc/ld.so.cache
17358 run 3 0 /lib/x86_64-linux-gnu/libnss_nis.so.2
17358 run 3 0 /lib/x86_64-linux-gnu/libnss_files.so.2
17358 run 3 0 /etc/passwd
17358 run 3 0 ./run
^C
While tracing, the snmpd process opened various /proc files (reading metrics),
and a "run" process read various libraries and config files (looks like it
was starting up: a new process).
opensnoop can be useful for discovering configuration and log files, if used
during application startup.
The -p option can be used to filter on a PID, which is filtered in-kernel. Here
I've used it with -T to print timestamps:
./opensnoop -Tp 1956
TIME(s) PID COMM FD ERR PATH
0.000000000 1956 supervise 9 0 supervise/status.new
0.000289999 1956 supervise 9 0 supervise/status.new
1.023068000 1956 supervise 9 0 supervise/status.new
1.023381997 1956 supervise 9 0 supervise/status.new
2.046030000 1956 supervise 9 0 supervise/status.new
2.046363000 1956 supervise 9 0 supervise/status.new
3.068203997 1956 supervise 9 0 supervise/status.new
3.068544999 1956 supervise 9 0 supervise/status.new
This shows the supervise process is opening the status.new file twice every
second.
The -x option only prints failed opens:
# ./opensnoop -x
PID COMM FD ERR PATH
18372 run -1 6 /dev/tty
18373 run -1 6 /dev/tty
18373 multilog -1 13 lock
18372 multilog -1 13 lock
18384 df -1 2 /usr/share/locale/en_US.UTF-8/LC_MESSAGES/coreutils.mo
18384 df -1 2 /usr/share/locale/en_US.utf8/LC_MESSAGES/coreutils.mo
18384 df -1 2 /usr/share/locale/en_US/LC_MESSAGES/coreutils.mo
18384 df -1 2 /usr/share/locale/en.UTF-8/LC_MESSAGES/coreutils.mo
18384 df -1 2 /usr/share/locale/en.utf8/LC_MESSAGES/coreutils.mo
18384 df -1 2 /usr/share/locale/en/LC_MESSAGES/coreutils.mo
18385 run -1 6 /dev/tty
18386 run -1 6 /dev/tty
This caught a df command failing to open a coreutils.mo file, and trying from
different directories.
The ERR column is the system error number. Error number 2 is ENOENT: no such
file or directory.
The -n option can be used to filter on process name using partial matches:
# ./opensnoop -n ed
PID COMM FD ERR PATH
2679 sed 3 0 /etc/ld.so.cache
2679 sed 3 0 /lib/x86_64-linux-gnu/libselinux.so.1
2679 sed 3 0 /lib/x86_64-linux-gnu/libc.so.6
2679 sed 3 0 /lib/x86_64-linux-gnu/libpcre.so.3
2679 sed 3 0 /lib/x86_64-linux-gnu/libdl.so.2
2679 sed 3 0 /lib/x86_64-linux-gnu/libpthread.so.0
2679 sed 3 0 /proc/filesystems
2679 sed 3 0 /usr/lib/locale/locale-archive
2679 sed -1 2
2679 sed 3 0 /usr/lib/x86_64-linux-gnu/gconv/gconv-modules.cache
2679 sed 3 0 /dev/null
2680 sed 3 0 /etc/ld.so.cache
2680 sed 3 0 /lib/x86_64-linux-gnu/libselinux.so.1
2680 sed 3 0 /lib/x86_64-linux-gnu/libc.so.6
2680 sed 3 0 /lib/x86_64-linux-gnu/libpcre.so.3
2680 sed 3 0 /lib/x86_64-linux-gnu/libdl.so.2
2680 sed 3 0 /lib/x86_64-linux-gnu/libpthread.so.0
2680 sed 3 0 /proc/filesystems
2680 sed 3 0 /usr/lib/locale/locale-archive
2680 sed -1 2
^C
This caught the 'sed' command because it partially matches 'ed' that's passed
to the '-n' option.
USAGE message:
# ./opensnoop -h
usage: opensnoop [-h] [-T] [-x] [-p PID] [-t TID] [-n NAME]
Trace open() syscalls
optional arguments:
-h, --help show this help message and exit
-T, --timestamp include timestamp on output
-x, --failed only show failed opens
-p PID, --pid PID trace this PID only
-t TID, --tid TID trace this TID only
-n NAME, --name NAME only print process names containing this name
examples:
./opensnoop # trace all open() syscalls
./opensnoop -T # include timestamps
./opensnoop -x # only show failed opens
./opensnoop -p 181 # only trace PID 181
./opensnoop -t 123 # only trace TID 123
./opensnoop -n main # only print process names containing "main"