~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/arch/Kconfig

Version: ~ [ linux-6.11.5 ] ~ [ linux-6.10.14 ] ~ [ linux-6.9.12 ] ~ [ linux-6.8.12 ] ~ [ linux-6.7.12 ] ~ [ linux-6.6.58 ] ~ [ linux-6.5.13 ] ~ [ linux-6.4.16 ] ~ [ linux-6.3.13 ] ~ [ linux-6.2.16 ] ~ [ linux-6.1.114 ] ~ [ linux-6.0.19 ] ~ [ linux-5.19.17 ] ~ [ linux-5.18.19 ] ~ [ linux-5.17.15 ] ~ [ linux-5.16.20 ] ~ [ linux-5.15.169 ] ~ [ linux-5.14.21 ] ~ [ linux-5.13.19 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.228 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.284 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.322 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.336 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.337 ] ~ [ linux-4.4.302 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.9 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

Diff markup

Differences between /arch/Kconfig (Version linux-6.11.5) and /arch/Kconfig (Version linux-6.3.13)


  1 # SPDX-License-Identifier: GPL-2.0                  1 # SPDX-License-Identifier: GPL-2.0
  2 #                                                   2 #
  3 # General architecture dependent options            3 # General architecture dependent options
  4 #                                                   4 #
  5                                                     5 
  6 #                                                   6 #
  7 # Note: arch/$(SRCARCH)/Kconfig needs to be in      7 # Note: arch/$(SRCARCH)/Kconfig needs to be included first so that it can
  8 # override the default values in this file.         8 # override the default values in this file.
  9 #                                                   9 #
 10 source "arch/$(SRCARCH)/Kconfig"                   10 source "arch/$(SRCARCH)/Kconfig"
 11                                                    11 
 12 config ARCH_CONFIGURES_CPU_MITIGATIONS         << 
 13         bool                                   << 
 14                                                << 
 15 if !ARCH_CONFIGURES_CPU_MITIGATIONS            << 
 16 config CPU_MITIGATIONS                         << 
 17         def_bool y                             << 
 18 endif                                          << 
 19                                                << 
 20 menu "General architecture-dependent options"      12 menu "General architecture-dependent options"
 21                                                    13 
 22 config ARCH_HAS_SUBPAGE_FAULTS                 !!  14 config CRASH_CORE
 23         bool                                       15         bool
 24         help                                   << 
 25           Select if the architecture can check << 
 26           granularity (e.g. arm64 MTE). The pr << 
 27           must be implemented.                 << 
 28                                                    16 
 29 config HOTPLUG_SMT                             !!  17 config KEXEC_CORE
                                                   >>  18         select CRASH_CORE
 30         bool                                       19         bool
 31                                                    20 
 32 config SMT_NUM_THREADS_DYNAMIC                 !!  21 config KEXEC_ELF
 33         bool                                       22         bool
 34                                                    23 
 35 # Selected by HOTPLUG_CORE_SYNC_DEAD or HOTPLU !!  24 config HAVE_IMA_KEXEC
 36 config HOTPLUG_CORE_SYNC                       << 
 37         bool                                       25         bool
 38                                                    26 
 39 # Basic CPU dead synchronization selected by a !!  27 config ARCH_HAS_SUBPAGE_FAULTS
 40 config HOTPLUG_CORE_SYNC_DEAD                  << 
 41         bool                                   << 
 42         select HOTPLUG_CORE_SYNC               << 
 43                                                << 
 44 # Full CPU synchronization with alive state se << 
 45 config HOTPLUG_CORE_SYNC_FULL                  << 
 46         bool                                   << 
 47         select HOTPLUG_CORE_SYNC_DEAD if HOTPL << 
 48         select HOTPLUG_CORE_SYNC               << 
 49                                                << 
 50 config HOTPLUG_SPLIT_STARTUP                   << 
 51         bool                                       28         bool
 52         select HOTPLUG_CORE_SYNC_FULL          !!  29         help
                                                   >>  30           Select if the architecture can check permissions at sub-page
                                                   >>  31           granularity (e.g. arm64 MTE). The probe_user_*() functions
                                                   >>  32           must be implemented.
 53                                                    33 
 54 config HOTPLUG_PARALLEL                        !!  34 config HOTPLUG_SMT
 55         bool                                       35         bool
 56         select HOTPLUG_SPLIT_STARTUP           << 
 57                                                    36 
 58 config GENERIC_ENTRY                               37 config GENERIC_ENTRY
 59         bool                                       38         bool
 60                                                    39 
 61 config KPROBES                                     40 config KPROBES
 62         bool "Kprobes"                             41         bool "Kprobes"
                                                   >>  42         depends on MODULES
 63         depends on HAVE_KPROBES                    43         depends on HAVE_KPROBES
 64         select KALLSYMS                            44         select KALLSYMS
 65         select EXECMEM                         !!  45         select TASKS_RCU if PREEMPTION
 66         select NEED_TASKS_RCU                  << 
 67         help                                       46         help
 68           Kprobes allows you to trap at almost     47           Kprobes allows you to trap at almost any kernel address and
 69           execute a callback function.  regist     48           execute a callback function.  register_kprobe() establishes
 70           a probepoint and specifies the callb     49           a probepoint and specifies the callback.  Kprobes is useful
 71           for kernel debugging, non-intrusive      50           for kernel debugging, non-intrusive instrumentation and testing.
 72           If in doubt, say "N".                    51           If in doubt, say "N".
 73                                                    52 
 74 config JUMP_LABEL                                  53 config JUMP_LABEL
 75         bool "Optimize very unlikely/likely br     54         bool "Optimize very unlikely/likely branches"
 76         depends on HAVE_ARCH_JUMP_LABEL            55         depends on HAVE_ARCH_JUMP_LABEL
 77         select OBJTOOL if HAVE_JUMP_LABEL_HACK     56         select OBJTOOL if HAVE_JUMP_LABEL_HACK
 78         help                                       57         help
 79           This option enables a transparent br     58           This option enables a transparent branch optimization that
 80           makes certain almost-always-true or      59           makes certain almost-always-true or almost-always-false branch
 81           conditions even cheaper to execute w     60           conditions even cheaper to execute within the kernel.
 82                                                    61 
 83           Certain performance-sensitive kernel     62           Certain performance-sensitive kernel code, such as trace points,
 84           scheduler functionality, networking      63           scheduler functionality, networking code and KVM have such
 85           branches and include support for thi     64           branches and include support for this optimization technique.
 86                                                    65 
 87           If it is detected that the compiler      66           If it is detected that the compiler has support for "asm goto",
 88           the kernel will compile such branche     67           the kernel will compile such branches with just a nop
 89           instruction. When the condition flag     68           instruction. When the condition flag is toggled to true, the
 90           nop will be converted to a jump inst     69           nop will be converted to a jump instruction to execute the
 91           conditional block of instructions.       70           conditional block of instructions.
 92                                                    71 
 93           This technique lowers overhead and s     72           This technique lowers overhead and stress on the branch prediction
 94           of the processor and generally makes     73           of the processor and generally makes the kernel faster. The update
 95           of the condition is slower, but thos     74           of the condition is slower, but those are always very rare.
 96                                                    75 
 97           ( On 32-bit x86, the necessary optio     76           ( On 32-bit x86, the necessary options added to the compiler
 98             flags may increase the size of the     77             flags may increase the size of the kernel slightly. )
 99                                                    78 
100 config STATIC_KEYS_SELFTEST                        79 config STATIC_KEYS_SELFTEST
101         bool "Static key selftest"                 80         bool "Static key selftest"
102         depends on JUMP_LABEL                      81         depends on JUMP_LABEL
103         help                                       82         help
104           Boot time self-test of the branch pa     83           Boot time self-test of the branch patching code.
105                                                    84 
106 config STATIC_CALL_SELFTEST                        85 config STATIC_CALL_SELFTEST
107         bool "Static call selftest"                86         bool "Static call selftest"
108         depends on HAVE_STATIC_CALL                87         depends on HAVE_STATIC_CALL
109         help                                       88         help
110           Boot time self-test of the call patc     89           Boot time self-test of the call patching code.
111                                                    90 
112 config OPTPROBES                                   91 config OPTPROBES
113         def_bool y                                 92         def_bool y
114         depends on KPROBES && HAVE_OPTPROBES       93         depends on KPROBES && HAVE_OPTPROBES
115         select NEED_TASKS_RCU                  !!  94         select TASKS_RCU if PREEMPTION
116                                                    95 
117 config KPROBES_ON_FTRACE                           96 config KPROBES_ON_FTRACE
118         def_bool y                                 97         def_bool y
119         depends on KPROBES && HAVE_KPROBES_ON_     98         depends on KPROBES && HAVE_KPROBES_ON_FTRACE
120         depends on DYNAMIC_FTRACE_WITH_REGS        99         depends on DYNAMIC_FTRACE_WITH_REGS
121         help                                      100         help
122           If function tracer is enabled and th    101           If function tracer is enabled and the arch supports full
123           passing of pt_regs to function traci    102           passing of pt_regs to function tracing, then kprobes can
124           optimize on top of function tracing.    103           optimize on top of function tracing.
125                                                   104 
126 config UPROBES                                    105 config UPROBES
127         def_bool n                                106         def_bool n
128         depends on ARCH_SUPPORTS_UPROBES          107         depends on ARCH_SUPPORTS_UPROBES
129         help                                      108         help
130           Uprobes is the user-space counterpar    109           Uprobes is the user-space counterpart to kprobes: they
131           enable instrumentation applications     110           enable instrumentation applications (such as 'perf probe')
132           to establish unintrusive probes in u    111           to establish unintrusive probes in user-space binaries and
133           libraries, by executing handler func    112           libraries, by executing handler functions when the probes
134           are hit by user-space applications.     113           are hit by user-space applications.
135                                                   114 
136           ( These probes come in the form of s    115           ( These probes come in the form of single-byte breakpoints,
137             managed by the kernel and kept tra    116             managed by the kernel and kept transparent to the probed
138             application. )                        117             application. )
139                                                   118 
140 config HAVE_64BIT_ALIGNED_ACCESS                  119 config HAVE_64BIT_ALIGNED_ACCESS
141         def_bool 64BIT && !HAVE_EFFICIENT_UNAL    120         def_bool 64BIT && !HAVE_EFFICIENT_UNALIGNED_ACCESS
142         help                                      121         help
143           Some architectures require 64 bit ac    122           Some architectures require 64 bit accesses to be 64 bit
144           aligned, which also requires structs    123           aligned, which also requires structs containing 64 bit values
145           to be 64 bit aligned too. This inclu    124           to be 64 bit aligned too. This includes some 32 bit
146           architectures which can do 64 bit ac    125           architectures which can do 64 bit accesses, as well as 64 bit
147           architectures without unaligned acce    126           architectures without unaligned access.
148                                                   127 
149           This symbol should be selected by an    128           This symbol should be selected by an architecture if 64 bit
150           accesses are required to be 64 bit a    129           accesses are required to be 64 bit aligned in this way even
151           though it is not a 64 bit architectu    130           though it is not a 64 bit architecture.
152                                                   131 
153           See Documentation/core-api/unaligned    132           See Documentation/core-api/unaligned-memory-access.rst for
154           more information on the topic of una    133           more information on the topic of unaligned memory accesses.
155                                                   134 
156 config HAVE_EFFICIENT_UNALIGNED_ACCESS            135 config HAVE_EFFICIENT_UNALIGNED_ACCESS
157         bool                                      136         bool
158         help                                      137         help
159           Some architectures are unable to per    138           Some architectures are unable to perform unaligned accesses
160           without the use of get_unaligned/put    139           without the use of get_unaligned/put_unaligned. Others are
161           unable to perform such accesses effi    140           unable to perform such accesses efficiently (e.g. trap on
162           unaligned access and require fixing     141           unaligned access and require fixing it up in the exception
163           handler.)                               142           handler.)
164                                                   143 
165           This symbol should be selected by an    144           This symbol should be selected by an architecture if it can
166           perform unaligned accesses efficient    145           perform unaligned accesses efficiently to allow different
167           code paths to be selected for these     146           code paths to be selected for these cases. Some network
168           drivers, for example, could opt to n    147           drivers, for example, could opt to not fix up alignment
169           problems with received packets if do    148           problems with received packets if doing so would not help
170           much.                                   149           much.
171                                                   150 
172           See Documentation/core-api/unaligned    151           See Documentation/core-api/unaligned-memory-access.rst for more
173           information on the topic of unaligne    152           information on the topic of unaligned memory accesses.
174                                                   153 
175 config ARCH_USE_BUILTIN_BSWAP                     154 config ARCH_USE_BUILTIN_BSWAP
176         bool                                      155         bool
177         help                                      156         help
178           Modern versions of GCC (since 4.4) h    157           Modern versions of GCC (since 4.4) have builtin functions
179           for handling byte-swapping. Using th    158           for handling byte-swapping. Using these, instead of the old
180           inline assembler that the architectu    159           inline assembler that the architecture code provides in the
181           __arch_bswapXX() macros, allows the     160           __arch_bswapXX() macros, allows the compiler to see what's
182           happening and offers more opportunit    161           happening and offers more opportunity for optimisation. In
183           particular, the compiler will be abl    162           particular, the compiler will be able to combine the byteswap
184           with a nearby load or store and use     163           with a nearby load or store and use load-and-swap or
185           store-and-swap instructions if the a    164           store-and-swap instructions if the architecture has them. It
186           should almost *never* result in code    165           should almost *never* result in code which is worse than the
187           hand-coded assembler in <asm/swab.h>    166           hand-coded assembler in <asm/swab.h>.  But just in case it
188           does, the use of the builtins is opt    167           does, the use of the builtins is optional.
189                                                   168 
190           Any architecture with load-and-swap     169           Any architecture with load-and-swap or store-and-swap
191           instructions should set this. And it    170           instructions should set this. And it shouldn't hurt to set it
192           on architectures that don't have suc    171           on architectures that don't have such instructions.
193                                                   172 
194 config KRETPROBES                                 173 config KRETPROBES
195         def_bool y                                174         def_bool y
196         depends on KPROBES && (HAVE_KRETPROBES    175         depends on KPROBES && (HAVE_KRETPROBES || HAVE_RETHOOK)
197                                                   176 
198 config KRETPROBE_ON_RETHOOK                       177 config KRETPROBE_ON_RETHOOK
199         def_bool y                                178         def_bool y
200         depends on HAVE_RETHOOK                   179         depends on HAVE_RETHOOK
201         depends on KRETPROBES                     180         depends on KRETPROBES
202         select RETHOOK                            181         select RETHOOK
203                                                   182 
204 config USER_RETURN_NOTIFIER                       183 config USER_RETURN_NOTIFIER
205         bool                                      184         bool
206         depends on HAVE_USER_RETURN_NOTIFIER      185         depends on HAVE_USER_RETURN_NOTIFIER
207         help                                      186         help
208           Provide a kernel-internal notificati    187           Provide a kernel-internal notification when a cpu is about to
209           switch to user mode.                    188           switch to user mode.
210                                                   189 
211 config HAVE_IOREMAP_PROT                          190 config HAVE_IOREMAP_PROT
212         bool                                      191         bool
213                                                   192 
214 config HAVE_KPROBES                               193 config HAVE_KPROBES
215         bool                                      194         bool
216                                                   195 
217 config HAVE_KRETPROBES                            196 config HAVE_KRETPROBES
218         bool                                      197         bool
219                                                   198 
220 config HAVE_OPTPROBES                             199 config HAVE_OPTPROBES
221         bool                                      200         bool
222                                                   201 
223 config HAVE_KPROBES_ON_FTRACE                     202 config HAVE_KPROBES_ON_FTRACE
224         bool                                      203         bool
225                                                   204 
226 config ARCH_CORRECT_STACKTRACE_ON_KRETPROBE       205 config ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
227         bool                                      206         bool
228         help                                      207         help
229           Since kretprobes modifies return add    208           Since kretprobes modifies return address on the stack, the
230           stacktrace may see the kretprobe tra    209           stacktrace may see the kretprobe trampoline address instead
231           of correct one. If the architecture     210           of correct one. If the architecture stacktrace code and
232           unwinder can adjust such entries, se    211           unwinder can adjust such entries, select this configuration.
233                                                   212 
234 config HAVE_FUNCTION_ERROR_INJECTION              213 config HAVE_FUNCTION_ERROR_INJECTION
235         bool                                      214         bool
236                                                   215 
237 config HAVE_NMI                                   216 config HAVE_NMI
238         bool                                      217         bool
239                                                   218 
240 config HAVE_FUNCTION_DESCRIPTORS                  219 config HAVE_FUNCTION_DESCRIPTORS
241         bool                                      220         bool
242                                                   221 
243 config TRACE_IRQFLAGS_SUPPORT                     222 config TRACE_IRQFLAGS_SUPPORT
244         bool                                      223         bool
245                                                   224 
246 config TRACE_IRQFLAGS_NMI_SUPPORT                 225 config TRACE_IRQFLAGS_NMI_SUPPORT
247         bool                                      226         bool
248                                                   227 
249 #                                                 228 #
250 # An arch should select this if it provides al    229 # An arch should select this if it provides all these things:
251 #                                                 230 #
252 #       task_pt_regs()          in asm/process    231 #       task_pt_regs()          in asm/processor.h or asm/ptrace.h
253 #       arch_has_single_step()  if there is ha    232 #       arch_has_single_step()  if there is hardware single-step support
254 #       arch_has_block_step()   if there is ha    233 #       arch_has_block_step()   if there is hardware block-step support
255 #       asm/syscall.h           supplying asm-    234 #       asm/syscall.h           supplying asm-generic/syscall.h interface
256 #       linux/regset.h          user_regset in    235 #       linux/regset.h          user_regset interfaces
257 #       CORE_DUMP_USE_REGSET    #define'd in l    236 #       CORE_DUMP_USE_REGSET    #define'd in linux/elf.h
258 #       TIF_SYSCALL_TRACE       calls ptrace_r    237 #       TIF_SYSCALL_TRACE       calls ptrace_report_syscall_{entry,exit}
259 #       TIF_NOTIFY_RESUME       calls resume_u    238 #       TIF_NOTIFY_RESUME       calls resume_user_mode_work()
260 #                                                 239 #
261 config HAVE_ARCH_TRACEHOOK                        240 config HAVE_ARCH_TRACEHOOK
262         bool                                      241         bool
263                                                   242 
264 config HAVE_DMA_CONTIGUOUS                        243 config HAVE_DMA_CONTIGUOUS
265         bool                                      244         bool
266                                                   245 
267 config GENERIC_SMP_IDLE_THREAD                    246 config GENERIC_SMP_IDLE_THREAD
268         bool                                      247         bool
269                                                   248 
270 config GENERIC_IDLE_POLL_SETUP                    249 config GENERIC_IDLE_POLL_SETUP
271         bool                                      250         bool
272                                                   251 
273 config ARCH_HAS_FORTIFY_SOURCE                    252 config ARCH_HAS_FORTIFY_SOURCE
274         bool                                      253         bool
275         help                                      254         help
276           An architecture should select this w    255           An architecture should select this when it can successfully
277           build and run with CONFIG_FORTIFY_SO    256           build and run with CONFIG_FORTIFY_SOURCE.
278                                                   257 
279 #                                                 258 #
280 # Select if the arch provides a historic keepi    259 # Select if the arch provides a historic keepinit alias for the retain_initrd
281 # command line option                             260 # command line option
282 #                                                 261 #
283 config ARCH_HAS_KEEPINITRD                        262 config ARCH_HAS_KEEPINITRD
284         bool                                      263         bool
285                                                   264 
286 # Select if arch has all set_memory_ro/rw/x/nx    265 # Select if arch has all set_memory_ro/rw/x/nx() functions in asm/cacheflush.h
287 config ARCH_HAS_SET_MEMORY                        266 config ARCH_HAS_SET_MEMORY
288         bool                                      267         bool
289                                                   268 
290 # Select if arch has all set_direct_map_invali    269 # Select if arch has all set_direct_map_invalid/default() functions
291 config ARCH_HAS_SET_DIRECT_MAP                    270 config ARCH_HAS_SET_DIRECT_MAP
292         bool                                      271         bool
293                                                   272 
294 #                                                 273 #
295 # Select if the architecture provides the arch    274 # Select if the architecture provides the arch_dma_set_uncached symbol to
296 # either provide an uncached segment alias for    275 # either provide an uncached segment alias for a DMA allocation, or
297 # to remap the page tables in place.              276 # to remap the page tables in place.
298 #                                                 277 #
299 config ARCH_HAS_DMA_SET_UNCACHED                  278 config ARCH_HAS_DMA_SET_UNCACHED
300         bool                                      279         bool
301                                                   280 
302 #                                                 281 #
303 # Select if the architectures provides the arc    282 # Select if the architectures provides the arch_dma_clear_uncached symbol
304 # to undo an in-place page table remap for unc    283 # to undo an in-place page table remap for uncached access.
305 #                                                 284 #
306 config ARCH_HAS_DMA_CLEAR_UNCACHED                285 config ARCH_HAS_DMA_CLEAR_UNCACHED
307         bool                                      286         bool
308                                                   287 
309 config ARCH_HAS_CPU_FINALIZE_INIT              !! 288 # Select if arch init_task must go in the __init_task_data section
                                                   >> 289 config ARCH_TASK_STRUCT_ON_STACK
310         bool                                      290         bool
311                                                   291 
312 # The architecture has a per-task state that i !! 292 # Select if arch has its private alloc_task_struct() function
313 config ARCH_HAS_CPU_PASID                      !! 293 config ARCH_TASK_STRUCT_ALLOCATOR
314         bool                                      294         bool
315         select IOMMU_MM_DATA                   << 
316                                                   295 
317 config HAVE_ARCH_THREAD_STRUCT_WHITELIST          296 config HAVE_ARCH_THREAD_STRUCT_WHITELIST
318         bool                                      297         bool
                                                   >> 298         depends on !ARCH_TASK_STRUCT_ALLOCATOR
319         help                                      299         help
320           An architecture should select this t    300           An architecture should select this to provide hardened usercopy
321           knowledge about what region of the t    301           knowledge about what region of the thread_struct should be
322           whitelisted for copying to userspace    302           whitelisted for copying to userspace. Normally this is only the
323           FPU registers. Specifically, arch_th    303           FPU registers. Specifically, arch_thread_struct_whitelist()
324           should be implemented. Without this,    304           should be implemented. Without this, the entire thread_struct
325           field in task_struct will be left wh    305           field in task_struct will be left whitelisted.
326                                                   306 
                                                   >> 307 # Select if arch has its private alloc_thread_stack() function
                                                   >> 308 config ARCH_THREAD_STACK_ALLOCATOR
                                                   >> 309         bool
                                                   >> 310 
327 # Select if arch wants to size task_struct dyn    311 # Select if arch wants to size task_struct dynamically via arch_task_struct_size:
328 config ARCH_WANTS_DYNAMIC_TASK_STRUCT             312 config ARCH_WANTS_DYNAMIC_TASK_STRUCT
329         bool                                      313         bool
330                                                   314 
331 config ARCH_WANTS_NO_INSTR                        315 config ARCH_WANTS_NO_INSTR
332         bool                                      316         bool
333         help                                      317         help
334           An architecture should select this i    318           An architecture should select this if the noinstr macro is being used on
335           functions to denote that the toolcha    319           functions to denote that the toolchain should avoid instrumenting such
336           functions and is required for correc    320           functions and is required for correctness.
337                                                   321 
338 config ARCH_32BIT_OFF_T                           322 config ARCH_32BIT_OFF_T
339         bool                                      323         bool
340         depends on !64BIT                         324         depends on !64BIT
341         help                                      325         help
342           All new 32-bit architectures should     326           All new 32-bit architectures should have 64-bit off_t type on
343           userspace side which corresponds to     327           userspace side which corresponds to the loff_t kernel type. This
344           is the requirement for modern ABIs.     328           is the requirement for modern ABIs. Some existing architectures
345           still support 32-bit off_t. This opt    329           still support 32-bit off_t. This option is enabled for all such
346           architectures explicitly.               330           architectures explicitly.
347                                                   331 
348 # Selected by 64 bit architectures which have     332 # Selected by 64 bit architectures which have a 32 bit f_tinode in struct ustat
349 config ARCH_32BIT_USTAT_F_TINODE                  333 config ARCH_32BIT_USTAT_F_TINODE
350         bool                                      334         bool
351                                                   335 
352 config HAVE_ASM_MODVERSIONS                       336 config HAVE_ASM_MODVERSIONS
353         bool                                      337         bool
354         help                                      338         help
355           This symbol should be selected by an    339           This symbol should be selected by an architecture if it provides
356           <asm/asm-prototypes.h> to support th    340           <asm/asm-prototypes.h> to support the module versioning for symbols
357           exported from assembly code.            341           exported from assembly code.
358                                                   342 
359 config HAVE_REGS_AND_STACK_ACCESS_API             343 config HAVE_REGS_AND_STACK_ACCESS_API
360         bool                                      344         bool
361         help                                      345         help
362           This symbol should be selected by an    346           This symbol should be selected by an architecture if it supports
363           the API needed to access registers a    347           the API needed to access registers and stack entries from pt_regs,
364           declared in asm/ptrace.h                348           declared in asm/ptrace.h
365           For example the kprobes-based event     349           For example the kprobes-based event tracer needs this API.
366                                                   350 
367 config HAVE_RSEQ                                  351 config HAVE_RSEQ
368         bool                                      352         bool
369         depends on HAVE_REGS_AND_STACK_ACCESS_    353         depends on HAVE_REGS_AND_STACK_ACCESS_API
370         help                                      354         help
371           This symbol should be selected by an    355           This symbol should be selected by an architecture if it
372           supports an implementation of restar    356           supports an implementation of restartable sequences.
373                                                   357 
374 config HAVE_RUST                                  358 config HAVE_RUST
375         bool                                      359         bool
376         help                                      360         help
377           This symbol should be selected by an    361           This symbol should be selected by an architecture if it
378           supports Rust.                          362           supports Rust.
379                                                   363 
380 config HAVE_FUNCTION_ARG_ACCESS_API               364 config HAVE_FUNCTION_ARG_ACCESS_API
381         bool                                      365         bool
382         help                                      366         help
383           This symbol should be selected by an    367           This symbol should be selected by an architecture if it supports
384           the API needed to access function ar    368           the API needed to access function arguments from pt_regs,
385           declared in asm/ptrace.h                369           declared in asm/ptrace.h
386                                                   370 
387 config HAVE_HW_BREAKPOINT                         371 config HAVE_HW_BREAKPOINT
388         bool                                      372         bool
389         depends on PERF_EVENTS                    373         depends on PERF_EVENTS
390                                                   374 
391 config HAVE_MIXED_BREAKPOINTS_REGS                375 config HAVE_MIXED_BREAKPOINTS_REGS
392         bool                                      376         bool
393         depends on HAVE_HW_BREAKPOINT             377         depends on HAVE_HW_BREAKPOINT
394         help                                      378         help
395           Depending on the arch implementation    379           Depending on the arch implementation of hardware breakpoints,
396           some of them have separate registers    380           some of them have separate registers for data and instruction
397           breakpoints addresses, others have m    381           breakpoints addresses, others have mixed registers to store
398           them but define the access type in a    382           them but define the access type in a control register.
399           Select this option if your arch impl    383           Select this option if your arch implements breakpoints under the
400           latter fashion.                         384           latter fashion.
401                                                   385 
402 config HAVE_USER_RETURN_NOTIFIER                  386 config HAVE_USER_RETURN_NOTIFIER
403         bool                                      387         bool
404                                                   388 
405 config HAVE_PERF_EVENTS_NMI                       389 config HAVE_PERF_EVENTS_NMI
406         bool                                      390         bool
407         help                                      391         help
408           System hardware can generate an NMI     392           System hardware can generate an NMI using the perf event
409           subsystem.  Also has support for cal    393           subsystem.  Also has support for calculating CPU cycle events
410           to determine how many clock cycles i    394           to determine how many clock cycles in a given period.
411                                                   395 
412 config HAVE_HARDLOCKUP_DETECTOR_PERF              396 config HAVE_HARDLOCKUP_DETECTOR_PERF
413         bool                                      397         bool
414         depends on HAVE_PERF_EVENTS_NMI           398         depends on HAVE_PERF_EVENTS_NMI
415         help                                      399         help
416           The arch chooses to use the generic     400           The arch chooses to use the generic perf-NMI-based hardlockup
417           detector. Must define HAVE_PERF_EVEN    401           detector. Must define HAVE_PERF_EVENTS_NMI.
418                                                   402 
419 config HAVE_HARDLOCKUP_DETECTOR_ARCH           !! 403 config HAVE_NMI_WATCHDOG
                                                   >> 404         depends on HAVE_NMI
420         bool                                      405         bool
421         help                                      406         help
422           The arch provides its own hardlockup !! 407           The arch provides a low level NMI watchdog. It provides
423           of the generic ones.                 !! 408           asm/nmi.h, and defines its own arch_touch_nmi_watchdog().
424                                                   409 
425           It uses the same command line parame !! 410 config HAVE_HARDLOCKUP_DETECTOR_ARCH
426           as the generic hardlockup detectors. !! 411         bool
                                                   >> 412         select HAVE_NMI_WATCHDOG
                                                   >> 413         help
                                                   >> 414           The arch chooses to provide its own hardlockup detector, which is
                                                   >> 415           a superset of the HAVE_NMI_WATCHDOG. It also conforms to config
                                                   >> 416           interfaces and parameters provided by hardlockup detector subsystem.
427                                                   417 
428 config HAVE_PERF_REGS                             418 config HAVE_PERF_REGS
429         bool                                      419         bool
430         help                                      420         help
431           Support selective register dumps for    421           Support selective register dumps for perf events. This includes
432           bit-mapping of each registers and a     422           bit-mapping of each registers and a unique architecture id.
433                                                   423 
434 config HAVE_PERF_USER_STACK_DUMP                  424 config HAVE_PERF_USER_STACK_DUMP
435         bool                                      425         bool
436         help                                      426         help
437           Support user stack dumps for perf ev    427           Support user stack dumps for perf event samples. This needs
438           access to the user stack pointer whi    428           access to the user stack pointer which is not unified across
439           architectures.                          429           architectures.
440                                                   430 
441 config HAVE_ARCH_JUMP_LABEL                       431 config HAVE_ARCH_JUMP_LABEL
442         bool                                      432         bool
443                                                   433 
444 config HAVE_ARCH_JUMP_LABEL_RELATIVE              434 config HAVE_ARCH_JUMP_LABEL_RELATIVE
445         bool                                      435         bool
446                                                   436 
447 config MMU_GATHER_TABLE_FREE                      437 config MMU_GATHER_TABLE_FREE
448         bool                                      438         bool
449                                                   439 
450 config MMU_GATHER_RCU_TABLE_FREE                  440 config MMU_GATHER_RCU_TABLE_FREE
451         bool                                      441         bool
452         select MMU_GATHER_TABLE_FREE              442         select MMU_GATHER_TABLE_FREE
453                                                   443 
454 config MMU_GATHER_PAGE_SIZE                       444 config MMU_GATHER_PAGE_SIZE
455         bool                                      445         bool
456                                                   446 
457 config MMU_GATHER_NO_RANGE                        447 config MMU_GATHER_NO_RANGE
458         bool                                      448         bool
459         select MMU_GATHER_MERGE_VMAS              449         select MMU_GATHER_MERGE_VMAS
460                                                   450 
461 config MMU_GATHER_NO_FLUSH_CACHE                  451 config MMU_GATHER_NO_FLUSH_CACHE
462         bool                                      452         bool
463                                                   453 
464 config MMU_GATHER_MERGE_VMAS                      454 config MMU_GATHER_MERGE_VMAS
465         bool                                      455         bool
466                                                   456 
467 config MMU_GATHER_NO_GATHER                       457 config MMU_GATHER_NO_GATHER
468         bool                                      458         bool
469         depends on MMU_GATHER_TABLE_FREE          459         depends on MMU_GATHER_TABLE_FREE
470                                                   460 
471 config ARCH_WANT_IRQS_OFF_ACTIVATE_MM             461 config ARCH_WANT_IRQS_OFF_ACTIVATE_MM
472         bool                                      462         bool
473         help                                      463         help
474           Temporary select until all architect    464           Temporary select until all architectures can be converted to have
475           irqs disabled over activate_mm. Arch    465           irqs disabled over activate_mm. Architectures that do IPI based TLB
476           shootdowns should enable this.          466           shootdowns should enable this.
477                                                   467 
478 # Use normal mm refcounting for MMU_LAZY_TLB k << 
479 # MMU_LAZY_TLB_REFCOUNT=n can improve the scal << 
480 # to/from kernel threads when the same mm is r << 
481 # multi-threaded application), by reducing con << 
482 #                                              << 
483 # This can be disabled if the architecture ens << 
484 # "lazy tlb" beyond its final refcount (i.e.,  << 
485 # or its kernel page tables). This could be ar << 
486 # final exit(2) TLB flush, for example.        << 
487 #                                              << 
488 # To implement this, an arch *must*:           << 
489 # Ensure the _lazy_tlb variants of mmgrab/mmdr << 
490 # the lazy tlb reference of a kthread's ->acti << 
491 # converted already).                          << 
492 config MMU_LAZY_TLB_REFCOUNT                   << 
493         def_bool y                             << 
494         depends on !MMU_LAZY_TLB_SHOOTDOWN     << 
495                                                << 
496 # This option allows MMU_LAZY_TLB_REFCOUNT=n.  << 
497 # mm as a lazy tlb beyond its last reference c << 
498 # users before the mm is deallocated. __mmdrop << 
499 # be using the mm as a lazy tlb, so that they  << 
500 # init_mm for their active mm. mm_cpumask(mm)  << 
501 # may be using mm as a lazy tlb mm.            << 
502 #                                              << 
503 # To implement this, an arch *must*:           << 
504 # - At the time of the final mmdrop of the mm, << 
505 #   at least all possible CPUs in which the mm << 
506 # - It must meet the requirements for MMU_LAZY << 
507 config MMU_LAZY_TLB_SHOOTDOWN                  << 
508         bool                                   << 
509                                                << 
510 config ARCH_HAVE_NMI_SAFE_CMPXCHG                 468 config ARCH_HAVE_NMI_SAFE_CMPXCHG
511         bool                                      469         bool
512                                                   470 
513 config ARCH_HAVE_EXTRA_ELF_NOTES               << 
514         bool                                   << 
515         help                                   << 
516           An architecture should select this i << 
517           arch-specific ELF note section to co << 
518           functions: elf_coredump_extra_notes_ << 
519           elf_coredump_extra_notes_write() whi << 
520           dumper.                              << 
521                                                << 
522 config ARCH_HAS_NMI_SAFE_THIS_CPU_OPS             471 config ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
523         bool                                      472         bool
524                                                   473 
525 config HAVE_ALIGNED_STRUCT_PAGE                   474 config HAVE_ALIGNED_STRUCT_PAGE
526         bool                                      475         bool
527         help                                      476         help
528           This makes sure that struct pages ar    477           This makes sure that struct pages are double word aligned and that
529           e.g. the SLUB allocator can perform     478           e.g. the SLUB allocator can perform double word atomic operations
530           on a struct page for better performa    479           on a struct page for better performance. However selecting this
531           might increase the size of a struct     480           might increase the size of a struct page by a word.
532                                                   481 
533 config HAVE_CMPXCHG_LOCAL                         482 config HAVE_CMPXCHG_LOCAL
534         bool                                      483         bool
535                                                   484 
536 config HAVE_CMPXCHG_DOUBLE                        485 config HAVE_CMPXCHG_DOUBLE
537         bool                                      486         bool
538                                                   487 
539 config ARCH_WEAK_RELEASE_ACQUIRE                  488 config ARCH_WEAK_RELEASE_ACQUIRE
540         bool                                      489         bool
541                                                   490 
542 config ARCH_WANT_IPC_PARSE_VERSION                491 config ARCH_WANT_IPC_PARSE_VERSION
543         bool                                      492         bool
544                                                   493 
545 config ARCH_WANT_COMPAT_IPC_PARSE_VERSION         494 config ARCH_WANT_COMPAT_IPC_PARSE_VERSION
546         bool                                      495         bool
547                                                   496 
548 config ARCH_WANT_OLD_COMPAT_IPC                   497 config ARCH_WANT_OLD_COMPAT_IPC
549         select ARCH_WANT_COMPAT_IPC_PARSE_VERS    498         select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
550         bool                                      499         bool
551                                                   500 
552 config HAVE_ARCH_SECCOMP                          501 config HAVE_ARCH_SECCOMP
553         bool                                      502         bool
554         help                                      503         help
555           An arch should select this symbol to    504           An arch should select this symbol to support seccomp mode 1 (the fixed
556           syscall policy), and must provide an    505           syscall policy), and must provide an overrides for __NR_seccomp_sigreturn,
557           and compat syscalls if the asm-gener    506           and compat syscalls if the asm-generic/seccomp.h defaults need adjustment:
558           - __NR_seccomp_read_32                  507           - __NR_seccomp_read_32
559           - __NR_seccomp_write_32                 508           - __NR_seccomp_write_32
560           - __NR_seccomp_exit_32                  509           - __NR_seccomp_exit_32
561           - __NR_seccomp_sigreturn_32             510           - __NR_seccomp_sigreturn_32
562                                                   511 
563 config HAVE_ARCH_SECCOMP_FILTER                   512 config HAVE_ARCH_SECCOMP_FILTER
564         bool                                      513         bool
565         select HAVE_ARCH_SECCOMP                  514         select HAVE_ARCH_SECCOMP
566         help                                      515         help
567           An arch should select this symbol if    516           An arch should select this symbol if it provides all of these things:
568           - all the requirements for HAVE_ARCH    517           - all the requirements for HAVE_ARCH_SECCOMP
569           - syscall_get_arch()                    518           - syscall_get_arch()
570           - syscall_get_arguments()               519           - syscall_get_arguments()
571           - syscall_rollback()                    520           - syscall_rollback()
572           - syscall_set_return_value()            521           - syscall_set_return_value()
573           - SIGSYS siginfo_t support              522           - SIGSYS siginfo_t support
574           - secure_computing is called from a     523           - secure_computing is called from a ptrace_event()-safe context
575           - secure_computing return value is c    524           - secure_computing return value is checked and a return value of -1
576             results in the system call being s    525             results in the system call being skipped immediately.
577           - seccomp syscall wired up              526           - seccomp syscall wired up
578           - if !HAVE_SPARSE_SYSCALL_NR, have S    527           - if !HAVE_SPARSE_SYSCALL_NR, have SECCOMP_ARCH_NATIVE,
579             SECCOMP_ARCH_NATIVE_NR, SECCOMP_AR    528             SECCOMP_ARCH_NATIVE_NR, SECCOMP_ARCH_NATIVE_NAME defined. If
580             COMPAT is supported, have the SECC    529             COMPAT is supported, have the SECCOMP_ARCH_COMPAT* defines too.
581                                                   530 
582 config SECCOMP                                    531 config SECCOMP
583         prompt "Enable seccomp to safely execu    532         prompt "Enable seccomp to safely execute untrusted bytecode"
584         def_bool y                                533         def_bool y
585         depends on HAVE_ARCH_SECCOMP              534         depends on HAVE_ARCH_SECCOMP
586         help                                      535         help
587           This kernel feature is useful for nu    536           This kernel feature is useful for number crunching applications
588           that may need to handle untrusted by    537           that may need to handle untrusted bytecode during their
589           execution. By using pipes or other t    538           execution. By using pipes or other transports made available
590           to the process as file descriptors s    539           to the process as file descriptors supporting the read/write
591           syscalls, it's possible to isolate t    540           syscalls, it's possible to isolate those applications in their
592           own address space using seccomp. Onc    541           own address space using seccomp. Once seccomp is enabled via
593           prctl(PR_SET_SECCOMP) or the seccomp    542           prctl(PR_SET_SECCOMP) or the seccomp() syscall, it cannot be
594           disabled and the task is only allowe    543           disabled and the task is only allowed to execute a few safe
595           syscalls defined by each seccomp mod    544           syscalls defined by each seccomp mode.
596                                                   545 
597           If unsure, say Y.                       546           If unsure, say Y.
598                                                   547 
599 config SECCOMP_FILTER                             548 config SECCOMP_FILTER
600         def_bool y                                549         def_bool y
601         depends on HAVE_ARCH_SECCOMP_FILTER &&    550         depends on HAVE_ARCH_SECCOMP_FILTER && SECCOMP && NET
602         help                                      551         help
603           Enable tasks to build secure computi    552           Enable tasks to build secure computing environments defined
604           in terms of Berkeley Packet Filter p    553           in terms of Berkeley Packet Filter programs which implement
605           task-defined system call filtering p    554           task-defined system call filtering polices.
606                                                   555 
607           See Documentation/userspace-api/secc    556           See Documentation/userspace-api/seccomp_filter.rst for details.
608                                                   557 
609 config SECCOMP_CACHE_DEBUG                        558 config SECCOMP_CACHE_DEBUG
610         bool "Show seccomp filter cache status    559         bool "Show seccomp filter cache status in /proc/pid/seccomp_cache"
611         depends on SECCOMP_FILTER && !HAVE_SPA    560         depends on SECCOMP_FILTER && !HAVE_SPARSE_SYSCALL_NR
612         depends on PROC_FS                        561         depends on PROC_FS
613         help                                      562         help
614           This enables the /proc/pid/seccomp_c    563           This enables the /proc/pid/seccomp_cache interface to monitor
615           seccomp cache data. The file format     564           seccomp cache data. The file format is subject to change. Reading
616           the file requires CAP_SYS_ADMIN.        565           the file requires CAP_SYS_ADMIN.
617                                                   566 
618           This option is for debugging only. E    567           This option is for debugging only. Enabling presents the risk that
619           an adversary may be able to infer th    568           an adversary may be able to infer the seccomp filter logic.
620                                                   569 
621           If unsure, say N.                       570           If unsure, say N.
622                                                   571 
623 config HAVE_ARCH_STACKLEAK                        572 config HAVE_ARCH_STACKLEAK
624         bool                                      573         bool
625         help                                      574         help
626           An architecture should select this i    575           An architecture should select this if it has the code which
627           fills the used part of the kernel st    576           fills the used part of the kernel stack with the STACKLEAK_POISON
628           value before returning from system c    577           value before returning from system calls.
629                                                   578 
630 config HAVE_STACKPROTECTOR                        579 config HAVE_STACKPROTECTOR
631         bool                                      580         bool
632         help                                      581         help
633           An arch should select this symbol if    582           An arch should select this symbol if:
634           - it has implemented a stack canary     583           - it has implemented a stack canary (e.g. __stack_chk_guard)
635                                                   584 
636 config STACKPROTECTOR                             585 config STACKPROTECTOR
637         bool "Stack Protector buffer overflow     586         bool "Stack Protector buffer overflow detection"
638         depends on HAVE_STACKPROTECTOR            587         depends on HAVE_STACKPROTECTOR
639         depends on $(cc-option,-fstack-protect    588         depends on $(cc-option,-fstack-protector)
640         default y                                 589         default y
641         help                                      590         help
642           This option turns on the "stack-prot    591           This option turns on the "stack-protector" GCC feature. This
643           feature puts, at the beginning of fu    592           feature puts, at the beginning of functions, a canary value on
644           the stack just before the return add    593           the stack just before the return address, and validates
645           the value just before actually retur    594           the value just before actually returning.  Stack based buffer
646           overflows (that need to overwrite th    595           overflows (that need to overwrite this return address) now also
647           overwrite the canary, which gets det    596           overwrite the canary, which gets detected and the attack is then
648           neutralized via a kernel panic.         597           neutralized via a kernel panic.
649                                                   598 
650           Functions will have the stack-protec    599           Functions will have the stack-protector canary logic added if they
651           have an 8-byte or larger character a    600           have an 8-byte or larger character array on the stack.
652                                                   601 
653           This feature requires gcc version 4.    602           This feature requires gcc version 4.2 or above, or a distribution
654           gcc with the feature backported ("-f    603           gcc with the feature backported ("-fstack-protector").
655                                                   604 
656           On an x86 "defconfig" build, this fe    605           On an x86 "defconfig" build, this feature adds canary checks to
657           about 3% of all kernel functions, wh    606           about 3% of all kernel functions, which increases kernel code size
658           by about 0.3%.                          607           by about 0.3%.
659                                                   608 
660 config STACKPROTECTOR_STRONG                      609 config STACKPROTECTOR_STRONG
661         bool "Strong Stack Protector"             610         bool "Strong Stack Protector"
662         depends on STACKPROTECTOR                 611         depends on STACKPROTECTOR
663         depends on $(cc-option,-fstack-protect    612         depends on $(cc-option,-fstack-protector-strong)
664         default y                                 613         default y
665         help                                      614         help
666           Functions will have the stack-protec    615           Functions will have the stack-protector canary logic added in any
667           of the following conditions:            616           of the following conditions:
668                                                   617 
669           - local variable's address used as p    618           - local variable's address used as part of the right hand side of an
670             assignment or function argument       619             assignment or function argument
671           - local variable is an array (or uni    620           - local variable is an array (or union containing an array),
672             regardless of array type or length    621             regardless of array type or length
673           - uses register local variables         622           - uses register local variables
674                                                   623 
675           This feature requires gcc version 4.    624           This feature requires gcc version 4.9 or above, or a distribution
676           gcc with the feature backported ("-f    625           gcc with the feature backported ("-fstack-protector-strong").
677                                                   626 
678           On an x86 "defconfig" build, this fe    627           On an x86 "defconfig" build, this feature adds canary checks to
679           about 20% of all kernel functions, w    628           about 20% of all kernel functions, which increases the kernel code
680           size by about 2%.                       629           size by about 2%.
681                                                   630 
682 config ARCH_SUPPORTS_SHADOW_CALL_STACK            631 config ARCH_SUPPORTS_SHADOW_CALL_STACK
683         bool                                      632         bool
684         help                                      633         help
685           An architecture should select this i    634           An architecture should select this if it supports the compiler's
686           Shadow Call Stack and implements run    635           Shadow Call Stack and implements runtime support for shadow stack
687           switching.                              636           switching.
688                                                   637 
689 config SHADOW_CALL_STACK                          638 config SHADOW_CALL_STACK
690         bool "Shadow Call Stack"                  639         bool "Shadow Call Stack"
691         depends on ARCH_SUPPORTS_SHADOW_CALL_S    640         depends on ARCH_SUPPORTS_SHADOW_CALL_STACK
692         depends on DYNAMIC_FTRACE_WITH_ARGS ||    641         depends on DYNAMIC_FTRACE_WITH_ARGS || DYNAMIC_FTRACE_WITH_REGS || !FUNCTION_GRAPH_TRACER
693         depends on MMU                         << 
694         help                                      642         help
695           This option enables the compiler's S    643           This option enables the compiler's Shadow Call Stack, which
696           uses a shadow stack to protect funct    644           uses a shadow stack to protect function return addresses from
697           being overwritten by an attacker. Mo    645           being overwritten by an attacker. More information can be found
698           in the compiler's documentation:        646           in the compiler's documentation:
699                                                   647 
700           - Clang: https://clang.llvm.org/docs    648           - Clang: https://clang.llvm.org/docs/ShadowCallStack.html
701           - GCC: https://gcc.gnu.org/onlinedoc    649           - GCC: https://gcc.gnu.org/onlinedocs/gcc/Instrumentation-Options.html#Instrumentation-Options
702                                                   650 
703           Note that security guarantees in the    651           Note that security guarantees in the kernel differ from the
704           ones documented for user space. The     652           ones documented for user space. The kernel must store addresses
705           of shadow stacks in memory, which me    653           of shadow stacks in memory, which means an attacker capable of
706           reading and writing arbitrary memory    654           reading and writing arbitrary memory may be able to locate them
707           and hijack control flow by modifying    655           and hijack control flow by modifying the stacks.
708                                                   656 
709 config DYNAMIC_SCS                                657 config DYNAMIC_SCS
710         bool                                      658         bool
711         help                                      659         help
712           Set by the arch code if it relies on    660           Set by the arch code if it relies on code patching to insert the
713           shadow call stack push and pop instr    661           shadow call stack push and pop instructions rather than on the
714           compiler.                               662           compiler.
715                                                   663 
716 config LTO                                        664 config LTO
717         bool                                      665         bool
718         help                                      666         help
719           Selected if the kernel will be built    667           Selected if the kernel will be built using the compiler's LTO feature.
720                                                   668 
721 config LTO_CLANG                                  669 config LTO_CLANG
722         bool                                      670         bool
723         select LTO                                671         select LTO
724         help                                      672         help
725           Selected if the kernel will be built    673           Selected if the kernel will be built using Clang's LTO feature.
726                                                   674 
727 config ARCH_SUPPORTS_LTO_CLANG                    675 config ARCH_SUPPORTS_LTO_CLANG
728         bool                                      676         bool
729         help                                      677         help
730           An architecture should select this o    678           An architecture should select this option if it supports:
731           - compiling with Clang,                 679           - compiling with Clang,
732           - compiling inline assembly with Cla    680           - compiling inline assembly with Clang's integrated assembler,
733           - and linking with LLD.                 681           - and linking with LLD.
734                                                   682 
735 config ARCH_SUPPORTS_LTO_CLANG_THIN               683 config ARCH_SUPPORTS_LTO_CLANG_THIN
736         bool                                      684         bool
737         help                                      685         help
738           An architecture should select this o    686           An architecture should select this option if it can support Clang's
739           ThinLTO mode.                           687           ThinLTO mode.
740                                                   688 
741 config HAS_LTO_CLANG                              689 config HAS_LTO_CLANG
742         def_bool y                                690         def_bool y
743         depends on CC_IS_CLANG && LD_IS_LLD &&    691         depends on CC_IS_CLANG && LD_IS_LLD && AS_IS_LLVM
744         depends on $(success,$(NM) --help | he    692         depends on $(success,$(NM) --help | head -n 1 | grep -qi llvm)
745         depends on $(success,$(AR) --help | he    693         depends on $(success,$(AR) --help | head -n 1 | grep -qi llvm)
746         depends on ARCH_SUPPORTS_LTO_CLANG        694         depends on ARCH_SUPPORTS_LTO_CLANG
747         depends on !FTRACE_MCOUNT_USE_RECORDMC    695         depends on !FTRACE_MCOUNT_USE_RECORDMCOUNT
748         # https://github.com/ClangBuiltLinux/l !! 696         depends on !KASAN || KASAN_HW_TAGS
749         depends on (!KASAN || KASAN_HW_TAGS || << 
750         depends on (!KCOV || CLANG_VERSION >=  << 
751         depends on !GCOV_KERNEL                   697         depends on !GCOV_KERNEL
752         help                                      698         help
753           The compiler and Kconfig options sup    699           The compiler and Kconfig options support building with Clang's
754           LTO.                                    700           LTO.
755                                                   701 
756 choice                                            702 choice
757         prompt "Link Time Optimization (LTO)"     703         prompt "Link Time Optimization (LTO)"
758         default LTO_NONE                          704         default LTO_NONE
759         help                                      705         help
760           This option enables Link Time Optimi    706           This option enables Link Time Optimization (LTO), which allows the
761           compiler to optimize binaries global    707           compiler to optimize binaries globally.
762                                                   708 
763           If unsure, select LTO_NONE. Note tha    709           If unsure, select LTO_NONE. Note that LTO is very resource-intensive
764           so it's disabled by default.            710           so it's disabled by default.
765                                                   711 
766 config LTO_NONE                                   712 config LTO_NONE
767         bool "None"                               713         bool "None"
768         help                                      714         help
769           Build the kernel normally, without L    715           Build the kernel normally, without Link Time Optimization (LTO).
770                                                   716 
771 config LTO_CLANG_FULL                             717 config LTO_CLANG_FULL
772         bool "Clang Full LTO (EXPERIMENTAL)"      718         bool "Clang Full LTO (EXPERIMENTAL)"
773         depends on HAS_LTO_CLANG                  719         depends on HAS_LTO_CLANG
774         depends on !COMPILE_TEST                  720         depends on !COMPILE_TEST
775         select LTO_CLANG                          721         select LTO_CLANG
776         help                                      722         help
777           This option enables Clang's full Lin    723           This option enables Clang's full Link Time Optimization (LTO), which
778           allows the compiler to optimize the     724           allows the compiler to optimize the kernel globally. If you enable
779           this option, the compiler generates     725           this option, the compiler generates LLVM bitcode instead of ELF
780           object files, and the actual compila    726           object files, and the actual compilation from bitcode happens at
781           the LTO link step, which may take se    727           the LTO link step, which may take several minutes depending on the
782           kernel configuration. More informati    728           kernel configuration. More information can be found from LLVM's
783           documentation:                          729           documentation:
784                                                   730 
785             https://llvm.org/docs/LinkTimeOpti    731             https://llvm.org/docs/LinkTimeOptimization.html
786                                                   732 
787           During link time, this option can us    733           During link time, this option can use a large amount of RAM, and
788           may take much longer than the ThinLT    734           may take much longer than the ThinLTO option.
789                                                   735 
790 config LTO_CLANG_THIN                             736 config LTO_CLANG_THIN
791         bool "Clang ThinLTO (EXPERIMENTAL)"       737         bool "Clang ThinLTO (EXPERIMENTAL)"
792         depends on HAS_LTO_CLANG && ARCH_SUPPO    738         depends on HAS_LTO_CLANG && ARCH_SUPPORTS_LTO_CLANG_THIN
793         select LTO_CLANG                          739         select LTO_CLANG
794         help                                      740         help
795           This option enables Clang's ThinLTO,    741           This option enables Clang's ThinLTO, which allows for parallel
796           optimization and faster incremental     742           optimization and faster incremental compiles compared to the
797           CONFIG_LTO_CLANG_FULL option. More i    743           CONFIG_LTO_CLANG_FULL option. More information can be found
798           from Clang's documentation:             744           from Clang's documentation:
799                                                   745 
800             https://clang.llvm.org/docs/ThinLT    746             https://clang.llvm.org/docs/ThinLTO.html
801                                                   747 
802           If unsure, say Y.                       748           If unsure, say Y.
803 endchoice                                         749 endchoice
804                                                   750 
805 config ARCH_SUPPORTS_CFI_CLANG                    751 config ARCH_SUPPORTS_CFI_CLANG
806         bool                                      752         bool
807         help                                      753         help
808           An architecture should select this o    754           An architecture should select this option if it can support Clang's
809           Control-Flow Integrity (CFI) checkin    755           Control-Flow Integrity (CFI) checking.
810                                                   756 
811 config ARCH_USES_CFI_TRAPS                        757 config ARCH_USES_CFI_TRAPS
812         bool                                      758         bool
813                                                   759 
814 config CFI_CLANG                                  760 config CFI_CLANG
815         bool "Use Clang's Control Flow Integri    761         bool "Use Clang's Control Flow Integrity (CFI)"
816         depends on ARCH_SUPPORTS_CFI_CLANG        762         depends on ARCH_SUPPORTS_CFI_CLANG
817         depends on $(cc-option,-fsanitize=kcfi    763         depends on $(cc-option,-fsanitize=kcfi)
818         help                                      764         help
819           This option enables Clang's forward- !! 765           This option enables Clang’s forward-edge Control Flow Integrity
820           (CFI) checking, where the compiler i    766           (CFI) checking, where the compiler injects a runtime check to each
821           indirect function call to ensure the    767           indirect function call to ensure the target is a valid function with
822           the correct static type. This restri    768           the correct static type. This restricts possible call targets and
823           makes it more difficult for an attac    769           makes it more difficult for an attacker to exploit bugs that allow
824           the modification of stored function     770           the modification of stored function pointers. More information can be
825           found from Clang's documentation:       771           found from Clang's documentation:
826                                                   772 
827             https://clang.llvm.org/docs/Contro    773             https://clang.llvm.org/docs/ControlFlowIntegrity.html
828                                                   774 
829 config CFI_PERMISSIVE                             775 config CFI_PERMISSIVE
830         bool "Use CFI in permissive mode"         776         bool "Use CFI in permissive mode"
831         depends on CFI_CLANG                      777         depends on CFI_CLANG
832         help                                      778         help
833           When selected, Control Flow Integrit    779           When selected, Control Flow Integrity (CFI) violations result in a
834           warning instead of a kernel panic. T    780           warning instead of a kernel panic. This option should only be used
835           for finding indirect call type misma    781           for finding indirect call type mismatches during development.
836                                                   782 
837           If unsure, say N.                       783           If unsure, say N.
838                                                   784 
839 config HAVE_ARCH_WITHIN_STACK_FRAMES              785 config HAVE_ARCH_WITHIN_STACK_FRAMES
840         bool                                      786         bool
841         help                                      787         help
842           An architecture should select this i    788           An architecture should select this if it can walk the kernel stack
843           frames to determine if an object is     789           frames to determine if an object is part of either the arguments
844           or local variables (i.e. that it exc    790           or local variables (i.e. that it excludes saved return addresses,
845           and similar) by implementing an inli    791           and similar) by implementing an inline arch_within_stack_frames(),
846           which is used by CONFIG_HARDENED_USE    792           which is used by CONFIG_HARDENED_USERCOPY.
847                                                   793 
848 config HAVE_CONTEXT_TRACKING_USER                 794 config HAVE_CONTEXT_TRACKING_USER
849         bool                                      795         bool
850         help                                      796         help
851           Provide kernel/user boundaries probe    797           Provide kernel/user boundaries probes necessary for subsystems
852           that need it, such as userspace RCU     798           that need it, such as userspace RCU extended quiescent state.
853           Syscalls need to be wrapped inside u    799           Syscalls need to be wrapped inside user_exit()-user_enter(), either
854           optimized behind static key or throu    800           optimized behind static key or through the slow path using TIF_NOHZ
855           flag. Exceptions handlers must be wr    801           flag. Exceptions handlers must be wrapped as well. Irqs are already
856           protected inside ct_irq_enter/ct_irq    802           protected inside ct_irq_enter/ct_irq_exit() but preemption or signal
857           handling on irq exit still need to b    803           handling on irq exit still need to be protected.
858                                                   804 
859 config HAVE_CONTEXT_TRACKING_USER_OFFSTACK        805 config HAVE_CONTEXT_TRACKING_USER_OFFSTACK
860         bool                                      806         bool
861         help                                      807         help
862           Architecture neither relies on excep    808           Architecture neither relies on exception_enter()/exception_exit()
863           nor on schedule_user(). Also preempt    809           nor on schedule_user(). Also preempt_schedule_notrace() and
864           preempt_schedule_irq() can't be call    810           preempt_schedule_irq() can't be called in a preemptible section
865           while context tracking is CONTEXT_US    811           while context tracking is CONTEXT_USER. This feature reflects a sane
866           entry implementation where the follo    812           entry implementation where the following requirements are met on
867           critical entry code, ie: before user    813           critical entry code, ie: before user_exit() or after user_enter():
868                                                   814 
869           - Critical entry code isn't preempti    815           - Critical entry code isn't preemptible (or better yet:
870             not interruptible).                   816             not interruptible).
871           - No use of RCU read side critical s    817           - No use of RCU read side critical sections, unless ct_nmi_enter()
872             got called.                           818             got called.
873           - No use of instrumentation, unless     819           - No use of instrumentation, unless instrumentation_begin() got
874             called.                               820             called.
875                                                   821 
876 config HAVE_TIF_NOHZ                              822 config HAVE_TIF_NOHZ
877         bool                                      823         bool
878         help                                      824         help
879           Arch relies on TIF_NOHZ and syscall     825           Arch relies on TIF_NOHZ and syscall slow path to implement context
880           tracking calls to user_enter()/user_    826           tracking calls to user_enter()/user_exit().
881                                                   827 
882 config HAVE_VIRT_CPU_ACCOUNTING                   828 config HAVE_VIRT_CPU_ACCOUNTING
883         bool                                      829         bool
884                                                   830 
885 config HAVE_VIRT_CPU_ACCOUNTING_IDLE              831 config HAVE_VIRT_CPU_ACCOUNTING_IDLE
886         bool                                      832         bool
887         help                                      833         help
888           Architecture has its own way to acco    834           Architecture has its own way to account idle CPU time and therefore
889           doesn't implement vtime_account_idle    835           doesn't implement vtime_account_idle().
890                                                   836 
891 config ARCH_HAS_SCALED_CPUTIME                    837 config ARCH_HAS_SCALED_CPUTIME
892         bool                                      838         bool
893                                                   839 
894 config HAVE_VIRT_CPU_ACCOUNTING_GEN               840 config HAVE_VIRT_CPU_ACCOUNTING_GEN
895         bool                                      841         bool
896         default y if 64BIT                        842         default y if 64BIT
897         help                                      843         help
898           With VIRT_CPU_ACCOUNTING_GEN, cputim    844           With VIRT_CPU_ACCOUNTING_GEN, cputime_t becomes 64-bit.
899           Before enabling this option, arch co    845           Before enabling this option, arch code must be audited
900           to ensure there are no races in conc    846           to ensure there are no races in concurrent read/write of
901           cputime_t. For example, reading/writ    847           cputime_t. For example, reading/writing 64-bit cputime_t on
902           some 32-bit arches may require multi    848           some 32-bit arches may require multiple accesses, so proper
903           locking is needed to protect against    849           locking is needed to protect against concurrent accesses.
904                                                   850 
905 config HAVE_IRQ_TIME_ACCOUNTING                   851 config HAVE_IRQ_TIME_ACCOUNTING
906         bool                                      852         bool
907         help                                      853         help
908           Archs need to ensure they use a high    854           Archs need to ensure they use a high enough resolution clock to
909           support irq time accounting and then    855           support irq time accounting and then call enable_sched_clock_irqtime().
910                                                   856 
911 config HAVE_MOVE_PUD                              857 config HAVE_MOVE_PUD
912         bool                                      858         bool
913         help                                      859         help
914           Architectures that select this are a    860           Architectures that select this are able to move page tables at the
915           PUD level. If there are only 3 page     861           PUD level. If there are only 3 page table levels, the move effectively
916           happens at the PGD level.               862           happens at the PGD level.
917                                                   863 
918 config HAVE_MOVE_PMD                              864 config HAVE_MOVE_PMD
919         bool                                      865         bool
920         help                                      866         help
921           Archs that select this are able to m    867           Archs that select this are able to move page tables at the PMD level.
922                                                   868 
923 config HAVE_ARCH_TRANSPARENT_HUGEPAGE             869 config HAVE_ARCH_TRANSPARENT_HUGEPAGE
924         bool                                      870         bool
925                                                   871 
926 config HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD         872 config HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
927         bool                                      873         bool
928                                                   874 
929 config HAVE_ARCH_HUGE_VMAP                        875 config HAVE_ARCH_HUGE_VMAP
930         bool                                      876         bool
931                                                   877 
932 #                                                 878 #
933 #  Archs that select this would be capable of     879 #  Archs that select this would be capable of PMD-sized vmaps (i.e.,
934 #  arch_vmap_pmd_supported() returns true). Th    880 #  arch_vmap_pmd_supported() returns true). The VM_ALLOW_HUGE_VMAP flag
935 #  must be used to enable allocations to use h    881 #  must be used to enable allocations to use hugepages.
936 #                                                 882 #
937 config HAVE_ARCH_HUGE_VMALLOC                     883 config HAVE_ARCH_HUGE_VMALLOC
938         depends on HAVE_ARCH_HUGE_VMAP            884         depends on HAVE_ARCH_HUGE_VMAP
939         bool                                      885         bool
940                                                   886 
941 config ARCH_WANT_HUGE_PMD_SHARE                   887 config ARCH_WANT_HUGE_PMD_SHARE
942         bool                                      888         bool
943                                                   889 
944 # Archs that want to use pmd_mkwrite on kernel << 
945 # if there are no userspace memory management  << 
946 config ARCH_WANT_KERNEL_PMD_MKWRITE            << 
947         bool                                   << 
948                                                << 
949 config ARCH_WANT_PMD_MKWRITE                   << 
950         def_bool TRANSPARENT_HUGEPAGE || ARCH_ << 
951                                                << 
952 config HAVE_ARCH_SOFT_DIRTY                       890 config HAVE_ARCH_SOFT_DIRTY
953         bool                                      891         bool
954                                                   892 
955 config HAVE_MOD_ARCH_SPECIFIC                     893 config HAVE_MOD_ARCH_SPECIFIC
956         bool                                      894         bool
957         help                                      895         help
958           The arch uses struct mod_arch_specif    896           The arch uses struct mod_arch_specific to store data.  Many arches
959           just need a simple module loader wit    897           just need a simple module loader without arch specific data - those
960           should not enable this.                 898           should not enable this.
961                                                   899 
962 config MODULES_USE_ELF_RELA                       900 config MODULES_USE_ELF_RELA
963         bool                                      901         bool
964         help                                      902         help
965           Modules only use ELF RELA relocation    903           Modules only use ELF RELA relocations.  Modules with ELF REL
966           relocations will give an error.         904           relocations will give an error.
967                                                   905 
968 config MODULES_USE_ELF_REL                        906 config MODULES_USE_ELF_REL
969         bool                                      907         bool
970         help                                      908         help
971           Modules only use ELF REL relocations    909           Modules only use ELF REL relocations.  Modules with ELF RELA
972           relocations will give an error.         910           relocations will give an error.
973                                                   911 
974 config ARCH_WANTS_MODULES_DATA_IN_VMALLOC         912 config ARCH_WANTS_MODULES_DATA_IN_VMALLOC
975         bool                                      913         bool
976         help                                      914         help
977           For architectures like powerpc/32 wh    915           For architectures like powerpc/32 which have constraints on module
978           allocation and need to allocate modu    916           allocation and need to allocate module data outside of module area.
979                                                   917 
980 config ARCH_WANTS_EXECMEM_LATE                 << 
981         bool                                   << 
982         help                                   << 
983           For architectures that do not alloca << 
984           boot, but rather require its initial << 
985           enough entropy for module space rand << 
986           arm64.                               << 
987                                                << 
988 config HAVE_IRQ_EXIT_ON_IRQ_STACK                 918 config HAVE_IRQ_EXIT_ON_IRQ_STACK
989         bool                                      919         bool
990         help                                      920         help
991           Architecture doesn't only execute th    921           Architecture doesn't only execute the irq handler on the irq stack
992           but also irq_exit(). This way we can    922           but also irq_exit(). This way we can process softirqs on this irq
993           stack instead of switching to a new     923           stack instead of switching to a new one when we call __do_softirq()
994           in the end of an hardirq.               924           in the end of an hardirq.
995           This spares a stack switch and impro    925           This spares a stack switch and improves cache usage on softirq
996           processing.                             926           processing.
997                                                   927 
998 config HAVE_SOFTIRQ_ON_OWN_STACK                  928 config HAVE_SOFTIRQ_ON_OWN_STACK
999         bool                                      929         bool
1000         help                                     930         help
1001           Architecture provides a function to    931           Architecture provides a function to run __do_softirq() on a
1002           separate stack.                        932           separate stack.
1003                                                  933 
1004 config SOFTIRQ_ON_OWN_STACK                      934 config SOFTIRQ_ON_OWN_STACK
1005         def_bool HAVE_SOFTIRQ_ON_OWN_STACK &&    935         def_bool HAVE_SOFTIRQ_ON_OWN_STACK && !PREEMPT_RT
1006                                                  936 
1007 config ALTERNATE_USER_ADDRESS_SPACE              937 config ALTERNATE_USER_ADDRESS_SPACE
1008         bool                                     938         bool
1009         help                                     939         help
1010           Architectures set this when the CPU    940           Architectures set this when the CPU uses separate address
1011           spaces for kernel and user space po    941           spaces for kernel and user space pointers. In this case, the
1012           access_ok() check on a __user point    942           access_ok() check on a __user pointer is skipped.
1013                                                  943 
1014 config PGTABLE_LEVELS                            944 config PGTABLE_LEVELS
1015         int                                      945         int
1016         default 2                                946         default 2
1017                                                  947 
1018 config ARCH_HAS_ELF_RANDOMIZE                    948 config ARCH_HAS_ELF_RANDOMIZE
1019         bool                                     949         bool
1020         help                                     950         help
1021           An architecture supports choosing r    951           An architecture supports choosing randomized locations for
1022           stack, mmap, brk, and ET_DYN. Defin    952           stack, mmap, brk, and ET_DYN. Defined functions:
1023           - arch_mmap_rnd()                      953           - arch_mmap_rnd()
1024           - arch_randomize_brk()                 954           - arch_randomize_brk()
1025                                                  955 
1026 config HAVE_ARCH_MMAP_RND_BITS                   956 config HAVE_ARCH_MMAP_RND_BITS
1027         bool                                     957         bool
1028         help                                     958         help
1029           An arch should select this symbol i    959           An arch should select this symbol if it supports setting a variable
1030           number of bits for use in establish    960           number of bits for use in establishing the base address for mmap
1031           allocations, has MMU enabled and pr    961           allocations, has MMU enabled and provides values for both:
1032           - ARCH_MMAP_RND_BITS_MIN               962           - ARCH_MMAP_RND_BITS_MIN
1033           - ARCH_MMAP_RND_BITS_MAX               963           - ARCH_MMAP_RND_BITS_MAX
1034                                                  964 
1035 config HAVE_EXIT_THREAD                          965 config HAVE_EXIT_THREAD
1036         bool                                     966         bool
1037         help                                     967         help
1038           An architecture implements exit_thr    968           An architecture implements exit_thread.
1039                                                  969 
1040 config ARCH_MMAP_RND_BITS_MIN                    970 config ARCH_MMAP_RND_BITS_MIN
1041         int                                      971         int
1042                                                  972 
1043 config ARCH_MMAP_RND_BITS_MAX                    973 config ARCH_MMAP_RND_BITS_MAX
1044         int                                      974         int
1045                                                  975 
1046 config ARCH_MMAP_RND_BITS_DEFAULT                976 config ARCH_MMAP_RND_BITS_DEFAULT
1047         int                                      977         int
1048                                                  978 
1049 config ARCH_MMAP_RND_BITS                        979 config ARCH_MMAP_RND_BITS
1050         int "Number of bits to use for ASLR o    980         int "Number of bits to use for ASLR of mmap base address" if EXPERT
1051         range ARCH_MMAP_RND_BITS_MIN ARCH_MMA    981         range ARCH_MMAP_RND_BITS_MIN ARCH_MMAP_RND_BITS_MAX
1052         default ARCH_MMAP_RND_BITS_DEFAULT if    982         default ARCH_MMAP_RND_BITS_DEFAULT if ARCH_MMAP_RND_BITS_DEFAULT
1053         default ARCH_MMAP_RND_BITS_MIN           983         default ARCH_MMAP_RND_BITS_MIN
1054         depends on HAVE_ARCH_MMAP_RND_BITS       984         depends on HAVE_ARCH_MMAP_RND_BITS
1055         help                                     985         help
1056           This value can be used to select th    986           This value can be used to select the number of bits to use to
1057           determine the random offset to the     987           determine the random offset to the base address of vma regions
1058           resulting from mmap allocations. Th    988           resulting from mmap allocations. This value will be bounded
1059           by the architecture's minimum and m    989           by the architecture's minimum and maximum supported values.
1060                                                  990 
1061           This value can be changed after boo    991           This value can be changed after boot using the
1062           /proc/sys/vm/mmap_rnd_bits tunable     992           /proc/sys/vm/mmap_rnd_bits tunable
1063                                                  993 
1064 config HAVE_ARCH_MMAP_RND_COMPAT_BITS            994 config HAVE_ARCH_MMAP_RND_COMPAT_BITS
1065         bool                                     995         bool
1066         help                                     996         help
1067           An arch should select this symbol i    997           An arch should select this symbol if it supports running applications
1068           in compatibility mode, supports set    998           in compatibility mode, supports setting a variable number of bits for
1069           use in establishing the base addres    999           use in establishing the base address for mmap allocations, has MMU
1070           enabled and provides values for bot    1000           enabled and provides values for both:
1071           - ARCH_MMAP_RND_COMPAT_BITS_MIN        1001           - ARCH_MMAP_RND_COMPAT_BITS_MIN
1072           - ARCH_MMAP_RND_COMPAT_BITS_MAX        1002           - ARCH_MMAP_RND_COMPAT_BITS_MAX
1073                                                  1003 
1074 config ARCH_MMAP_RND_COMPAT_BITS_MIN             1004 config ARCH_MMAP_RND_COMPAT_BITS_MIN
1075         int                                      1005         int
1076                                                  1006 
1077 config ARCH_MMAP_RND_COMPAT_BITS_MAX             1007 config ARCH_MMAP_RND_COMPAT_BITS_MAX
1078         int                                      1008         int
1079                                                  1009 
1080 config ARCH_MMAP_RND_COMPAT_BITS_DEFAULT         1010 config ARCH_MMAP_RND_COMPAT_BITS_DEFAULT
1081         int                                      1011         int
1082                                                  1012 
1083 config ARCH_MMAP_RND_COMPAT_BITS                 1013 config ARCH_MMAP_RND_COMPAT_BITS
1084         int "Number of bits to use for ASLR o    1014         int "Number of bits to use for ASLR of mmap base address for compatible applications" if EXPERT
1085         range ARCH_MMAP_RND_COMPAT_BITS_MIN A    1015         range ARCH_MMAP_RND_COMPAT_BITS_MIN ARCH_MMAP_RND_COMPAT_BITS_MAX
1086         default ARCH_MMAP_RND_COMPAT_BITS_DEF    1016         default ARCH_MMAP_RND_COMPAT_BITS_DEFAULT if ARCH_MMAP_RND_COMPAT_BITS_DEFAULT
1087         default ARCH_MMAP_RND_COMPAT_BITS_MIN    1017         default ARCH_MMAP_RND_COMPAT_BITS_MIN
1088         depends on HAVE_ARCH_MMAP_RND_COMPAT_    1018         depends on HAVE_ARCH_MMAP_RND_COMPAT_BITS
1089         help                                     1019         help
1090           This value can be used to select th    1020           This value can be used to select the number of bits to use to
1091           determine the random offset to the     1021           determine the random offset to the base address of vma regions
1092           resulting from mmap allocations for    1022           resulting from mmap allocations for compatible applications This
1093           value will be bounded by the archit    1023           value will be bounded by the architecture's minimum and maximum
1094           supported values.                      1024           supported values.
1095                                                  1025 
1096           This value can be changed after boo    1026           This value can be changed after boot using the
1097           /proc/sys/vm/mmap_rnd_compat_bits t    1027           /proc/sys/vm/mmap_rnd_compat_bits tunable
1098                                                  1028 
1099 config HAVE_ARCH_COMPAT_MMAP_BASES               1029 config HAVE_ARCH_COMPAT_MMAP_BASES
1100         bool                                     1030         bool
1101         help                                     1031         help
1102           This allows 64bit applications to i    1032           This allows 64bit applications to invoke 32-bit mmap() syscall
1103           and vice-versa 32-bit applications     1033           and vice-versa 32-bit applications to call 64-bit mmap().
1104           Required for applications doing dif    1034           Required for applications doing different bitness syscalls.
1105                                                  1035 
1106 config HAVE_PAGE_SIZE_4KB                     << 
1107         bool                                  << 
1108                                               << 
1109 config HAVE_PAGE_SIZE_8KB                     << 
1110         bool                                  << 
1111                                               << 
1112 config HAVE_PAGE_SIZE_16KB                    << 
1113         bool                                  << 
1114                                               << 
1115 config HAVE_PAGE_SIZE_32KB                    << 
1116         bool                                  << 
1117                                               << 
1118 config HAVE_PAGE_SIZE_64KB                    << 
1119         bool                                  << 
1120                                               << 
1121 config HAVE_PAGE_SIZE_256KB                   << 
1122         bool                                  << 
1123                                               << 
1124 choice                                        << 
1125         prompt "MMU page size"                << 
1126                                               << 
1127 config PAGE_SIZE_4KB                          << 
1128         bool "4KiB pages"                     << 
1129         depends on HAVE_PAGE_SIZE_4KB         << 
1130         help                                  << 
1131           This option select the standard 4Ki << 
1132           available option on many architectu << 
1133           minimize memory consumption and is  << 
1134           memory systems.                     << 
1135           Some software that is written for x << 
1136           assumptions about the page size and << 
1137                                               << 
1138 config PAGE_SIZE_8KB                          << 
1139         bool "8KiB pages"                     << 
1140         depends on HAVE_PAGE_SIZE_8KB         << 
1141         help                                  << 
1142           This option is the only supported p << 
1143           processors, and can be slightly fas << 
1144                                               << 
1145 config PAGE_SIZE_16KB                         << 
1146         bool "16KiB pages"                    << 
1147         depends on HAVE_PAGE_SIZE_16KB        << 
1148         help                                  << 
1149           This option is usually a good compr << 
1150           consumption and performance for typ << 
1151           workloads, often saving a level of  << 
1152           to 4KB pages as well as reducing TL << 
1153           per-page operations in the kernel a << 
1154           page cache.                         << 
1155                                               << 
1156 config PAGE_SIZE_32KB                         << 
1157         bool "32KiB pages"                    << 
1158         depends on HAVE_PAGE_SIZE_32KB        << 
1159         help                                  << 
1160           Using 32KiB page size will result i << 
1161           kernel at the price of higher memor << 
1162           16KiB pages.  This option is availa << 
1163           Note that you will need a suitable  << 
1164           support this.                       << 
1165                                               << 
1166 config PAGE_SIZE_64KB                         << 
1167         bool "64KiB pages"                    << 
1168         depends on HAVE_PAGE_SIZE_64KB        << 
1169         help                                  << 
1170           Using 64KiB page size will result i << 
1171           kernel at the price of much higher  << 
1172           4KiB or 16KiB pages.                << 
1173           This is not suitable for general-pu << 
1174           better performance may be worth the << 
1175           supercomputing or database applicat << 
1176           large in-memory data rather than sm << 
1177                                               << 
1178 config PAGE_SIZE_256KB                        << 
1179         bool "256KiB pages"                   << 
1180         depends on HAVE_PAGE_SIZE_256KB       << 
1181         help                                  << 
1182           256KiB pages have little practical  << 
1183           memory usage.  The kernel will only << 
1184           that have been compiled with '-zmax << 
1185           (the default is 64KiB or 4KiB on mo << 
1186                                               << 
1187 endchoice                                     << 
1188                                               << 
1189 config PAGE_SIZE_LESS_THAN_64KB                  1036 config PAGE_SIZE_LESS_THAN_64KB
1190         def_bool y                               1037         def_bool y
                                                   >> 1038         depends on !ARM64_64K_PAGES
                                                   >> 1039         depends on !IA64_PAGE_SIZE_64KB
1191         depends on !PAGE_SIZE_64KB               1040         depends on !PAGE_SIZE_64KB
                                                   >> 1041         depends on !PARISC_PAGE_SIZE_64KB
1192         depends on PAGE_SIZE_LESS_THAN_256KB     1042         depends on PAGE_SIZE_LESS_THAN_256KB
1193                                                  1043 
1194 config PAGE_SIZE_LESS_THAN_256KB                 1044 config PAGE_SIZE_LESS_THAN_256KB
1195         def_bool y                               1045         def_bool y
1196         depends on !PAGE_SIZE_256KB              1046         depends on !PAGE_SIZE_256KB
1197                                                  1047 
1198 config PAGE_SHIFT                             << 
1199         int                                   << 
1200         default 12 if PAGE_SIZE_4KB           << 
1201         default 13 if PAGE_SIZE_8KB           << 
1202         default 14 if PAGE_SIZE_16KB          << 
1203         default 15 if PAGE_SIZE_32KB          << 
1204         default 16 if PAGE_SIZE_64KB          << 
1205         default 18 if PAGE_SIZE_256KB         << 
1206                                               << 
1207 # This allows to use a set of generic functio    1048 # This allows to use a set of generic functions to determine mmap base
1208 # address by giving priority to top-down sche    1049 # address by giving priority to top-down scheme only if the process
1209 # is not in legacy mode (compat task, unlimit    1050 # is not in legacy mode (compat task, unlimited stack size or
1210 # sysctl_legacy_va_layout).                      1051 # sysctl_legacy_va_layout).
1211 # Architecture that selects this option can p    1052 # Architecture that selects this option can provide its own version of:
1212 # - STACK_RND_MASK                               1053 # - STACK_RND_MASK
1213 config ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT     1054 config ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
1214         bool                                     1055         bool
1215         depends on MMU                           1056         depends on MMU
1216         select ARCH_HAS_ELF_RANDOMIZE            1057         select ARCH_HAS_ELF_RANDOMIZE
1217                                                  1058 
1218 config HAVE_OBJTOOL                              1059 config HAVE_OBJTOOL
1219         bool                                     1060         bool
1220                                                  1061 
1221 config HAVE_JUMP_LABEL_HACK                      1062 config HAVE_JUMP_LABEL_HACK
1222         bool                                     1063         bool
1223                                                  1064 
1224 config HAVE_NOINSTR_HACK                         1065 config HAVE_NOINSTR_HACK
1225         bool                                     1066         bool
1226                                                  1067 
1227 config HAVE_NOINSTR_VALIDATION                   1068 config HAVE_NOINSTR_VALIDATION
1228         bool                                     1069         bool
1229                                                  1070 
1230 config HAVE_UACCESS_VALIDATION                   1071 config HAVE_UACCESS_VALIDATION
1231         bool                                     1072         bool
1232         select OBJTOOL                           1073         select OBJTOOL
1233                                                  1074 
1234 config HAVE_STACK_VALIDATION                     1075 config HAVE_STACK_VALIDATION
1235         bool                                     1076         bool
1236         help                                     1077         help
1237           Architecture supports objtool compi    1078           Architecture supports objtool compile-time frame pointer rule
1238           validation.                            1079           validation.
1239                                                  1080 
1240 config HAVE_RELIABLE_STACKTRACE                  1081 config HAVE_RELIABLE_STACKTRACE
1241         bool                                     1082         bool
1242         help                                     1083         help
1243           Architecture has either save_stack_    1084           Architecture has either save_stack_trace_tsk_reliable() or
1244           arch_stack_walk_reliable() function    1085           arch_stack_walk_reliable() function which only returns a stack trace
1245           if it can guarantee the trace is re    1086           if it can guarantee the trace is reliable.
1246                                                  1087 
1247 config HAVE_ARCH_HASH                            1088 config HAVE_ARCH_HASH
1248         bool                                     1089         bool
1249         default n                                1090         default n
1250         help                                     1091         help
1251           If this is set, the architecture pr    1092           If this is set, the architecture provides an <asm/hash.h>
1252           file which provides platform-specif    1093           file which provides platform-specific implementations of some
1253           functions in <linux/hash.h> or fs/n    1094           functions in <linux/hash.h> or fs/namei.c.
1254                                                  1095 
1255 config HAVE_ARCH_NVRAM_OPS                       1096 config HAVE_ARCH_NVRAM_OPS
1256         bool                                     1097         bool
1257                                                  1098 
1258 config ISA_BUS_API                               1099 config ISA_BUS_API
1259         def_bool ISA                             1100         def_bool ISA
1260                                                  1101 
1261 #                                                1102 #
1262 # ABI hall of shame                              1103 # ABI hall of shame
1263 #                                                1104 #
1264 config CLONE_BACKWARDS                           1105 config CLONE_BACKWARDS
1265         bool                                     1106         bool
1266         help                                     1107         help
1267           Architecture has tls passed as the     1108           Architecture has tls passed as the 4th argument of clone(2),
1268           not the 5th one.                       1109           not the 5th one.
1269                                                  1110 
1270 config CLONE_BACKWARDS2                          1111 config CLONE_BACKWARDS2
1271         bool                                     1112         bool
1272         help                                     1113         help
1273           Architecture has the first two argu    1114           Architecture has the first two arguments of clone(2) swapped.
1274                                                  1115 
1275 config CLONE_BACKWARDS3                          1116 config CLONE_BACKWARDS3
1276         bool                                     1117         bool
1277         help                                     1118         help
1278           Architecture has tls passed as the     1119           Architecture has tls passed as the 3rd argument of clone(2),
1279           not the 5th one.                       1120           not the 5th one.
1280                                                  1121 
1281 config ODD_RT_SIGACTION                          1122 config ODD_RT_SIGACTION
1282         bool                                     1123         bool
1283         help                                     1124         help
1284           Architecture has unusual rt_sigacti    1125           Architecture has unusual rt_sigaction(2) arguments
1285                                                  1126 
1286 config OLD_SIGSUSPEND                            1127 config OLD_SIGSUSPEND
1287         bool                                     1128         bool
1288         help                                     1129         help
1289           Architecture has old sigsuspend(2)     1130           Architecture has old sigsuspend(2) syscall, of one-argument variety
1290                                                  1131 
1291 config OLD_SIGSUSPEND3                           1132 config OLD_SIGSUSPEND3
1292         bool                                     1133         bool
1293         help                                     1134         help
1294           Even weirder antique ABI - three-ar    1135           Even weirder antique ABI - three-argument sigsuspend(2)
1295                                                  1136 
1296 config OLD_SIGACTION                             1137 config OLD_SIGACTION
1297         bool                                     1138         bool
1298         help                                     1139         help
1299           Architecture has old sigaction(2) s    1140           Architecture has old sigaction(2) syscall.  Nope, not the same
1300           as OLD_SIGSUSPEND | OLD_SIGSUSPEND3    1141           as OLD_SIGSUSPEND | OLD_SIGSUSPEND3 - alpha has sigsuspend(2),
1301           but fairly different variant of sig    1142           but fairly different variant of sigaction(2), thanks to OSF/1
1302           compatibility...                       1143           compatibility...
1303                                                  1144 
1304 config COMPAT_OLD_SIGACTION                      1145 config COMPAT_OLD_SIGACTION
1305         bool                                     1146         bool
1306                                                  1147 
1307 config COMPAT_32BIT_TIME                         1148 config COMPAT_32BIT_TIME
1308         bool "Provide system calls for 32-bit    1149         bool "Provide system calls for 32-bit time_t"
1309         default !64BIT || COMPAT                 1150         default !64BIT || COMPAT
1310         help                                     1151         help
1311           This enables 32 bit time_t support     1152           This enables 32 bit time_t support in addition to 64 bit time_t support.
1312           This is relevant on all 32-bit arch    1153           This is relevant on all 32-bit architectures, and 64-bit architectures
1313           as part of compat syscall handling.    1154           as part of compat syscall handling.
1314                                                  1155 
1315 config ARCH_NO_PREEMPT                           1156 config ARCH_NO_PREEMPT
1316         bool                                     1157         bool
1317                                                  1158 
                                                   >> 1159 config ARCH_EPHEMERAL_INODES
                                                   >> 1160         def_bool n
                                                   >> 1161         help
                                                   >> 1162           An arch should select this symbol if it doesn't keep track of inode
                                                   >> 1163           instances on its own, but instead relies on something else (e.g. the
                                                   >> 1164           host kernel for an UML kernel).
                                                   >> 1165 
1318 config ARCH_SUPPORTS_RT                          1166 config ARCH_SUPPORTS_RT
1319         bool                                     1167         bool
1320                                                  1168 
1321 config CPU_NO_EFFICIENT_FFS                      1169 config CPU_NO_EFFICIENT_FFS
1322         def_bool n                               1170         def_bool n
1323                                                  1171 
1324 config HAVE_ARCH_VMAP_STACK                      1172 config HAVE_ARCH_VMAP_STACK
1325         def_bool n                               1173         def_bool n
1326         help                                     1174         help
1327           An arch should select this symbol i    1175           An arch should select this symbol if it can support kernel stacks
1328           in vmalloc space.  This means:         1176           in vmalloc space.  This means:
1329                                                  1177 
1330           - vmalloc space must be large enoug    1178           - vmalloc space must be large enough to hold many kernel stacks.
1331             This may rule out many 32-bit arc    1179             This may rule out many 32-bit architectures.
1332                                                  1180 
1333           - Stacks in vmalloc space need to w    1181           - Stacks in vmalloc space need to work reliably.  For example, if
1334             vmap page tables are created on d    1182             vmap page tables are created on demand, either this mechanism
1335             needs to work while the stack poi    1183             needs to work while the stack points to a virtual address with
1336             unpopulated page tables or arch c    1184             unpopulated page tables or arch code (switch_to() and switch_mm(),
1337             most likely) needs to ensure that    1185             most likely) needs to ensure that the stack's page table entries
1338             are populated before running on a    1186             are populated before running on a possibly unpopulated stack.
1339                                                  1187 
1340           - If the stack overflows into a gua    1188           - If the stack overflows into a guard page, something reasonable
1341             should happen.  The definition of    1189             should happen.  The definition of "reasonable" is flexible, but
1342             instantly rebooting without loggi    1190             instantly rebooting without logging anything would be unfriendly.
1343                                                  1191 
1344 config VMAP_STACK                                1192 config VMAP_STACK
1345         default y                                1193         default y
1346         bool "Use a virtually-mapped stack"      1194         bool "Use a virtually-mapped stack"
1347         depends on HAVE_ARCH_VMAP_STACK          1195         depends on HAVE_ARCH_VMAP_STACK
1348         depends on !KASAN || KASAN_HW_TAGS ||    1196         depends on !KASAN || KASAN_HW_TAGS || KASAN_VMALLOC
1349         help                                     1197         help
1350           Enable this if you want the use vir    1198           Enable this if you want the use virtually-mapped kernel stacks
1351           with guard pages.  This causes kern    1199           with guard pages.  This causes kernel stack overflows to be
1352           caught immediately rather than caus    1200           caught immediately rather than causing difficult-to-diagnose
1353           corruption.                            1201           corruption.
1354                                                  1202 
1355           To use this with software KASAN mod    1203           To use this with software KASAN modes, the architecture must support
1356           backing virtual mappings with real     1204           backing virtual mappings with real shadow memory, and KASAN_VMALLOC
1357           must be enabled.                       1205           must be enabled.
1358                                                  1206 
1359 config HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET         1207 config HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
1360         def_bool n                               1208         def_bool n
1361         help                                     1209         help
1362           An arch should select this symbol i    1210           An arch should select this symbol if it can support kernel stack
1363           offset randomization with calls to     1211           offset randomization with calls to add_random_kstack_offset()
1364           during syscall entry and choose_ran    1212           during syscall entry and choose_random_kstack_offset() during
1365           syscall exit. Careful removal of -f    1213           syscall exit. Careful removal of -fstack-protector-strong and
1366           -fstack-protector should also be ap    1214           -fstack-protector should also be applied to the entry code and
1367           closely examined, as the artificial    1215           closely examined, as the artificial stack bump looks like an array
1368           to the compiler, so it will attempt    1216           to the compiler, so it will attempt to add canary checks regardless
1369           of the static branch state.            1217           of the static branch state.
1370                                                  1218 
1371 config RANDOMIZE_KSTACK_OFFSET                   1219 config RANDOMIZE_KSTACK_OFFSET
1372         bool "Support for randomizing kernel     1220         bool "Support for randomizing kernel stack offset on syscall entry" if EXPERT
1373         default y                                1221         default y
1374         depends on HAVE_ARCH_RANDOMIZE_KSTACK    1222         depends on HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
1375         depends on INIT_STACK_NONE || !CC_IS_    1223         depends on INIT_STACK_NONE || !CC_IS_CLANG || CLANG_VERSION >= 140000
1376         help                                     1224         help
1377           The kernel stack offset can be rand    1225           The kernel stack offset can be randomized (after pt_regs) by
1378           roughly 5 bits of entropy, frustrat    1226           roughly 5 bits of entropy, frustrating memory corruption
1379           attacks that depend on stack addres    1227           attacks that depend on stack address determinism or
1380           cross-syscall address exposures.       1228           cross-syscall address exposures.
1381                                                  1229 
1382           The feature is controlled via the "    1230           The feature is controlled via the "randomize_kstack_offset=on/off"
1383           kernel boot param, and if turned of    1231           kernel boot param, and if turned off has zero overhead due to its use
1384           of static branches (see JUMP_LABEL)    1232           of static branches (see JUMP_LABEL).
1385                                                  1233 
1386           If unsure, say Y.                      1234           If unsure, say Y.
1387                                                  1235 
1388 config RANDOMIZE_KSTACK_OFFSET_DEFAULT           1236 config RANDOMIZE_KSTACK_OFFSET_DEFAULT
1389         bool "Default state of kernel stack o    1237         bool "Default state of kernel stack offset randomization"
1390         depends on RANDOMIZE_KSTACK_OFFSET       1238         depends on RANDOMIZE_KSTACK_OFFSET
1391         help                                     1239         help
1392           Kernel stack offset randomization i    1240           Kernel stack offset randomization is controlled by kernel boot param
1393           "randomize_kstack_offset=on/off", a    1241           "randomize_kstack_offset=on/off", and this config chooses the default
1394           boot state.                            1242           boot state.
1395                                                  1243 
1396 config ARCH_OPTIONAL_KERNEL_RWX                  1244 config ARCH_OPTIONAL_KERNEL_RWX
1397         def_bool n                               1245         def_bool n
1398                                                  1246 
1399 config ARCH_OPTIONAL_KERNEL_RWX_DEFAULT          1247 config ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
1400         def_bool n                               1248         def_bool n
1401                                                  1249 
1402 config ARCH_HAS_STRICT_KERNEL_RWX                1250 config ARCH_HAS_STRICT_KERNEL_RWX
1403         def_bool n                               1251         def_bool n
1404                                                  1252 
1405 config STRICT_KERNEL_RWX                         1253 config STRICT_KERNEL_RWX
1406         bool "Make kernel text and rodata rea    1254         bool "Make kernel text and rodata read-only" if ARCH_OPTIONAL_KERNEL_RWX
1407         depends on ARCH_HAS_STRICT_KERNEL_RWX    1255         depends on ARCH_HAS_STRICT_KERNEL_RWX
1408         default !ARCH_OPTIONAL_KERNEL_RWX ||     1256         default !ARCH_OPTIONAL_KERNEL_RWX || ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
1409         help                                     1257         help
1410           If this is set, kernel text and rod    1258           If this is set, kernel text and rodata memory will be made read-only,
1411           and non-text memory will be made no    1259           and non-text memory will be made non-executable. This provides
1412           protection against certain security    1260           protection against certain security exploits (e.g. executing the heap
1413           or modifying text)                     1261           or modifying text)
1414                                                  1262 
1415           These features are considered stand    1263           These features are considered standard security practice these days.
1416           You should say Y here in almost all    1264           You should say Y here in almost all cases.
1417                                                  1265 
1418 config ARCH_HAS_STRICT_MODULE_RWX                1266 config ARCH_HAS_STRICT_MODULE_RWX
1419         def_bool n                               1267         def_bool n
1420                                                  1268 
1421 config STRICT_MODULE_RWX                         1269 config STRICT_MODULE_RWX
1422         bool "Set loadable kernel module data    1270         bool "Set loadable kernel module data as NX and text as RO" if ARCH_OPTIONAL_KERNEL_RWX
1423         depends on ARCH_HAS_STRICT_MODULE_RWX    1271         depends on ARCH_HAS_STRICT_MODULE_RWX && MODULES
1424         default !ARCH_OPTIONAL_KERNEL_RWX ||     1272         default !ARCH_OPTIONAL_KERNEL_RWX || ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
1425         help                                     1273         help
1426           If this is set, module text and rod    1274           If this is set, module text and rodata memory will be made read-only,
1427           and non-text memory will be made no    1275           and non-text memory will be made non-executable. This provides
1428           protection against certain security    1276           protection against certain security exploits (e.g. writing to text)
1429                                                  1277 
1430 # select if the architecture provides an asm/    1278 # select if the architecture provides an asm/dma-direct.h header
1431 config ARCH_HAS_PHYS_TO_DMA                      1279 config ARCH_HAS_PHYS_TO_DMA
1432         bool                                     1280         bool
1433                                                  1281 
1434 config HAVE_ARCH_COMPILER_H                      1282 config HAVE_ARCH_COMPILER_H
1435         bool                                     1283         bool
1436         help                                     1284         help
1437           An architecture can select this if     1285           An architecture can select this if it provides an
1438           asm/compiler.h header that should b    1286           asm/compiler.h header that should be included after
1439           linux/compiler-*.h in order to over    1287           linux/compiler-*.h in order to override macro definitions that those
1440           headers generally provide.             1288           headers generally provide.
1441                                                  1289 
1442 config HAVE_ARCH_PREL32_RELOCATIONS              1290 config HAVE_ARCH_PREL32_RELOCATIONS
1443         bool                                     1291         bool
1444         help                                     1292         help
1445           May be selected by an architecture     1293           May be selected by an architecture if it supports place-relative
1446           32-bit relocations, both in the too    1294           32-bit relocations, both in the toolchain and in the module loader,
1447           in which case relative references c    1295           in which case relative references can be used in special sections
1448           for PCI fixup, initcalls etc which     1296           for PCI fixup, initcalls etc which are only half the size on 64 bit
1449           architectures, and don't require ru    1297           architectures, and don't require runtime relocation on relocatable
1450           kernels.                               1298           kernels.
1451                                                  1299 
1452 config ARCH_USE_MEMREMAP_PROT                    1300 config ARCH_USE_MEMREMAP_PROT
1453         bool                                     1301         bool
1454                                                  1302 
1455 config LOCK_EVENT_COUNTS                         1303 config LOCK_EVENT_COUNTS
1456         bool "Locking event counts collection    1304         bool "Locking event counts collection"
1457         depends on DEBUG_FS                      1305         depends on DEBUG_FS
1458         help                                     1306         help
1459           Enable light-weight counting of var    1307           Enable light-weight counting of various locking related events
1460           in the system with minimal performa    1308           in the system with minimal performance impact. This reduces
1461           the chance of application behavior     1309           the chance of application behavior change because of timing
1462           differences. The counts are reporte    1310           differences. The counts are reported via debugfs.
1463                                                  1311 
1464 # Select if the architecture has support for     1312 # Select if the architecture has support for applying RELR relocations.
1465 config ARCH_HAS_RELR                             1313 config ARCH_HAS_RELR
1466         bool                                     1314         bool
1467                                                  1315 
1468 config RELR                                      1316 config RELR
1469         bool "Use RELR relocation packing"       1317         bool "Use RELR relocation packing"
1470         depends on ARCH_HAS_RELR && TOOLS_SUP    1318         depends on ARCH_HAS_RELR && TOOLS_SUPPORT_RELR
1471         default y                                1319         default y
1472         help                                     1320         help
1473           Store the kernel's dynamic relocati    1321           Store the kernel's dynamic relocations in the RELR relocation packing
1474           format. Requires a compatible linke    1322           format. Requires a compatible linker (LLD supports this feature), as
1475           well as compatible NM and OBJCOPY u    1323           well as compatible NM and OBJCOPY utilities (llvm-nm and llvm-objcopy
1476           are compatible).                       1324           are compatible).
1477                                                  1325 
1478 config ARCH_HAS_MEM_ENCRYPT                      1326 config ARCH_HAS_MEM_ENCRYPT
1479         bool                                     1327         bool
1480                                                  1328 
1481 config ARCH_HAS_CC_PLATFORM                      1329 config ARCH_HAS_CC_PLATFORM
1482         bool                                     1330         bool
1483                                                  1331 
1484 config HAVE_SPARSE_SYSCALL_NR                    1332 config HAVE_SPARSE_SYSCALL_NR
1485         bool                                     1333         bool
1486         help                                     1334         help
1487           An architecture should select this     1335           An architecture should select this if its syscall numbering is sparse
1488           to save space. For example, MIPS ar    1336           to save space. For example, MIPS architecture has a syscall array with
1489           entries at 4000, 5000 and 6000 loca    1337           entries at 4000, 5000 and 6000 locations. This option turns on syscall
1490           related optimizations for a given a    1338           related optimizations for a given architecture.
1491                                                  1339 
1492 config ARCH_HAS_VDSO_DATA                        1340 config ARCH_HAS_VDSO_DATA
1493         bool                                     1341         bool
1494                                                  1342 
1495 config HAVE_STATIC_CALL                          1343 config HAVE_STATIC_CALL
1496         bool                                     1344         bool
1497                                                  1345 
1498 config HAVE_STATIC_CALL_INLINE                   1346 config HAVE_STATIC_CALL_INLINE
1499         bool                                     1347         bool
1500         depends on HAVE_STATIC_CALL              1348         depends on HAVE_STATIC_CALL
1501         select OBJTOOL                           1349         select OBJTOOL
1502                                                  1350 
1503 config HAVE_PREEMPT_DYNAMIC                      1351 config HAVE_PREEMPT_DYNAMIC
1504         bool                                     1352         bool
1505                                                  1353 
1506 config HAVE_PREEMPT_DYNAMIC_CALL                 1354 config HAVE_PREEMPT_DYNAMIC_CALL
1507         bool                                     1355         bool
1508         depends on HAVE_STATIC_CALL              1356         depends on HAVE_STATIC_CALL
1509         select HAVE_PREEMPT_DYNAMIC              1357         select HAVE_PREEMPT_DYNAMIC
1510         help                                     1358         help
1511           An architecture should select this     1359           An architecture should select this if it can handle the preemption
1512           model being selected at boot time u    1360           model being selected at boot time using static calls.
1513                                                  1361 
1514           Where an architecture selects HAVE_    1362           Where an architecture selects HAVE_STATIC_CALL_INLINE, any call to a
1515           preemption function will be patched    1363           preemption function will be patched directly.
1516                                                  1364 
1517           Where an architecture does not sele    1365           Where an architecture does not select HAVE_STATIC_CALL_INLINE, any
1518           call to a preemption function will     1366           call to a preemption function will go through a trampoline, and the
1519           trampoline will be patched.            1367           trampoline will be patched.
1520                                                  1368 
1521           It is strongly advised to support i    1369           It is strongly advised to support inline static call to avoid any
1522           overhead.                              1370           overhead.
1523                                                  1371 
1524 config HAVE_PREEMPT_DYNAMIC_KEY                  1372 config HAVE_PREEMPT_DYNAMIC_KEY
1525         bool                                     1373         bool
1526         depends on HAVE_ARCH_JUMP_LABEL          1374         depends on HAVE_ARCH_JUMP_LABEL
1527         select HAVE_PREEMPT_DYNAMIC              1375         select HAVE_PREEMPT_DYNAMIC
1528         help                                     1376         help
1529           An architecture should select this     1377           An architecture should select this if it can handle the preemption
1530           model being selected at boot time u    1378           model being selected at boot time using static keys.
1531                                                  1379 
1532           Each preemption function will be gi    1380           Each preemption function will be given an early return based on a
1533           static key. This should have slight    1381           static key. This should have slightly lower overhead than non-inline
1534           static calls, as this effectively i    1382           static calls, as this effectively inlines each trampoline into the
1535           start of its callee. This may avoid    1383           start of its callee. This may avoid redundant work, and may
1536           integrate better with CFI schemes.     1384           integrate better with CFI schemes.
1537                                                  1385 
1538           This will have greater overhead tha    1386           This will have greater overhead than using inline static calls as
1539           the call to the preemption function    1387           the call to the preemption function cannot be entirely elided.
1540                                                  1388 
1541 config ARCH_WANT_LD_ORPHAN_WARN                  1389 config ARCH_WANT_LD_ORPHAN_WARN
1542         bool                                     1390         bool
1543         help                                     1391         help
1544           An arch should select this symbol o    1392           An arch should select this symbol once all linker sections are explicitly
1545           included, size-asserted, or discard    1393           included, size-asserted, or discarded in the linker scripts. This is
1546           important because we never want exp    1394           important because we never want expected sections to be placed heuristically
1547           by the linker, since the locations     1395           by the linker, since the locations of such sections can change between linker
1548           versions.                              1396           versions.
1549                                                  1397 
1550 config HAVE_ARCH_PFN_VALID                       1398 config HAVE_ARCH_PFN_VALID
1551         bool                                     1399         bool
1552                                                  1400 
1553 config ARCH_SUPPORTS_DEBUG_PAGEALLOC             1401 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
1554         bool                                     1402         bool
1555                                                  1403 
1556 config ARCH_SUPPORTS_PAGE_TABLE_CHECK            1404 config ARCH_SUPPORTS_PAGE_TABLE_CHECK
1557         bool                                     1405         bool
1558                                                  1406 
1559 config ARCH_SPLIT_ARG64                          1407 config ARCH_SPLIT_ARG64
1560         bool                                     1408         bool
1561         help                                     1409         help
1562           If a 32-bit architecture requires 6    1410           If a 32-bit architecture requires 64-bit arguments to be split into
1563           pairs of 32-bit arguments, select t    1411           pairs of 32-bit arguments, select this option.
1564                                                  1412 
1565 config ARCH_HAS_ELFCORE_COMPAT                   1413 config ARCH_HAS_ELFCORE_COMPAT
1566         bool                                     1414         bool
1567                                                  1415 
1568 config ARCH_HAS_PARANOID_L1D_FLUSH               1416 config ARCH_HAS_PARANOID_L1D_FLUSH
1569         bool                                     1417         bool
1570                                                  1418 
1571 config ARCH_HAVE_TRACE_MMIO_ACCESS               1419 config ARCH_HAVE_TRACE_MMIO_ACCESS
1572         bool                                     1420         bool
1573                                                  1421 
1574 config DYNAMIC_SIGFRAME                          1422 config DYNAMIC_SIGFRAME
1575         bool                                     1423         bool
1576                                                  1424 
1577 # Select, if arch has a named attribute group    1425 # Select, if arch has a named attribute group bound to NUMA device nodes.
1578 config HAVE_ARCH_NODE_DEV_GROUP                  1426 config HAVE_ARCH_NODE_DEV_GROUP
1579         bool                                     1427         bool
1580                                                  1428 
1581 config ARCH_HAS_HW_PTE_YOUNG                  << 
1582         bool                                  << 
1583         help                                  << 
1584           Architectures that select this opti << 
1585           accessed bit in PTE entries when us << 
1586           translations. Architectures that re << 
1587           this option and override arch_has_h << 
1588                                               << 
1589 config ARCH_HAS_NONLEAF_PMD_YOUNG                1429 config ARCH_HAS_NONLEAF_PMD_YOUNG
1590         bool                                     1430         bool
1591         help                                     1431         help
1592           Architectures that select this opti    1432           Architectures that select this option are capable of setting the
1593           accessed bit in non-leaf PMD entrie    1433           accessed bit in non-leaf PMD entries when using them as part of linear
1594           address translations. Page table wa    1434           address translations. Page table walkers that clear the accessed bit
1595           may use this capability to reduce t    1435           may use this capability to reduce their search space.
1596                                                  1436 
1597 config ARCH_HAS_KERNEL_FPU_SUPPORT            << 
1598         bool                                  << 
1599         help                                  << 
1600           Architectures that select this opti << 
1601           the kernel, as described in Documen << 
1602                                               << 
1603 source "kernel/gcov/Kconfig"                     1437 source "kernel/gcov/Kconfig"
1604                                                  1438 
1605 source "scripts/gcc-plugins/Kconfig"             1439 source "scripts/gcc-plugins/Kconfig"
1606                                                  1440 
1607 config FUNCTION_ALIGNMENT_4B                     1441 config FUNCTION_ALIGNMENT_4B
1608         bool                                     1442         bool
1609                                                  1443 
1610 config FUNCTION_ALIGNMENT_8B                     1444 config FUNCTION_ALIGNMENT_8B
1611         bool                                     1445         bool
1612                                                  1446 
1613 config FUNCTION_ALIGNMENT_16B                    1447 config FUNCTION_ALIGNMENT_16B
1614         bool                                     1448         bool
1615                                                  1449 
1616 config FUNCTION_ALIGNMENT_32B                    1450 config FUNCTION_ALIGNMENT_32B
1617         bool                                     1451         bool
1618                                                  1452 
1619 config FUNCTION_ALIGNMENT_64B                    1453 config FUNCTION_ALIGNMENT_64B
1620         bool                                     1454         bool
1621                                                  1455 
1622 config FUNCTION_ALIGNMENT                        1456 config FUNCTION_ALIGNMENT
1623         int                                      1457         int
1624         default 64 if FUNCTION_ALIGNMENT_64B     1458         default 64 if FUNCTION_ALIGNMENT_64B
1625         default 32 if FUNCTION_ALIGNMENT_32B     1459         default 32 if FUNCTION_ALIGNMENT_32B
1626         default 16 if FUNCTION_ALIGNMENT_16B     1460         default 16 if FUNCTION_ALIGNMENT_16B
1627         default 8 if FUNCTION_ALIGNMENT_8B       1461         default 8 if FUNCTION_ALIGNMENT_8B
1628         default 4 if FUNCTION_ALIGNMENT_4B       1462         default 4 if FUNCTION_ALIGNMENT_4B
1629         default 0                                1463         default 0
1630                                               << 
1631 config CC_HAS_MIN_FUNCTION_ALIGNMENT          << 
1632         # Detect availability of the GCC opti << 
1633         # guarantees minimal alignment for al << 
1634         # -falign-functions which the compile << 
1635         def_bool $(cc-option, -fmin-function- << 
1636                                               << 
1637 config CC_HAS_SANE_FUNCTION_ALIGNMENT         << 
1638         # Set if the guaranteed alignment wit << 
1639         # available or extra care is required << 
1640         # strict alignment always, even with  << 
1641         def_bool CC_HAS_MIN_FUNCTION_ALIGNMEN << 
1642                                               << 
1643 config ARCH_NEED_CMPXCHG_1_EMU                << 
1644         bool                                  << 
1645                                                  1464 
1646 endmenu                                          1465 endmenu
                                                      

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

sflogo.php