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| author | Quentin Monnet <quentin.monnet@netronome.com> | 2018-12-05 11:28:24 +0100 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2018-12-05 16:41:52 +0100 |
| commit | 30da46b5dc3a9a14db11706d841440e28b12bb53 (patch) | |
| tree | 32ed4dde5cbce0f5ec6cdba14b33ef245de2579a /tools/bpf/bpftool/Documentation/bpftool-prog.rst | |
| parent | Merge branch 'bpf-jit-overridable-alloc' (diff) | |
| download | linux-30da46b5dc3a9a14db11706d841440e28b12bb53.tar.xz linux-30da46b5dc3a9a14db11706d841440e28b12bb53.zip | |
tools: bpftool: add a command to dump the trace pipe
BPF programs can use the bpf_trace_printk() helper to print debug
information into the trace pipe. Add a subcommand
"bpftool prog tracelog" to simply dump this pipe to the console.
This is for a good part copied from iproute2, where the feature is
available with "tc exec bpf dbg". Changes include dumping pipe content
to stdout instead of stderr and adding JSON support (content is dumped
as an array of strings, one per line read from the pipe). This version
is dual-licensed, with Daniel's permission.
Cc: Daniel Borkmann <daniel@iogearbox.net>
Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'tools/bpf/bpftool/Documentation/bpftool-prog.rst')
| -rw-r--r-- | tools/bpf/bpftool/Documentation/bpftool-prog.rst | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/tools/bpf/bpftool/Documentation/bpftool-prog.rst b/tools/bpf/bpftool/Documentation/bpftool-prog.rst index ab36e920e552..5524b6dccd85 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-prog.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-prog.rst @@ -26,8 +26,9 @@ MAP COMMANDS | **bpftool** **prog dump jited** *PROG* [{**file** *FILE* | **opcodes**}] | **bpftool** **prog pin** *PROG* *FILE* | **bpftool** **prog { load | loadall }** *OBJ* *PATH* [**type** *TYPE*] [**map** {**idx** *IDX* | **name** *NAME*} *MAP*] [**dev** *NAME*] -| **bpftool** **prog attach** *PROG* *ATTACH_TYPE* [*MAP*] -| **bpftool** **prog detach** *PROG* *ATTACH_TYPE* [*MAP*] +| **bpftool** **prog attach** *PROG* *ATTACH_TYPE* [*MAP*] +| **bpftool** **prog detach** *PROG* *ATTACH_TYPE* [*MAP*] +| **bpftool** **prog tracelog** | **bpftool** **prog help** | | *MAP* := { **id** *MAP_ID* | **pinned** *FILE* } @@ -117,6 +118,14 @@ DESCRIPTION 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 help** Print short help message. |