# SPDX-License-Identifier: GPL-2.0
#
# General architecture dependent options
#
#
# Note: arch/$(SRCARCH)/Kconfig needs to be included first so that it can
# override the default values in this file.
#
source "arch/$(SRCARCH)/Kconfig"
config ARCH_CONFIGURES_CPU_MITIGATIONS
bool
if !ARCH_CONFIGURES_CPU_MITIGATIONS
config CPU_MITIGATIONS
def_bool y
endif
menu "General architecture-dependent options"
config ARCH_HAS_SUBPAGE_FAULTS
bool
help
Select if the architecture can check permissions at sub-page
granularity (e.g. arm64 MTE). The probe_user_*() functions
must be implemented.
config HOTPLUG_SMT
bool
config SMT_NUM_THREADS_DYNAMIC
bool
# Selected by HOTPLUG_CORE_SYNC_DEAD or HOTPLUG_CORE_SYNC_FULL
config HOTPLUG_CORE_SYNC
bool
# Basic CPU dead synchronization selected by architecture
config HOTPLUG_CORE_SYNC_DEAD
bool
select HOTPLUG_CORE_SYNC
# Full CPU synchronization with alive state selected by architecture
config HOTPLUG_CORE_SYNC_FULL
bool
select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
select HOTPLUG_CORE_SYNC
config HOTPLUG_SPLIT_STARTUP
bool
select HOTPLUG_CORE_SYNC_FULL
config HOTPLUG_PARALLEL
bool
select HOTPLUG_SPLIT_STARTUP
config GENERIC_ENTRY
bool
config KPROBES
bool "Kprobes"
depends on HAVE_KPROBES
select KALLSYMS
select EXECMEM
select NEED_TASKS_RCU
help
Kprobes allows you to trap at almost any kernel address and
execute a callback function. register_kprobe() establishes
a probepoint and specifies the callback. Kprobes is useful
for kernel debugging, non-intrusive instrumentation and testing.
If in doubt, say "N".
config JUMP_LABEL
bool "Optimize very unlikely/likely branches"
depends on HAVE_ARCH_JUMP_LABEL
select OBJTOOL if HAVE_JUMP_LABEL_HACK
help
This option enables a transparent branch optimization that
makes certain almost-always-true or almost-always-false branch
conditions even cheaper to execute within the kernel.
Certain performance-sensitive kernel code, such as trace points,
scheduler functionality, networking code and KVM have such
branches and include support for this optimization technique.
If it is detected that the compiler has support for "asm goto",
the kernel will compile such branches with just a nop
instruction. When the condition flag is toggled to true, the
nop will be converted to a jump instruction to execute the
conditional block of instructions.
This technique lowers overhead and stress on the branch prediction
of the processor and generally makes the kernel faster. The update
of the condition is slower, but those are always very rare.
( On 32-bit x86, the necessary options added to the compiler
flags may increase the size of the kernel slightly. )
config STATIC_KEYS_SELFTEST
bool "Static key selftest"
depends on JUMP_LABEL
help
Boot time self-test of the branch patching code.
config STATIC_CALL_SELFTEST
bool "Static call selftest"
depends on HAVE_STATIC_CALL
help
Boot time self-test of the call patching code.
config OPTPROBES
def_bool y
depends on KPROBES && HAVE_OPTPROBES
select NEED_TASKS_RCU
config KPROBES_ON_FTRACE
def_bool y
depends on KPROBES && HAVE_KPROBES_ON_FTRACE
depends on DYNAMIC_FTRACE_WITH_REGS
help
If function tracer is enabled and the arch supports full
passing of pt_regs to function tracing, then kprobes can
optimize on top of function tracing.
config UPROBES
def_bool n
depends on ARCH_SUPPORTS_UPROBES
help
Uprobes is the user-space counterpart to kpr
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