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As part of the seccomp benchmarking, include the expectations with regard to the timing behavior of the constant action bitmaps, and report inconsistencies better. Example output with constant action bitmaps on x86: $ sudo ./seccomp_benchmark 100000000 Current BPF sysctl settings: net.core.bpf_jit_enable = 1 net.core.bpf_jit_harden = 0 Benchmarking 200000000 syscalls... 129.359381409 - 0.008724424 = 129350656985 (129.4s) getpid native: 646 ns 264.385890006 - 129.360453229 = 135025436777 (135.0s) getpid RET_ALLOW 1 filter (bitmap): 675 ns 399.400511893 - 264.387045901 = 135013465992 (135.0s) getpid RET_ALLOW 2 filters (bitmap): 675 ns 545.872866260 - 399.401718327 = 146471147933 (146.5s) getpid RET_ALLOW 3 filters (full): 732 ns 696.337101319 - 545.874097681 = 150463003638 (150.5s) getpid RET_ALLOW 4 filters (full): 752 ns Estimated total seccomp overhead for 1 bitmapped filter: 29 ns Estimated total seccomp overhead for 2 bitmapped filters: 29 ns Estimated total seccomp overhead for 3 full filters: 86 ns Estimated total seccomp overhead for 4 full filters: 106 ns Estimated seccomp entry overhead: 29 ns Estimated seccomp per-filter overhead (last 2 diff): 20 ns Estimated seccomp per-filter overhead (filters / 4): 19 ns Expectations: native ≤ 1 bitmap (646 ≤ 675): ✔️ native ≤ 1 filter (646 ≤ 732): ✔️ per-filter (last 2 diff) ≈ per-filter (filters / 4) (20 ≈ 19): ✔️ 1 bitmapped ≈ 2 bitmapped (29 ≈ 29): ✔️ entry ≈ 1 bitmapped (29 ≈ 29): ✔️ entry ≈ 2 bitmapped (29 ≈ 29): ✔️ native + entry + (per filter * 4) ≈ 4 filters total (755 ≈ 752): ✔️ [YiFei: Changed commit message to show stats for this patch series] Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/1b61df3db85c5f7f1b9202722c45e7b39df73ef2.1602431034.git.yifeifz2@illinois.edu
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.