original_kernel/tools/bpf/bpftool/Documentation/bpftool-feature.rst

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===============
bpftool-feature
===============
-------------------------------------------------------------------------------
tool for inspection of eBPF-related parameters for Linux kernel or net device
-------------------------------------------------------------------------------
:Manual section: 8
SYNOPSIS
========
**bpftool** [*OPTIONS*] **feature** *COMMAND*
*OPTIONS* := { { **-j** | **--json** } [{ **-p** | **--pretty** }] }
*COMMANDS* := { **probe** | **help** }
FEATURE COMMANDS
================
| **bpftool** **feature probe** [*COMPONENT*] [**macros** [**prefix** *PREFIX*]]
| **bpftool** **feature help**
|
| *COMPONENT* := { **kernel** | **dev** *NAME* }
DESCRIPTION
===========
**bpftool feature probe** [**kernel**] [**macros** [**prefix** *PREFIX*]]
Probe the running kernel and dump a number of eBPF-related
parameters, such as availability of the **bpf()** system call,
JIT status, eBPF program types availability, eBPF helper
functions availability, and more.
If the **macros** keyword (but not the **-j** option) is
passed, a subset of the output is dumped as a list of
**#define** macros that are ready to be included in a C
header file, for example. If, additionally, **prefix** is
used to define a *PREFIX*, the provided string will be used
as a prefix to the names of the macros: this can be used to
avoid conflicts on macro names when including the output of
this command as a header file.
Keyword **kernel** can be omitted. If no probe target is
specified, probing the kernel is the default behaviour.
Note that when probed, some eBPF helpers (e.g.
**bpf_trace_printk**\ () or **bpf_probe_write_user**\ ()) may
print warnings to kernel logs.
**bpftool feature probe dev** *NAME* [**macros** [**prefix** *PREFIX*]]
Probe network device for supported eBPF features and dump
results to the console.
The two keywords **macros** and **prefix** have the same
role as when probing the kernel.
**bpftool feature help**
Print short help message.
OPTIONS
=======
-h, --help
Print short generic help message (similar to **bpftool help**).
-V, --version
Print version number (similar to **bpftool version**).
-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**.
SEE ALSO
========
**bpf**\ (2),
**bpf-helpers**\ (7),
**bpftool**\ (8),
**bpftool-prog**\ (8),
**bpftool-map**\ (8),
**bpftool-cgroup**\ (8),
**bpftool-net**\ (8),
**bpftool-perf**\ (8),
**bpftool-btf**\ (8)