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-rw-r--r--tools/bpf/bpftool/Documentation/bpftool-feature.rst19
1 files changed, 10 insertions, 9 deletions
diff --git a/tools/bpf/bpftool/Documentation/bpftool-feature.rst b/tools/bpf/bpftool/Documentation/bpftool-feature.rst
index 4d08f35034a2..b04156cfd7a3 100644
--- a/tools/bpf/bpftool/Documentation/bpftool-feature.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool-feature.rst
@@ -19,19 +19,24 @@ SYNOPSIS
FEATURE COMMANDS
================
-| **bpftool** **feature probe** [*COMPONENT*] [**macros** [**prefix** *PREFIX*]]
+| **bpftool** **feature probe** [*COMPONENT*] [**full**] [**macros** [**prefix** *PREFIX*]]
| **bpftool** **feature help**
|
| *COMPONENT* := { **kernel** | **dev** *NAME* }
DESCRIPTION
===========
- **bpftool feature probe** [**kernel**] [**macros** [**prefix** *PREFIX*]]
+ **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
@@ -44,16 +49,12 @@ DESCRIPTION
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*]]
+ **bpftool feature probe dev** *NAME* [**full**] [**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.
+ The keywords **full**, **macros** and **prefix** have the
+ same role as when probing the kernel.
**bpftool feature help**
Print short help message.