kernel/tools/bpf/bpftool/Documentation, branch linux-5.1.y

tools/bpftool: recognize bpf_prog_info run_time_ns and run_cnt

2019-02-27T16:22:51Z

$ bpftool p s 1: kprobe tag a56587d488d216c9 gpl run_time_ns 79786 run_cnt 8 loaded_at 2019-02-22T12:22:51-0800 uid 0 xlated 352B not jited memlock 4096B $ bpftool --json --pretty p s [{ "id": 1, "type": "kprobe", "tag": "a56587d488d216c9", "gpl_compatible": true, "run_time_ns": 79786, "run_cnt": 8, "loaded_at": 1550866971, "uid": 0, "bytes_xlated": 352, "jited": false, "bytes_memlock": 4096 } ] Signed-off-by: Alexei Starovoitov Signed-off-by: Daniel Borkmann

bpf: bpftool, fix documentation for attach types

2019-02-19T16:23:18Z

bpftool has support for attach types "stream_verdict" and "stream_parser" but the documentation was referring to them as "skb_verdict" and "skb_parse". The inconsistency comes from commit b7d3826c2ed6 ("bpf: bpftool, add support for attaching programs to maps"). This patch changes the documentation to match the implementation: - "bpftool prog help" - man pages - bash completion Signed-off-by: Alban Crequy Reviewed-by: Quentin Monnet Signed-off-by: Daniel Borkmann

tools: bpftool: doc, add text about feature-subcommand

2019-02-12T16:06:18Z

This patch adds missing information about feature-subcommand in bpftool.rst Signed-off-by: Prashant Bhole Reviewed-by: Quentin Monnet Signed-off-by: Daniel Borkmann

tools: bpftool: doc, fix incorrect text

2019-02-06T14:39:15Z

Documentation about cgroup, feature, prog uses wrong header 'MAP COMMANDS' while listing commands. This patch corrects the header in respective doc files. Signed-off-by: Prashant Bhole Acked-by: Yonghong Song Reviewed-by: Quentin Monnet Signed-off-by: Daniel Borkmann

tools: bpftool: add probes for a network device

2019-01-23T06:15:40Z

bpftool gained support for probing the current system in order to see what program and map types, and what helpers are available on that system. This patch adds the possibility to pass an interface index to libbpf (and hence to the kernel) when trying to load the programs or to create the maps, in order to see what items a given network device can support. A new keyword "dev " can be used as an alternative to "kernel" to indicate that the given device should be tested. If no target ("dev" or "kernel") is specified bpftool defaults to probing the kernel. Sample output: # bpftool -p feature probe dev lo { "syscall_config": { "have_bpf_syscall": true }, "program_types": { "have_sched_cls_prog_type": false, "have_xdp_prog_type": false }, ... } As the target is a network device, /proc/ parameters and kernel configuration are NOT dumped. Availability of the bpf() syscall is still probed, so we can return early if that syscall is not usable (since there is no point in attempting the remaining probes in this case). Among the program types, only the ones that can be offloaded are probed. All map types are probed, as there is no specific rule telling which one could or could not be supported by a device in the future. All helpers are probed (but only for offload-able program types). Caveat: as bpftool does not attempt to attach programs to the device at the moment, probes do not entirely reflect what the device accepts: typically, for Netronome's nfp, results will announce that TC cls offload is available even if support has been deactivated (with e.g. ethtool -K eth1 hw-tc-offload off). v2: - All helpers are probed, whereas previous version would only probe the ones compatible with an offload-able program type. This is because we do not keep a default compatible program type for each helper anymore. Signed-off-by: Quentin Monnet Reviewed-by: Jakub Kicinski Reviewed-by: Stanislav Fomichev Signed-off-by: Alexei Starovoitov

tools: bpftool: add C-style "#define" output for probes

2019-01-23T06:15:40Z

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 is available for , * 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 is available for program . 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 Reviewed-by: Jakub Kicinski Reviewed-by: Stanislav Fomichev Signed-off-by: Alexei Starovoitov

tools: bpftool: add probes for eBPF helper functions

2019-01-23T06:15:40Z

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 Reviewed-by: Jakub Kicinski Reviewed-by: Stanislav Fomichev Signed-off-by: Alexei Starovoitov

tools: bpftool: add basic probe capability, probe syscall availability

2019-01-23T06:15:40Z

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 Reviewed-by: Jakub Kicinski Reviewed-by: Stanislav Fomichev Signed-off-by: Alexei Starovoitov

bpftool: add pop and dequeue commands

2019-01-17T09:30:32Z

This is intended to be used with queues and stacks, it pops and prints the last element via bpf_map_lookup_and_delete_elem. Example: bpftool map create /sys/fs/bpf/q type queue value 4 entries 10 name q bpftool map push pinned /sys/fs/bpf/q value 0 1 2 3 bpftool map pop pinned /sys/fs/bpf/q value: 00 01 02 03 bpftool map pop pinned /sys/fs/bpf/q Error: empty map bpftool map create /sys/fs/bpf/s type stack value 4 entries 10 name s bpftool map enqueue pinned /sys/fs/bpf/s value 0 1 2 3 bpftool map dequeue pinned /sys/fs/bpf/s value: 00 01 02 03 bpftool map dequeue pinned /sys/fs/bpf/s Error: empty map Signed-off-by: Stanislav Fomichev Signed-off-by: Daniel Borkmann

bpftool: add push and enqueue commands

2019-01-17T09:30:31Z

This is intended to be used with queues and stacks and be more user-friendly than 'update' without the key. Example: bpftool map create /sys/fs/bpf/q type queue value 4 entries 10 name q bpftool map push pinned /sys/fs/bpf/q value 0 1 2 3 bpftool map peek pinned /sys/fs/bpf/q value: 00 01 02 03 bpftool map create /sys/fs/bpf/s type stack value 4 entries 10 name s bpftool map enqueue pinned /sys/fs/bpf/s value 0 1 2 3 bpftool map peek pinned /sys/fs/bpf/s value: 00 01 02 03 Signed-off-by: Stanislav Fomichev Signed-off-by: Daniel Borkmann