| .. SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) |
| |
| ================ |
| bpftool-prog |
| ================ |
| ------------------------------------------------------------------------------- |
| tool for inspection and simple manipulation of eBPF progs |
| ------------------------------------------------------------------------------- |
| |
| :Manual section: 8 |
| |
| .. include:: substitutions.rst |
| |
| SYNOPSIS |
| ======== |
| |
| **bpftool** [*OPTIONS*] **prog** *COMMAND* |
| |
| *OPTIONS* := { |COMMON_OPTIONS| | |
| { **-f** | **--bpffs** } | { **-m** | **--mapcompat** } | { **-n** | **--nomount** } | |
| { **-L** | **--use-loader** } } |
| |
| *COMMANDS* := |
| { **show** | **list** | **dump xlated** | **dump jited** | **pin** | **load** | |
| **loadall** | **help** } |
| |
| PROG COMMANDS |
| ============= |
| |
| | **bpftool** **prog** { **show** | **list** } [*PROG*] |
| | **bpftool** **prog dump xlated** *PROG* [{ **file** *FILE* | [**opcodes**] [**linum**] [**visual**] }] |
| | **bpftool** **prog dump jited** *PROG* [{ **file** *FILE* | [**opcodes**] [**linum**] }] |
| | **bpftool** **prog pin** *PROG* *FILE* |
| | **bpftool** **prog** { **load** | **loadall** } *OBJ* *PATH* [**type** *TYPE*] [**map** {**idx** *IDX* | **name** *NAME*} *MAP*] [**dev** *NAME*] [**pinmaps** *MAP_DIR*] [**autoattach**] |
| | **bpftool** **prog attach** *PROG* *ATTACH_TYPE* [*MAP*] |
| | **bpftool** **prog detach** *PROG* *ATTACH_TYPE* [*MAP*] |
| | **bpftool** **prog tracelog** |
| | **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*] |
| | **bpftool** **prog profile** *PROG* [**duration** *DURATION*] *METRICs* |
| | **bpftool** **prog help** |
| | |
| | *MAP* := { **id** *MAP_ID* | **pinned** *FILE* } |
| | *PROG* := { **id** *PROG_ID* | **pinned** *FILE* | **tag** *PROG_TAG* | **name** *PROG_NAME* } |
| | *TYPE* := { |
| | **socket** | **kprobe** | **kretprobe** | **classifier** | **action** | |
| | **tracepoint** | **raw_tracepoint** | **xdp** | **perf_event** | **cgroup/skb** | |
| | **cgroup/sock** | **cgroup/dev** | **lwt_in** | **lwt_out** | **lwt_xmit** | |
| | **lwt_seg6local** | **sockops** | **sk_skb** | **sk_msg** | **lirc_mode2** | |
| | **cgroup/bind4** | **cgroup/bind6** | **cgroup/post_bind4** | **cgroup/post_bind6** | |
| | **cgroup/connect4** | **cgroup/connect6** | **cgroup/getpeername4** | **cgroup/getpeername6** | |
| | **cgroup/getsockname4** | **cgroup/getsockname6** | **cgroup/sendmsg4** | **cgroup/sendmsg6** | |
| | **cgroup/recvmsg4** | **cgroup/recvmsg6** | **cgroup/sysctl** | |
| | **cgroup/getsockopt** | **cgroup/setsockopt** | **cgroup/sock_release** | |
| | **struct_ops** | **fentry** | **fexit** | **freplace** | **sk_lookup** |
| | } |
| | *ATTACH_TYPE* := { |
| | **sk_msg_verdict** | **sk_skb_verdict** | **sk_skb_stream_verdict** | |
| | **sk_skb_stream_parser** | **flow_dissector** |
| | } |
| | *METRICs* := { |
| | **cycles** | **instructions** | **l1d_loads** | **llc_misses** | |
| | **itlb_misses** | **dtlb_misses** |
| | } |
| |
| |
| DESCRIPTION |
| =========== |
| **bpftool prog { show | list }** [*PROG*] |
| Show information about loaded programs. If *PROG* is |
| specified show information only about given programs, |
| otherwise list all programs currently loaded on the system. |
| In case of **tag** or **name**, *PROG* may match several |
| programs which will all be shown. |
| |
| Output will start with program ID followed by program type and |
| zero or more named attributes (depending on kernel version). |
| |
| Since Linux 5.1 the kernel can collect statistics on BPF |
| programs (such as the total time spent running the program, |
| and the number of times it was run). If available, bpftool |
| shows such statistics. However, the kernel does not collect |
| them by defaults, as it slightly impacts performance on each |
| program run. Activation or deactivation of the feature is |
| performed via the **kernel.bpf_stats_enabled** sysctl knob. |
| |
| Since Linux 5.8 bpftool is able to discover information about |
| processes that hold open file descriptors (FDs) against BPF |
| programs. On such kernels bpftool will automatically emit this |
| information as well. |
| |
| **bpftool prog dump xlated** *PROG* [{ **file** *FILE* | [**opcodes**] [**linum**] [**visual**] }] |
| Dump eBPF instructions of the programs from the kernel. By |
| default, eBPF will be disassembled and printed to standard |
| output in human-readable format. In this case, **opcodes** |
| controls if raw opcodes should be printed as well. |
| |
| In case of **tag** or **name**, *PROG* may match several |
| programs which will all be dumped. However, if **file** or |
| **visual** is specified, *PROG* must match a single program. |
| |
| If **file** is specified, the binary image will instead be |
| written to *FILE*. |
| |
| If **visual** is specified, control flow graph (CFG) will be |
| built instead, and eBPF instructions will be presented with |
| CFG in DOT format, on standard output. |
| |
| If the programs have line_info available, the source line will |
| be displayed. If **linum** is specified, the filename, line |
| number and line column will also be displayed. |
| |
| **bpftool prog dump jited** *PROG* [{ **file** *FILE* | [**opcodes**] [**linum**] }] |
| Dump jited image (host machine code) of the program. |
| |
| If *FILE* is specified image will be written to a file, |
| otherwise it will be disassembled and printed to stdout. |
| *PROG* must match a single program when **file** is specified. |
| |
| **opcodes** controls if raw opcodes will be printed. |
| |
| If the prog has line_info available, the source line will |
| be displayed. If **linum** is specified, the filename, line |
| number and line column will also be displayed. |
| |
| **bpftool prog pin** *PROG* *FILE* |
| Pin program *PROG* as *FILE*. |
| |
| Note: *FILE* must be located in *bpffs* mount. It must not |
| contain a dot character ('.'), which is reserved for future |
| extensions of *bpffs*. |
| |
| **bpftool prog { load | loadall }** *OBJ* *PATH* [**type** *TYPE*] [**map** {**idx** *IDX* | **name** *NAME*} *MAP*] [**dev** *NAME*] [**pinmaps** *MAP_DIR*] [**autoattach**] |
| Load bpf program(s) from binary *OBJ* and pin as *PATH*. |
| **bpftool prog load** pins only the first program from the |
| *OBJ* as *PATH*. **bpftool prog loadall** pins all programs |
| from the *OBJ* under *PATH* directory. |
| **type** is optional, if not specified program type will be |
| inferred from section names. |
| By default bpftool will create new maps as declared in the ELF |
| object being loaded. **map** parameter allows for the reuse |
| of existing maps. It can be specified multiple times, each |
| time for a different map. *IDX* refers to index of the map |
| to be replaced in the ELF file counting from 0, while *NAME* |
| allows to replace a map by name. *MAP* specifies the map to |
| use, referring to it by **id** or through a **pinned** file. |
| If **dev** *NAME* is specified program will be loaded onto |
| given networking device (offload). |
| Optional **pinmaps** argument can be provided to pin all |
| maps under *MAP_DIR* directory. |
| |
| If **autoattach** is specified program will be attached |
| before pin. In that case, only the link (representing the |
| program attached to its hook) is pinned, not the program as |
| such, so the path won't show in **bpftool prog show -f**, |
| only show in **bpftool link show -f**. Also, this only works |
| when bpftool (libbpf) is able to infer all necessary |
| information from the object file, in particular, it's not |
| supported for all program types. If a program does not |
| support autoattach, bpftool falls back to regular pinning |
| for that program instead. |
| |
| Note: *PATH* must be located in *bpffs* mount. It must not |
| contain a dot character ('.'), which is reserved for future |
| extensions of *bpffs*. |
| |
| **bpftool prog attach** *PROG* *ATTACH_TYPE* [*MAP*] |
| Attach bpf program *PROG* (with type specified by |
| *ATTACH_TYPE*). Most *ATTACH_TYPEs* require a *MAP* |
| parameter, with the exception of *flow_dissector* which is |
| attached to current networking name space. |
| |
| **bpftool prog detach** *PROG* *ATTACH_TYPE* [*MAP*] |
| Detach bpf program *PROG* (with type specified by |
| *ATTACH_TYPE*). Most *ATTACH_TYPEs* require a *MAP* |
| parameter, with the exception of *flow_dissector* which is |
| detached from the current networking name space. |
| |
| **bpftool prog tracelog** |
| Dump the trace pipe of the system to the console (stdout). |
| Hit <Ctrl+C> to stop printing. BPF programs can write to this |
| trace pipe at runtime with the **bpf_trace_printk**\ () helper. |
| This should be used only for debugging purposes. For |
| streaming data from BPF programs to user space, one can use |
| perf events (see also **bpftool-map**\ (8)). |
| |
| **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*] |
| Run BPF program *PROG* in the kernel testing infrastructure |
| for BPF, meaning that the program works on the data and |
| context provided by the user, and not on actual packets or |
| monitored functions etc. Return value and duration for the |
| test run are printed out to the console. |
| |
| Input data is read from the *FILE* passed with **data_in**. |
| If this *FILE* is "**-**", input data is read from standard |
| input. Input context, if any, is read from *FILE* passed with |
| **ctx_in**. Again, "**-**" can be used to read from standard |
| input, but only if standard input is not already in use for |
| input data. If a *FILE* is passed with **data_out**, output |
| data is written to that file. Similarly, output context is |
| written to the *FILE* passed with **ctx_out**. For both |
| output flows, "**-**" can be used to print to the standard |
| output (as plain text, or JSON if relevant option was |
| passed). If output keywords are omitted, output data and |
| context are discarded. Keywords **data_size_out** and |
| **ctx_size_out** are used to pass the size (in bytes) for the |
| output buffers to the kernel, although the default of 32 kB |
| should be more than enough for most cases. |
| |
| Keyword **repeat** is used to indicate the number of |
| consecutive runs to perform. Note that output data and |
| context printed to files correspond to the last of those |
| runs. The duration printed out at the end of the runs is an |
| average over all runs performed by the command. |
| |
| Not all program types support test run. Among those which do, |
| not all of them can take the **ctx_in**/**ctx_out** |
| arguments. bpftool does not perform checks on program types. |
| |
| **bpftool prog profile** *PROG* [**duration** *DURATION*] *METRICs* |
| Profile *METRICs* for bpf program *PROG* for *DURATION* |
| seconds or until user hits <Ctrl+C>. *DURATION* is optional. |
| If *DURATION* is not specified, the profiling will run up to |
| **UINT_MAX** seconds. |
| |
| **bpftool prog help** |
| Print short help message. |
| |
| OPTIONS |
| ======= |
| .. include:: common_options.rst |
| |
| -f, --bpffs |
| When showing BPF programs, show file names of pinned |
| programs. |
| |
| -m, --mapcompat |
| Allow loading maps with unknown map definitions. |
| |
| -n, --nomount |
| Do not automatically attempt to mount any virtual file system |
| (such as tracefs or BPF virtual file system) when necessary. |
| |
| -L, --use-loader |
| Load program as a "loader" program. This is useful to debug |
| the generation of such programs. When this option is in |
| use, bpftool attempts to load the programs from the object |
| file into the kernel, but does not pin them (therefore, the |
| *PATH* must not be provided). |
| |
| When combined with the **-d**\ \|\ **--debug** option, |
| additional debug messages are generated, and the execution |
| of the loader program will use the **bpf_trace_printk**\ () |
| helper to log each step of loading BTF, creating the maps, |
| and loading the programs (see **bpftool prog tracelog** as |
| a way to dump those messages). |
| |
| EXAMPLES |
| ======== |
| **# bpftool prog show** |
| |
| :: |
| |
| 10: xdp name some_prog tag 005a3d2123620c8b gpl run_time_ns 81632 run_cnt 10 |
| loaded_at 2017-09-29T20:11:00+0000 uid 0 |
| xlated 528B jited 370B memlock 4096B map_ids 10 |
| pids systemd(1) |
| |
| **# bpftool --json --pretty prog show** |
| |
| :: |
| |
| [{ |
| "id": 10, |
| "type": "xdp", |
| "tag": "005a3d2123620c8b", |
| "gpl_compatible": true, |
| "run_time_ns": 81632, |
| "run_cnt": 10, |
| "loaded_at": 1506715860, |
| "uid": 0, |
| "bytes_xlated": 528, |
| "jited": true, |
| "bytes_jited": 370, |
| "bytes_memlock": 4096, |
| "map_ids": [10 |
| ], |
| "pids": [{ |
| "pid": 1, |
| "comm": "systemd" |
| } |
| ] |
| } |
| ] |
| |
| | |
| | **# bpftool prog dump xlated id 10 file /tmp/t** |
| | **$ ls -l /tmp/t** |
| |
| :: |
| |
| -rw------- 1 root root 560 Jul 22 01:42 /tmp/t |
| |
| **# bpftool prog dump jited tag 005a3d2123620c8b** |
| |
| :: |
| |
| 0: push %rbp |
| 1: mov %rsp,%rbp |
| 2: sub $0x228,%rsp |
| 3: sub $0x28,%rbp |
| 4: mov %rbx,0x0(%rbp) |
| |
| | |
| | **# mount -t bpf none /sys/fs/bpf/** |
| | **# bpftool prog pin id 10 /sys/fs/bpf/prog** |
| | **# bpftool prog load ./my_prog.o /sys/fs/bpf/prog2** |
| | **# ls -l /sys/fs/bpf/** |
| |
| :: |
| |
| -rw------- 1 root root 0 Jul 22 01:43 prog |
| -rw------- 1 root root 0 Jul 22 01:44 prog2 |
| |
| **# bpftool prog dump jited pinned /sys/fs/bpf/prog opcodes** |
| |
| :: |
| |
| 0: push %rbp |
| 55 |
| 1: mov %rsp,%rbp |
| 48 89 e5 |
| 4: sub $0x228,%rsp |
| 48 81 ec 28 02 00 00 |
| b: sub $0x28,%rbp |
| 48 83 ed 28 |
| f: mov %rbx,0x0(%rbp) |
| 48 89 5d 00 |
| |
| | |
| | **# bpftool prog load xdp1_kern.o /sys/fs/bpf/xdp1 type xdp map name rxcnt id 7** |
| | **# bpftool prog show pinned /sys/fs/bpf/xdp1** |
| |
| :: |
| |
| 9: xdp name xdp_prog1 tag 539ec6ce11b52f98 gpl |
| loaded_at 2018-06-25T16:17:31-0700 uid 0 |
| xlated 488B jited 336B memlock 4096B map_ids 7 |
| |
| **# rm /sys/fs/bpf/xdp1** |
| |
| | |
| | **# bpftool prog profile id 337 duration 10 cycles instructions llc_misses** |
| |
| :: |
| |
| 51397 run_cnt |
| 40176203 cycles (83.05%) |
| 42518139 instructions # 1.06 insns per cycle (83.39%) |
| 123 llc_misses # 2.89 LLC misses per million insns (83.15%) |
| |
| | |
| | Output below is for the trace logs. |
| | Run in separate terminals: |
| | **# bpftool prog tracelog** |
| | **# bpftool prog load -L -d file.o** |
| |
| :: |
| |
| bpftool-620059 [004] d... 2634685.517903: bpf_trace_printk: btf_load size 665 r=5 |
| 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 |
| bpftool-620059 [004] d... 2634685.517997: bpf_trace_printk: prog_load sample insn_cnt 13 r=7 |
| bpftool-620059 [004] d... 2634685.517999: bpf_trace_printk: close(5) = 0 |
