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path: root/tools/lib/bpf/libbpf_probes.c
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2019-01-22tools: bpftool: add probes for eBPF helper functionsQuentin Monnet
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", ... ], ... } } v5: - In libbpf.map, move global symbol to the new LIBBPF_0.0.2 section. v4: - Use "enum bpf_func_id" instead of "__u32" in bpf_probe_helper() declaration for the type of the argument used to pass the id of the helper to probe. - Undef BPF_HELPER_MAKE_ENTRY after using it. 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.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>
2019-01-22tools: bpftool: add probes for eBPF map typesQuentin Monnet
Add new probes for eBPF map types, to detect what are the ones available on the system. Try creating one map of each type, and see if the kernel complains. Sample output: # bpftool feature probe kernel ... Scanning eBPF map types... eBPF map_type hash is available eBPF map_type array is available eBPF map_type prog_array is available ... # bpftool --json --pretty feature probe kernel { ... "map_types": { "have_hash_map_type": true, "have_array_map_type": true, "have_prog_array_map_type": true, ... } } v5: - In libbpf.map, move global symbol to the new LIBBPF_0.0.2 section. v3: - Use a switch with all enum values for setting specific map parameters, so that gcc complains at compile time (-Wswitch-enum) if new map types were added to the kernel but libbpf was not updated. v2: - Move probes from bpftool to libbpf. - Remove C-style macros output from this patch. 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>
2019-01-22tools: bpftool: add probes for eBPF program typesQuentin Monnet
Introduce probes for supported BPF program types in libbpf, and call it from bpftool to test what types are available on the system. The probe simply consists in loading a very basic program of that type and see if the verifier complains or not. Sample output: # bpftool feature probe kernel ... Scanning eBPF program types... eBPF program_type socket_filter is available eBPF program_type kprobe is available eBPF program_type sched_cls is available ... # bpftool --json --pretty feature probe kernel { ... "program_types": { "have_socket_filter_prog_type": true, "have_kprobe_prog_type": true, "have_sched_cls_prog_type": true, ... } } v5: - In libbpf.map, move global symbol to a new LIBBPF_0.0.2 section. - Rename (non-API function) prog_load() as probe_load(). v3: - Get kernel version for checking kprobes availability from libbpf instead of from bpftool. Do not pass kernel_version as an argument when calling libbpf probes. - Use a switch with all enum values for setting specific program parameters just before probing, so that gcc complains at compile time (-Wswitch-enum) if new prog types were added to the kernel but libbpf was not updated. - Add a comment in libbpf.h about setrlimit() usage to allow many consecutive probe attempts. v2: - Move probes from bpftool to libbpf. - Remove C-style macros output from this patch. 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>