2019-01-03 09:15 UTC-0800 ~ Stanislav Fomichev <s...@google.com>
> On Thu, Jan 3, 2019 at 6:03 AM Quentin Monnet
> <quentin.mon...@netronome.com> wrote:
>>
>> Similarly to what was done for program types and map types, add a set of
>> probes to test the availability of the different eBPF helper functions
>> on the current system.
>>
>> For each known program type, all known helpers are tested, in order to
>> establish a compatibility matrix. Output is provided as a set of lists
>> of available helpers, one per program type.
>>
>> Sample output:
>>
>> # bpftool feature probe kernel
>> ...
>> Scanning eBPF helper functions...
>> eBPF helpers supported for program type socket_filter:
>> - bpf_map_lookup_elem
>> - bpf_map_update_elem
>> - bpf_map_delete_elem
>> ...
>> eBPF helpers supported for program type kprobe:
>> - bpf_map_lookup_elem
>> - bpf_map_update_elem
>> - bpf_map_delete_elem
>> ...
>>
>> # bpftool --json --pretty feature probe kernel
>> {
>> ...
>> "helpers": {
>> "socket_filter_available_helpers": ["bpf_map_lookup_elem", \
>> "bpf_map_update_elem","bpf_map_delete_elem", ...
>> ],
>> "kprobe_available_helpers": ["bpf_map_lookup_elem", \
>> "bpf_map_update_elem","bpf_map_delete_elem", ...
>> ],
>> ...
>> }
>> }
>>
>> v3:
>> - Do not pass kernel version from bpftool to libbpf probes (kernel
>> version for testing program with kprobes is retrieved directly from
>> libbpf).
>> - Dump one list of available helpers per program type (instead of one
>> list of compatible program types per helper).
>>
>> v2:
>> - Move probes from bpftool to libbpf.
>> - Test all program types for each helper, print a list of working prog
>> types for each helper.
>> - Fall back on include/uapi/linux/bpf.h for names and ids of helpers.
>> - Remove C-style macros output from this patch.
>>
>> Signed-off-by: Quentin Monnet <quentin.mon...@netronome.com>
>> ---
>> .../bpftool/Documentation/bpftool-feature.rst | 4 ++
>> tools/bpf/bpftool/feature.c | 49 +++++++++++++++
>> tools/lib/bpf/libbpf.h | 2 +
>> tools/lib/bpf/libbpf.map | 1 +
>> tools/lib/bpf/libbpf_probes.c | 62 +++++++++++++++++++
>> 5 files changed, 118 insertions(+)
>>
>> diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
>> index 72385f6f9415..6ab275933d2e 100644
>> --- a/tools/lib/bpf/libbpf.h
>> +++ b/tools/lib/bpf/libbpf.h
>> @@ -366,6 +366,8 @@ bpf_prog_linfo__lfind(const struct bpf_prog_linfo
>> *prog_linfo,
>> LIBBPF_API bool bpf_probe_prog_type(enum bpf_prog_type prog_type,
>> __u32 ifindex);
>> LIBBPF_API bool bpf_probe_map_type(enum bpf_map_type map_type, __u32
>> ifindex);
>> +LIBBPF_API bool bpf_probe_helper(__u32 id, enum bpf_prog_type prog_type,
> Any reason not to use enum bpf_func_id as id type (instead of __u32)?
No reason (other than me forgetting about that enum when writing the
function), I'll fix it, thanks!
