Lines Matching +full:processor +full:- +full:intensive
1 # SPDX-License-Identifier: GPL-2.0
12 menu "General architecture-dependent options"
30 Select if the architecture can check permissions at sub-page
50 for kernel debugging, non-intrusive instrumentation and testing.
59 makes certain almost-always-true or almost-always-false branch
62 Certain performance-sensitive kernel code, such as trace points,
73 of the processor and generally makes the kernel faster. The update
76 ( On 32-bit x86, the necessary options added to the compiler
83 Boot time self-test of the branch patching code.
89 Boot time self-test of the call patching code.
109 Uprobes is the user-space counterpart to kprobes: they
111 to establish unintrusive probes in user-space binaries and
113 are hit by user-space applications.
115 ( These probes come in the form of single-byte breakpoints,
132 See Documentation/core-api/unaligned-memory-access.rst for
151 See Documentation/core-api/unaligned-memory-access.rst for more
158 for handling byte-swapping. Using these, instead of the old
163 with a nearby load or store and use load-and-swap or
164 store-and-swap instructions if the architecture has them. It
166 hand-coded assembler in <asm/swab.h>. But just in case it
169 Any architecture with load-and-swap or store-and-swap
187 Provide a kernel-internal notification when a cpu is about to
231 # task_pt_regs() in asm/processor.h or asm/ptrace.h
232 # arch_has_single_step() if there is hardware single-step support
233 # arch_has_block_step() if there is hardware block-step support
234 # asm/syscall.h supplying asm-generic/syscall.h interface
283 # to undo an in-place page table remap for uncached access.
326 All new 32-bit architectures should have 64-bit off_t type on
329 still support 32-bit off_t. This option is enabled for all such
340 <asm/asm-prototypes.h> to support the module versioning for symbols
349 For example the kprobes-based event tracer needs this API.
400 The arch chooses to use the generic perf-NMI-based hardlockup
422 bit-mapping of each registers and a unique architecture id.
503 and compat syscalls if the asm-generic/seccomp.h defaults need adjustment:
504 - __NR_seccomp_read_32
505 - __NR_seccomp_write_32
506 - __NR_seccomp_exit_32
507 - __NR_seccomp_sigreturn_32
514 - all the requirements for HAVE_ARCH_SECCOMP
515 - syscall_get_arch()
516 - syscall_get_arguments()
517 - syscall_rollback()
518 - syscall_set_return_value()
519 - SIGSYS siginfo_t support
520 - secure_computing is called from a ptrace_event()-safe context
521 - secure_computing return value is checked and a return value of -1
523 - seccomp syscall wired up
524 - if !HAVE_SPARSE_SYSCALL_NR, have SECCOMP_ARCH_NATIVE,
551 task-defined system call filtering polices.
553 See Documentation/userspace-api/seccomp_filter.rst for details.
580 - it has implemented a stack canary (e.g. __stack_chk_guard)
585 depends on $(cc-option,-fstack-protector)
588 This option turns on the "stack-protector" GCC feature. This
596 Functions will have the stack-protector canary logic added if they
597 have an 8-byte or larger character array on the stack.
600 gcc with the feature backported ("-fstack-protector").
609 depends on $(cc-option,-fstack-protector-strong)
612 Functions will have the stack-protector canary logic added in any
615 - local variable's address used as part of the right hand side of an
617 - local variable is an array (or union containing an array),
619 - uses register local variables
622 gcc with the feature backported ("-fstack-protector-strong").
645 - Clang: https://clang.llvm.org/docs/ShadowCallStack.html
646 - GCC: https://gcc.gnu.org/onlinedocs/gcc/Instrumentation-Options.html#Instrumentation-Options
669 - compiling with Clang,
670 - compiling inline assembly with Clang's integrated assembler,
671 - and linking with LLD.
682 depends on $(success,$(NM) --help | head -n 1 | grep -qi llvm)
683 depends on $(success,$(AR) --help | head -n 1 | grep -qi llvm)
699 If unsure, select LTO_NONE. Note that LTO is very resource-intensive
745 Control-Flow Integrity (CFI) checking.
753 depends on $(cc-option,-fsanitize=kcfi)
755 This option enables Clang’s forward-edge Control Flow Integrity
789 Syscalls need to be wrapped inside user_exit()-user_enter(), either
805 - Critical entry code isn't preemptible (or better yet:
807 - No use of RCU read side critical sections, unless ct_nmi_enter()
809 - No use of instrumentation, unless instrumentation_begin() got
834 With VIRT_CPU_ACCOUNTING_GEN, cputime_t becomes 64-bit.
837 cputime_t. For example, reading/writing 64-bit cputime_t on
838 some 32-bit arches may require multiple accesses, so proper
869 # Archs that select this would be capable of PMD-sized vmaps (i.e.,
887 just need a simple module loader without arch specific data - those
943 - arch_mmap_rnd()
944 - arch_randomize_brk()
952 - ARCH_MMAP_RND_BITS_MIN
953 - ARCH_MMAP_RND_BITS_MAX
991 - ARCH_MMAP_RND_COMPAT_BITS_MIN
992 - ARCH_MMAP_RND_COMPAT_BITS_MAX
1022 This allows 64bit applications to invoke 32-bit mmap() syscall
1023 and vice-versa 32-bit applications to call 64-bit mmap().
1039 # address by giving priority to top-down scheme only if the process
1043 # - STACK_RND_MASK
1068 Architecture supports objtool compile-time frame pointer rule
1083 file which provides platform-specific implementations of some
1120 Architecture has old sigsuspend(2) syscall, of one-argument variety
1125 Even weirder antique ABI - three-argument sigsuspend(2)
1131 as OLD_SIGSUSPEND | OLD_SIGSUSPEND3 - alpha has sigsuspend(2),
1139 bool "Provide system calls for 32-bit time_t"
1143 This is relevant on all 32-bit architectures, and 64-bit architectures
1168 - vmalloc space must be large enough to hold many kernel stacks.
1169 This may rule out many 32-bit architectures.
1171 - Stacks in vmalloc space need to work reliably. For example, if
1178 - If the stack overflows into a guard page, something reasonable
1184 bool "Use a virtually-mapped stack"
1188 Enable this if you want the use virtually-mapped kernel stacks
1190 caught immediately rather than causing difficult-to-diagnose
1203 syscall exit. Careful removal of -fstack-protector-strong and
1204 -fstack-protector should also be applied to the entry code and
1218 cross-syscall address exposures.
1244 bool "Make kernel text and rodata read-only" if ARCH_OPTIONAL_KERNEL_RWX
1248 If this is set, kernel text and rodata memory will be made read-only,
1249 and non-text memory will be made non-executable. This provides
1264 If this is set, module text and rodata memory will be made read-only,
1265 and non-text memory will be made non-executable. This provides
1268 # select if the architecture provides an asm/dma-direct.h header
1277 linux/compiler-*.h in order to override macro definitions that those
1283 May be selected by an architecture if it supports place-relative
1284 32-bit relocations, both in the toolchain and in the module loader,
1297 Enable light-weight counting of various locking related events
1313 well as compatible NM and OBJCOPY utilities (llvm-nm and llvm-objcopy
1371 static key. This should have slightly lower overhead than non-inline
1383 included, size-asserted, or discarded in the linker scripts. This is
1400 If a 32-bit architecture requires 64-bit arguments to be split into
1401 pairs of 32-bit arguments, select this option.
1423 accessed bit in non-leaf PMD entries when using them as part of linear
1429 source "scripts/gcc-plugins/Kconfig"