Kconfig - OpenGrok cross reference for /OK3568_Linux_fs/kernel/arch/Kconfig

1 # SPDX-License-Identifier: GPL-2.0
12 menu "General architecture-dependent options"
77 	  for kernel debugging, non-intrusive instrumentation and testing.
86 	 makes certain almost-always-true or almost-always-false branch
89 	 Certain performance-sensitive kernel code, such as trace points,
103 	 ( On 32-bit x86, the necessary options added to the compiler
110 	  Boot time self-test of the branch patching code.
116 	  Boot time self-test of the call patching code.
136 	  Uprobes is the user-space counterpart to kprobes: they
137 	  enable instrumentation applications (such as 'perf probe')
138 	  to establish unintrusive probes in user-space binaries and
140 	  are hit by user-space applications.
142 	  ( These probes come in the form of single-byte breakpoints,
159 	  See Documentation/unaligned-memory-access.txt for more
178 	  See Documentation/core-api/unaligned-memory-access.rst for more
185 	 for handling byte-swapping. Using these, instead of the old
190 	 with a nearby load or store and use load-and-swap or
191 	 store-and-swap instructions if the architecture has them. It
193 	 hand-coded assembler in <asm/swab.h>.  But just in case it
196 	 Any architecture with load-and-swap or store-and-swap
208 	  Provide a kernel-internal notification when a cpu is about to
236 #	arch_has_single_step()	if there is hardware single-step support
237 #	arch_has_block_step()	if there is hardware block-step support
238 #	asm/syscall.h		supplying asm-generic/syscall.h interface
288 # to undo an in-place page table remap for uncached access.
324 	  All new 32-bit architectures should have 64-bit off_t type on
327 	  still support 32-bit off_t. This option is enabled for all such
334 	  <asm/asm-prototypes.h> to support the module versioning for symbols
343 	  For example the kprobes-based event tracer needs this API.
388 	  The arch chooses to use the generic perf-NMI-based hardlockup
410 	  bit-mapping of each registers and a unique architecture id.
447 	  shootdowns should enable this.
484 	  and compat syscalls if the asm-generic/seccomp.h defaults need adjustment:
485 	  - __NR_seccomp_read_32
486 	  - __NR_seccomp_write_32
487 	  - __NR_seccomp_exit_32
488 	  - __NR_seccomp_sigreturn_32
495 	  - all the requirements for HAVE_ARCH_SECCOMP
496 	  - syscall_get_arch()
497 	  - syscall_get_arguments()
498 	  - syscall_rollback()
499 	  - syscall_set_return_value()
500 	  - SIGSYS siginfo_t support
501 	  - secure_computing is called from a ptrace_event()-safe context
502 	  - secure_computing return value is checked and a return value of -1
504 	  - seccomp syscall wired up
507 	prompt "Enable seccomp to safely execute untrusted bytecode"
527 	  Enable tasks to build secure computing environments defined
529 	  task-defined system call filtering polices.
531 	  See Documentation/userspace-api/seccomp_filter.rst for details.
544 	  - it has implemented a stack canary (e.g. __stack_chk_guard)
549 	depends on $(cc-option,-fstack-protector)
552 	  This option turns on the "stack-protector" GCC feature. This
560 	  Functions will have the stack-protector canary logic added if they
561 	  have an 8-byte or larger character array on the stack.
564 	  gcc with the feature backported ("-fstack-protector").
573 	depends on $(cc-option,-fstack-protector-strong)
576 	  Functions will have the stack-protector canary logic added in any
579 	  - local variable's address used as part of the right hand side of an
581 	  - local variable is an array (or union containing an array),
583 	  - uses register local variables
586 	  gcc with the feature backported ("-fstack-protector-strong").
632 	  - compiling with Clang,
633 	  - compiling inline assembly with Clang's integrated assembler,
634 	  - and linking with LLD.
646 	depends on $(success,test $(LLVM) -eq 1)
647 	depends on $(success,test $(LLVM_IAS) -eq 1)
648 	depends on $(success,$(NM) --help | head -n 1 | grep -qi llvm)
649 	depends on $(success,$(AR) --help | head -n 1 | grep -qi llvm)
665 	  If unsure, select LTO_NONE. Note that LTO is very resource-intensive
680           allows the compiler to optimize the kernel globally. If you enable
715 	bool "Use CFI shadow to speed up cross-module checks"
719 	  If you select this option, the kernel builds a fast look-up table of
744 	  Syscalls need to be wrapped inside user_exit()-user_enter(), either
766 	  With VIRT_CPU_ACCOUNTING_GEN, cputime_t becomes 64-bit.
769 	  cputime_t. For example, reading/writing 64-bit cputime_t on
770 	  some 32-bit arches may require multiple accesses, so proper
811 	  just need a simple module loader without arch specific data - those
812 	  should not enable this.
845 	  - arch_mmap_rnd()
846 	  - arch_randomize_brk()
854 	  - ARCH_MMAP_RND_BITS_MIN
855 	  - ARCH_MMAP_RND_BITS_MAX
893 	  - ARCH_MMAP_RND_COMPAT_BITS_MIN
894 	  - ARCH_MMAP_RND_COMPAT_BITS_MAX
924 	  This allows 64bit applications to invoke 32-bit mmap() syscall
925 	  and vice-versa 32-bit applications to call 64-bit mmap().
929 # address by giving priority to top-down scheme only if the process
933 # - STACK_RND_MASK
943 	  performs compile-time stack metadata validation.
957 	  file which provides platform-specific implementations of some
967 # ABI hall of shame
994 	  Architecture has old sigsuspend(2) syscall, of one-argument variety
999 	  Even weirder antique ABI - three-argument sigsuspend(2)
1005 	  as OLD_SIGSUSPEND | OLD_SIGSUSPEND3 - alpha has sigsuspend(2),
1013 	bool "Provide system calls for 32-bit time_t"
1017 	  This is relevant on all 32-bit architectures, and 64-bit architectures
1035 	  - vmalloc space must be large enough to hold many kernel stacks.
1036 	    This may rule out many 32-bit architectures.
1038 	  - Stacks in vmalloc space need to work reliably.  For example, if
1045 	  - If the stack overflows into a guard page, something reasonable
1051 	bool "Use a virtually-mapped stack"
1055 	  Enable this if you want the use virtually-mapped kernel stacks
1057 	  caught immediately rather than causing difficult-to-diagnose
1074 	bool "Make kernel text and rodata read-only" if ARCH_OPTIONAL_KERNEL_RWX
1078 	  If this is set, kernel text and rodata memory will be made read-only,
1079 	  and non-text memory will be made non-executable. This provides
1094 	  If this is set, module text and rodata memory will be made read-only,
1095 	  and non-text memory will be made non-executable. This provides
1098 # select if the architecture provides an asm/dma-direct.h header
1107 	  linux/compiler-*.h in order to override macro definitions that those
1113 	  May be selected by an architecture if it supports place-relative
1114 	  32-bit relocations, both in the toolchain and in the module loader,
1127 	  Enable light-weight counting of various locking related events
1143 	  well as compatible NM and OBJCOPY utilities (llvm-nm and llvm-objcopy
1174 	  included, size-asserted, or discarded in the linker scripts. This is
1182 	   If a 32-bit architecture requires 64-bit arguments to be split into
1183 	   pairs of 32-bit arguments, select this option.
1187 source "scripts/gcc-plugins/Kconfig"