blob: 4ce9a77bc1e06f73800f80609de92797ce82d515 [file] [log] [blame]
.. SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
===============
bpftool-feature
===============
-------------------------------------------------------------------------------
tool for inspection of eBPF-related parameters for Linux kernel or net device
-------------------------------------------------------------------------------
:Manual section: 8
.. include:: substitutions.rst
SYNOPSIS
========
**bpftool** [*OPTIONS*] **feature** *COMMAND*
*OPTIONS* := { |COMMON_OPTIONS| }
*COMMANDS* := { **probe** | **help** }
FEATURE COMMANDS
================
| **bpftool** **feature probe** [*COMPONENT*] [**full**] [**unprivileged**] [**macros** [**prefix** *PREFIX*]]
| **bpftool** **feature help**
|
| *COMPONENT* := { **kernel** | **dev** *NAME* }
DESCRIPTION
===========
**bpftool feature probe** [**kernel**] [**full**] [**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.
By default, bpftool **does not run probes** for
**bpf_probe_write_user**\ () and **bpf_trace_printk**\()
helpers which print warnings to kernel logs. To enable them
and run all probes, the **full** keyword should be used.
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.
When the **unprivileged** keyword is used, bpftool will dump
only the features available to a user who does not have the
**CAP_SYS_ADMIN** capability set. The features available in
that case usually represent a small subset of the parameters
supported by the system. Unprivileged users MUST use the
**unprivileged** keyword: This is to avoid misdetection if
bpftool is inadvertently run as non-root, for example. This
keyword is unavailable if bpftool was compiled without
libcap.
**bpftool feature probe dev** *NAME* [**full**] [**macros** [**prefix** *PREFIX*]]
Probe network device for supported eBPF features and dump
results to the console.
The keywords **full**, **macros** and **prefix** have the
same role as when probing the kernel.
**bpftool feature help**
Print short help message.
OPTIONS
=======
.. include:: common_options.rst