linux/tools/bpf/bpftool
Quentin Monnet d267cff467 tools: bpftool: add C-style "#define" output for probes
Make bpftool able to dump a subset of the parameters collected by
probing the system as a listing of C-style #define macros, so that
external projects can reuse the result of this probing and build
BPF-based project in accordance with the features available on the
system.

The new "macros" keyword is used to select this output. An additional
"prefix" keyword is added so that users can select a custom prefix for
macro names, in order to avoid any namespace conflict.

Sample output:

    # bpftool feature probe kernel macros prefix FOO_
    /*** System call availability ***/
    #define FOO_HAVE_BPF_SYSCALL

    /*** eBPF program types ***/
    #define FOO_HAVE_SOCKET_FILTER_PROG_TYPE
    #define FOO_HAVE_KPROBE_PROG_TYPE
    #define FOO_HAVE_SCHED_CLS_PROG_TYPE
    ...

    /*** eBPF map types ***/
    #define FOO_HAVE_HASH_MAP_TYPE
    #define FOO_HAVE_ARRAY_MAP_TYPE
    #define FOO_HAVE_PROG_ARRAY_MAP_TYPE
    ...

    /*** eBPF helper functions ***/
    /*
     * Use FOO_HAVE_PROG_TYPE_HELPER(prog_type_name, helper_name)
     * to determine if <helper_name> is available for <prog_type_name>,
     * e.g.
     *      #if FOO_HAVE_PROG_TYPE_HELPER(xdp, bpf_redirect)
     *              // do stuff with this helper
     *      #elif
     *              // use a workaround
     *      #endif
     */
    #define FOO_HAVE_PROG_TYPE_HELPER(prog_type, helper)        \
            FOO_BPF__PROG_TYPE_ ## prog_type ## __HELPER_ ## helper
    ...
    #define FOO_BPF__PROG_TYPE_socket_filter__HELPER_bpf_probe_read 0
    #define FOO_BPF__PROG_TYPE_socket_filter__HELPER_bpf_ktime_get_ns 1
    #define FOO_BPF__PROG_TYPE_socket_filter__HELPER_bpf_trace_printk 1
    ...

v3:
- Change output for helpers again: add a
  HAVE_PROG_TYPE_HELPER(type, helper) macro that can be used to tell
  if <helper> is available for program <type>.

v2:
- #define-based output added as a distinct patch.
- "HAVE_" prefix appended to macro names.
- Output limited to bpf() syscall availability, BPF prog and map types,
  helper functions. In this version kernel config options, procfs
  parameter or kernel version are intentionally left aside.
- Following the change on helper probes, format for helper probes in
  this output style has changed (now a list of compatible program
  types).

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>
2019-01-22 22:15:40 -08:00
..
bash-completion bpftool: add bash completion for peek/push/enqueue/pop/dequeue 2019-01-17 10:30:32 +01:00
Documentation tools: bpftool: add C-style "#define" output for probes 2019-01-22 22:15:40 -08:00
.gitignore tools/bpftool: ignore build products 2018-07-26 02:50:26 +02:00
btf_dumper.c tools/bpf: support __int128 in bpftool map pretty dumper 2019-01-16 22:53:44 +01:00
cfg.c tools: bpftool: replace Netronome boilerplate with SPDX license headers 2018-12-13 12:08:44 +01:00
cfg.h tools: bpftool: replace Netronome boilerplate with SPDX license headers 2018-12-13 12:08:44 +01:00
cgroup.c tools: bpftool: dual license all files 2018-12-13 12:08:44 +01:00
common.c tools: bpftool: add an option to prevent auto-mount of bpffs, tracefs 2018-12-18 14:47:17 +01:00
feature.c tools: bpftool: add C-style "#define" output for probes 2019-01-22 22:15:40 -08:00
jit_disasm.c tools: bpftool: dual license all files 2018-12-13 12:08:44 +01:00
json_writer.c tools: bpftool: fix -Wmissing declaration warnings 2018-12-15 01:31:49 +01:00
json_writer.h tools: bpftool: dual license all files 2018-12-13 12:08:44 +01:00
main.c tools: bpftool: add basic probe capability, probe syscall availability 2019-01-22 22:15:40 -08:00
main.h tools: bpftool: add probes for eBPF map types 2019-01-22 22:15:40 -08:00
Makefile tools: bpftool: do not force gcc as CC 2018-12-19 21:57:25 +01:00
map_perf_ring.c tools: bpftool: dual license all files 2018-12-13 12:08:44 +01:00
map.c tools: bpftool: add probes for eBPF map types 2019-01-22 22:15:40 -08:00
net.c tools: bpftool: dual license all files 2018-12-13 12:08:44 +01:00
netlink_dumper.c tools: bpftool: dual license all files 2018-12-13 12:08:44 +01:00
netlink_dumper.h tools: bpftool: dual license all files 2018-12-13 12:08:44 +01:00
perf.c tools: bpftool: dual license all files 2018-12-13 12:08:44 +01:00
prog.c tools: bpftool: fix -Wmissing declaration warnings 2018-12-15 01:31:49 +01:00
tracelog.c tools: bpftool: add an option to prevent auto-mount of bpffs, tracefs 2018-12-18 14:47:17 +01:00
xlated_dumper.c tools: bpftool: fix -Wmissing declaration warnings 2018-12-15 01:31:49 +01:00
xlated_dumper.h tools: bpftool: replace Netronome boilerplate with SPDX license headers 2018-12-13 12:08:44 +01:00