bpf: add boot parameters for sysctl knobs

Some BPF sysctl knobs affect the loading of BPF programs, and during system boot/init stages these sysctls are not yet configured. A concrete example is systemd, that has implemented loading of BPF programs.

Thus, to allow controlling these setting at early boot, this patch set adds the ability to change the default setting of these sysctl knobs as well as option to override them via a boot-time kernel parameter (in order to avoid rebuilding kernel each time a need of changing these defaults arises).

The sysctl knobs in question are kernel.unprivileged_bpf_disable, net.core.bpf_jit_harden, and net.core.bpf_jit_kallsyms.

Eugene Syromiatnikov (3):
bpf: add ability to configure unprivileged BPF via boot-time parameter
bpf: add ability to configure BPF JIT hardening via boot-time
parameter
bpf: add ability to configure BPF JIT kallsyms export at the boot time

 Documentation/admin-guide/kernel-parameters.txt | 28 ++++++++
 init/Kconfig                                    | 90 +++++++++++++++++++++++++
 kernel/bpf/core.c                               | 31 +++++++++
 kernel/bpf/syscall.c                            | 16 +++++
 4 files changed, 165 insertions(+)

2.1.4