On 01/16, Quentin Monnet wrote: > Hi, > This set adds a new command to bpftool in order to dump a list of > eBPF-related parameters for the system (or for a specific network > device) to the console. Once again, this is based on a suggestion from > Daniel. > > At this time, output includes: > > - Availability of bpf() system call > - Availability of bpf() system call for unprivileged users > - JIT status (enabled or not, with or without debugging traces) > - JIT hardening status > - JIT kallsyms exports status > - Global memory limit for JIT compiler for unprivileged users > - Status of kernel compilation options related to BPF features > - Availability of known eBPF program types > - Availability of known eBPF map types > - Availability of known eBPF helper functions > > There are three different ways to dump this information at this time: > > - Plain output dumps probe results in plain text. It is the most > flexible options for providing descriptive output to the user, but > should not be relied upon for parsing the output. > - JSON output is supported. > - A third mode, available through the "macros" keyword appended to the > command line, dumps some of those parameters (not all) as a series of > "#define" directives, that can be included into a C header file for > example. > > Probes for supported program and map types, and supported helpers, are > directly added to libbpf, so that other applications (or selftests) can > reuse them as necessary. > > If the user does not have root privileges (or more precisely, the > CAP_SYS_ADMIN capability) detection will be erroneous for most > parameters. Therefore, forbid non-root users to run the command. > > v4: > - Probe bpf_jit_limit parameter (patch 2). > - Probe some additional kernel config options (patch 3). > - Minor fixes on patch 6. Looks great! For the whole series:
Reviewed-by: Stanislav Fomichev <s...@google.com> > > v3: > - Do not probe kernel version in bpftool (just retrieve it to probe support > for kprobes in libbpf). > - Change the way results for helper support is displayed: now one list of > compatible helpers for each program type (and C-style output gets a > HAVE_PROG_TYPE_HELPER(prog_type, helper) macro to help with tests. See > patches 6, 7. > - Address other comments from feedback from v2 (please refer to individual > patches' history). > > v2 (please also refer to individual patches' history): > - Move probes for prog/map types, helpers, from bpftool to libbpf. > - Move C-style output as a separate patch, and restrict it to a subset of > collected information (bpf() availability, prog/map types, helpers). > - Now probe helpers with all supported program types, and display a list of > compatible program types (as supported on the system) for each helper. > - NOT addressed: grouping compilation options for kernel into subsections > (patch 3) (I don't see an easy way of grouping them at the moment, please > see also the discussion on v1 thread). > > Cc: Arnaldo Carvalho de Melo <a...@kernel.org> > Cc: Jesper Dangaard Brouer <bro...@redhat.com> > Cc: Stanislav Fomichev <s...@google.com> > > Quentin Monnet (9): > tools: bpftool: add basic probe capability, probe syscall availability > tools: bpftool: add probes for /proc/ eBPF parameters > tools: bpftool: add probes for kernel configuration options > tools: bpftool: add probes for eBPF program types > tools: bpftool: add probes for eBPF map types > tools: bpftool: add probes for eBPF helper functions > tools: bpftool: add C-style "#define" output for probes > tools: bpftool: add probes for a network device > tools: bpftool: add bash completion for bpftool probes > > .../bpftool/Documentation/bpftool-cgroup.rst | 1 + > .../bpftool/Documentation/bpftool-feature.rst | 85 ++ > .../bpf/bpftool/Documentation/bpftool-map.rst | 1 + > .../bpf/bpftool/Documentation/bpftool-net.rst | 1 + > .../bpftool/Documentation/bpftool-perf.rst | 1 + > .../bpftool/Documentation/bpftool-prog.rst | 1 + > tools/bpf/bpftool/Documentation/bpftool.rst | 1 + > tools/bpf/bpftool/bash-completion/bpftool | 19 + > tools/bpf/bpftool/feature.c | 764 ++++++++++++++++++ > tools/bpf/bpftool/main.c | 3 +- > tools/bpf/bpftool/main.h | 4 + > tools/bpf/bpftool/map.c | 4 +- > tools/lib/bpf/Build | 2 +- > tools/lib/bpf/libbpf.h | 14 + > tools/lib/bpf/libbpf.map | 3 + > tools/lib/bpf/libbpf_probes.c | 242 ++++++ > 16 files changed, 1143 insertions(+), 3 deletions(-) > create mode 100644 tools/bpf/bpftool/Documentation/bpftool-feature.rst > create mode 100644 tools/bpf/bpftool/feature.c > create mode 100644 tools/lib/bpf/libbpf_probes.c > > -- > 2.17.1 >
