Lines Matching +full:has +full:- +full:builtin +full:- +full:dma
1 # SPDX-License-Identifier: GPL-2.0
21 # Selected by architectures that need custom DMA operations for e.g. legacy
22 # IOMMUs not handled by dma-iommu. Drivers must never select this symbol.
29 menu "General architecture-dependent options"
34 Select if the architecture can check permissions at sub-page
89 for kernel debugging, non-intrusive instrumentation and testing.
98 makes certain almost-always-true or almost-always-false branch
101 Certain performance-sensitive kernel code, such as trace points,
105 If it is detected that the compiler has support for "asm goto",
115 ( On 32-bit x86, the necessary options added to the compiler
122 Boot time self-test of the branch patching code.
128 Boot time self-test of the call patching code.
149 Uprobes is the user-space counterpart to kprobes: they
151 to establish unintrusive probes in user-space binaries and
153 are hit by user-space applications.
155 ( These probes come in the form of single-byte breakpoints,
172 See Documentation/core-api/unaligned-memory-access.rst for
191 See Documentation/core-api/unaligned-memory-access.rst for more
197 Modern versions of GCC (since 4.4) have builtin functions
198 for handling byte-swapping. Using these, instead of the old
203 with a nearby load or store and use load-and-swap or
204 store-and-swap instructions if the architecture has them. It
206 hand-coded assembler in <asm/swab.h>. But just in case it
209 Any architecture with load-and-swap or store-and-swap
227 Provide a kernel-internal notification when a cpu is about to
272 # arch_has_single_step() if there is hardware single-step support
273 # arch_has_block_step() if there is hardware block-step support
274 # asm/syscall.h supplying asm-generic/syscall.h interface
305 # Select if arch has all set_memory_ro/rw/x/nx() functions in asm/cacheflush.h
309 # Select if arch has all set_direct_map_invalid/default() functions
315 # either provide an uncached segment alias for a DMA allocation, or
323 # to undo an in-place page table remap for uncached access.
331 # The architecture has a per-task state that includes the mm's PASID
361 All new 32-bit architectures should have 64-bit off_t type on
364 still support 32-bit off_t. This option is enabled for all such
375 <asm/asm-prototypes.h> to support the module versioning for symbols
384 For example the kprobes-based event tracer needs this API.
428 subsystem. Also has support for calculating CPU cycle events
435 The arch chooses to use the generic perf-NMI-based hardlockup
458 bit-mapping of each registers and a unique architecture id.
507 # multi-threaded application), by reducing contention on the mm refcount.
516 # the lazy tlb reference of a kthread's ->active_mm (non-arch code has been
530 # - At the time of the final mmdrop of the mm, ensure mm_cpumask(mm) contains
532 # - It must meet the requirements for MMU_LAZY_TLB_REFCOUNT=n (see above).
543 arch-specific ELF note section to core files. It must provide two
583 and compat syscalls if the asm-generic/seccomp.h defaults need adjustment:
584 - __NR_seccomp_read_32
585 - __NR_seccomp_write_32
586 - __NR_seccomp_exit_32
587 - __NR_seccomp_sigreturn_32
594 - all the requirements for HAVE_ARCH_SECCOMP
595 - syscall_get_arch()
596 - syscall_get_arguments()
597 - syscall_rollback()
598 - syscall_set_return_value()
599 - SIGSYS siginfo_t support
600 - secure_computing is called from a ptrace_event()-safe context
601 - secure_computing return value is checked and a return value of -1
603 - seccomp syscall wired up
604 - if !HAVE_SPARSE_SYSCALL_NR, have SECCOMP_ARCH_NATIVE,
631 task-defined system call filtering polices.
633 See Documentation/userspace-api/seccomp_filter.rst for details.
652 An architecture should select this if it has the code which
660 - it has implemented a stack canary (e.g. __stack_chk_guard)
665 depends on $(cc-option,-fstack-protector)
668 This option turns on the "stack-protector" GCC feature. This
676 Functions will have the stack-protector canary logic added if they
677 have an 8-byte or larger character array on the stack.
680 gcc with the feature backported ("-fstack-protector").
689 depends on $(cc-option,-fstack-protector-strong)
692 Functions will have the stack-protector canary logic added in any
695 - local variable's address used as part of the right hand side of an
697 - local variable is an array (or union containing an array),
699 - uses register local variables
702 gcc with the feature backported ("-fstack-protector-strong").
726 - Clang: https://clang.llvm.org/docs/ShadowCallStack.html
727 - GCC: https://gcc.gnu.org/onlinedocs/gcc/Instrumentation-Options.html#Instrumentation-Options
757 - compiling with Clang,
758 - compiling inline assembly with Clang's integrated assembler,
759 - and linking with LLD.
770 depends on $(success,$(NM) --help | head -n 1 | grep -qi llvm)
771 depends on $(success,$(AR) --help | head -n 1 | grep -qi llvm)
789 If unsure, select LTO_NONE. Note that LTO is very resource-intensive
874 Control-Flow Integrity (CFI) checking.
882 depends on $(cc-option,-fsanitize=kcfi)
884 This option enables Clang's forward-edge Control Flow Integrity
912 depends on $(cc-option,-fsanitize=kcfi -fsanitize-cfi-icall-experimental-normalize-integers)
913 # With GCOV/KASAN we need this fix: https://github.com/llvm/llvm-project/pull/104826
920 # With GCOV/KASAN we need this fix: https://github.com/rust-lang/rust/pull/129373
948 Syscalls need to be wrapped inside user_exit()-user_enter(), either
964 - Critical entry code isn't preemptible (or better yet:
966 - No use of RCU read side critical sections, unless ct_nmi_enter()
968 - No use of instrumentation, unless instrumentation_begin() got
983 Architecture has its own way to account idle CPU time and therefore
993 With VIRT_CPU_ACCOUNTING_GEN, cputime_t becomes 64-bit.
996 cputime_t. For example, reading/writing 64-bit cputime_t on
997 some 32-bit arches may require multiple accesses, so proper
1028 # Archs that select this would be capable of PMD-sized vmaps (i.e.,
1054 just need a simple module loader without arch specific data - those
1088 with read-only execute permissions. Architecture must implement
1126 - arch_mmap_rnd()
1127 - arch_randomize_brk()
1134 allocations, has MMU enabled and provides values for both:
1135 - ARCH_MMAP_RND_BITS_MIN
1136 - ARCH_MMAP_RND_BITS_MAX
1172 use in establishing the base address for mmap allocations, has MMU
1174 - ARCH_MMAP_RND_COMPAT_BITS_MIN
1175 - ARCH_MMAP_RND_COMPAT_BITS_MAX
1205 This allows 64bit applications to invoke 32-bit mmap() syscall
1206 and vice-versa 32-bit applications to call 64-bit mmap().
1256 per-page operations in the kernel at the expense of a larger
1276 This is not suitable for general-purpose workloads but the
1279 large in-memory data rather than small files.
1287 that have been compiled with '-zmax-page-size' set to 256KiB
1311 # address by giving priority to top-down scheme only if the process
1315 # - STACK_RND_MASK
1340 Architecture supports objtool compile-time frame pointer rule
1346 Architecture has either save_stack_trace_tsk_reliable() or
1355 file which provides platform-specific implementations of some
1370 Architecture has tls passed as the 4th argument of clone(2),
1376 Architecture has the first two arguments of clone(2) swapped.
1381 Architecture has tls passed as the 3rd argument of clone(2),
1387 Architecture has unusual rt_sigaction(2) arguments
1392 Architecture has old sigsuspend(2) syscall, of one-argument variety
1397 Even weirder antique ABI - three-argument sigsuspend(2)
1402 Architecture has old sigaction(2) syscall. Nope, not the same
1403 as OLD_SIGSUSPEND | OLD_SIGSUSPEND3 - alpha has sigsuspend(2),
1411 bool "Provide system calls for 32-bit time_t"
1415 This is relevant on all 32-bit architectures, and 64-bit architectures
1433 - vmalloc space must be large enough to hold many kernel stacks.
1434 This may rule out many 32-bit architectures.
1436 - Stacks in vmalloc space need to work reliably. For example, if
1443 - If the stack overflows into a guard page, something reasonable
1449 bool "Use a virtually-mapped stack"
1453 Enable this if you want the use virtually-mapped kernel stacks
1455 caught immediately rather than causing difficult-to-diagnose
1468 syscall exit. Careful removal of -fstack-protector-strong and
1469 -fstack-protector should also be applied to the entry code and
1483 cross-syscall address exposures.
1486 kernel boot param, and if turned off has zero overhead due to its use
1509 bool "Make kernel text and rodata read-only" if ARCH_OPTIONAL_KERNEL_RWX
1513 If this is set, kernel text and rodata memory will be made read-only,
1514 and non-text memory will be made non-executable. This provides
1529 If this is set, module text and rodata memory will be made read-only,
1530 and non-text memory will be made non-executable. This provides
1533 # select if the architecture provides an asm/dma-direct.h header
1550 linux/compiler-*.h in order to override macro definitions that those
1564 May be selected by an architecture if it supports place-relative
1565 32-bit relocations, both in the toolchain and in the module loader,
1578 Enable light-weight counting of various locking related events
1583 # Select if the architecture has support for applying RELR relocations.
1594 well as compatible NM and OBJCOPY utilities (llvm-nm and llvm-objcopy
1607 to save space. For example, MIPS architecture has a syscall array with
1656 static key. This should have slightly lower overhead than non-inline
1668 included, size-asserted, or discarded in the linker scripts. This is
1685 If a 32-bit architecture requires 64-bit arguments to be split into
1686 pairs of 32-bit arguments, select this option.
1700 # Select, if arch has a named attribute group bound to NUMA device nodes.
1716 accessed bit in non-leaf PMD entries when using them as part of linear
1723 Architectures that select this option can run floating-point code in
1724 the kernel, as described in Documentation/core-api/floating-point.rst.
1735 source "scripts/gcc-plugins/Kconfig"
1762 # Detect availability of the GCC option -fmin-function-alignment which
1764 # -falign-functions which the compiler ignores for cold functions.
1765 def_bool $(cc-option, -fmin-function-alignment=8)
1768 # Set if the guaranteed alignment with -fmin-function-alignment is
1770 # strict alignment always, even with -falign-functions.