1 # SPDX-License-Identifier: GPL-2.0
3 # General architecture dependent options
20 tristate "OProfile system profiling"
22 depends on HAVE_OPROFILE
24 select RING_BUFFER_ALLOW_SWAP
26 OProfile is a profiling system capable of profiling the
27 whole system, include the kernel, kernel modules, libraries,
32 config OPROFILE_EVENT_MULTIPLEX
33 bool "OProfile multiplexing support (EXPERIMENTAL)"
35 depends on OPROFILE && X86
37 The number of hardware counters is limited. The multiplexing
38 feature enables OProfile to gather more events than counters
39 are provided by the hardware. This is realized by switching
40 between events at a user specified time interval.
47 config OPROFILE_NMI_TIMER
49 depends on PERF_EVENTS && HAVE_PERF_EVENTS_NMI && !PPC64
54 depends on HAVE_KPROBES
57 Kprobes allows you to trap at almost any kernel address and
58 execute a callback function. register_kprobe() establishes
59 a probepoint and specifies the callback. Kprobes is useful
60 for kernel debugging, non-intrusive instrumentation and testing.
64 bool "Optimize very unlikely/likely branches"
65 depends on HAVE_ARCH_JUMP_LABEL
67 This option enables a transparent branch optimization that
68 makes certain almost-always-true or almost-always-false branch
69 conditions even cheaper to execute within the kernel.
71 Certain performance-sensitive kernel code, such as trace points,
72 scheduler functionality, networking code and KVM have such
73 branches and include support for this optimization technique.
75 If it is detected that the compiler has support for "asm goto",
76 the kernel will compile such branches with just a nop
77 instruction. When the condition flag is toggled to true, the
78 nop will be converted to a jump instruction to execute the
79 conditional block of instructions.
81 This technique lowers overhead and stress on the branch prediction
82 of the processor and generally makes the kernel faster. The update
83 of the condition is slower, but those are always very rare.
85 ( On 32-bit x86, the necessary options added to the compiler
86 flags may increase the size of the kernel slightly. )
88 config STATIC_KEYS_SELFTEST
89 bool "Static key selftest"
92 Boot time self-test of the branch patching code.
96 depends on KPROBES && HAVE_OPTPROBES
97 select TASKS_RCU if PREEMPT
99 config KPROBES_ON_FTRACE
101 depends on KPROBES && HAVE_KPROBES_ON_FTRACE
102 depends on DYNAMIC_FTRACE_WITH_REGS
104 If function tracer is enabled and the arch supports full
105 passing of pt_regs to function tracing, then kprobes can
106 optimize on top of function tracing.
110 depends on ARCH_SUPPORTS_UPROBES
112 Uprobes is the user-space counterpart to kprobes: they
113 enable instrumentation applications (such as 'perf probe')
114 to establish unintrusive probes in user-space binaries and
115 libraries, by executing handler functions when the probes
116 are hit by user-space applications.
118 ( These probes come in the form of single-byte breakpoints,
119 managed by the kernel and kept transparent to the probed
122 config HAVE_64BIT_ALIGNED_ACCESS
123 def_bool 64BIT && !HAVE_EFFICIENT_UNALIGNED_ACCESS
125 Some architectures require 64 bit accesses to be 64 bit
126 aligned, which also requires structs containing 64 bit values
127 to be 64 bit aligned too. This includes some 32 bit
128 architectures which can do 64 bit accesses, as well as 64 bit
129 architectures without unaligned access.
131 This symbol should be selected by an architecture if 64 bit
132 accesses are required to be 64 bit aligned in this way even
133 though it is not a 64 bit architecture.
135 See Documentation/unaligned-memory-access.txt for more
136 information on the topic of unaligned memory accesses.
138 config HAVE_EFFICIENT_UNALIGNED_ACCESS
141 Some architectures are unable to perform unaligned accesses
142 without the use of get_unaligned/put_unaligned. Others are
143 unable to perform such accesses efficiently (e.g. trap on
144 unaligned access and require fixing it up in the exception
147 This symbol should be selected by an architecture if it can
148 perform unaligned accesses efficiently to allow different
149 code paths to be selected for these cases. Some network
150 drivers, for example, could opt to not fix up alignment
151 problems with received packets if doing so would not help
154 See Documentation/unaligned-memory-access.txt for more
155 information on the topic of unaligned memory accesses.
157 config ARCH_USE_BUILTIN_BSWAP
160 Modern versions of GCC (since 4.4) have builtin functions
161 for handling byte-swapping. Using these, instead of the old
162 inline assembler that the architecture code provides in the
163 __arch_bswapXX() macros, allows the compiler to see what's
164 happening and offers more opportunity for optimisation. In
165 particular, the compiler will be able to combine the byteswap
166 with a nearby load or store and use load-and-swap or
167 store-and-swap instructions if the architecture has them. It
168 should almost *never* result in code which is worse than the
169 hand-coded assembler in <asm/swab.h>. But just in case it
170 does, the use of the builtins is optional.
172 Any architecture with load-and-swap or store-and-swap
173 instructions should set this. And it shouldn't hurt to set it
174 on architectures that don't have such instructions.
178 depends on KPROBES && HAVE_KRETPROBES
180 config USER_RETURN_NOTIFIER
182 depends on HAVE_USER_RETURN_NOTIFIER
184 Provide a kernel-internal notification when a cpu is about to
187 config HAVE_IOREMAP_PROT
193 config HAVE_KRETPROBES
196 config HAVE_OPTPROBES
199 config HAVE_KPROBES_ON_FTRACE
202 config HAVE_FUNCTION_ERROR_INJECTION
209 # An arch should select this if it provides all these things:
211 # task_pt_regs() in asm/processor.h or asm/ptrace.h
212 # arch_has_single_step() if there is hardware single-step support
213 # arch_has_block_step() if there is hardware block-step support
214 # asm/syscall.h supplying asm-generic/syscall.h interface
215 # linux/regset.h user_regset interfaces
216 # CORE_DUMP_USE_REGSET #define'd in linux/elf.h
217 # TIF_SYSCALL_TRACE calls tracehook_report_syscall_{entry,exit}
218 # TIF_NOTIFY_RESUME calls tracehook_notify_resume()
219 # signal delivery calls tracehook_signal_handler()
221 config HAVE_ARCH_TRACEHOOK
224 config HAVE_DMA_CONTIGUOUS
227 config GENERIC_SMP_IDLE_THREAD
230 config GENERIC_IDLE_POLL_SETUP
233 config ARCH_HAS_FORTIFY_SOURCE
236 An architecture should select this when it can successfully
237 build and run with CONFIG_FORTIFY_SOURCE.
239 # Select if arch has all set_memory_ro/rw/x/nx() functions in asm/cacheflush.h
240 config ARCH_HAS_SET_MEMORY
243 # Select if arch init_task must go in the __init_task_data section
244 config ARCH_TASK_STRUCT_ON_STACK
247 # Select if arch has its private alloc_task_struct() function
248 config ARCH_TASK_STRUCT_ALLOCATOR
251 config HAVE_ARCH_THREAD_STRUCT_WHITELIST
253 depends on !ARCH_TASK_STRUCT_ALLOCATOR
255 An architecture should select this to provide hardened usercopy
256 knowledge about what region of the thread_struct should be
257 whitelisted for copying to userspace. Normally this is only the
258 FPU registers. Specifically, arch_thread_struct_whitelist()
259 should be implemented. Without this, the entire thread_struct
260 field in task_struct will be left whitelisted.
262 # Select if arch has its private alloc_thread_stack() function
263 config ARCH_THREAD_STACK_ALLOCATOR
266 # Select if arch wants to size task_struct dynamically via arch_task_struct_size:
267 config ARCH_WANTS_DYNAMIC_TASK_STRUCT
270 config HAVE_REGS_AND_STACK_ACCESS_API
273 This symbol should be selected by an architecure if it supports
274 the API needed to access registers and stack entries from pt_regs,
275 declared in asm/ptrace.h
276 For example the kprobes-based event tracer needs this API.
280 depends on HAVE_REGS_AND_STACK_ACCESS_API
282 This symbol should be selected by an architecture if it
283 supports an implementation of restartable sequences.
288 The <linux/clk.h> calls support software clock gating and
289 thus are a key power management tool on many systems.
291 config HAVE_HW_BREAKPOINT
293 depends on PERF_EVENTS
295 config HAVE_MIXED_BREAKPOINTS_REGS
297 depends on HAVE_HW_BREAKPOINT
299 Depending on the arch implementation of hardware breakpoints,
300 some of them have separate registers for data and instruction
301 breakpoints addresses, others have mixed registers to store
302 them but define the access type in a control register.
303 Select this option if your arch implements breakpoints under the
306 config HAVE_USER_RETURN_NOTIFIER
309 config HAVE_PERF_EVENTS_NMI
312 System hardware can generate an NMI using the perf event
313 subsystem. Also has support for calculating CPU cycle events
314 to determine how many clock cycles in a given period.
316 config HAVE_HARDLOCKUP_DETECTOR_PERF
318 depends on HAVE_PERF_EVENTS_NMI
320 The arch chooses to use the generic perf-NMI-based hardlockup
321 detector. Must define HAVE_PERF_EVENTS_NMI.
323 config HAVE_NMI_WATCHDOG
327 The arch provides a low level NMI watchdog. It provides
328 asm/nmi.h, and defines its own arch_touch_nmi_watchdog().
330 config HAVE_HARDLOCKUP_DETECTOR_ARCH
332 select HAVE_NMI_WATCHDOG
334 The arch chooses to provide its own hardlockup detector, which is
335 a superset of the HAVE_NMI_WATCHDOG. It also conforms to config
336 interfaces and parameters provided by hardlockup detector subsystem.
338 config HAVE_PERF_REGS
341 Support selective register dumps for perf events. This includes
342 bit-mapping of each registers and a unique architecture id.
344 config HAVE_PERF_USER_STACK_DUMP
347 Support user stack dumps for perf event samples. This needs
348 access to the user stack pointer which is not unified across
351 config HAVE_ARCH_JUMP_LABEL
354 config HAVE_RCU_TABLE_FREE
357 config ARCH_HAVE_NMI_SAFE_CMPXCHG
360 config HAVE_ALIGNED_STRUCT_PAGE
363 This makes sure that struct pages are double word aligned and that
364 e.g. the SLUB allocator can perform double word atomic operations
365 on a struct page for better performance. However selecting this
366 might increase the size of a struct page by a word.
368 config HAVE_CMPXCHG_LOCAL
371 config HAVE_CMPXCHG_DOUBLE
374 config ARCH_WEAK_RELEASE_ACQUIRE
377 config ARCH_WANT_IPC_PARSE_VERSION
380 config ARCH_WANT_COMPAT_IPC_PARSE_VERSION
383 config ARCH_WANT_OLD_COMPAT_IPC
384 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
387 config HAVE_ARCH_SECCOMP_FILTER
390 An arch should select this symbol if it provides all of these things:
392 - syscall_get_arguments()
394 - syscall_set_return_value()
395 - SIGSYS siginfo_t support
396 - secure_computing is called from a ptrace_event()-safe context
397 - secure_computing return value is checked and a return value of -1
398 results in the system call being skipped immediately.
399 - seccomp syscall wired up
401 config SECCOMP_FILTER
403 depends on HAVE_ARCH_SECCOMP_FILTER && SECCOMP && NET
405 Enable tasks to build secure computing environments defined
406 in terms of Berkeley Packet Filter programs which implement
407 task-defined system call filtering polices.
409 See Documentation/userspace-api/seccomp_filter.rst for details.
411 config HAVE_STACKPROTECTOR
414 An arch should select this symbol if:
415 - it has implemented a stack canary (e.g. __stack_chk_guard)
417 config CC_HAS_STACKPROTECTOR_NONE
418 def_bool $(cc-option,-fno-stack-protector)
420 config STACKPROTECTOR
421 bool "Stack Protector buffer overflow detection"
422 depends on HAVE_STACKPROTECTOR
423 depends on $(cc-option,-fstack-protector)
426 This option turns on the "stack-protector" GCC feature. This
427 feature puts, at the beginning of functions, a canary value on
428 the stack just before the return address, and validates
429 the value just before actually returning. Stack based buffer
430 overflows (that need to overwrite this return address) now also
431 overwrite the canary, which gets detected and the attack is then
432 neutralized via a kernel panic.
434 Functions will have the stack-protector canary logic added if they
435 have an 8-byte or larger character array on the stack.
437 This feature requires gcc version 4.2 or above, or a distribution
438 gcc with the feature backported ("-fstack-protector").
440 On an x86 "defconfig" build, this feature adds canary checks to
441 about 3% of all kernel functions, which increases kernel code size
444 config STACKPROTECTOR_STRONG
445 bool "Strong Stack Protector"
446 depends on STACKPROTECTOR
447 depends on $(cc-option,-fstack-protector-strong)
450 Functions will have the stack-protector canary logic added in any
451 of the following conditions:
453 - local variable's address used as part of the right hand side of an
454 assignment or function argument
455 - local variable is an array (or union containing an array),
456 regardless of array type or length
457 - uses register local variables
459 This feature requires gcc version 4.9 or above, or a distribution
460 gcc with the feature backported ("-fstack-protector-strong").
462 On an x86 "defconfig" build, this feature adds canary checks to
463 about 20% of all kernel functions, which increases the kernel code
466 config HAVE_ARCH_WITHIN_STACK_FRAMES
469 An architecture should select this if it can walk the kernel stack
470 frames to determine if an object is part of either the arguments
471 or local variables (i.e. that it excludes saved return addresses,
472 and similar) by implementing an inline arch_within_stack_frames(),
473 which is used by CONFIG_HARDENED_USERCOPY.
475 config HAVE_CONTEXT_TRACKING
478 Provide kernel/user boundaries probes necessary for subsystems
479 that need it, such as userspace RCU extended quiescent state.
480 Syscalls need to be wrapped inside user_exit()-user_enter() through
481 the slow path using TIF_NOHZ flag. Exceptions handlers must be
482 wrapped as well. Irqs are already protected inside
483 rcu_irq_enter/rcu_irq_exit() but preemption or signal handling on
484 irq exit still need to be protected.
486 config HAVE_VIRT_CPU_ACCOUNTING
489 config ARCH_HAS_SCALED_CPUTIME
492 config HAVE_VIRT_CPU_ACCOUNTING_GEN
496 With VIRT_CPU_ACCOUNTING_GEN, cputime_t becomes 64-bit.
497 Before enabling this option, arch code must be audited
498 to ensure there are no races in concurrent read/write of
499 cputime_t. For example, reading/writing 64-bit cputime_t on
500 some 32-bit arches may require multiple accesses, so proper
501 locking is needed to protect against concurrent accesses.
504 config HAVE_IRQ_TIME_ACCOUNTING
507 Archs need to ensure they use a high enough resolution clock to
508 support irq time accounting and then call enable_sched_clock_irqtime().
510 config HAVE_ARCH_TRANSPARENT_HUGEPAGE
513 config HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
516 config HAVE_ARCH_HUGE_VMAP
519 config HAVE_ARCH_SOFT_DIRTY
522 config HAVE_MOD_ARCH_SPECIFIC
525 The arch uses struct mod_arch_specific to store data. Many arches
526 just need a simple module loader without arch specific data - those
527 should not enable this.
529 config MODULES_USE_ELF_RELA
532 Modules only use ELF RELA relocations. Modules with ELF REL
533 relocations will give an error.
535 config MODULES_USE_ELF_REL
538 Modules only use ELF REL relocations. Modules with ELF RELA
539 relocations will give an error.
541 config HAVE_IRQ_EXIT_ON_IRQ_STACK
544 Architecture doesn't only execute the irq handler on the irq stack
545 but also irq_exit(). This way we can process softirqs on this irq
546 stack instead of switching to a new one when we call __do_softirq()
547 in the end of an hardirq.
548 This spares a stack switch and improves cache usage on softirq
551 config PGTABLE_LEVELS
555 config ARCH_HAS_ELF_RANDOMIZE
558 An architecture supports choosing randomized locations for
559 stack, mmap, brk, and ET_DYN. Defined functions:
561 - arch_randomize_brk()
563 config HAVE_ARCH_MMAP_RND_BITS
566 An arch should select this symbol if it supports setting a variable
567 number of bits for use in establishing the base address for mmap
568 allocations, has MMU enabled and provides values for both:
569 - ARCH_MMAP_RND_BITS_MIN
570 - ARCH_MMAP_RND_BITS_MAX
572 config HAVE_EXIT_THREAD
575 An architecture implements exit_thread.
577 config ARCH_MMAP_RND_BITS_MIN
580 config ARCH_MMAP_RND_BITS_MAX
583 config ARCH_MMAP_RND_BITS_DEFAULT
586 config ARCH_MMAP_RND_BITS
587 int "Number of bits to use for ASLR of mmap base address" if EXPERT
588 range ARCH_MMAP_RND_BITS_MIN ARCH_MMAP_RND_BITS_MAX
589 default ARCH_MMAP_RND_BITS_DEFAULT if ARCH_MMAP_RND_BITS_DEFAULT
590 default ARCH_MMAP_RND_BITS_MIN
591 depends on HAVE_ARCH_MMAP_RND_BITS
593 This value can be used to select the number of bits to use to
594 determine the random offset to the base address of vma regions
595 resulting from mmap allocations. This value will be bounded
596 by the architecture's minimum and maximum supported values.
598 This value can be changed after boot using the
599 /proc/sys/vm/mmap_rnd_bits tunable
601 config HAVE_ARCH_MMAP_RND_COMPAT_BITS
604 An arch should select this symbol if it supports running applications
605 in compatibility mode, supports setting a variable number of bits for
606 use in establishing the base address for mmap allocations, has MMU
607 enabled and provides values for both:
608 - ARCH_MMAP_RND_COMPAT_BITS_MIN
609 - ARCH_MMAP_RND_COMPAT_BITS_MAX
611 config ARCH_MMAP_RND_COMPAT_BITS_MIN
614 config ARCH_MMAP_RND_COMPAT_BITS_MAX
617 config ARCH_MMAP_RND_COMPAT_BITS_DEFAULT
620 config ARCH_MMAP_RND_COMPAT_BITS
621 int "Number of bits to use for ASLR of mmap base address for compatible applications" if EXPERT
622 range ARCH_MMAP_RND_COMPAT_BITS_MIN ARCH_MMAP_RND_COMPAT_BITS_MAX
623 default ARCH_MMAP_RND_COMPAT_BITS_DEFAULT if ARCH_MMAP_RND_COMPAT_BITS_DEFAULT
624 default ARCH_MMAP_RND_COMPAT_BITS_MIN
625 depends on HAVE_ARCH_MMAP_RND_COMPAT_BITS
627 This value can be used to select the number of bits to use to
628 determine the random offset to the base address of vma regions
629 resulting from mmap allocations for compatible applications This
630 value will be bounded by the architecture's minimum and maximum
633 This value can be changed after boot using the
634 /proc/sys/vm/mmap_rnd_compat_bits tunable
636 config HAVE_ARCH_COMPAT_MMAP_BASES
639 This allows 64bit applications to invoke 32-bit mmap() syscall
640 and vice-versa 32-bit applications to call 64-bit mmap().
641 Required for applications doing different bitness syscalls.
643 config HAVE_COPY_THREAD_TLS
646 Architecture provides copy_thread_tls to accept tls argument via
647 normal C parameter passing, rather than extracting the syscall
648 argument from pt_regs.
650 config HAVE_STACK_VALIDATION
653 Architecture supports the 'objtool check' host tool command, which
654 performs compile-time stack metadata validation.
656 config HAVE_RELIABLE_STACKTRACE
659 Architecture has a save_stack_trace_tsk_reliable() function which
660 only returns a stack trace if it can guarantee the trace is reliable.
662 config HAVE_ARCH_HASH
666 If this is set, the architecture provides an <asm/hash.h>
667 file which provides platform-specific implementations of some
668 functions in <linux/hash.h> or fs/namei.c.
676 config CLONE_BACKWARDS
679 Architecture has tls passed as the 4th argument of clone(2),
682 config CLONE_BACKWARDS2
685 Architecture has the first two arguments of clone(2) swapped.
687 config CLONE_BACKWARDS3
690 Architecture has tls passed as the 3rd argument of clone(2),
693 config ODD_RT_SIGACTION
696 Architecture has unusual rt_sigaction(2) arguments
698 config OLD_SIGSUSPEND
701 Architecture has old sigsuspend(2) syscall, of one-argument variety
703 config OLD_SIGSUSPEND3
706 Even weirder antique ABI - three-argument sigsuspend(2)
711 Architecture has old sigaction(2) syscall. Nope, not the same
712 as OLD_SIGSUSPEND | OLD_SIGSUSPEND3 - alpha has sigsuspend(2),
713 but fairly different variant of sigaction(2), thanks to OSF/1
716 config COMPAT_OLD_SIGACTION
720 def_bool ARCH_HAS_64BIT_TIME
722 This should be selected by all architectures that need to support
723 new system calls with a 64-bit time_t. This is relevant on all 32-bit
724 architectures, and 64-bit architectures as part of compat syscall
727 config COMPAT_32BIT_TIME
728 def_bool (!64BIT && 64BIT_TIME) || COMPAT
730 This enables 32 bit time_t support in addition to 64 bit time_t support.
731 This is relevant on all 32-bit architectures, and 64-bit architectures
732 as part of compat syscall handling.
734 config ARCH_NO_COHERENT_DMA_MMAP
737 config CPU_NO_EFFICIENT_FFS
740 config HAVE_ARCH_VMAP_STACK
743 An arch should select this symbol if it can support kernel stacks
744 in vmalloc space. This means:
746 - vmalloc space must be large enough to hold many kernel stacks.
747 This may rule out many 32-bit architectures.
749 - Stacks in vmalloc space need to work reliably. For example, if
750 vmap page tables are created on demand, either this mechanism
751 needs to work while the stack points to a virtual address with
752 unpopulated page tables or arch code (switch_to() and switch_mm(),
753 most likely) needs to ensure that the stack's page table entries
754 are populated before running on a possibly unpopulated stack.
756 - If the stack overflows into a guard page, something reasonable
757 should happen. The definition of "reasonable" is flexible, but
758 instantly rebooting without logging anything would be unfriendly.
762 bool "Use a virtually-mapped stack"
763 depends on HAVE_ARCH_VMAP_STACK && !KASAN
765 Enable this if you want the use virtually-mapped kernel stacks
766 with guard pages. This causes kernel stack overflows to be
767 caught immediately rather than causing difficult-to-diagnose
770 This is presently incompatible with KASAN because KASAN expects
771 the stack to map directly to the KASAN shadow map using a formula
772 that is incorrect if the stack is in vmalloc space.
774 config ARCH_OPTIONAL_KERNEL_RWX
777 config ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
780 config ARCH_HAS_STRICT_KERNEL_RWX
783 config STRICT_KERNEL_RWX
784 bool "Make kernel text and rodata read-only" if ARCH_OPTIONAL_KERNEL_RWX
785 depends on ARCH_HAS_STRICT_KERNEL_RWX
786 default !ARCH_OPTIONAL_KERNEL_RWX || ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
788 If this is set, kernel text and rodata memory will be made read-only,
789 and non-text memory will be made non-executable. This provides
790 protection against certain security exploits (e.g. executing the heap
793 These features are considered standard security practice these days.
794 You should say Y here in almost all cases.
796 config ARCH_HAS_STRICT_MODULE_RWX
799 config STRICT_MODULE_RWX
800 bool "Set loadable kernel module data as NX and text as RO" if ARCH_OPTIONAL_KERNEL_RWX
801 depends on ARCH_HAS_STRICT_MODULE_RWX && MODULES
802 default !ARCH_OPTIONAL_KERNEL_RWX || ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
804 If this is set, module text and rodata memory will be made read-only,
805 and non-text memory will be made non-executable. This provides
806 protection against certain security exploits (e.g. writing to text)
808 # select if the architecture provides an asm/dma-direct.h header
809 config ARCH_HAS_PHYS_TO_DMA
812 config ARCH_HAS_REFCOUNT
815 An architecture selects this when it has implemented refcount_t
816 using open coded assembly primitives that provide an optimized
817 refcount_t implementation, possibly at the expense of some full
818 refcount state checks of CONFIG_REFCOUNT_FULL=y.
820 The refcount overflow check behavior, however, must be retained.
821 Catching overflows is the primary security concern for protecting
822 against bugs in reference counts.
825 bool "Perform full reference count validation at the expense of speed"
827 Enabling this switches the refcounting infrastructure from a fast
828 unchecked atomic_t implementation to a fully state checked
829 implementation, which can be (slightly) slower but provides protections
830 against various use-after-free conditions that can be used in
831 security flaw exploits.
833 source "kernel/gcov/Kconfig"
835 source "scripts/gcc-plugins/Kconfig"