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) = 0 375