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/connect_unix** | 51| **cgroup/getpeername4** | **cgroup/getpeername6** | **cgroup/getpeername_unix** | 52| **cgroup/getsockname4** | **cgroup/getsockname6** | **cgroup/getsockname_unix** | 53| **cgroup/sendmsg4** | **cgroup/sendmsg6** | **cgroup/sendmsg_unix** | 54| **cgroup/recvmsg4** | **cgroup/recvmsg6** | **cgroup/recvmsg_unix** | **cgroup/sysctl** | 55| **cgroup/getsockopt** | **cgroup/setsockopt** | **cgroup/sock_release** | 56| **struct_ops** | **fentry** | **fexit** | **freplace** | **sk_lookup** 57| } 58| *ATTACH_TYPE* := { 59| **sk_msg_verdict** | **sk_skb_verdict** | **sk_skb_stream_verdict** | 60| **sk_skb_stream_parser** | **flow_dissector** 61| } 62| *METRICs* := { 63| **cycles** | **instructions** | **l1d_loads** | **llc_misses** | 64| **itlb_misses** | **dtlb_misses** 65| } 66 67 68DESCRIPTION 69=========== 70 **bpftool prog { show | list }** [*PROG*] 71 Show information about loaded programs. If *PROG* is 72 specified show information only about given programs, 73 otherwise list all programs currently loaded on the system. 74 In case of **tag** or **name**, *PROG* may match several 75 programs which will all be shown. 76 77 Output will start with program ID followed by program type and 78 zero or more named attributes (depending on kernel version). 79 80 Since Linux 5.1 the kernel can collect statistics on BPF 81 programs (such as the total time spent running the program, 82 and the number of times it was run). If available, bpftool 83 shows such statistics. However, the kernel does not collect 84 them by defaults, as it slightly impacts performance on each 85 program run. Activation or deactivation of the feature is 86 performed via the **kernel.bpf_stats_enabled** sysctl knob. 87 88 Since Linux 5.8 bpftool is able to discover information about 89 processes that hold open file descriptors (FDs) against BPF 90 programs. On such kernels bpftool will automatically emit this 91 information as well. 92 93 **bpftool prog dump xlated** *PROG* [{ **file** *FILE* | [**opcodes**] [**linum**] [**visual**] }] 94 Dump eBPF instructions of the programs from the kernel. By 95 default, eBPF will be disassembled and printed to standard 96 output in human-readable format. In this case, **opcodes** 97 controls if raw opcodes should be printed as well. 98 99 In case of **tag** or **name**, *PROG* may match several 100 programs which will all be dumped. However, if **file** or 101 **visual** is specified, *PROG* must match a single program. 102 103 If **file** is specified, the binary image will instead be 104 written to *FILE*. 105 106 If **visual** is specified, control flow graph (CFG) will be 107 built instead, and eBPF instructions will be presented with 108 CFG in DOT format, on standard output. 109 110 If the programs have line_info available, the source line will 111 be displayed. If **linum** is specified, the filename, line 112 number and line column will also be displayed. 113 114 **bpftool prog dump jited** *PROG* [{ **file** *FILE* | [**opcodes**] [**linum**] }] 115 Dump jited image (host machine code) of the program. 116 117 If *FILE* is specified image will be written to a file, 118 otherwise it will be disassembled and printed to stdout. 119 *PROG* must match a single program when **file** is specified. 120 121 **opcodes** controls if raw opcodes will be printed. 122 123 If the prog has line_info available, the source line will 124 be displayed. If **linum** is specified, the filename, line 125 number and line column will also be displayed. 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*] [{ **offload_dev** | **xdpmeta_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 **offload_dev** *NAME* is specified program will be loaded 149 onto given networking device (offload). 150 If **xdpmeta_dev** *NAME* is specified program will become 151 device-bound without offloading, this facilitates access 152 to XDP metadata. 153 Optional **pinmaps** argument can be provided to pin all 154 maps under *MAP_DIR* directory. 155 156 If **autoattach** is specified program will be attached 157 before pin. In that case, only the link (representing the 158 program attached to its hook) is pinned, not the program as 159 such, so the path won't show in **bpftool prog show -f**, 160 only show in **bpftool link show -f**. Also, this only works 161 when bpftool (libbpf) is able to infer all necessary 162 information from the object file, in particular, it's not 163 supported for all program types. If a program does not 164 support autoattach, bpftool falls back to regular pinning 165 for that program instead. 166 167 Note: *PATH* must be located in *bpffs* mount. It must not 168 contain a dot character ('.'), which is reserved for future 169 extensions of *bpffs*. 170 171 **bpftool prog attach** *PROG* *ATTACH_TYPE* [*MAP*] 172 Attach bpf program *PROG* (with type specified by 173 *ATTACH_TYPE*). Most *ATTACH_TYPEs* require a *MAP* 174 parameter, with the exception of *flow_dissector* which is 175 attached to current networking name space. 176 177 **bpftool prog detach** *PROG* *ATTACH_TYPE* [*MAP*] 178 Detach bpf program *PROG* (with type specified by 179 *ATTACH_TYPE*). Most *ATTACH_TYPEs* require a *MAP* 180 parameter, with the exception of *flow_dissector* which is 181 detached from the current networking name space. 182 183 **bpftool prog tracelog** 184 Dump the trace pipe of the system to the console (stdout). 185 Hit <Ctrl+C> to stop printing. BPF programs can write to this 186 trace pipe at runtime with the **bpf_trace_printk**\ () helper. 187 This should be used only for debugging purposes. For 188 streaming data from BPF programs to user space, one can use 189 perf events (see also **bpftool-map**\ (8)). 190 191 **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*] 192 Run BPF program *PROG* in the kernel testing infrastructure 193 for BPF, meaning that the program works on the data and 194 context provided by the user, and not on actual packets or 195 monitored functions etc. Return value and duration for the 196 test run are printed out to the console. 197 198 Input data is read from the *FILE* passed with **data_in**. 199 If this *FILE* is "**-**", input data is read from standard 200 input. Input context, if any, is read from *FILE* passed with 201 **ctx_in**. Again, "**-**" can be used to read from standard 202 input, but only if standard input is not already in use for 203 input data. If a *FILE* is passed with **data_out**, output 204 data is written to that file. Similarly, output context is 205 written to the *FILE* passed with **ctx_out**. For both 206 output flows, "**-**" can be used to print to the standard 207 output (as plain text, or JSON if relevant option was 208 passed). If output keywords are omitted, output data and 209 context are discarded. Keywords **data_size_out** and 210 **ctx_size_out** are used to pass the size (in bytes) for the 211 output buffers to the kernel, although the default of 32 kB 212 should be more than enough for most cases. 213 214 Keyword **repeat** is used to indicate the number of 215 consecutive runs to perform. Note that output data and 216 context printed to files correspond to the last of those 217 runs. The duration printed out at the end of the runs is an 218 average over all runs performed by the command. 219 220 Not all program types support test run. Among those which do, 221 not all of them can take the **ctx_in**/**ctx_out** 222 arguments. bpftool does not perform checks on program types. 223 224 **bpftool prog profile** *PROG* [**duration** *DURATION*] *METRICs* 225 Profile *METRICs* for bpf program *PROG* for *DURATION* 226 seconds or until user hits <Ctrl+C>. *DURATION* is optional. 227 If *DURATION* is not specified, the profiling will run up to 228 **UINT_MAX** seconds. 229 230 **bpftool prog help** 231 Print short help message. 232 233OPTIONS 234======= 235 .. include:: common_options.rst 236 237 -f, --bpffs 238 When showing BPF programs, show file names of pinned 239 programs. 240 241 -m, --mapcompat 242 Allow loading maps with unknown map definitions. 243 244 -n, --nomount 245 Do not automatically attempt to mount any virtual file system 246 (such as tracefs or BPF virtual file system) when necessary. 247 248 -L, --use-loader 249 Load program as a "loader" program. This is useful to debug 250 the generation of such programs. When this option is in 251 use, bpftool attempts to load the programs from the object 252 file into the kernel, but does not pin them (therefore, the 253 *PATH* must not be provided). 254 255 When combined with the **-d**\ \|\ **--debug** option, 256 additional debug messages are generated, and the execution 257 of the loader program will use the **bpf_trace_printk**\ () 258 helper to log each step of loading BTF, creating the maps, 259 and loading the programs (see **bpftool prog tracelog** as 260 a way to dump those messages). 261 262EXAMPLES 263======== 264**# bpftool prog show** 265 266:: 267 268 10: xdp name some_prog tag 005a3d2123620c8b gpl run_time_ns 81632 run_cnt 10 269 loaded_at 2017-09-29T20:11:00+0000 uid 0 270 xlated 528B jited 370B memlock 4096B map_ids 10 271 pids systemd(1) 272 273**# bpftool --json --pretty prog show** 274 275:: 276 277 [{ 278 "id": 10, 279 "type": "xdp", 280 "tag": "005a3d2123620c8b", 281 "gpl_compatible": true, 282 "run_time_ns": 81632, 283 "run_cnt": 10, 284 "loaded_at": 1506715860, 285 "uid": 0, 286 "bytes_xlated": 528, 287 "jited": true, 288 "bytes_jited": 370, 289 "bytes_memlock": 4096, 290 "map_ids": [10 291 ], 292 "pids": [{ 293 "pid": 1, 294 "comm": "systemd" 295 } 296 ] 297 } 298 ] 299 300| 301| **# bpftool prog dump xlated id 10 file /tmp/t** 302| **$ ls -l /tmp/t** 303 304:: 305 306 -rw------- 1 root root 560 Jul 22 01:42 /tmp/t 307 308**# bpftool prog dump jited tag 005a3d2123620c8b** 309 310:: 311 312 0: push %rbp 313 1: mov %rsp,%rbp 314 2: sub $0x228,%rsp 315 3: sub $0x28,%rbp 316 4: mov %rbx,0x0(%rbp) 317 318| 319| **# mount -t bpf none /sys/fs/bpf/** 320| **# bpftool prog pin id 10 /sys/fs/bpf/prog** 321| **# bpftool prog load ./my_prog.o /sys/fs/bpf/prog2** 322| **# ls -l /sys/fs/bpf/** 323 324:: 325 326 -rw------- 1 root root 0 Jul 22 01:43 prog 327 -rw------- 1 root root 0 Jul 22 01:44 prog2 328 329**# bpftool prog dump jited pinned /sys/fs/bpf/prog opcodes** 330 331:: 332 333 0: push %rbp 334 55 335 1: mov %rsp,%rbp 336 48 89 e5 337 4: sub $0x228,%rsp 338 48 81 ec 28 02 00 00 339 b: sub $0x28,%rbp 340 48 83 ed 28 341 f: mov %rbx,0x0(%rbp) 342 48 89 5d 00 343 344| 345| **# bpftool prog load xdp1_kern.o /sys/fs/bpf/xdp1 type xdp map name rxcnt id 7** 346| **# bpftool prog show pinned /sys/fs/bpf/xdp1** 347 348:: 349 350 9: xdp name xdp_prog1 tag 539ec6ce11b52f98 gpl 351 loaded_at 2018-06-25T16:17:31-0700 uid 0 352 xlated 488B jited 336B memlock 4096B map_ids 7 353 354**# rm /sys/fs/bpf/xdp1** 355 356| 357| **# bpftool prog profile id 337 duration 10 cycles instructions llc_misses** 358 359:: 360 361 51397 run_cnt 362 40176203 cycles (83.05%) 363 42518139 instructions # 1.06 insns per cycle (83.39%) 364 123 llc_misses # 2.89 LLC misses per million insns (83.15%) 365 366| 367| Output below is for the trace logs. 368| Run in separate terminals: 369| **# bpftool prog tracelog** 370| **# bpftool prog load -L -d file.o** 371 372:: 373 374 bpftool-620059 [004] d... 2634685.517903: bpf_trace_printk: btf_load size 665 r=5 375 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=6 376 bpftool-620059 [004] d... 2634685.517997: bpf_trace_printk: prog_load sample insn_cnt 13 r=7 377 bpftool-620059 [004] d... 2634685.517999: bpf_trace_printk: close(5) = 0 378