Loading...
Note: File does not exist in v3.1.
1.. SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2
3================
4bpftool-prog
5================
6-------------------------------------------------------------------------------
7tool for inspection and simple manipulation of eBPF progs
8-------------------------------------------------------------------------------
9
10:Manual section: 8
11
12.. include:: substitutions.rst
13
14SYNOPSIS
15========
16
17 **bpftool** [*OPTIONS*] **prog** *COMMAND*
18
19 *OPTIONS* := { |COMMON_OPTIONS| |
20 { **-f** | **--bpffs** } | { **-m** | **--mapcompat** } | { **-n** | **--nomount** } |
21 { **-L** | **--use-loader** } }
22
23 *COMMANDS* :=
24 { **show** | **list** | **dump xlated** | **dump jited** | **pin** | **load** |
25 **loadall** | **help** }
26
27PROG COMMANDS
28=============
29
30| **bpftool** **prog** { **show** | **list** } [*PROG*]
31| **bpftool** **prog dump xlated** *PROG* [{**file** *FILE* | **opcodes** | **visual** | **linum**}]
32| **bpftool** **prog dump jited** *PROG* [{**file** *FILE* | **opcodes** | **linum**}]
33| **bpftool** **prog pin** *PROG* *FILE*
34| **bpftool** **prog** { **load** | **loadall** } *OBJ* *PATH* [**type** *TYPE*] [**map** {**idx** *IDX* | **name** *NAME*} *MAP*] [**dev** *NAME*] [**pinmaps** *MAP_DIR*] [**autoattach**]
35| **bpftool** **prog attach** *PROG* *ATTACH_TYPE* [*MAP*]
36| **bpftool** **prog detach** *PROG* *ATTACH_TYPE* [*MAP*]
37| **bpftool** **prog tracelog**
38| **bpftool** **prog run** *PROG* **data_in** *FILE* [**data_out** *FILE* [**data_size_out** *L*]] [**ctx_in** *FILE* [**ctx_out** *FILE* [**ctx_size_out** *M*]]] [**repeat** *N*]
39| **bpftool** **prog profile** *PROG* [**duration** *DURATION*] *METRICs*
40| **bpftool** **prog help**
41|
42| *MAP* := { **id** *MAP_ID* | **pinned** *FILE* }
43| *PROG* := { **id** *PROG_ID* | **pinned** *FILE* | **tag** *PROG_TAG* | **name** *PROG_NAME* }
44| *TYPE* := {
45| **socket** | **kprobe** | **kretprobe** | **classifier** | **action** |
46| **tracepoint** | **raw_tracepoint** | **xdp** | **perf_event** | **cgroup/skb** |
47| **cgroup/sock** | **cgroup/dev** | **lwt_in** | **lwt_out** | **lwt_xmit** |
48| **lwt_seg6local** | **sockops** | **sk_skb** | **sk_msg** | **lirc_mode2** |
49| **cgroup/bind4** | **cgroup/bind6** | **cgroup/post_bind4** | **cgroup/post_bind6** |
50| **cgroup/connect4** | **cgroup/connect6** | **cgroup/getpeername4** | **cgroup/getpeername6** |
51| **cgroup/getsockname4** | **cgroup/getsockname6** | **cgroup/sendmsg4** | **cgroup/sendmsg6** |
52| **cgroup/recvmsg4** | **cgroup/recvmsg6** | **cgroup/sysctl** |
53| **cgroup/getsockopt** | **cgroup/setsockopt** | **cgroup/sock_release** |
54| **struct_ops** | **fentry** | **fexit** | **freplace** | **sk_lookup**
55| }
56| *ATTACH_TYPE* := {
57| **sk_msg_verdict** | **sk_skb_verdict** | **sk_skb_stream_verdict** |
58| **sk_skb_stream_parser** | **flow_dissector**
59| }
60| *METRICs* := {
61| **cycles** | **instructions** | **l1d_loads** | **llc_misses** |
62| **itlb_misses** | **dtlb_misses**
63| }
64
65
66DESCRIPTION
67===========
68 **bpftool prog { show | list }** [*PROG*]
69 Show information about loaded programs. If *PROG* is
70 specified show information only about given programs,
71 otherwise list all programs currently loaded on the system.
72 In case of **tag** or **name**, *PROG* may match several
73 programs which will all be shown.
74
75 Output will start with program ID followed by program type and
76 zero or more named attributes (depending on kernel version).
77
78 Since Linux 5.1 the kernel can collect statistics on BPF
79 programs (such as the total time spent running the program,
80 and the number of times it was run). If available, bpftool
81 shows such statistics. However, the kernel does not collect
82 them by defaults, as it slightly impacts performance on each
83 program run. Activation or deactivation of the feature is
84 performed via the **kernel.bpf_stats_enabled** sysctl knob.
85
86 Since Linux 5.8 bpftool is able to discover information about
87 processes that hold open file descriptors (FDs) against BPF
88 programs. On such kernels bpftool will automatically emit this
89 information as well.
90
91 **bpftool prog dump xlated** *PROG* [{ **file** *FILE* | **opcodes** | **visual** | **linum** }]
92 Dump eBPF instructions of the programs from the kernel. By
93 default, eBPF will be disassembled and printed to standard
94 output in human-readable format. In this case, **opcodes**
95 controls if raw opcodes should be printed as well.
96
97 In case of **tag** or **name**, *PROG* may match several
98 programs which will all be dumped. However, if **file** or
99 **visual** is specified, *PROG* must match a single program.
100
101 If **file** is specified, the binary image will instead be
102 written to *FILE*.
103
104 If **visual** is specified, control flow graph (CFG) will be
105 built instead, and eBPF instructions will be presented with
106 CFG in DOT format, on standard output.
107
108 If the programs have line_info available, the source line will
109 be displayed by default. If **linum** is specified,
110 the filename, line number and line column will also be
111 displayed on top of the source line.
112
113 **bpftool prog dump jited** *PROG* [{ **file** *FILE* | **opcodes** | **linum** }]
114 Dump jited image (host machine code) of the program.
115
116 If *FILE* is specified image will be written to a file,
117 otherwise it will be disassembled and printed to stdout.
118 *PROG* must match a single program when **file** is specified.
119
120 **opcodes** controls if raw opcodes will be printed.
121
122 If the prog has line_info available, the source line will
123 be displayed by default. If **linum** is specified,
124 the filename, line number and line column will also be
125 displayed on top of the source line.
126
127 **bpftool prog pin** *PROG* *FILE*
128 Pin program *PROG* as *FILE*.
129
130 Note: *FILE* must be located in *bpffs* mount. It must not
131 contain a dot character ('.'), which is reserved for future
132 extensions of *bpffs*.
133
134 **bpftool prog { load | loadall }** *OBJ* *PATH* [**type** *TYPE*] [**map** {**idx** *IDX* | **name** *NAME*} *MAP*] [**dev** *NAME*] [**pinmaps** *MAP_DIR*] [**autoattach**]
135 Load bpf program(s) from binary *OBJ* and pin as *PATH*.
136 **bpftool prog load** pins only the first program from the
137 *OBJ* as *PATH*. **bpftool prog loadall** pins all programs
138 from the *OBJ* under *PATH* directory.
139 **type** is optional, if not specified program type will be
140 inferred from section names.
141 By default bpftool will create new maps as declared in the ELF
142 object being loaded. **map** parameter allows for the reuse
143 of existing maps. It can be specified multiple times, each
144 time for a different map. *IDX* refers to index of the map
145 to be replaced in the ELF file counting from 0, while *NAME*
146 allows to replace a map by name. *MAP* specifies the map to
147 use, referring to it by **id** or through a **pinned** file.
148 If **dev** *NAME* is specified program will be loaded onto
149 given networking device (offload).
150 Optional **pinmaps** argument can be provided to pin all
151 maps under *MAP_DIR* directory.
152
153 If **autoattach** is specified program will be attached
154 before pin. In that case, only the link (representing the
155 program attached to its hook) is pinned, not the program as
156 such, so the path won't show in **bpftool prog show -f**,
157 only show in **bpftool link show -f**. Also, this only works
158 when bpftool (libbpf) is able to infer all necessary
159 information from the object file, in particular, it's not
160 supported for all program types. If a program does not
161 support autoattach, bpftool falls back to regular pinning
162 for that program instead.
163
164 Note: *PATH* must be located in *bpffs* mount. It must not
165 contain a dot character ('.'), which is reserved for future
166 extensions of *bpffs*.
167
168 **bpftool prog attach** *PROG* *ATTACH_TYPE* [*MAP*]
169 Attach bpf program *PROG* (with type specified by
170 *ATTACH_TYPE*). Most *ATTACH_TYPEs* require a *MAP*
171 parameter, with the exception of *flow_dissector* which is
172 attached to current networking name space.
173
174 **bpftool prog detach** *PROG* *ATTACH_TYPE* [*MAP*]
175 Detach bpf program *PROG* (with type specified by
176 *ATTACH_TYPE*). Most *ATTACH_TYPEs* require a *MAP*
177 parameter, with the exception of *flow_dissector* which is
178 detached from the current networking name space.
179
180 **bpftool prog tracelog**
181 Dump the trace pipe of the system to the console (stdout).
182 Hit <Ctrl+C> to stop printing. BPF programs can write to this
183 trace pipe at runtime with the **bpf_trace_printk**\ () helper.
184 This should be used only for debugging purposes. For
185 streaming data from BPF programs to user space, one can use
186 perf events (see also **bpftool-map**\ (8)).
187
188 **bpftool prog run** *PROG* **data_in** *FILE* [**data_out** *FILE* [**data_size_out** *L*]] [**ctx_in** *FILE* [**ctx_out** *FILE* [**ctx_size_out** *M*]]] [**repeat** *N*]
189 Run BPF program *PROG* in the kernel testing infrastructure
190 for BPF, meaning that the program works on the data and
191 context provided by the user, and not on actual packets or
192 monitored functions etc. Return value and duration for the
193 test run are printed out to the console.
194
195 Input data is read from the *FILE* passed with **data_in**.
196 If this *FILE* is "**-**", input data is read from standard
197 input. Input context, if any, is read from *FILE* passed with
198 **ctx_in**. Again, "**-**" can be used to read from standard
199 input, but only if standard input is not already in use for
200 input data. If a *FILE* is passed with **data_out**, output
201 data is written to that file. Similarly, output context is
202 written to the *FILE* passed with **ctx_out**. For both
203 output flows, "**-**" can be used to print to the standard
204 output (as plain text, or JSON if relevant option was
205 passed). If output keywords are omitted, output data and
206 context are discarded. Keywords **data_size_out** and
207 **ctx_size_out** are used to pass the size (in bytes) for the
208 output buffers to the kernel, although the default of 32 kB
209 should be more than enough for most cases.
210
211 Keyword **repeat** is used to indicate the number of
212 consecutive runs to perform. Note that output data and
213 context printed to files correspond to the last of those
214 runs. The duration printed out at the end of the runs is an
215 average over all runs performed by the command.
216
217 Not all program types support test run. Among those which do,
218 not all of them can take the **ctx_in**/**ctx_out**
219 arguments. bpftool does not perform checks on program types.
220
221 **bpftool prog profile** *PROG* [**duration** *DURATION*] *METRICs*
222 Profile *METRICs* for bpf program *PROG* for *DURATION*
223 seconds or until user hits <Ctrl+C>. *DURATION* is optional.
224 If *DURATION* is not specified, the profiling will run up to
225 **UINT_MAX** seconds.
226
227 **bpftool prog help**
228 Print short help message.
229
230OPTIONS
231=======
232 .. include:: common_options.rst
233
234 -f, --bpffs
235 When showing BPF programs, show file names of pinned
236 programs.
237
238 -m, --mapcompat
239 Allow loading maps with unknown map definitions.
240
241 -n, --nomount
242 Do not automatically attempt to mount any virtual file system
243 (such as tracefs or BPF virtual file system) when necessary.
244
245 -L, --use-loader
246 Load program as a "loader" program. This is useful to debug
247 the generation of such programs. When this option is in
248 use, bpftool attempts to load the programs from the object
249 file into the kernel, but does not pin them (therefore, the
250 *PATH* must not be provided).
251
252 When combined with the **-d**\ \|\ **--debug** option,
253 additional debug messages are generated, and the execution
254 of the loader program will use the **bpf_trace_printk**\ ()
255 helper to log each step of loading BTF, creating the maps,
256 and loading the programs (see **bpftool prog tracelog** as
257 a way to dump those messages).
258
259EXAMPLES
260========
261**# bpftool prog show**
262
263::
264
265 10: xdp name some_prog tag 005a3d2123620c8b gpl run_time_ns 81632 run_cnt 10
266 loaded_at 2017-09-29T20:11:00+0000 uid 0
267 xlated 528B jited 370B memlock 4096B map_ids 10
268 pids systemd(1)
269
270**# bpftool --json --pretty prog show**
271
272::
273
274 [{
275 "id": 10,
276 "type": "xdp",
277 "tag": "005a3d2123620c8b",
278 "gpl_compatible": true,
279 "run_time_ns": 81632,
280 "run_cnt": 10,
281 "loaded_at": 1506715860,
282 "uid": 0,
283 "bytes_xlated": 528,
284 "jited": true,
285 "bytes_jited": 370,
286 "bytes_memlock": 4096,
287 "map_ids": [10
288 ],
289 "pids": [{
290 "pid": 1,
291 "comm": "systemd"
292 }
293 ]
294 }
295 ]
296
297|
298| **# bpftool prog dump xlated id 10 file /tmp/t**
299| **$ ls -l /tmp/t**
300
301::
302
303 -rw------- 1 root root 560 Jul 22 01:42 /tmp/t
304
305**# bpftool prog dump jited tag 005a3d2123620c8b**
306
307::
308
309 0: push %rbp
310 1: mov %rsp,%rbp
311 2: sub $0x228,%rsp
312 3: sub $0x28,%rbp
313 4: mov %rbx,0x0(%rbp)
314
315|
316| **# mount -t bpf none /sys/fs/bpf/**
317| **# bpftool prog pin id 10 /sys/fs/bpf/prog**
318| **# bpftool prog load ./my_prog.o /sys/fs/bpf/prog2**
319| **# ls -l /sys/fs/bpf/**
320
321::
322
323 -rw------- 1 root root 0 Jul 22 01:43 prog
324 -rw------- 1 root root 0 Jul 22 01:44 prog2
325
326**# bpftool prog dump jited pinned /sys/fs/bpf/prog opcodes**
327
328::
329
330 0: push %rbp
331 55
332 1: mov %rsp,%rbp
333 48 89 e5
334 4: sub $0x228,%rsp
335 48 81 ec 28 02 00 00
336 b: sub $0x28,%rbp
337 48 83 ed 28
338 f: mov %rbx,0x0(%rbp)
339 48 89 5d 00
340
341|
342| **# bpftool prog load xdp1_kern.o /sys/fs/bpf/xdp1 type xdp map name rxcnt id 7**
343| **# bpftool prog show pinned /sys/fs/bpf/xdp1**
344
345::
346
347 9: xdp name xdp_prog1 tag 539ec6ce11b52f98 gpl
348 loaded_at 2018-06-25T16:17:31-0700 uid 0
349 xlated 488B jited 336B memlock 4096B map_ids 7
350
351**# rm /sys/fs/bpf/xdp1**
352
353|
354| **# bpftool prog profile id 337 duration 10 cycles instructions llc_misses**
355
356::
357
358 51397 run_cnt
359 40176203 cycles (83.05%)
360 42518139 instructions # 1.06 insns per cycle (83.39%)
361 123 llc_misses # 2.89 LLC misses per million insns (83.15%)
362
363|
364| Output below is for the trace logs.
365| Run in separate terminals:
366| **# bpftool prog tracelog**
367| **# bpftool prog load -L -d file.o**
368
369::
370
371 bpftool-620059 [004] d... 2634685.517903: bpf_trace_printk: btf_load size 665 r=5
372 bpftool-620059 [004] d... 2634685.517912: bpf_trace_printk: map_create sample_map idx 0 type 2 value_size 4 value_btf_id 0 r=6
373 bpftool-620059 [004] d... 2634685.517997: bpf_trace_printk: prog_load sample insn_cnt 13 r=7
374 bpftool-620059 [004] d... 2634685.517999: bpf_trace_printk: close(5) = 0