From 5d8e5aee0e9391141fe2ab892d0ac98de5783537 Mon Sep 17 00:00:00 2001 From: Stephen Kitt Date: Sun, 15 Mar 2020 13:26:48 +0100 Subject: [PATCH] docs: sysctl/kernel: document BPF entries Based on the implementation in kernel/bpf/syscall.c, kernel/bpf/trampoline.c, include/linux/filter.h, and the documentation in bpftool-prog.rst. Signed-off-by: Stephen Kitt Link: https://lore.kernel.org/r/20200315122648.20558-1-steve@sk2.org Signed-off-by: Jonathan Corbet --- Documentation/admin-guide/sysctl/kernel.rst | 24 +++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst index 0d427fd10941..55b24eada13c 100644 --- a/Documentation/admin-guide/sysctl/kernel.rst +++ b/Documentation/admin-guide/sysctl/kernel.rst @@ -102,6 +102,20 @@ See the ``type_of_loader`` and ``ext_loader_ver`` fields in :doc:`/x86/boot` for additional information. +bpf_stats_enabled +================= + +Controls whether the kernel should collect statistics on BPF programs +(total time spent running, number of times run...). Enabling +statistics causes a slight reduction in performance on each program +run. The statistics can be seen using ``bpftool``. + += =================================== +0 Don't collect statistics (default). +1 Collect statistics. += =================================== + + cap_last_cap ============ @@ -1178,6 +1192,16 @@ NMI switch that most IA32 servers have fires unknown NMI up, for example. If a system hangs up, try pressing the NMI switch. +unprivileged_bpf_disabled +========================= + +Writing 1 to this entry will disable unprivileged calls to ``bpf()``; +once disabled, calling ``bpf()`` without ``CAP_SYS_ADMIN`` will return +``-EPERM``. + +Once set, this can't be cleared. + + watchdog ========