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*] [{ **offload_dev** | **xdpmeta_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*] [{ **offload_dev** | **xdpmeta_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 **offload_dev** *NAME* is specified program will be loaded 147 onto given networking device (offload). 148 If **xdpmeta_dev** *NAME* is specified program will become 149 device-bound without offloading, this facilitates access 150 to XDP metadata. 151 Optional **pinmaps** argument can be provided to pin all 152 maps under *MAP_DIR* directory. 153 154 If **autoattach** is specified program will be attached 155 before pin. In that case, only the link (representing the 156 program attached to its hook) is pinned, not the program as 157 such, so the path won't show in **bpftool prog show -f**, 158 only show in **bpftool link show -f**. Also, this only works 159 when bpftool (libbpf) is able to infer all necessary 160 information from the object file, in particular, it's not 161 supported for all program types. If a program does not 162 support autoattach, bpftool falls back to regular pinning 163 for that program instead. 164 165 Note: *PATH* must be located in *bpffs* mount. It must not 166 contain a dot character ('.'), which is reserved for future 167 extensions of *bpffs*. 168 169 **bpftool prog attach** *PROG* *ATTACH_TYPE* [*MAP*] 170 Attach bpf program *PROG* (with type specified by 171 *ATTACH_TYPE*). Most *ATTACH_TYPEs* require a *MAP* 172 parameter, with the exception of *flow_dissector* which is 173 attached to current networking name space. 174 175 **bpftool prog detach** *PROG* *ATTACH_TYPE* [*MAP*] 176 Detach bpf program *PROG* (with type specified by 177 *ATTACH_TYPE*). Most *ATTACH_TYPEs* require a *MAP* 178 parameter, with the exception of *flow_dissector* which is 179 detached from the current networking name space. 180 181 **bpftool prog tracelog** 182 Dump the trace pipe of the system to the console (stdout). 183 Hit <Ctrl+C> to stop printing. BPF programs can write to this 184 trace pipe at runtime with the **bpf_trace_printk**\ () helper. 185 This should be used only for debugging purposes. For 186 streaming data from BPF programs to user space, one can use 187 perf events (see also **bpftool-map**\ (8)). 188 189 **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*] 190 Run BPF program *PROG* in the kernel testing infrastructure 191 for BPF, meaning that the program works on the data and 192 context provided by the user, and not on actual packets or 193 monitored functions etc. Return value and duration for the 194 test run are printed out to the console. 195 196 Input data is read from the *FILE* passed with **data_in**. 197 If this *FILE* is "**-**", input data is read from standard 198 input. Input context, if any, is read from *FILE* passed with 199 **ctx_in**. Again, "**-**" can be used to read from standard 200 input, but only if standard input is not already in use for 201 input data. If a *FILE* is passed with **data_out**, output 202 data is written to that file. Similarly, output context is 203 written to the *FILE* passed with **ctx_out**. For both 204 output flows, "**-**" can be used to print to the standard 205 output (as plain text, or JSON if relevant option was 206 passed). If output keywords are omitted, output data and 207 context are discarded. Keywords **data_size_out** and 208 **ctx_size_out** are used to pass the size (in bytes) for the 209 output buffers to the kernel, although the default of 32 kB 210 should be more than enough for most cases. 211 212 Keyword **repeat** is used to indicate the number of 213 consecutive runs to perform. Note that output data and 214 context printed to files correspond to the last of those 215 runs. The duration printed out at the end of the runs is an 216 average over all runs performed by the command. 217 218 Not all program types support test run. Among those which do, 219 not all of them can take the **ctx_in**/**ctx_out** 220 arguments. bpftool does not perform checks on program types. 221 222 **bpftool prog profile** *PROG* [**duration** *DURATION*] *METRICs* 223 Profile *METRICs* for bpf program *PROG* for *DURATION* 224 seconds or until user hits <Ctrl+C>. *DURATION* is optional. 225 If *DURATION* is not specified, the profiling will run up to 226 **UINT_MAX** seconds. 227 228 **bpftool prog help** 229 Print short help message. 230 231OPTIONS 232======= 233 .. include:: common_options.rst 234 235 -f, --bpffs 236 When showing BPF programs, show file names of pinned 237 programs. 238 239 -m, --mapcompat 240 Allow loading maps with unknown map definitions. 241 242 -n, --nomount 243 Do not automatically attempt to mount any virtual file system 244 (such as tracefs or BPF virtual file system) when necessary. 245 246 -L, --use-loader 247 Load program as a "loader" program. This is useful to debug 248 the generation of such programs. When this option is in 249 use, bpftool attempts to load the programs from the object 250 file into the kernel, but does not pin them (therefore, the 251 *PATH* must not be provided). 252 253 When combined with the **-d**\ \|\ **--debug** option, 254 additional debug messages are generated, and the execution 255 of the loader program will use the **bpf_trace_printk**\ () 256 helper to log each step of loading BTF, creating the maps, 257 and loading the programs (see **bpftool prog tracelog** as 258 a way to dump those messages). 259 260EXAMPLES 261======== 262**# bpftool prog show** 263 264:: 265 266 10: xdp name some_prog tag 005a3d2123620c8b gpl run_time_ns 81632 run_cnt 10 267 loaded_at 2017-09-29T20:11:00+0000 uid 0 268 xlated 528B jited 370B memlock 4096B map_ids 10 269 pids systemd(1) 270 271**# bpftool --json --pretty prog show** 272 273:: 274 275 [{ 276 "id": 10, 277 "type": "xdp", 278 "tag": "005a3d2123620c8b", 279 "gpl_compatible": true, 280 "run_time_ns": 81632, 281 "run_cnt": 10, 282 "loaded_at": 1506715860, 283 "uid": 0, 284 "bytes_xlated": 528, 285 "jited": true, 286 "bytes_jited": 370, 287 "bytes_memlock": 4096, 288 "map_ids": [10 289 ], 290 "pids": [{ 291 "pid": 1, 292 "comm": "systemd" 293 } 294 ] 295 } 296 ] 297 298| 299| **# bpftool prog dump xlated id 10 file /tmp/t** 300| **$ ls -l /tmp/t** 301 302:: 303 304 -rw------- 1 root root 560 Jul 22 01:42 /tmp/t 305 306**# bpftool prog dump jited tag 005a3d2123620c8b** 307 308:: 309 310 0: push %rbp 311 1: mov %rsp,%rbp 312 2: sub $0x228,%rsp 313 3: sub $0x28,%rbp 314 4: mov %rbx,0x0(%rbp) 315 316| 317| **# mount -t bpf none /sys/fs/bpf/** 318| **# bpftool prog pin id 10 /sys/fs/bpf/prog** 319| **# bpftool prog load ./my_prog.o /sys/fs/bpf/prog2** 320| **# ls -l /sys/fs/bpf/** 321 322:: 323 324 -rw------- 1 root root 0 Jul 22 01:43 prog 325 -rw------- 1 root root 0 Jul 22 01:44 prog2 326 327**# bpftool prog dump jited pinned /sys/fs/bpf/prog opcodes** 328 329:: 330 331 0: push %rbp 332 55 333 1: mov %rsp,%rbp 334 48 89 e5 335 4: sub $0x228,%rsp 336 48 81 ec 28 02 00 00 337 b: sub $0x28,%rbp 338 48 83 ed 28 339 f: mov %rbx,0x0(%rbp) 340 48 89 5d 00 341 342| 343| **# bpftool prog load xdp1_kern.o /sys/fs/bpf/xdp1 type xdp map name rxcnt id 7** 344| **# bpftool prog show pinned /sys/fs/bpf/xdp1** 345 346:: 347 348 9: xdp name xdp_prog1 tag 539ec6ce11b52f98 gpl 349 loaded_at 2018-06-25T16:17:31-0700 uid 0 350 xlated 488B jited 336B memlock 4096B map_ids 7 351 352**# rm /sys/fs/bpf/xdp1** 353 354| 355| **# bpftool prog profile id 337 duration 10 cycles instructions llc_misses** 356 357:: 358 359 51397 run_cnt 360 40176203 cycles (83.05%) 361 42518139 instructions # 1.06 insns per cycle (83.39%) 362 123 llc_misses # 2.89 LLC misses per million insns (83.15%) 363 364| 365| Output below is for the trace logs. 366| Run in separate terminals: 367| **# bpftool prog tracelog** 368| **# bpftool prog load -L -d file.o** 369 370:: 371 372 bpftool-620059 [004] d... 2634685.517903: bpf_trace_printk: btf_load size 665 r=5 373 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=6 374 bpftool-620059 [004] d... 2634685.517997: bpf_trace_printk: prog_load sample insn_cnt 13 r=7 375 bpftool-620059 [004] d... 2634685.517999: bpf_trace_printk: close(5) = 0 376