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