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authorQuentin Monnet <quentin.monnet@netronome.com>2019-01-17 18:27:50 +0300
committerAlexei Starovoitov <ast@kernel.org>2019-01-23 09:15:40 +0300
commit49eb7ab3b2b5a106307494d2a46248ecb1530578 (patch)
treecab3e6a5ae00f54acb4e43fbfa9d74497ee075bb /tools/bpf/bpftool/main.c
parentd0b2818efbe27e6c2e0c52621c8db18eb5abb5e1 (diff)
downloadlinux-49eb7ab3b2b5a106307494d2a46248ecb1530578.tar.xz
tools: bpftool: add basic probe capability, probe syscall availability
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>
Diffstat (limited to 'tools/bpf/bpftool/main.c')
-rw-r--r--tools/bpf/bpftool/main.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/tools/bpf/bpftool/main.c b/tools/bpf/bpftool/main.c
index f44a1c2c4ea0..a9d5e9e6a732 100644
--- a/tools/bpf/bpftool/main.c
+++ b/tools/bpf/bpftool/main.c
@@ -56,7 +56,7 @@ static int do_help(int argc, char **argv)
" %s batch file FILE\n"
" %s version\n"
"\n"
- " OBJECT := { prog | map | cgroup | perf | net }\n"
+ " OBJECT := { prog | map | cgroup | perf | net | feature }\n"
" " HELP_SPEC_OPTIONS "\n"
"",
bin_name, bin_name, bin_name);
@@ -187,6 +187,7 @@ static const struct cmd cmds[] = {
{ "cgroup", do_cgroup },
{ "perf", do_perf },
{ "net", do_net },
+ { "feature", do_feature },
{ "version", do_version },
{ 0 }
};