Commit | Line | Data |
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b2441318 | 1 | # SPDX-License-Identifier: GPL-2.0 |
fb32e03f MD |
2 | # |
3 | # General architecture dependent options | |
4 | # | |
125e5645 | 5 | |
1572497c CH |
6 | # |
7 | # Note: arch/$(SRCARCH)/Kconfig needs to be included first so that it can | |
8 | # override the default values in this file. | |
9 | # | |
10 | source "arch/$(SRCARCH)/Kconfig" | |
11 | ||
22471e13 RD |
12 | menu "General architecture-dependent options" |
13 | ||
692f66f2 HB |
14 | config CRASH_CORE |
15 | bool | |
16 | ||
2965faa5 | 17 | config KEXEC_CORE |
692f66f2 | 18 | select CRASH_CORE |
2965faa5 DY |
19 | bool |
20 | ||
175fca3b SS |
21 | config KEXEC_ELF |
22 | bool | |
23 | ||
467d2782 TJB |
24 | config HAVE_IMA_KEXEC |
25 | bool | |
26 | ||
5e6e9852 CH |
27 | config SET_FS |
28 | bool | |
29 | ||
05736e4a TG |
30 | config HOTPLUG_SMT |
31 | bool | |
32 | ||
142781e1 TG |
33 | config GENERIC_ENTRY |
34 | bool | |
35 | ||
125e5645 | 36 | config OPROFILE |
b309a294 | 37 | tristate "OProfile system profiling" |
125e5645 MD |
38 | depends on PROFILING |
39 | depends on HAVE_OPROFILE | |
d69d59f4 | 40 | select RING_BUFFER |
9a5963eb | 41 | select RING_BUFFER_ALLOW_SWAP |
125e5645 MD |
42 | help |
43 | OProfile is a profiling system capable of profiling the | |
44 | whole system, include the kernel, kernel modules, libraries, | |
45 | and applications. | |
46 | ||
47 | If unsure, say N. | |
48 | ||
4d4036e0 JY |
49 | config OPROFILE_EVENT_MULTIPLEX |
50 | bool "OProfile multiplexing support (EXPERIMENTAL)" | |
51 | default n | |
52 | depends on OPROFILE && X86 | |
53 | help | |
54 | The number of hardware counters is limited. The multiplexing | |
55 | feature enables OProfile to gather more events than counters | |
56 | are provided by the hardware. This is realized by switching | |
9332ef9d | 57 | between events at a user specified time interval. |
4d4036e0 JY |
58 | |
59 | If unsure, say N. | |
60 | ||
125e5645 | 61 | config HAVE_OPROFILE |
9ba16087 | 62 | bool |
125e5645 | 63 | |
dcfce4a0 RR |
64 | config OPROFILE_NMI_TIMER |
65 | def_bool y | |
af9feebe | 66 | depends on PERF_EVENTS && HAVE_PERF_EVENTS_NMI && !PPC64 |
dcfce4a0 | 67 | |
125e5645 MD |
68 | config KPROBES |
69 | bool "Kprobes" | |
05ed160e | 70 | depends on MODULES |
125e5645 | 71 | depends on HAVE_KPROBES |
05ed160e | 72 | select KALLSYMS |
125e5645 MD |
73 | help |
74 | Kprobes allows you to trap at almost any kernel address and | |
75 | execute a callback function. register_kprobe() establishes | |
76 | a probepoint and specifies the callback. Kprobes is useful | |
77 | for kernel debugging, non-intrusive instrumentation and testing. | |
78 | If in doubt, say "N". | |
79 | ||
45f81b1c | 80 | config JUMP_LABEL |
24b54fee KK |
81 | bool "Optimize very unlikely/likely branches" |
82 | depends on HAVE_ARCH_JUMP_LABEL | |
83 | depends on CC_HAS_ASM_GOTO | |
84 | help | |
85 | This option enables a transparent branch optimization that | |
c5905afb IM |
86 | makes certain almost-always-true or almost-always-false branch |
87 | conditions even cheaper to execute within the kernel. | |
88 | ||
89 | Certain performance-sensitive kernel code, such as trace points, | |
90 | scheduler functionality, networking code and KVM have such | |
91 | branches and include support for this optimization technique. | |
92 | ||
24b54fee | 93 | If it is detected that the compiler has support for "asm goto", |
c5905afb IM |
94 | the kernel will compile such branches with just a nop |
95 | instruction. When the condition flag is toggled to true, the | |
96 | nop will be converted to a jump instruction to execute the | |
97 | conditional block of instructions. | |
98 | ||
99 | This technique lowers overhead and stress on the branch prediction | |
100 | of the processor and generally makes the kernel faster. The update | |
101 | of the condition is slower, but those are always very rare. | |
45f81b1c | 102 | |
c5905afb IM |
103 | ( On 32-bit x86, the necessary options added to the compiler |
104 | flags may increase the size of the kernel slightly. ) | |
45f81b1c | 105 | |
1987c947 PZ |
106 | config STATIC_KEYS_SELFTEST |
107 | bool "Static key selftest" | |
108 | depends on JUMP_LABEL | |
109 | help | |
110 | Boot time self-test of the branch patching code. | |
111 | ||
f03c4129 PZ |
112 | config STATIC_CALL_SELFTEST |
113 | bool "Static call selftest" | |
114 | depends on HAVE_STATIC_CALL | |
115 | help | |
116 | Boot time self-test of the call patching code. | |
117 | ||
afd66255 | 118 | config OPTPROBES |
5cc718b9 MH |
119 | def_bool y |
120 | depends on KPROBES && HAVE_OPTPROBES | |
01b1d88b | 121 | select TASKS_RCU if PREEMPTION |
afd66255 | 122 | |
e7dbfe34 MH |
123 | config KPROBES_ON_FTRACE |
124 | def_bool y | |
125 | depends on KPROBES && HAVE_KPROBES_ON_FTRACE | |
126 | depends on DYNAMIC_FTRACE_WITH_REGS | |
127 | help | |
128 | If function tracer is enabled and the arch supports full | |
129 | passing of pt_regs to function tracing, then kprobes can | |
130 | optimize on top of function tracing. | |
131 | ||
2b144498 | 132 | config UPROBES |
09294e31 | 133 | def_bool n |
e8f4aa60 | 134 | depends on ARCH_SUPPORTS_UPROBES |
2b144498 | 135 | help |
7b2d81d4 IM |
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 | |
139 | libraries, by executing handler functions when the probes | |
140 | are hit by user-space applications. | |
141 | ||
142 | ( These probes come in the form of single-byte breakpoints, | |
143 | managed by the kernel and kept transparent to the probed | |
144 | application. ) | |
2b144498 | 145 | |
adab66b7 SRV |
146 | config HAVE_64BIT_ALIGNED_ACCESS |
147 | def_bool 64BIT && !HAVE_EFFICIENT_UNALIGNED_ACCESS | |
148 | help | |
149 | Some architectures require 64 bit accesses to be 64 bit | |
150 | aligned, which also requires structs containing 64 bit values | |
151 | to be 64 bit aligned too. This includes some 32 bit | |
152 | architectures which can do 64 bit accesses, as well as 64 bit | |
153 | architectures without unaligned access. | |
154 | ||
155 | This symbol should be selected by an architecture if 64 bit | |
156 | accesses are required to be 64 bit aligned in this way even | |
157 | though it is not a 64 bit architecture. | |
158 | ||
159 | See Documentation/unaligned-memory-access.txt for more | |
160 | information on the topic of unaligned memory accesses. | |
161 | ||
58340a07 | 162 | config HAVE_EFFICIENT_UNALIGNED_ACCESS |
9ba16087 | 163 | bool |
58340a07 JB |
164 | help |
165 | Some architectures are unable to perform unaligned accesses | |
166 | without the use of get_unaligned/put_unaligned. Others are | |
167 | unable to perform such accesses efficiently (e.g. trap on | |
168 | unaligned access and require fixing it up in the exception | |
169 | handler.) | |
170 | ||
171 | This symbol should be selected by an architecture if it can | |
172 | perform unaligned accesses efficiently to allow different | |
173 | code paths to be selected for these cases. Some network | |
174 | drivers, for example, could opt to not fix up alignment | |
175 | problems with received packets if doing so would not help | |
176 | much. | |
177 | ||
c9b54d6f | 178 | See Documentation/core-api/unaligned-memory-access.rst for more |
58340a07 JB |
179 | information on the topic of unaligned memory accesses. |
180 | ||
cf66bb93 | 181 | config ARCH_USE_BUILTIN_BSWAP |
24b54fee KK |
182 | bool |
183 | help | |
cf66bb93 DW |
184 | Modern versions of GCC (since 4.4) have builtin functions |
185 | for handling byte-swapping. Using these, instead of the old | |
186 | inline assembler that the architecture code provides in the | |
187 | __arch_bswapXX() macros, allows the compiler to see what's | |
188 | happening and offers more opportunity for optimisation. In | |
189 | particular, the compiler will be able to combine the byteswap | |
190 | with a nearby load or store and use load-and-swap or | |
191 | store-and-swap instructions if the architecture has them. It | |
192 | should almost *never* result in code which is worse than the | |
193 | hand-coded assembler in <asm/swab.h>. But just in case it | |
194 | does, the use of the builtins is optional. | |
195 | ||
196 | Any architecture with load-and-swap or store-and-swap | |
197 | instructions should set this. And it shouldn't hurt to set it | |
198 | on architectures that don't have such instructions. | |
199 | ||
9edddaa2 AM |
200 | config KRETPROBES |
201 | def_bool y | |
202 | depends on KPROBES && HAVE_KRETPROBES | |
203 | ||
7c68af6e AK |
204 | config USER_RETURN_NOTIFIER |
205 | bool | |
206 | depends on HAVE_USER_RETURN_NOTIFIER | |
207 | help | |
208 | Provide a kernel-internal notification when a cpu is about to | |
209 | switch to user mode. | |
210 | ||
28b2ee20 | 211 | config HAVE_IOREMAP_PROT |
9ba16087 | 212 | bool |
28b2ee20 | 213 | |
125e5645 | 214 | config HAVE_KPROBES |
9ba16087 | 215 | bool |
9edddaa2 AM |
216 | |
217 | config HAVE_KRETPROBES | |
9ba16087 | 218 | bool |
74bc7cee | 219 | |
afd66255 MH |
220 | config HAVE_OPTPROBES |
221 | bool | |
d314d74c | 222 | |
e7dbfe34 MH |
223 | config HAVE_KPROBES_ON_FTRACE |
224 | bool | |
225 | ||
540adea3 | 226 | config HAVE_FUNCTION_ERROR_INJECTION |
9802d865 JB |
227 | bool |
228 | ||
42a0bb3f PM |
229 | config HAVE_NMI |
230 | bool | |
231 | ||
1f5a4ad9 RM |
232 | # |
233 | # An arch should select this if it provides all these things: | |
234 | # | |
235 | # task_pt_regs() in asm/processor.h or asm/ptrace.h | |
236 | # arch_has_single_step() if there is hardware single-step support | |
237 | # arch_has_block_step() if there is hardware block-step support | |
1f5a4ad9 RM |
238 | # asm/syscall.h supplying asm-generic/syscall.h interface |
239 | # linux/regset.h user_regset interfaces | |
240 | # CORE_DUMP_USE_REGSET #define'd in linux/elf.h | |
241 | # TIF_SYSCALL_TRACE calls tracehook_report_syscall_{entry,exit} | |
242 | # TIF_NOTIFY_RESUME calls tracehook_notify_resume() | |
243 | # signal delivery calls tracehook_signal_handler() | |
244 | # | |
245 | config HAVE_ARCH_TRACEHOOK | |
9ba16087 | 246 | bool |
1f5a4ad9 | 247 | |
c64be2bb MS |
248 | config HAVE_DMA_CONTIGUOUS |
249 | bool | |
250 | ||
29d5e047 | 251 | config GENERIC_SMP_IDLE_THREAD |
24b54fee | 252 | bool |
29d5e047 | 253 | |
485cf5da | 254 | config GENERIC_IDLE_POLL_SETUP |
24b54fee | 255 | bool |
485cf5da | 256 | |
6974f0c4 DM |
257 | config ARCH_HAS_FORTIFY_SOURCE |
258 | bool | |
259 | help | |
260 | An architecture should select this when it can successfully | |
261 | build and run with CONFIG_FORTIFY_SOURCE. | |
262 | ||
d8ae8a37 CH |
263 | # |
264 | # Select if the arch provides a historic keepinit alias for the retain_initrd | |
265 | # command line option | |
266 | # | |
267 | config ARCH_HAS_KEEPINITRD | |
268 | bool | |
269 | ||
d2852a22 DB |
270 | # Select if arch has all set_memory_ro/rw/x/nx() functions in asm/cacheflush.h |
271 | config ARCH_HAS_SET_MEMORY | |
272 | bool | |
273 | ||
d253ca0c RE |
274 | # Select if arch has all set_direct_map_invalid/default() functions |
275 | config ARCH_HAS_SET_DIRECT_MAP | |
276 | bool | |
277 | ||
c30700db | 278 | # |
fa7e2247 | 279 | # Select if the architecture provides the arch_dma_set_uncached symbol to |
a86ecfa6 | 280 | # either provide an uncached segment alias for a DMA allocation, or |
fa7e2247 | 281 | # to remap the page tables in place. |
c30700db | 282 | # |
fa7e2247 | 283 | config ARCH_HAS_DMA_SET_UNCACHED |
c30700db CH |
284 | bool |
285 | ||
999a5d12 CH |
286 | # |
287 | # Select if the architectures provides the arch_dma_clear_uncached symbol | |
288 | # to undo an in-place page table remap for uncached access. | |
289 | # | |
290 | config ARCH_HAS_DMA_CLEAR_UNCACHED | |
c30700db CH |
291 | bool |
292 | ||
0500871f DH |
293 | # Select if arch init_task must go in the __init_task_data section |
294 | config ARCH_TASK_STRUCT_ON_STACK | |
24b54fee | 295 | bool |
a4a2eb49 | 296 | |
f5e10287 TG |
297 | # Select if arch has its private alloc_task_struct() function |
298 | config ARCH_TASK_STRUCT_ALLOCATOR | |
299 | bool | |
300 | ||
5905429a KC |
301 | config HAVE_ARCH_THREAD_STRUCT_WHITELIST |
302 | bool | |
303 | depends on !ARCH_TASK_STRUCT_ALLOCATOR | |
304 | help | |
305 | An architecture should select this to provide hardened usercopy | |
306 | knowledge about what region of the thread_struct should be | |
307 | whitelisted for copying to userspace. Normally this is only the | |
308 | FPU registers. Specifically, arch_thread_struct_whitelist() | |
309 | should be implemented. Without this, the entire thread_struct | |
310 | field in task_struct will be left whitelisted. | |
311 | ||
b235beea LT |
312 | # Select if arch has its private alloc_thread_stack() function |
313 | config ARCH_THREAD_STACK_ALLOCATOR | |
f5e10287 TG |
314 | bool |
315 | ||
5aaeb5c0 IM |
316 | # Select if arch wants to size task_struct dynamically via arch_task_struct_size: |
317 | config ARCH_WANTS_DYNAMIC_TASK_STRUCT | |
318 | bool | |
319 | ||
942fa985 YN |
320 | config ARCH_32BIT_OFF_T |
321 | bool | |
322 | depends on !64BIT | |
323 | help | |
324 | All new 32-bit architectures should have 64-bit off_t type on | |
325 | userspace side which corresponds to the loff_t kernel type. This | |
326 | is the requirement for modern ABIs. Some existing architectures | |
327 | still support 32-bit off_t. This option is enabled for all such | |
328 | architectures explicitly. | |
329 | ||
2ff2b7ec MY |
330 | config HAVE_ASM_MODVERSIONS |
331 | bool | |
332 | help | |
a86ecfa6 | 333 | This symbol should be selected by an architecture if it provides |
2ff2b7ec MY |
334 | <asm/asm-prototypes.h> to support the module versioning for symbols |
335 | exported from assembly code. | |
336 | ||
f850c30c HC |
337 | config HAVE_REGS_AND_STACK_ACCESS_API |
338 | bool | |
e01292b1 | 339 | help |
a86ecfa6 | 340 | This symbol should be selected by an architecture if it supports |
e01292b1 HC |
341 | the API needed to access registers and stack entries from pt_regs, |
342 | declared in asm/ptrace.h | |
343 | For example the kprobes-based event tracer needs this API. | |
f850c30c | 344 | |
d7822b1e MD |
345 | config HAVE_RSEQ |
346 | bool | |
347 | depends on HAVE_REGS_AND_STACK_ACCESS_API | |
348 | help | |
349 | This symbol should be selected by an architecture if it | |
350 | supports an implementation of restartable sequences. | |
351 | ||
3c88ee19 MH |
352 | config HAVE_FUNCTION_ARG_ACCESS_API |
353 | bool | |
354 | help | |
a86ecfa6 | 355 | This symbol should be selected by an architecture if it supports |
3c88ee19 MH |
356 | the API needed to access function arguments from pt_regs, |
357 | declared in asm/ptrace.h | |
358 | ||
62a038d3 P |
359 | config HAVE_HW_BREAKPOINT |
360 | bool | |
99e8c5a3 | 361 | depends on PERF_EVENTS |
62a038d3 | 362 | |
0102752e FW |
363 | config HAVE_MIXED_BREAKPOINTS_REGS |
364 | bool | |
365 | depends on HAVE_HW_BREAKPOINT | |
366 | help | |
367 | Depending on the arch implementation of hardware breakpoints, | |
368 | some of them have separate registers for data and instruction | |
369 | breakpoints addresses, others have mixed registers to store | |
370 | them but define the access type in a control register. | |
371 | Select this option if your arch implements breakpoints under the | |
372 | latter fashion. | |
373 | ||
7c68af6e AK |
374 | config HAVE_USER_RETURN_NOTIFIER |
375 | bool | |
a1922ed6 | 376 | |
c01d4323 FW |
377 | config HAVE_PERF_EVENTS_NMI |
378 | bool | |
23637d47 FW |
379 | help |
380 | System hardware can generate an NMI using the perf event | |
381 | subsystem. Also has support for calculating CPU cycle events | |
382 | to determine how many clock cycles in a given period. | |
c01d4323 | 383 | |
05a4a952 NP |
384 | config HAVE_HARDLOCKUP_DETECTOR_PERF |
385 | bool | |
386 | depends on HAVE_PERF_EVENTS_NMI | |
387 | help | |
388 | The arch chooses to use the generic perf-NMI-based hardlockup | |
389 | detector. Must define HAVE_PERF_EVENTS_NMI. | |
390 | ||
391 | config HAVE_NMI_WATCHDOG | |
392 | depends on HAVE_NMI | |
393 | bool | |
394 | help | |
395 | The arch provides a low level NMI watchdog. It provides | |
396 | asm/nmi.h, and defines its own arch_touch_nmi_watchdog(). | |
397 | ||
398 | config HAVE_HARDLOCKUP_DETECTOR_ARCH | |
399 | bool | |
400 | select HAVE_NMI_WATCHDOG | |
401 | help | |
402 | The arch chooses to provide its own hardlockup detector, which is | |
403 | a superset of the HAVE_NMI_WATCHDOG. It also conforms to config | |
404 | interfaces and parameters provided by hardlockup detector subsystem. | |
405 | ||
c5e63197 JO |
406 | config HAVE_PERF_REGS |
407 | bool | |
408 | help | |
409 | Support selective register dumps for perf events. This includes | |
410 | bit-mapping of each registers and a unique architecture id. | |
411 | ||
c5ebcedb JO |
412 | config HAVE_PERF_USER_STACK_DUMP |
413 | bool | |
414 | help | |
415 | Support user stack dumps for perf event samples. This needs | |
416 | access to the user stack pointer which is not unified across | |
417 | architectures. | |
418 | ||
bf5438fc JB |
419 | config HAVE_ARCH_JUMP_LABEL |
420 | bool | |
421 | ||
50ff18ab AB |
422 | config HAVE_ARCH_JUMP_LABEL_RELATIVE |
423 | bool | |
424 | ||
0d6e24d4 PZ |
425 | config MMU_GATHER_TABLE_FREE |
426 | bool | |
427 | ||
ff2e6d72 | 428 | config MMU_GATHER_RCU_TABLE_FREE |
26723911 | 429 | bool |
0d6e24d4 | 430 | select MMU_GATHER_TABLE_FREE |
26723911 | 431 | |
3af4bd03 | 432 | config MMU_GATHER_PAGE_SIZE |
ed6a7935 PZ |
433 | bool |
434 | ||
27796d03 PZ |
435 | config MMU_GATHER_NO_RANGE |
436 | bool | |
437 | ||
580a586c | 438 | config MMU_GATHER_NO_GATHER |
952a31c9 | 439 | bool |
0d6e24d4 | 440 | depends on MMU_GATHER_TABLE_FREE |
952a31c9 | 441 | |
d53c3dfb NP |
442 | config ARCH_WANT_IRQS_OFF_ACTIVATE_MM |
443 | bool | |
444 | help | |
445 | Temporary select until all architectures can be converted to have | |
446 | irqs disabled over activate_mm. Architectures that do IPI based TLB | |
447 | shootdowns should enable this. | |
448 | ||
df013ffb HY |
449 | config ARCH_HAVE_NMI_SAFE_CMPXCHG |
450 | bool | |
451 | ||
43570fd2 HC |
452 | config HAVE_ALIGNED_STRUCT_PAGE |
453 | bool | |
454 | help | |
455 | This makes sure that struct pages are double word aligned and that | |
456 | e.g. the SLUB allocator can perform double word atomic operations | |
457 | on a struct page for better performance. However selecting this | |
458 | might increase the size of a struct page by a word. | |
459 | ||
4156153c HC |
460 | config HAVE_CMPXCHG_LOCAL |
461 | bool | |
462 | ||
2565409f HC |
463 | config HAVE_CMPXCHG_DOUBLE |
464 | bool | |
465 | ||
77e58496 PM |
466 | config ARCH_WEAK_RELEASE_ACQUIRE |
467 | bool | |
468 | ||
c1d7e01d WD |
469 | config ARCH_WANT_IPC_PARSE_VERSION |
470 | bool | |
471 | ||
472 | config ARCH_WANT_COMPAT_IPC_PARSE_VERSION | |
473 | bool | |
474 | ||
48b25c43 | 475 | config ARCH_WANT_OLD_COMPAT_IPC |
c1d7e01d | 476 | select ARCH_WANT_COMPAT_IPC_PARSE_VERSION |
48b25c43 CM |
477 | bool |
478 | ||
282a181b YZ |
479 | config HAVE_ARCH_SECCOMP |
480 | bool | |
481 | help | |
482 | An arch should select this symbol to support seccomp mode 1 (the fixed | |
483 | syscall policy), and must provide an overrides for __NR_seccomp_sigreturn, | |
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 | |
489 | ||
e2cfabdf WD |
490 | config HAVE_ARCH_SECCOMP_FILTER |
491 | bool | |
282a181b | 492 | select HAVE_ARCH_SECCOMP |
e2cfabdf | 493 | help |
fb0fadf9 | 494 | An arch should select this symbol if it provides all of these things: |
282a181b | 495 | - all the requirements for HAVE_ARCH_SECCOMP |
bb6ea430 WD |
496 | - syscall_get_arch() |
497 | - syscall_get_arguments() | |
498 | - syscall_rollback() | |
499 | - syscall_set_return_value() | |
fb0fadf9 WD |
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 | |
503 | results in the system call being skipped immediately. | |
48dc92b9 | 504 | - seccomp syscall wired up |
0d8315dd YZ |
505 | - if !HAVE_SPARSE_SYSCALL_NR, have SECCOMP_ARCH_NATIVE, |
506 | SECCOMP_ARCH_NATIVE_NR, SECCOMP_ARCH_NATIVE_NAME defined. If | |
507 | COMPAT is supported, have the SECCOMP_ARCH_COMPAT* defines too. | |
e2cfabdf | 508 | |
282a181b YZ |
509 | config SECCOMP |
510 | prompt "Enable seccomp to safely execute untrusted bytecode" | |
511 | def_bool y | |
512 | depends on HAVE_ARCH_SECCOMP | |
513 | help | |
514 | This kernel feature is useful for number crunching applications | |
515 | that may need to handle untrusted bytecode during their | |
516 | execution. By using pipes or other transports made available | |
517 | to the process as file descriptors supporting the read/write | |
518 | syscalls, it's possible to isolate those applications in their | |
519 | own address space using seccomp. Once seccomp is enabled via | |
520 | prctl(PR_SET_SECCOMP) or the seccomp() syscall, it cannot be | |
521 | disabled and the task is only allowed to execute a few safe | |
522 | syscalls defined by each seccomp mode. | |
523 | ||
524 | If unsure, say Y. | |
525 | ||
e2cfabdf WD |
526 | config SECCOMP_FILTER |
527 | def_bool y | |
528 | depends on HAVE_ARCH_SECCOMP_FILTER && SECCOMP && NET | |
529 | help | |
530 | Enable tasks to build secure computing environments defined | |
531 | in terms of Berkeley Packet Filter programs which implement | |
532 | task-defined system call filtering polices. | |
533 | ||
5fb94e9c | 534 | See Documentation/userspace-api/seccomp_filter.rst for details. |
e2cfabdf | 535 | |
0d8315dd YZ |
536 | config SECCOMP_CACHE_DEBUG |
537 | bool "Show seccomp filter cache status in /proc/pid/seccomp_cache" | |
538 | depends on SECCOMP_FILTER && !HAVE_SPARSE_SYSCALL_NR | |
539 | depends on PROC_FS | |
540 | help | |
541 | This enables the /proc/pid/seccomp_cache interface to monitor | |
542 | seccomp cache data. The file format is subject to change. Reading | |
543 | the file requires CAP_SYS_ADMIN. | |
544 | ||
545 | This option is for debugging only. Enabling presents the risk that | |
546 | an adversary may be able to infer the seccomp filter logic. | |
547 | ||
548 | If unsure, say N. | |
549 | ||
afaef01c AP |
550 | config HAVE_ARCH_STACKLEAK |
551 | bool | |
552 | help | |
553 | An architecture should select this if it has the code which | |
554 | fills the used part of the kernel stack with the STACKLEAK_POISON | |
555 | value before returning from system calls. | |
556 | ||
d148eac0 | 557 | config HAVE_STACKPROTECTOR |
19952a92 KC |
558 | bool |
559 | help | |
560 | An arch should select this symbol if: | |
19952a92 KC |
561 | - it has implemented a stack canary (e.g. __stack_chk_guard) |
562 | ||
050e9baa | 563 | config STACKPROTECTOR |
2a61f474 | 564 | bool "Stack Protector buffer overflow detection" |
d148eac0 | 565 | depends on HAVE_STACKPROTECTOR |
2a61f474 MY |
566 | depends on $(cc-option,-fstack-protector) |
567 | default y | |
19952a92 | 568 | help |
8779657d | 569 | This option turns on the "stack-protector" GCC feature. This |
19952a92 KC |
570 | feature puts, at the beginning of functions, a canary value on |
571 | the stack just before the return address, and validates | |
572 | the value just before actually returning. Stack based buffer | |
573 | overflows (that need to overwrite this return address) now also | |
574 | overwrite the canary, which gets detected and the attack is then | |
575 | neutralized via a kernel panic. | |
576 | ||
8779657d KC |
577 | Functions will have the stack-protector canary logic added if they |
578 | have an 8-byte or larger character array on the stack. | |
579 | ||
19952a92 | 580 | This feature requires gcc version 4.2 or above, or a distribution |
8779657d KC |
581 | gcc with the feature backported ("-fstack-protector"). |
582 | ||
583 | On an x86 "defconfig" build, this feature adds canary checks to | |
584 | about 3% of all kernel functions, which increases kernel code size | |
585 | by about 0.3%. | |
586 | ||
050e9baa | 587 | config STACKPROTECTOR_STRONG |
2a61f474 | 588 | bool "Strong Stack Protector" |
050e9baa | 589 | depends on STACKPROTECTOR |
2a61f474 MY |
590 | depends on $(cc-option,-fstack-protector-strong) |
591 | default y | |
8779657d KC |
592 | help |
593 | Functions will have the stack-protector canary logic added in any | |
594 | of the following conditions: | |
595 | ||
596 | - local variable's address used as part of the right hand side of an | |
597 | assignment or function argument | |
598 | - local variable is an array (or union containing an array), | |
599 | regardless of array type or length | |
600 | - uses register local variables | |
601 | ||
602 | This feature requires gcc version 4.9 or above, or a distribution | |
603 | gcc with the feature backported ("-fstack-protector-strong"). | |
604 | ||
605 | On an x86 "defconfig" build, this feature adds canary checks to | |
606 | about 20% of all kernel functions, which increases the kernel code | |
607 | size by about 2%. | |
608 | ||
d08b9f0c ST |
609 | config ARCH_SUPPORTS_SHADOW_CALL_STACK |
610 | bool | |
611 | help | |
612 | An architecture should select this if it supports Clang's Shadow | |
aa7a65ae WD |
613 | Call Stack and implements runtime support for shadow stack |
614 | switching. | |
d08b9f0c ST |
615 | |
616 | config SHADOW_CALL_STACK | |
617 | bool "Clang Shadow Call Stack" | |
618 | depends on CC_IS_CLANG && ARCH_SUPPORTS_SHADOW_CALL_STACK | |
ddc9863e | 619 | depends on DYNAMIC_FTRACE_WITH_REGS || !FUNCTION_GRAPH_TRACER |
d08b9f0c ST |
620 | help |
621 | This option enables Clang's Shadow Call Stack, which uses a | |
622 | shadow stack to protect function return addresses from being | |
623 | overwritten by an attacker. More information can be found in | |
624 | Clang's documentation: | |
625 | ||
626 | https://clang.llvm.org/docs/ShadowCallStack.html | |
627 | ||
628 | Note that security guarantees in the kernel differ from the | |
629 | ones documented for user space. The kernel must store addresses | |
630 | of shadow stacks in memory, which means an attacker capable of | |
631 | reading and writing arbitrary memory may be able to locate them | |
632 | and hijack control flow by modifying the stacks. | |
633 | ||
0f60a8ef KC |
634 | config HAVE_ARCH_WITHIN_STACK_FRAMES |
635 | bool | |
636 | help | |
637 | An architecture should select this if it can walk the kernel stack | |
638 | frames to determine if an object is part of either the arguments | |
639 | or local variables (i.e. that it excludes saved return addresses, | |
640 | and similar) by implementing an inline arch_within_stack_frames(), | |
641 | which is used by CONFIG_HARDENED_USERCOPY. | |
642 | ||
91d1aa43 | 643 | config HAVE_CONTEXT_TRACKING |
2b1d5024 FW |
644 | bool |
645 | help | |
91d1aa43 FW |
646 | Provide kernel/user boundaries probes necessary for subsystems |
647 | that need it, such as userspace RCU extended quiescent state. | |
490f561b FW |
648 | Syscalls need to be wrapped inside user_exit()-user_enter(), either |
649 | optimized behind static key or through the slow path using TIF_NOHZ | |
650 | flag. Exceptions handlers must be wrapped as well. Irqs are already | |
651 | protected inside rcu_irq_enter/rcu_irq_exit() but preemption or signal | |
652 | handling on irq exit still need to be protected. | |
653 | ||
83c2da2e FW |
654 | config HAVE_CONTEXT_TRACKING_OFFSTACK |
655 | bool | |
656 | help | |
657 | Architecture neither relies on exception_enter()/exception_exit() | |
658 | nor on schedule_user(). Also preempt_schedule_notrace() and | |
659 | preempt_schedule_irq() can't be called in a preemptible section | |
660 | while context tracking is CONTEXT_USER. This feature reflects a sane | |
661 | entry implementation where the following requirements are met on | |
662 | critical entry code, ie: before user_exit() or after user_enter(): | |
663 | ||
664 | - Critical entry code isn't preemptible (or better yet: | |
665 | not interruptible). | |
666 | - No use of RCU read side critical sections, unless rcu_nmi_enter() | |
667 | got called. | |
668 | - No use of instrumentation, unless instrumentation_begin() got | |
669 | called. | |
670 | ||
490f561b FW |
671 | config HAVE_TIF_NOHZ |
672 | bool | |
673 | help | |
674 | Arch relies on TIF_NOHZ and syscall slow path to implement context | |
675 | tracking calls to user_enter()/user_exit(). | |
2b1d5024 | 676 | |
b952741c FW |
677 | config HAVE_VIRT_CPU_ACCOUNTING |
678 | bool | |
679 | ||
2b91ec9f FW |
680 | config HAVE_VIRT_CPU_ACCOUNTING_IDLE |
681 | bool | |
682 | help | |
683 | Architecture has its own way to account idle CPU time and therefore | |
684 | doesn't implement vtime_account_idle(). | |
685 | ||
40565b5a SG |
686 | config ARCH_HAS_SCALED_CPUTIME |
687 | bool | |
688 | ||
554b0004 KH |
689 | config HAVE_VIRT_CPU_ACCOUNTING_GEN |
690 | bool | |
691 | default y if 64BIT | |
692 | help | |
693 | With VIRT_CPU_ACCOUNTING_GEN, cputime_t becomes 64-bit. | |
694 | Before enabling this option, arch code must be audited | |
695 | to ensure there are no races in concurrent read/write of | |
696 | cputime_t. For example, reading/writing 64-bit cputime_t on | |
697 | some 32-bit arches may require multiple accesses, so proper | |
698 | locking is needed to protect against concurrent accesses. | |
699 | ||
fdf9c356 FW |
700 | config HAVE_IRQ_TIME_ACCOUNTING |
701 | bool | |
702 | help | |
703 | Archs need to ensure they use a high enough resolution clock to | |
704 | support irq time accounting and then call enable_sched_clock_irqtime(). | |
705 | ||
c49dd340 KS |
706 | config HAVE_MOVE_PUD |
707 | bool | |
708 | help | |
709 | Architectures that select this are able to move page tables at the | |
710 | PUD level. If there are only 3 page table levels, the move effectively | |
711 | happens at the PGD level. | |
712 | ||
2c91bd4a JFG |
713 | config HAVE_MOVE_PMD |
714 | bool | |
715 | help | |
716 | Archs that select this are able to move page tables at the PMD level. | |
717 | ||
15626062 GS |
718 | config HAVE_ARCH_TRANSPARENT_HUGEPAGE |
719 | bool | |
720 | ||
a00cc7d9 MW |
721 | config HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD |
722 | bool | |
723 | ||
0ddab1d2 TK |
724 | config HAVE_ARCH_HUGE_VMAP |
725 | bool | |
726 | ||
3876d4a3 AG |
727 | config ARCH_WANT_HUGE_PMD_SHARE |
728 | bool | |
729 | ||
0f8975ec PE |
730 | config HAVE_ARCH_SOFT_DIRTY |
731 | bool | |
732 | ||
786d35d4 DH |
733 | config HAVE_MOD_ARCH_SPECIFIC |
734 | bool | |
735 | help | |
736 | The arch uses struct mod_arch_specific to store data. Many arches | |
737 | just need a simple module loader without arch specific data - those | |
738 | should not enable this. | |
739 | ||
740 | config MODULES_USE_ELF_RELA | |
741 | bool | |
742 | help | |
743 | Modules only use ELF RELA relocations. Modules with ELF REL | |
744 | relocations will give an error. | |
745 | ||
746 | config MODULES_USE_ELF_REL | |
747 | bool | |
748 | help | |
749 | Modules only use ELF REL relocations. Modules with ELF RELA | |
750 | relocations will give an error. | |
751 | ||
cc1f0274 FW |
752 | config HAVE_IRQ_EXIT_ON_IRQ_STACK |
753 | bool | |
754 | help | |
755 | Architecture doesn't only execute the irq handler on the irq stack | |
756 | but also irq_exit(). This way we can process softirqs on this irq | |
757 | stack instead of switching to a new one when we call __do_softirq() | |
758 | in the end of an hardirq. | |
759 | This spares a stack switch and improves cache usage on softirq | |
760 | processing. | |
761 | ||
235a8f02 KS |
762 | config PGTABLE_LEVELS |
763 | int | |
764 | default 2 | |
765 | ||
2b68f6ca KC |
766 | config ARCH_HAS_ELF_RANDOMIZE |
767 | bool | |
768 | help | |
769 | An architecture supports choosing randomized locations for | |
770 | stack, mmap, brk, and ET_DYN. Defined functions: | |
771 | - arch_mmap_rnd() | |
204db6ed | 772 | - arch_randomize_brk() |
2b68f6ca | 773 | |
d07e2259 DC |
774 | config HAVE_ARCH_MMAP_RND_BITS |
775 | bool | |
776 | help | |
777 | An arch should select this symbol if it supports setting a variable | |
778 | number of bits for use in establishing the base address for mmap | |
779 | allocations, has MMU enabled and provides values for both: | |
780 | - ARCH_MMAP_RND_BITS_MIN | |
781 | - ARCH_MMAP_RND_BITS_MAX | |
782 | ||
5f56a5df JS |
783 | config HAVE_EXIT_THREAD |
784 | bool | |
785 | help | |
786 | An architecture implements exit_thread. | |
787 | ||
d07e2259 DC |
788 | config ARCH_MMAP_RND_BITS_MIN |
789 | int | |
790 | ||
791 | config ARCH_MMAP_RND_BITS_MAX | |
792 | int | |
793 | ||
794 | config ARCH_MMAP_RND_BITS_DEFAULT | |
795 | int | |
796 | ||
797 | config ARCH_MMAP_RND_BITS | |
798 | int "Number of bits to use for ASLR of mmap base address" if EXPERT | |
799 | range ARCH_MMAP_RND_BITS_MIN ARCH_MMAP_RND_BITS_MAX | |
800 | default ARCH_MMAP_RND_BITS_DEFAULT if ARCH_MMAP_RND_BITS_DEFAULT | |
801 | default ARCH_MMAP_RND_BITS_MIN | |
802 | depends on HAVE_ARCH_MMAP_RND_BITS | |
803 | help | |
804 | This value can be used to select the number of bits to use to | |
805 | determine the random offset to the base address of vma regions | |
806 | resulting from mmap allocations. This value will be bounded | |
807 | by the architecture's minimum and maximum supported values. | |
808 | ||
809 | This value can be changed after boot using the | |
810 | /proc/sys/vm/mmap_rnd_bits tunable | |
811 | ||
812 | config HAVE_ARCH_MMAP_RND_COMPAT_BITS | |
813 | bool | |
814 | help | |
815 | An arch should select this symbol if it supports running applications | |
816 | in compatibility mode, supports setting a variable number of bits for | |
817 | use in establishing the base address for mmap allocations, has MMU | |
818 | enabled and provides values for both: | |
819 | - ARCH_MMAP_RND_COMPAT_BITS_MIN | |
820 | - ARCH_MMAP_RND_COMPAT_BITS_MAX | |
821 | ||
822 | config ARCH_MMAP_RND_COMPAT_BITS_MIN | |
823 | int | |
824 | ||
825 | config ARCH_MMAP_RND_COMPAT_BITS_MAX | |
826 | int | |
827 | ||
828 | config ARCH_MMAP_RND_COMPAT_BITS_DEFAULT | |
829 | int | |
830 | ||
831 | config ARCH_MMAP_RND_COMPAT_BITS | |
832 | int "Number of bits to use for ASLR of mmap base address for compatible applications" if EXPERT | |
833 | range ARCH_MMAP_RND_COMPAT_BITS_MIN ARCH_MMAP_RND_COMPAT_BITS_MAX | |
834 | default ARCH_MMAP_RND_COMPAT_BITS_DEFAULT if ARCH_MMAP_RND_COMPAT_BITS_DEFAULT | |
835 | default ARCH_MMAP_RND_COMPAT_BITS_MIN | |
836 | depends on HAVE_ARCH_MMAP_RND_COMPAT_BITS | |
837 | help | |
838 | This value can be used to select the number of bits to use to | |
839 | determine the random offset to the base address of vma regions | |
840 | resulting from mmap allocations for compatible applications This | |
841 | value will be bounded by the architecture's minimum and maximum | |
842 | supported values. | |
843 | ||
844 | This value can be changed after boot using the | |
845 | /proc/sys/vm/mmap_rnd_compat_bits tunable | |
846 | ||
1b028f78 DS |
847 | config HAVE_ARCH_COMPAT_MMAP_BASES |
848 | bool | |
849 | help | |
850 | This allows 64bit applications to invoke 32-bit mmap() syscall | |
851 | and vice-versa 32-bit applications to call 64-bit mmap(). | |
852 | Required for applications doing different bitness syscalls. | |
853 | ||
67f3977f AG |
854 | # This allows to use a set of generic functions to determine mmap base |
855 | # address by giving priority to top-down scheme only if the process | |
856 | # is not in legacy mode (compat task, unlimited stack size or | |
857 | # sysctl_legacy_va_layout). | |
858 | # Architecture that selects this option can provide its own version of: | |
859 | # - STACK_RND_MASK | |
860 | config ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT | |
861 | bool | |
862 | depends on MMU | |
e7142bf5 | 863 | select ARCH_HAS_ELF_RANDOMIZE |
67f3977f | 864 | |
b9ab5ebb JP |
865 | config HAVE_STACK_VALIDATION |
866 | bool | |
867 | help | |
868 | Architecture supports the 'objtool check' host tool command, which | |
869 | performs compile-time stack metadata validation. | |
870 | ||
af085d90 JP |
871 | config HAVE_RELIABLE_STACKTRACE |
872 | bool | |
873 | help | |
140d7e88 MB |
874 | Architecture has either save_stack_trace_tsk_reliable() or |
875 | arch_stack_walk_reliable() function which only returns a stack trace | |
876 | if it can guarantee the trace is reliable. | |
af085d90 | 877 | |
468a9428 GS |
878 | config HAVE_ARCH_HASH |
879 | bool | |
880 | default n | |
881 | help | |
882 | If this is set, the architecture provides an <asm/hash.h> | |
883 | file which provides platform-specific implementations of some | |
884 | functions in <linux/hash.h> or fs/namei.c. | |
885 | ||
666047fe FT |
886 | config HAVE_ARCH_NVRAM_OPS |
887 | bool | |
888 | ||
3a495511 WBG |
889 | config ISA_BUS_API |
890 | def_bool ISA | |
891 | ||
d2125043 AV |
892 | # |
893 | # ABI hall of shame | |
894 | # | |
895 | config CLONE_BACKWARDS | |
896 | bool | |
897 | help | |
898 | Architecture has tls passed as the 4th argument of clone(2), | |
899 | not the 5th one. | |
900 | ||
901 | config CLONE_BACKWARDS2 | |
902 | bool | |
903 | help | |
904 | Architecture has the first two arguments of clone(2) swapped. | |
905 | ||
dfa9771a MS |
906 | config CLONE_BACKWARDS3 |
907 | bool | |
908 | help | |
909 | Architecture has tls passed as the 3rd argument of clone(2), | |
910 | not the 5th one. | |
911 | ||
eaca6eae AV |
912 | config ODD_RT_SIGACTION |
913 | bool | |
914 | help | |
915 | Architecture has unusual rt_sigaction(2) arguments | |
916 | ||
0a0e8cdf AV |
917 | config OLD_SIGSUSPEND |
918 | bool | |
919 | help | |
920 | Architecture has old sigsuspend(2) syscall, of one-argument variety | |
921 | ||
922 | config OLD_SIGSUSPEND3 | |
923 | bool | |
924 | help | |
925 | Even weirder antique ABI - three-argument sigsuspend(2) | |
926 | ||
495dfbf7 AV |
927 | config OLD_SIGACTION |
928 | bool | |
929 | help | |
930 | Architecture has old sigaction(2) syscall. Nope, not the same | |
931 | as OLD_SIGSUSPEND | OLD_SIGSUSPEND3 - alpha has sigsuspend(2), | |
932 | but fairly different variant of sigaction(2), thanks to OSF/1 | |
933 | compatibility... | |
934 | ||
935 | config COMPAT_OLD_SIGACTION | |
936 | bool | |
937 | ||
17435e5f | 938 | config COMPAT_32BIT_TIME |
942437c9 AB |
939 | bool "Provide system calls for 32-bit time_t" |
940 | default !64BIT || COMPAT | |
17435e5f DD |
941 | help |
942 | This enables 32 bit time_t support in addition to 64 bit time_t support. | |
943 | This is relevant on all 32-bit architectures, and 64-bit architectures | |
944 | as part of compat syscall handling. | |
945 | ||
87a4c375 CH |
946 | config ARCH_NO_PREEMPT |
947 | bool | |
948 | ||
a50a3f4b TG |
949 | config ARCH_SUPPORTS_RT |
950 | bool | |
951 | ||
fff7fb0b ZZ |
952 | config CPU_NO_EFFICIENT_FFS |
953 | def_bool n | |
954 | ||
ba14a194 AL |
955 | config HAVE_ARCH_VMAP_STACK |
956 | def_bool n | |
957 | help | |
958 | An arch should select this symbol if it can support kernel stacks | |
959 | in vmalloc space. This means: | |
960 | ||
961 | - vmalloc space must be large enough to hold many kernel stacks. | |
962 | This may rule out many 32-bit architectures. | |
963 | ||
964 | - Stacks in vmalloc space need to work reliably. For example, if | |
965 | vmap page tables are created on demand, either this mechanism | |
966 | needs to work while the stack points to a virtual address with | |
967 | unpopulated page tables or arch code (switch_to() and switch_mm(), | |
968 | most likely) needs to ensure that the stack's page table entries | |
969 | are populated before running on a possibly unpopulated stack. | |
970 | ||
971 | - If the stack overflows into a guard page, something reasonable | |
972 | should happen. The definition of "reasonable" is flexible, but | |
973 | instantly rebooting without logging anything would be unfriendly. | |
974 | ||
975 | config VMAP_STACK | |
976 | default y | |
977 | bool "Use a virtually-mapped stack" | |
eafb149e | 978 | depends on HAVE_ARCH_VMAP_STACK |
38dd767d | 979 | depends on !KASAN || KASAN_HW_TAGS || KASAN_VMALLOC |
a7f7f624 | 980 | help |
ba14a194 AL |
981 | Enable this if you want the use virtually-mapped kernel stacks |
982 | with guard pages. This causes kernel stack overflows to be | |
983 | caught immediately rather than causing difficult-to-diagnose | |
984 | corruption. | |
985 | ||
38dd767d AK |
986 | To use this with software KASAN modes, the architecture must support |
987 | backing virtual mappings with real shadow memory, and KASAN_VMALLOC | |
988 | must be enabled. | |
ba14a194 | 989 | |
ad21fc4f LA |
990 | config ARCH_OPTIONAL_KERNEL_RWX |
991 | def_bool n | |
992 | ||
993 | config ARCH_OPTIONAL_KERNEL_RWX_DEFAULT | |
994 | def_bool n | |
995 | ||
996 | config ARCH_HAS_STRICT_KERNEL_RWX | |
997 | def_bool n | |
998 | ||
0f5bf6d0 | 999 | config STRICT_KERNEL_RWX |
ad21fc4f LA |
1000 | bool "Make kernel text and rodata read-only" if ARCH_OPTIONAL_KERNEL_RWX |
1001 | depends on ARCH_HAS_STRICT_KERNEL_RWX | |
1002 | default !ARCH_OPTIONAL_KERNEL_RWX || ARCH_OPTIONAL_KERNEL_RWX_DEFAULT | |
1003 | help | |
1004 | If this is set, kernel text and rodata memory will be made read-only, | |
1005 | and non-text memory will be made non-executable. This provides | |
1006 | protection against certain security exploits (e.g. executing the heap | |
1007 | or modifying text) | |
1008 | ||
1009 | These features are considered standard security practice these days. | |
1010 | You should say Y here in almost all cases. | |
1011 | ||
1012 | config ARCH_HAS_STRICT_MODULE_RWX | |
1013 | def_bool n | |
1014 | ||
0f5bf6d0 | 1015 | config STRICT_MODULE_RWX |
ad21fc4f LA |
1016 | bool "Set loadable kernel module data as NX and text as RO" if ARCH_OPTIONAL_KERNEL_RWX |
1017 | depends on ARCH_HAS_STRICT_MODULE_RWX && MODULES | |
1018 | default !ARCH_OPTIONAL_KERNEL_RWX || ARCH_OPTIONAL_KERNEL_RWX_DEFAULT | |
1019 | help | |
1020 | If this is set, module text and rodata memory will be made read-only, | |
1021 | and non-text memory will be made non-executable. This provides | |
1022 | protection against certain security exploits (e.g. writing to text) | |
1023 | ||
ea8c64ac CH |
1024 | # select if the architecture provides an asm/dma-direct.h header |
1025 | config ARCH_HAS_PHYS_TO_DMA | |
1026 | bool | |
1027 | ||
04f264d3 PB |
1028 | config HAVE_ARCH_COMPILER_H |
1029 | bool | |
1030 | help | |
1031 | An architecture can select this if it provides an | |
1032 | asm/compiler.h header that should be included after | |
1033 | linux/compiler-*.h in order to override macro definitions that those | |
1034 | headers generally provide. | |
1035 | ||
271ca788 AB |
1036 | config HAVE_ARCH_PREL32_RELOCATIONS |
1037 | bool | |
1038 | help | |
1039 | May be selected by an architecture if it supports place-relative | |
1040 | 32-bit relocations, both in the toolchain and in the module loader, | |
1041 | in which case relative references can be used in special sections | |
1042 | for PCI fixup, initcalls etc which are only half the size on 64 bit | |
1043 | architectures, and don't require runtime relocation on relocatable | |
1044 | kernels. | |
1045 | ||
ce9084ba AB |
1046 | config ARCH_USE_MEMREMAP_PROT |
1047 | bool | |
1048 | ||
fb346fd9 WL |
1049 | config LOCK_EVENT_COUNTS |
1050 | bool "Locking event counts collection" | |
1051 | depends on DEBUG_FS | |
a7f7f624 | 1052 | help |
fb346fd9 WL |
1053 | Enable light-weight counting of various locking related events |
1054 | in the system with minimal performance impact. This reduces | |
1055 | the chance of application behavior change because of timing | |
1056 | differences. The counts are reported via debugfs. | |
1057 | ||
5cf896fb PC |
1058 | # Select if the architecture has support for applying RELR relocations. |
1059 | config ARCH_HAS_RELR | |
1060 | bool | |
1061 | ||
1062 | config RELR | |
1063 | bool "Use RELR relocation packing" | |
1064 | depends on ARCH_HAS_RELR && TOOLS_SUPPORT_RELR | |
1065 | default y | |
1066 | help | |
1067 | Store the kernel's dynamic relocations in the RELR relocation packing | |
1068 | format. Requires a compatible linker (LLD supports this feature), as | |
1069 | well as compatible NM and OBJCOPY utilities (llvm-nm and llvm-objcopy | |
1070 | are compatible). | |
1071 | ||
0c9c1d56 TJB |
1072 | config ARCH_HAS_MEM_ENCRYPT |
1073 | bool | |
1074 | ||
0e242208 HN |
1075 | config HAVE_SPARSE_SYSCALL_NR |
1076 | bool | |
1077 | help | |
1078 | An architecture should select this if its syscall numbering is sparse | |
1079 | to save space. For example, MIPS architecture has a syscall array with | |
1080 | entries at 4000, 5000 and 6000 locations. This option turns on syscall | |
1081 | related optimizations for a given architecture. | |
1082 | ||
d60d7de3 SS |
1083 | config ARCH_HAS_VDSO_DATA |
1084 | bool | |
1085 | ||
115284d8 JP |
1086 | config HAVE_STATIC_CALL |
1087 | bool | |
1088 | ||
9183c3f9 JP |
1089 | config HAVE_STATIC_CALL_INLINE |
1090 | bool | |
1091 | depends on HAVE_STATIC_CALL | |
1092 | ||
59612b24 NC |
1093 | config ARCH_WANT_LD_ORPHAN_WARN |
1094 | bool | |
1095 | help | |
1096 | An arch should select this symbol once all linker sections are explicitly | |
1097 | included, size-asserted, or discarded in the linker scripts. This is | |
1098 | important because we never want expected sections to be placed heuristically | |
1099 | by the linker, since the locations of such sections can change between linker | |
1100 | versions. | |
1101 | ||
4f5b0c17 MR |
1102 | config HAVE_ARCH_PFN_VALID |
1103 | bool | |
1104 | ||
5d6ad668 MR |
1105 | config ARCH_SUPPORTS_DEBUG_PAGEALLOC |
1106 | bool | |
1107 | ||
2521f2c2 | 1108 | source "kernel/gcov/Kconfig" |
45332b1b MY |
1109 | |
1110 | source "scripts/gcc-plugins/Kconfig" | |
fa1b5d09 | 1111 | |
22471e13 | 1112 | endmenu |