2026-01-29 22:25:33 +08:00

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# SPDX-License-Identifier: GPL-2.0-only
# BPF interpreter that, for example, classic socket filters depend on.
config BPF
bool
# Used by archs to tell that they support BPF JIT compiler plus which
# flavour. Only one of the two can be selected for a specific arch since
# eBPF JIT supersedes the cBPF JIT.
# Classic BPF JIT (cBPF)
config HAVE_CBPF_JIT
bool
# Extended BPF JIT (eBPF)
config HAVE_EBPF_JIT
bool
# Used by archs to tell that they want the BPF JIT compiler enabled by
# default for kernels that were compiled with BPF JIT support.
config ARCH_WANT_DEFAULT_BPF_JIT
bool
menu "BPF subsystem"
config BPF_SYSCALL
bool "Enable bpf() system call"
select BPF
select IRQ_WORK
select TASKS_RCU if PREEMPTION
select TASKS_TRACE_RCU
select BINARY_PRINTF
select NET_SOCK_MSG if NET
select NET_XGRESS if NET
select PAGE_POOL if NET
default n
help
Enable the bpf() system call that allows to manipulate BPF programs
and maps via file descriptors.
config BPF_JIT
bool "Enable BPF Just In Time compiler"
depends on BPF
depends on HAVE_CBPF_JIT || HAVE_EBPF_JIT
depends on MODULES
help
BPF programs are normally handled by a BPF interpreter. This option
allows the kernel to generate native code when a program is loaded
into the kernel. This will significantly speed-up processing of BPF
programs.
Note, an admin should enable this feature changing:
/proc/sys/net/core/bpf_jit_enable
/proc/sys/net/core/bpf_jit_harden (optional)
/proc/sys/net/core/bpf_jit_kallsyms (optional)
config BPF_JIT_ALWAYS_ON
bool "Permanently enable BPF JIT and remove BPF interpreter"
depends on BPF_SYSCALL && HAVE_EBPF_JIT && BPF_JIT
help
Enables BPF JIT and removes BPF interpreter to avoid speculative
execution of BPF instructions by the interpreter.
When CONFIG_BPF_JIT_ALWAYS_ON is enabled, /proc/sys/net/core/bpf_jit_enable
is permanently set to 1 and setting any other value than that will
return failure.
config BPF_JIT_DEFAULT_ON
def_bool ARCH_WANT_DEFAULT_BPF_JIT || BPF_JIT_ALWAYS_ON
depends on HAVE_EBPF_JIT && BPF_JIT
config BPF_UNPRIV_DEFAULT_OFF
bool "Disable unprivileged BPF by default"
default y
depends on BPF_SYSCALL
help
Disables unprivileged BPF by default by setting the corresponding
/proc/sys/kernel/unprivileged_bpf_disabled knob to 2. An admin can
still reenable it by setting it to 0 later on, or permanently
disable it by setting it to 1 (from which no other transition to
0 is possible anymore).
Unprivileged BPF could be used to exploit certain potential
speculative execution side-channel vulnerabilities on unmitigated
affected hardware.
If you are unsure how to answer this question, answer Y.
source "kernel/bpf/preload/Kconfig"
config BPF_LSM
bool "Enable BPF LSM Instrumentation"
depends on BPF_EVENTS
depends on BPF_SYSCALL
depends on SECURITY
depends on BPF_JIT
help
Enables instrumentation of the security hooks with BPF programs for
implementing dynamic MAC and Audit Policies.
If you are unsure how to answer this question, answer N.
config BPF_SCHED
bool "Sched Instrumentation with BPF"
depends on BPF_EVENTS
depends on BPF_SYSCALL
depends on BPF_JIT
help
Enables instrumentation of the sched hooks with eBPF programs for
implementing dynamic scheduling policies. When CONFIG_BPF_SCHED
is enabled, privileged BPF could be used to expand scheduling
capabilities.
If you are unsure how to answer this question, answer N.
endmenu # "BPF subsystem"