noble (8) bpftool-prog.8.gz

Provided by: linux-tools-common_6.8.0-54.56_all bug

NAME

       bpftool-prog - tool for inspection and simple manipulation of eBPF progs

SYNOPSIS

          bpftool [OPTIONS] prog COMMAND

          OPTIONS  :=  {  {  -j  |  --json  } [{ -p | --pretty }] | { -d | --debug } | { -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] [{ offload_dev | xdpmeta_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/connect_unix |
         cgroup/getpeername4 | cgroup/getpeername6 | cgroup/getpeername_unix |
         cgroup/getsockname4 | cgroup/getsockname6 | cgroup/getsockname_unix |
         cgroup/sendmsg4 | cgroup/sendmsg6 | cgroup/sendmsg_unix |
         cgroup/recvmsg4 | cgroup/recvmsg6 | cgroup/recvmsg_unix | 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] [{ offload_dev
          | xdpmeta_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 offload_dev NAME is specified program will
                 be loaded onto given networking device (offload).  If xdpmeta_dev  NAME  is  specified  program
                 will become device-bound without offloading, this facilitates access to XDP metadata.  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

          -h, --help
                 Print short help message (similar to bpftool help).

          -V, --version
                 Print bpftool's version number (similar to bpftool version), the number of the  libbpf  version
                 in  use,  and optional features that were included when bpftool was compiled. Optional features
                 include linking against LLVM or  libbfd  to  provide  the  disassembler  for  JIT-ted  programs
                 (bpftool  prog  dump jited) and usage of BPF skeletons (some features like bpftool prog profile
                 or showing pids associated to BPF objects may rely on it).

          -j, --json
                 Generate JSON output. For commands that cannot produce JSON, this option has no effect.

          -p, --pretty
                 Generate human-readable JSON output. Implies -j.

          -d, --debug
                 Print all logs available, even debug-level information. This includes logs from libbpf as  well
                 as from the verifier, when attempting to load programs.

          -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

SEE ALSO

          bpf(2),    bpf-helpers(7),    bpftool(8),   bpftool-btf(8),   bpftool-cgroup(8),   bpftool-feature(8),
          bpftool-gen(8), bpftool-iter(8),  bpftool-link(8),  bpftool-map(8),  bpftool-net(8),  bpftool-perf(8),
          bpftool-struct_ops(8)

                                                                                                 BPFTOOL-PROG(8)