49eb7ab3b2
Add a new component and command for bpftool, in order to probe the
system to dump a set of eBPF-related parameters so that users can know
what features are available on the system.
Parameters are dumped in plain or JSON output (with -j/-p options).
The current patch introduces probing of one simple parameter:
availability of the bpf() system call. Later commits
will add other probes.
Sample output:
# bpftool feature probe kernel
Scanning system call availability...
bpf() syscall is available
# bpftool --json --pretty feature probe kernel
{
"syscall_config": {
"have_bpf_syscall": true
}
}
The optional "kernel" keyword enforces probing of the current system,
which is the only possible behaviour at this stage. It can be safely
omitted.
The feature comes with the relevant man page, but bash completion will
come in a dedicated commit.
v3:
- Do not probe kernel version. Contrarily to what is written below for
v2, we can have the kernel version retrieved in libbpf instead of
bpftool (in the patch adding probing for program types).
v2:
- Remove C-style macros output from this patch.
- Even though kernel version is no longer needed for testing kprobes
availability, note that we still collect it in this patch so that
bpftool gets able to probe (in next patches) older kernels as well.
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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2.4 KiB
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89 lines
2.4 KiB
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================
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bpftool-perf
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================
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-------------------------------------------------------------------------------
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tool for inspection of perf related bpf prog attachments
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-------------------------------------------------------------------------------
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:Manual section: 8
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SYNOPSIS
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========
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**bpftool** [*OPTIONS*] **perf** *COMMAND*
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*OPTIONS* := { [{ **-j** | **--json** }] [{ **-p** | **--pretty** }] }
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*COMMANDS* :=
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{ **show** | **list** | **help** }
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PERF COMMANDS
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=============
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| **bpftool** **perf { show | list }**
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| **bpftool** **perf help**
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DESCRIPTION
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===========
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**bpftool perf { show | list }**
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List all raw_tracepoint, tracepoint, kprobe attachment in the system.
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Output will start with process id and file descriptor in that process,
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followed by bpf program id, attachment information, and attachment point.
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The attachment point for raw_tracepoint/tracepoint is the trace probe name.
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The attachment point for k[ret]probe is either symbol name and offset,
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or a kernel virtual address.
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The attachment point for u[ret]probe is the file name and the file offset.
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**bpftool perf help**
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Print short help message.
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OPTIONS
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=======
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-h, --help
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Print short generic help message (similar to **bpftool help**).
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-v, --version
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Print version number (similar to **bpftool version**).
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-j, --json
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Generate JSON output. For commands that cannot produce JSON, this
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option has no effect.
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-p, --pretty
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Generate human-readable JSON output. Implies **-j**.
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EXAMPLES
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========
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| **# bpftool perf**
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::
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pid 21711 fd 5: prog_id 5 kprobe func __x64_sys_write offset 0
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pid 21765 fd 5: prog_id 7 kretprobe func __x64_sys_nanosleep offset 0
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pid 21767 fd 5: prog_id 8 tracepoint sys_enter_nanosleep
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pid 21800 fd 5: prog_id 9 uprobe filename /home/yhs/a.out offset 1159
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| **# bpftool -j perf**
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::
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[{"pid":21711,"fd":5,"prog_id":5,"fd_type":"kprobe","func":"__x64_sys_write","offset":0}, \
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{"pid":21765,"fd":5,"prog_id":7,"fd_type":"kretprobe","func":"__x64_sys_nanosleep","offset":0}, \
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{"pid":21767,"fd":5,"prog_id":8,"fd_type":"tracepoint","tracepoint":"sys_enter_nanosleep"}, \
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{"pid":21800,"fd":5,"prog_id":9,"fd_type":"uprobe","filename":"/home/yhs/a.out","offset":1159}]
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SEE ALSO
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========
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**bpf**\ (2),
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**bpf-helpers**\ (7),
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**bpftool**\ (8),
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**bpftool-prog**\ (8),
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**bpftool-map**\ (8),
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**bpftool-cgroup**\ (8),
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**bpftool-feature**\ (8),
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**bpftool-net**\ (8)
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