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Diffstat (limited to 'tools/bpf/bpftool/Documentation/bpftool-feature.rst')
| -rw-r--r-- | tools/bpf/bpftool/Documentation/bpftool-feature.rst | 115 |
1 files changed, 54 insertions, 61 deletions
diff --git a/tools/bpf/bpftool/Documentation/bpftool-feature.rst b/tools/bpf/bpftool/Documentation/bpftool-feature.rst index e44039f89b..c7f837898b 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-feature.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-feature.rst @@ -14,77 +14,70 @@ tool for inspection of eBPF-related parameters for Linux kernel or net device SYNOPSIS ======== - **bpftool** [*OPTIONS*] **feature** *COMMAND* +**bpftool** [*OPTIONS*] **feature** *COMMAND* - *OPTIONS* := { |COMMON_OPTIONS| } +*OPTIONS* := { |COMMON_OPTIONS| } - *COMMANDS* := { **probe** | **help** } +*COMMANDS* := { **probe** | **help** } FEATURE COMMANDS ================ -| **bpftool** **feature probe** [*COMPONENT*] [**full**] [**unprivileged**] [**macros** [**prefix** *PREFIX*]] -| **bpftool** **feature list_builtins** *GROUP* -| **bpftool** **feature help** +| **bpftool** **feature probe** [*COMPONENT*] [**full**] [**unprivileged**] [**macros** [**prefix** *PREFIX*]] +| **bpftool** **feature list_builtins** *GROUP* +| **bpftool** **feature help** | -| *COMPONENT* := { **kernel** | **dev** *NAME* } -| *GROUP* := { **prog_types** | **map_types** | **attach_types** | **link_types** | **helpers** } +| *COMPONENT* := { **kernel** | **dev** *NAME* } +| *GROUP* := { **prog_types** | **map_types** | **attach_types** | **link_types** | **helpers** } 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 list_builtins** *GROUP* - List items known to bpftool. These can be BPF program types - (**prog_types**), BPF map types (**map_types**), attach types - (**attach_types**), link types (**link_types**), or BPF helper - functions (**helpers**). The command does not probe the system, but - simply lists the elements that bpftool knows from compilation time, - as provided from libbpf (for all object types) or from the BPF UAPI - header (list of helpers). This can be used in scripts to iterate over - BPF types or helpers. - - **bpftool feature help** - Print short help message. +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 list_builtins *GROUP* + List items known to bpftool. These can be BPF program types + (**prog_types**), BPF map types (**map_types**), attach types + (**attach_types**), link types (**link_types**), or BPF helper functions + (**helpers**). The command does not probe the system, but simply lists the + elements that bpftool knows from compilation time, as provided from libbpf + (for all object types) or from the BPF UAPI header (list of helpers). This + can be used in scripts to iterate over BPF types or helpers. + +bpftool feature help + Print short help message. OPTIONS ======= - .. include:: common_options.rst +.. include:: common_options.rst |