Lines Matching +full:segment +full:- +full:no +full:- +full:remap
1 # SPDX-License-Identifier: GPL-2.0
20 menu "General architecture-dependent options"
25 Select if the architecture can check permissions at sub-page
71 for kernel debugging, non-intrusive instrumentation and testing.
80 makes certain almost-always-true or almost-always-false branch
83 Certain performance-sensitive kernel code, such as trace points,
97 ( On 32-bit x86, the necessary options added to the compiler
104 Boot time self-test of the branch patching code.
110 Boot time self-test of the call patching code.
130 Uprobes is the user-space counterpart to kprobes: they
132 to establish unintrusive probes in user-space binaries and
134 are hit by user-space applications.
136 ( These probes come in the form of single-byte breakpoints,
153 See Documentation/core-api/unaligned-memory-access.rst for
172 See Documentation/core-api/unaligned-memory-access.rst for more
179 for handling byte-swapping. Using these, instead of the old
184 with a nearby load or store and use load-and-swap or
185 store-and-swap instructions if the architecture has them. It
187 hand-coded assembler in <asm/swab.h>. But just in case it
190 Any architecture with load-and-swap or store-and-swap
208 Provide a kernel-internal notification when a cpu is about to
253 # arch_has_single_step() if there is hardware single-step support
254 # arch_has_block_step() if there is hardware block-step support
255 # asm/syscall.h supplying asm-generic/syscall.h interface
296 # either provide an uncached segment alias for a DMA allocation, or
297 # to remap the page tables in place.
304 # to undo an in-place page table remap for uncached access.
350 All new 32-bit architectures should have 64-bit off_t type on
353 still support 32-bit off_t. This option is enabled for all such
364 <asm/asm-prototypes.h> to support the module versioning for symbols
373 For example the kprobes-based event tracer needs this API.
424 The arch chooses to use the generic perf-NMI-based hardlockup
440 bit-mapping of each registers and a unique architecture id.
489 # multi-threaded application), by reducing contention on the mm refcount.
491 # This can be disabled if the architecture ensures no CPUs are using an mm as a
498 # the lazy tlb reference of a kthread's ->active_mm (non-arch code has been
504 # This option allows MMU_LAZY_TLB_REFCOUNT=n. It ensures no CPUs are using an
512 # - At the time of the final mmdrop of the mm, ensure mm_cpumask(mm) contains
514 # - It must meet the requirements for MMU_LAZY_TLB_REFCOUNT=n (see above).
556 and compat syscalls if the asm-generic/seccomp.h defaults need adjustment:
557 - __NR_seccomp_read_32
558 - __NR_seccomp_write_32
559 - __NR_seccomp_exit_32
560 - __NR_seccomp_sigreturn_32
567 - all the requirements for HAVE_ARCH_SECCOMP
568 - syscall_get_arch()
569 - syscall_get_arguments()
570 - syscall_rollback()
571 - syscall_set_return_value()
572 - SIGSYS siginfo_t support
573 - secure_computing is called from a ptrace_event()-safe context
574 - secure_computing return value is checked and a return value of -1
576 - seccomp syscall wired up
577 - if !HAVE_SPARSE_SYSCALL_NR, have SECCOMP_ARCH_NATIVE,
604 task-defined system call filtering polices.
606 See Documentation/userspace-api/seccomp_filter.rst for details.
633 - it has implemented a stack canary (e.g. __stack_chk_guard)
638 depends on $(cc-option,-fstack-protector)
641 This option turns on the "stack-protector" GCC feature. This
649 Functions will have the stack-protector canary logic added if they
650 have an 8-byte or larger character array on the stack.
653 gcc with the feature backported ("-fstack-protector").
662 depends on $(cc-option,-fstack-protector-strong)
665 Functions will have the stack-protector canary logic added in any
668 - local variable's address used as part of the right hand side of an
670 - local variable is an array (or union containing an array),
672 - uses register local variables
675 gcc with the feature backported ("-fstack-protector-strong").
699 - Clang: https://clang.llvm.org/docs/ShadowCallStack.html
700 - GCC: https://gcc.gnu.org/onlinedocs/gcc/Instrumentation-Options.html#Instrumentation-Options
730 - compiling with Clang,
731 - compiling inline assembly with Clang's integrated assembler,
732 - and linking with LLD.
743 depends on $(success,$(NM) --help | head -n 1 | grep -qi llvm)
744 depends on $(success,$(AR) --help | head -n 1 | grep -qi llvm)
762 If unsure, select LTO_NONE. Note that LTO is very resource-intensive
808 Control-Flow Integrity (CFI) checking.
816 depends on $(cc-option,-fsanitize=kcfi)
818 This option enables Clang’s forward-edge Control Flow Integrity
852 Syscalls need to be wrapped inside user_exit()-user_enter(), either
868 - Critical entry code isn't preemptible (or better yet:
870 - No use of RCU read side critical sections, unless ct_nmi_enter()
872 - No use of instrumentation, unless instrumentation_begin() got
897 With VIRT_CPU_ACCOUNTING_GEN, cputime_t becomes 64-bit.
899 to ensure there are no races in concurrent read/write of
900 cputime_t. For example, reading/writing 64-bit cputime_t on
901 some 32-bit arches may require multiple accesses, so proper
932 # Archs that select this would be capable of PMD-sized vmaps (i.e.,
944 # if there are no userspace memory management features that use it
958 just need a simple module loader without arch specific data - those
1014 - arch_mmap_rnd()
1015 - arch_randomize_brk()
1023 - ARCH_MMAP_RND_BITS_MIN
1024 - ARCH_MMAP_RND_BITS_MAX
1062 - ARCH_MMAP_RND_COMPAT_BITS_MIN
1063 - ARCH_MMAP_RND_COMPAT_BITS_MAX
1093 This allows 64bit applications to invoke 32-bit mmap() syscall
1094 and vice-versa 32-bit applications to call 64-bit mmap().
1110 # address by giving priority to top-down scheme only if the process
1114 # - STACK_RND_MASK
1139 Architecture supports objtool compile-time frame pointer rule
1154 file which provides platform-specific implementations of some
1191 Architecture has old sigsuspend(2) syscall, of one-argument variety
1196 Even weirder antique ABI - three-argument sigsuspend(2)
1202 as OLD_SIGSUSPEND | OLD_SIGSUSPEND3 - alpha has sigsuspend(2),
1210 bool "Provide system calls for 32-bit time_t"
1214 This is relevant on all 32-bit architectures, and 64-bit architectures
1232 - vmalloc space must be large enough to hold many kernel stacks.
1233 This may rule out many 32-bit architectures.
1235 - Stacks in vmalloc space need to work reliably. For example, if
1242 - If the stack overflows into a guard page, something reasonable
1248 bool "Use a virtually-mapped stack"
1252 Enable this if you want the use virtually-mapped kernel stacks
1254 caught immediately rather than causing difficult-to-diagnose
1267 syscall exit. Careful removal of -fstack-protector-strong and
1268 -fstack-protector should also be applied to the entry code and
1282 cross-syscall address exposures.
1308 bool "Make kernel text and rodata read-only" if ARCH_OPTIONAL_KERNEL_RWX
1312 If this is set, kernel text and rodata memory will be made read-only,
1313 and non-text memory will be made non-executable. This provides
1328 If this is set, module text and rodata memory will be made read-only,
1329 and non-text memory will be made non-executable. This provides
1332 # select if the architecture provides an asm/dma-direct.h header
1341 linux/compiler-*.h in order to override macro definitions that those
1347 May be selected by an architecture if it supports place-relative
1348 32-bit relocations, both in the toolchain and in the module loader,
1361 Enable light-weight counting of various locking related events
1377 well as compatible NM and OBJCOPY utilities (llvm-nm and llvm-objcopy
1435 static key. This should have slightly lower overhead than non-inline
1447 included, size-asserted, or discarded in the linker scripts. This is
1464 If a 32-bit architecture requires 64-bit arguments to be split into
1465 pairs of 32-bit arguments, select this option.
1487 accessed bit in non-leaf PMD entries when using them as part of linear
1493 source "scripts/gcc-plugins/Kconfig"