linux-toradex.git/tools/bpf/bpftool/feature.c, branch v5.18 Linux kernel for Apalis and Colibri modules bpf/bpftool: Add unprivileged_bpf_disabled check against value of 2 2022-03-29T02:01:54+00:00 Milan Landaverde milan@mdaverde.com 2022-03-22T14:49:45+00:00 8c1b21198551d795a44f08ad185f716732b47bbe In [1], we added a kconfig knob that can set /proc/sys/kernel/unprivileged_bpf_disabled to 2 We now check against this value in bpftool feature probe [1] https://lore.kernel.org/bpf/74ec548079189e4e4dffaeb42b8987bb3c852eee.1620765074.git.daniel@iogearbox.net Signed-off-by: Milan Landaverde <milan@mdaverde.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Quentin Monnet <quentin@isovalent.com> Acked-by: KP Singh <kpsingh@kernel.org> Link: https://lore.kernel.org/bpf/20220322145012.1315376-1-milan@mdaverde.com 
In [1], we added a kconfig knob that can set
/proc/sys/kernel/unprivileged_bpf_disabled to 2

We now check against this value in bpftool feature probe

[1] https://lore.kernel.org/bpf/74ec548079189e4e4dffaeb42b8987bb3c852eee.1620765074.git.daniel@iogearbox.net

Signed-off-by: Milan Landaverde <milan@mdaverde.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Quentin Monnet <quentin@isovalent.com>
Acked-by: KP Singh <kpsingh@kernel.org>
Link: https://lore.kernel.org/bpf/20220322145012.1315376-1-milan@mdaverde.com
bpftool: Restore support for BPF offload-enabled feature probing 2022-03-10T15:09:47+00:00 Niklas Söderlund niklas.soderlund@corigine.com 2022-03-10T12:18:46+00:00 f655c088e74f4681134f650b5743174586a61016 Commit 1a56c18e6c2e4e74 ("bpftool: Stop supporting BPF offload-enabled feature probing") removed the support to probe for BPF offload features. This is still something that is useful for NFP NIC that can support offloading of BPF programs. The reason for the dropped support was that libbpf starting with v1.0 would drop support for passing the ifindex to the BPF prog/map/helper feature probing APIs. In order to keep this useful feature for NFP restore the functionality by moving it directly into bpftool. The code restored is a simplified version of the code that existed in libbpf which supposed passing the ifindex. The simplification is that it only targets the cases where ifindex is given and call into libbpf for the cases where it's not. Before restoring support for probing offload features: # bpftool feature probe dev ens4np0 Scanning system call availability... bpf() syscall is available Scanning eBPF program types... Scanning eBPF map types... Scanning eBPF helper functions... eBPF helpers supported for program type sched_cls: eBPF helpers supported for program type xdp: Scanning miscellaneous eBPF features... Large program size limit is NOT available Bounded loop support is NOT available ISA extension v2 is NOT available ISA extension v3 is NOT available With support for probing offload features restored: # bpftool feature probe dev ens4np0 Scanning system call availability... bpf() syscall is available Scanning eBPF program types... eBPF program_type sched_cls is available eBPF program_type xdp is available Scanning eBPF map types... eBPF map_type hash is available eBPF map_type array is available Scanning eBPF helper functions... eBPF helpers supported for program type sched_cls: - bpf_map_lookup_elem - bpf_get_prandom_u32 - bpf_perf_event_output eBPF helpers supported for program type xdp: - bpf_map_lookup_elem - bpf_get_prandom_u32 - bpf_perf_event_output - bpf_xdp_adjust_head - bpf_xdp_adjust_tail Scanning miscellaneous eBPF features... Large program size limit is NOT available Bounded loop support is NOT available ISA extension v2 is NOT available ISA extension v3 is NOT available Signed-off-by: Niklas Söderlund <niklas.soderlund@corigine.com> Signed-off-by: Simon Horman <simon.horman@corigine.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/20220310121846.921256-1-niklas.soderlund@corigine.com 
Commit 1a56c18e6c2e4e74 ("bpftool: Stop supporting BPF offload-enabled
feature probing") removed the support to probe for BPF offload features.
This is still something that is useful for NFP NIC that can support
offloading of BPF programs.

The reason for the dropped support was that libbpf starting with v1.0
would drop support for passing the ifindex to the BPF prog/map/helper
feature probing APIs. In order to keep this useful feature for NFP
restore the functionality by moving it directly into bpftool.

The code restored is a simplified version of the code that existed in
libbpf which supposed passing the ifindex. The simplification is that it
only targets the cases where ifindex is given and call into libbpf for
the cases where it's not.

Before restoring support for probing offload features:

  # bpftool feature probe dev ens4np0
  Scanning system call availability...
  bpf() syscall is available

  Scanning eBPF program types...

  Scanning eBPF map types...

  Scanning eBPF helper functions...
  eBPF helpers supported for program type sched_cls:
  eBPF helpers supported for program type xdp:

  Scanning miscellaneous eBPF features...
  Large program size limit is NOT available
  Bounded loop support is NOT available
  ISA extension v2 is NOT available
  ISA extension v3 is NOT available

With support for probing offload features restored:

  # bpftool feature probe dev ens4np0
  Scanning system call availability...
  bpf() syscall is available

  Scanning eBPF program types...
  eBPF program_type sched_cls is available
  eBPF program_type xdp is available

  Scanning eBPF map types...
  eBPF map_type hash is available
  eBPF map_type array is available

  Scanning eBPF helper functions...
  eBPF helpers supported for program type sched_cls:
  	- bpf_map_lookup_elem
  	- bpf_get_prandom_u32
  	- bpf_perf_event_output
  eBPF helpers supported for program type xdp:
  	- bpf_map_lookup_elem
  	- bpf_get_prandom_u32
  	- bpf_perf_event_output
  	- bpf_xdp_adjust_head
  	- bpf_xdp_adjust_tail

  Scanning miscellaneous eBPF features...
  Large program size limit is NOT available
  Bounded loop support is NOT available
  ISA extension v2 is NOT available
  ISA extension v3 is NOT available

Signed-off-by: Niklas Söderlund <niklas.soderlund@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20220310121846.921256-1-niklas.soderlund@corigine.com
bpftool: Stop supporting BPF offload-enabled feature probing 2022-02-03T15:32:25+00:00 Andrii Nakryiko andrii@kernel.org 2022-02-02T22:59:12+00:00 1a56c18e6c2e4e7482ac9e1a4ffe1770841dd6bd libbpf 1.0 is not going to support passing ifindex to BPF prog/map/helper feature probing APIs. Remove the support for BPF offload feature probing. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/20220202225916.3313522-3-andrii@kernel.org 
libbpf 1.0 is not going to support passing ifindex to BPF
prog/map/helper feature probing APIs. Remove the support for BPF offload
feature probing.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20220202225916.3313522-3-andrii@kernel.org
bpftool: Probe for instruction set extensions 2022-01-05T12:31:40+00:00 Paul Chaignon paul@isovalent.com 2022-01-04T18:00:13+00:00 0fd800b2456cf90ed738a1260b53acaa8843b5ae This patch introduces new probes to check whether the kernel supports instruction set extensions v2 and v3. The first introduced eBPF instructions BPF_J{LT,LE,SLT,SLE} in commit 92b31a9af73b ("bpf: add BPF_J{LT,LE,SLT,SLE} instructions"). The second introduces 32-bit variants of all jump instructions in commit 092ed0968bb6 ("bpf: verifier support JMP32"). These probes are useful for userspace BPF projects that want to use newer instruction set extensions on newer kernels, to reduce the programs' sizes or their complexity. LLVM already provides an mcpu=probe option to automatically probe the kernel and select the newest-supported instruction set extension. That is however not flexible enough for all use cases. For example, in Cilium, we only want to use the v3 instruction set extension on v5.10+, even though it is supported on all kernels v5.1+. Signed-off-by: Paul Chaignon <paul@isovalent.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/3bfedcd9898c1f41ac67ca61f144fec84c6c3a92.1641314075.git.paul@isovalent.com 
This patch introduces new probes to check whether the kernel supports
instruction set extensions v2 and v3. The first introduced eBPF
instructions BPF_J{LT,LE,SLT,SLE} in commit 92b31a9af73b ("bpf: add
BPF_J{LT,LE,SLT,SLE} instructions"). The second introduces 32-bit
variants of all jump instructions in commit 092ed0968bb6 ("bpf:
verifier support JMP32").

These probes are useful for userspace BPF projects that want to use newer
instruction set extensions on newer kernels, to reduce the programs'
sizes or their complexity. LLVM already provides an mcpu=probe option to
automatically probe the kernel and select the newest-supported
instruction set extension. That is however not flexible enough for all
use cases. For example, in Cilium, we only want to use the v3
instruction set extension on v5.10+, even though it is supported on all
kernels v5.1+.

Signed-off-by: Paul Chaignon <paul@isovalent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/3bfedcd9898c1f41ac67ca61f144fec84c6c3a92.1641314075.git.paul@isovalent.com
bpftool: Probe for bounded loop support 2022-01-05T12:31:40+00:00 Paul Chaignon paul@isovalent.com 2022-01-04T17:59:57+00:00 c04fb2b0bd9275969be3b0a95f9c3ef76b1bfb73 This patch introduces a new probe to check whether the verifier supports bounded loops as introduced in commit 2589726d12a1 ("bpf: introduce bounded loops"). This patch will allow BPF users such as Cilium to probe for loop support on startup and only unconditionally unroll loops on older kernels. The results are displayed as part of the miscellaneous section, as shown below. $ bpftool feature probe | grep loops Bounded loop support is available $ bpftool feature probe macro | grep LOOPS #define HAVE_BOUNDED_LOOPS $ bpftool feature probe -j | jq .misc { "have_large_insn_limit": true, "have_bounded_loops": true } Signed-off-by: Paul Chaignon <paul@isovalent.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/f7807c0b27d79f48e71de7b5a99c680ca4bd0151.1641314075.git.paul@isovalent.com 
This patch introduces a new probe to check whether the verifier supports
bounded loops as introduced in commit 2589726d12a1 ("bpf: introduce
bounded loops"). This patch will allow BPF users such as Cilium to probe
for loop support on startup and only unconditionally unroll loops on
older kernels.

The results are displayed as part of the miscellaneous section, as shown
below.

  $ bpftool feature probe | grep loops
  Bounded loop support is available
  $ bpftool feature probe macro | grep LOOPS
  #define HAVE_BOUNDED_LOOPS
  $ bpftool feature probe -j | jq .misc
  {
    "have_large_insn_limit": true,
    "have_bounded_loops": true
  }

Signed-off-by: Paul Chaignon <paul@isovalent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/f7807c0b27d79f48e71de7b5a99c680ca4bd0151.1641314075.git.paul@isovalent.com
bpftool: Refactor misc. feature probe 2022-01-05T12:31:40+00:00 Paul Chaignon paul@isovalent.com 2022-01-04T17:59:29+00:00 b22bf1b9979a608827dea98c61ed9ec297bcc513 There is currently a single miscellaneous feature probe, HAVE_LARGE_INSN_LIMIT, to check for the 1M instructions limit in the verifier. Subsequent patches will add additional miscellaneous probes, which follow the same pattern at the existing probe. This patch therefore refactors the probe to avoid code duplication in subsequent patches. The BPF program type and the checked error numbers in the HAVE_LARGE_INSN_LIMIT probe are changed to better generalize to other probes. The feature probe retains its current behavior despite those changes. Signed-off-by: Paul Chaignon <paul@isovalent.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/956c9329a932c75941194f91790d01f31dfbe01b.1641314075.git.paul@isovalent.com 
There is currently a single miscellaneous feature probe,
HAVE_LARGE_INSN_LIMIT, to check for the 1M instructions limit in the
verifier. Subsequent patches will add additional miscellaneous probes,
which follow the same pattern at the existing probe. This patch
therefore refactors the probe to avoid code duplication in subsequent
patches.

The BPF program type and the checked error numbers in the
HAVE_LARGE_INSN_LIMIT probe are changed to better generalize to other
probes. The feature probe retains its current behavior despite those
changes.

Signed-off-by: Paul Chaignon <paul@isovalent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/956c9329a932c75941194f91790d01f31dfbe01b.1641314075.git.paul@isovalent.com
bpftool: Reimplement large insn size limit feature probing 2021-12-17T22:11:13+00:00 Andrii Nakryiko andrii@kernel.org 2021-12-17T17:12:02+00:00 e967a20a8fabc6442a78e2e2059e63a4bb6aed08 Reimplement bpf_probe_large_insn_limit() in bpftool, as that libbpf API is scheduled for deprecation in v0.8. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Dave Marchevsky <davemarchevsky@fb.com> Link: https://lore.kernel.org/bpf/20211217171202.3352835-4-andrii@kernel.org 
Reimplement bpf_probe_large_insn_limit() in bpftool, as that libbpf API
is scheduled for deprecation in v0.8.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20211217171202.3352835-4-andrii@kernel.org
bpftool: Stop using deprecated bpf_load_program() 2021-11-07T16:34:23+00:00 Andrii Nakryiko andrii@kernel.org 2021-11-03T22:08:39+00:00 a3c7c7e8050fc299b42fa3d89bac253a8dfa5c0c Switch to bpf_prog_load() instead. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211103220845.2676888-7-andrii@kernel.org 
Switch to bpf_prog_load() instead.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211103220845.2676888-7-andrii@kernel.org
bpftool: Only probe trace_vprintk feature in 'full' mode 2021-09-17T21:02:05+00:00 Dave Marchevsky davemarchevsky@fb.com 2021-09-17T18:29:08+00:00 4190c299a49f323232221e73fe1846c53e3fc3f1 Since commit 368cb0e7cdb5e ("bpftool: Make probes which emit dmesg warnings optional"), some helpers aren't probed by bpftool unless `full` arg is added to `bpftool feature probe`. bpf_trace_vprintk can emit dmesg warnings when probed, so include it. Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210917182911.2426606-7-davemarchevsky@fb.com 
Since commit 368cb0e7cdb5e ("bpftool: Make probes which emit dmesg
warnings optional"), some helpers aren't probed by bpftool unless
`full` arg is added to `bpftool feature probe`.

bpf_trace_vprintk can emit dmesg warnings when probed, so include it.

Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210917182911.2426606-7-davemarchevsky@fb.com
tools: bpftool: Update and synchronise option list in doc and help msg 2021-07-30T22:40:27+00:00 Quentin Monnet quentin@isovalent.com 2021-07-30T21:54:32+00:00 c07ba629df97b796ca7bbdfbf4748266ead27745 All bpftool commands support the options for JSON output and debug from libbpf. In addition, some commands support additional options corresponding to specific use cases. The list of options described in the man pages for the different commands are not always accurate. The messages for interactive help are mostly limited to HELP_SPEC_OPTIONS, and are even less representative of the actual set of options supported for the commands. Let's update the lists: - HELP_SPEC_OPTIONS is modified to contain the "default" options (JSON and debug), and to be extensible (no ending curly bracket). - All commands use HELP_SPEC_OPTIONS in their help message, and then complete the list with their specific options. - The lists of options in the man pages are updated. - The formatting of the list for bpftool.rst is adjusted to match formatting for the other man pages. This is for consistency, and also because it will be helpful in a future patch to automatically check that the files are synchronised. Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210730215435.7095-5-quentin@isovalent.com 
All bpftool commands support the options for JSON output and debug from
libbpf. In addition, some commands support additional options
corresponding to specific use cases.

The list of options described in the man pages for the different
commands are not always accurate. The messages for interactive help are
mostly limited to HELP_SPEC_OPTIONS, and are even less representative of
the actual set of options supported for the commands.

Let's update the lists:

- HELP_SPEC_OPTIONS is modified to contain the "default" options (JSON
  and debug), and to be extensible (no ending curly bracket).
- All commands use HELP_SPEC_OPTIONS in their help message, and then
  complete the list with their specific options.
- The lists of options in the man pages are updated.
- The formatting of the list for bpftool.rst is adjusted to match
  formatting for the other man pages. This is for consistency, and also
  because it will be helpful in a future patch to automatically check
  that the files are synchronised.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210730215435.7095-5-quentin@isovalent.com