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**] [**linum**] [**visual**] }] 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**] [**linum**] [**visual**] }] 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. If **linum** is specified, the filename, line 110 number and line column will also be displayed. 111 112 **bpftool prog dump jited** *PROG* [{ **file** *FILE* | [**opcodes**] [**linum**] }] 113 Dump jited image (host machine code) of the program. 114 115 If *FILE* is specified image will be written to a file, 116 otherwise it will be disassembled and printed to stdout. 117 *PROG* must match a single program when **file** is specified. 118 119 **opcodes** controls if raw opcodes will be printed. 120 121 If the prog has line_info available, the source line will 122 be displayed. If **linum** is specified, the filename, line 123 number and line column will also be displayed. 124 125 **bpftool prog pin** *PROG* *FILE* 126 Pin program *PROG* as *FILE*. 127 128 Note: *FILE* must be located in *bpffs* mount. It must not 129 contain a dot character ('.'), which is reserved for future 130 extensions of *bpffs*. 131 132 **bpftool prog { load | loadall }** *OBJ* *PATH* [**type** *TYPE*] [**map** {**idx** *IDX* | **name** *NAME*} *MAP*] [**dev** *NAME*] [**pinmaps** *MAP_DIR*] [**autoattach**] 133 Load bpf program(s) from binary *OBJ* and pin as *PATH*. 134 **bpftool prog load** pins only the first program from the 135 *OBJ* as *PATH*. **bpftool prog loadall** pins all programs 136 from the *OBJ* under *PATH* directory. 137 **type** is optional, if not specified program type will be 138 inferred from section names. 139 By default bpftool will create new maps as declared in the ELF 140 object being loaded. **map** parameter allows for the reuse 141 of existing maps. It can be specified multiple times, each 142 time for a different map. *IDX* refers to index of the map 143 to be replaced in the ELF file counting from 0, while *NAME* 144 allows to replace a map by name. *MAP* specifies the map to 145 use, referring to it by **id** or through a **pinned** file. 146 If **dev** *NAME* is specified program will be loaded onto 147 given networking device (offload). 148 Optional **pinmaps** argument can be provided to pin all 149 maps under *MAP_DIR* directory. 150 151 If **autoattach** is specified program will be attached 152 before pin. In that case, only the link (representing the 153 program attached to its hook) is pinned, not the program as 154 such, so the path won't show in **bpftool prog show -f**, 155 only show in **bpftool link show -f**. Also, this only works 156 when bpftool (libbpf) is able to infer all necessary 157 information from the object file, in particular, it's not 158 supported for all program types. If a program does not 159 support autoattach, bpftool falls back to regular pinning 160 for that program instead. 161 162 Note: *PATH* must be located in *bpffs* mount. It must not 163 contain a dot character ('.'), which is reserved for future 164 extensions of *bpffs*. 165 166 **bpftool prog attach** *PROG* *ATTACH_TYPE* [*MAP*] 167 Attach bpf program *PROG* (with type specified by 168 *ATTACH_TYPE*). Most *ATTACH_TYPEs* require a *MAP* 169 parameter, with the exception of *flow_dissector* which is 170 attached to current networking name space. 171 172 **bpftool prog detach** *PROG* *ATTACH_TYPE* [*MAP*] 173 Detach bpf program *PROG* (with type specified by 174 *ATTACH_TYPE*). Most *ATTACH_TYPEs* require a *MAP* 175 parameter, with the exception of *flow_dissector* which is 176 detached from the current networking name space. 177 178 **bpftool prog tracelog** 179 Dump the trace pipe of the system to the console (stdout). 180 Hit <Ctrl+C> to stop printing. BPF programs can write to this 181 trace pipe at runtime with the **bpf_trace_printk**\ () helper. 182 This should be used only for debugging purposes. For 183 streaming data from BPF programs to user space, one can use 184 perf events (see also **bpftool-map**\ (8)). 185 186 **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*] 187 Run BPF program *PROG* in the kernel testing infrastructure 188 for BPF, meaning that the program works on the data and 189 context provided by the user, and not on actual packets or 190 monitored functions etc. Return value and duration for the 191 test run are printed out to the console. 192 193 Input data is read from the *FILE* passed with **data_in**. 194 If this *FILE* is "**-**", input data is read from standard 195 input. Input context, if any, is read from *FILE* passed with 196 **ctx_in**. Again, "**-**" can be used to read from standard 197 input, but only if standard input is not already in use for 198 input data. If a *FILE* is passed with **data_out**, output 199 data is written to that file. Similarly, output context is 200 written to the *FILE* passed with **ctx_out**. For both 201 output flows, "**-**" can be used to print to the standard 202 output (as plain text, or JSON if relevant option was 203 passed). If output keywords are omitted, output data and 204 context are discarded. Keywords **data_size_out** and 205 **ctx_size_out** are used to pass the size (in bytes) for the 206 output buffers to the kernel, although the default of 32 kB 207 should be more than enough for most cases. 208 209 Keyword **repeat** is used to indicate the number of 210 consecutive runs to perform. Note that output data and 211 context printed to files correspond to the last of those 212 runs. The duration printed out at the end of the runs is an 213 average over all runs performed by the command. 214 215 Not all program types support test run. Among those which do, 216 not all of them can take the **ctx_in**/**ctx_out** 217 arguments. bpftool does not perform checks on program types. 218 219 **bpftool prog profile** *PROG* [**duration** *DURATION*] *METRICs* 220 Profile *METRICs* for bpf program *PROG* for *DURATION* 221 seconds or until user hits <Ctrl+C>. *DURATION* is optional. 222 If *DURATION* is not specified, the profiling will run up to 223 **UINT_MAX** seconds. 224 225 **bpftool prog help** 226 Print short help message. 227 228OPTIONS 229======= 230 .. include:: common_options.rst 231 232 -f, --bpffs 233 When showing BPF programs, show file names of pinned 234 programs. 235 236 -m, --mapcompat 237 Allow loading maps with unknown map definitions. 238 239 -n, --nomount 240 Do not automatically attempt to mount any virtual file system 241 (such as tracefs or BPF virtual file system) when necessary. 242 243 -L, --use-loader 244 Load program as a "loader" program. This is useful to debug 245 the generation of such programs. When this option is in 246 use, bpftool attempts to load the programs from the object 247 file into the kernel, but does not pin them (therefore, the 248 *PATH* must not be provided). 249 250 When combined with the **-d**\ \|\ **--debug** option, 251 additional debug messages are generated, and the execution 252 of the loader program will use the **bpf_trace_printk**\ () 253 helper to log each step of loading BTF, creating the maps, 254 and loading the programs (see **bpftool prog tracelog** as 255 a way to dump those messages). 256 257EXAMPLES 258======== 259**# bpftool prog show** 260 261:: 262 263 10: xdp name some_prog tag 005a3d2123620c8b gpl run_time_ns 81632 run_cnt 10 264 loaded_at 2017-09-29T20:11:00+0000 uid 0 265 xlated 528B jited 370B memlock 4096B map_ids 10 266 pids systemd(1) 267 268**# bpftool --json --pretty prog show** 269 270:: 271 272 [{ 273 "id": 10, 274 "type": "xdp", 275 "tag": "005a3d2123620c8b", 276 "gpl_compatible": true, 277 "run_time_ns": 81632, 278 "run_cnt": 10, 279 "loaded_at": 1506715860, 280 "uid": 0, 281 "bytes_xlated": 528, 282 "jited": true, 283 "bytes_jited": 370, 284 "bytes_memlock": 4096, 285 "map_ids": [10 286 ], 287 "pids": [{ 288 "pid": 1, 289 "comm": "systemd" 290 } 291 ] 292 } 293 ] 294 295| 296| **# bpftool prog dump xlated id 10 file /tmp/t** 297| **$ ls -l /tmp/t** 298 299:: 300 301 -rw------- 1 root root 560 Jul 22 01:42 /tmp/t 302 303**# bpftool prog dump jited tag 005a3d2123620c8b** 304 305:: 306 307 0: push %rbp 308 1: mov %rsp,%rbp 309 2: sub $0x228,%rsp 310 3: sub $0x28,%rbp 311 4: mov %rbx,0x0(%rbp) 312 313| 314| **# mount -t bpf none /sys/fs/bpf/** 315| **# bpftool prog pin id 10 /sys/fs/bpf/prog** 316| **# bpftool prog load ./my_prog.o /sys/fs/bpf/prog2** 317| **# ls -l /sys/fs/bpf/** 318 319:: 320 321 -rw------- 1 root root 0 Jul 22 01:43 prog 322 -rw------- 1 root root 0 Jul 22 01:44 prog2 323 324**# bpftool prog dump jited pinned /sys/fs/bpf/prog opcodes** 325 326:: 327 328 0: push %rbp 329 55 330 1: mov %rsp,%rbp 331 48 89 e5 332 4: sub $0x228,%rsp 333 48 81 ec 28 02 00 00 334 b: sub $0x28,%rbp 335 48 83 ed 28 336 f: mov %rbx,0x0(%rbp) 337 48 89 5d 00 338 339| 340| **# bpftool prog load xdp1_kern.o /sys/fs/bpf/xdp1 type xdp map name rxcnt id 7** 341| **# bpftool prog show pinned /sys/fs/bpf/xdp1** 342 343:: 344 345 9: xdp name xdp_prog1 tag 539ec6ce11b52f98 gpl 346 loaded_at 2018-06-25T16:17:31-0700 uid 0 347 xlated 488B jited 336B memlock 4096B map_ids 7 348 349**# rm /sys/fs/bpf/xdp1** 350 351| 352| **# bpftool prog profile id 337 duration 10 cycles instructions llc_misses** 353 354:: 355 356 51397 run_cnt 357 40176203 cycles (83.05%) 358 42518139 instructions # 1.06 insns per cycle (83.39%) 359 123 llc_misses # 2.89 LLC misses per million insns (83.15%) 360 361| 362| Output below is for the trace logs. 363| Run in separate terminals: 364| **# bpftool prog tracelog** 365| **# bpftool prog load -L -d file.o** 366 367:: 368 369 bpftool-620059 [004] d... 2634685.517903: bpf_trace_printk: btf_load size 665 r=5 370 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=6 371 bpftool-620059 [004] d... 2634685.517997: bpf_trace_printk: prog_load sample insn_cnt 13 r=7 372 bpftool-620059 [004] d... 2634685.517999: bpf_trace_printk: close(5) = 0 373