Mathieu Desnoyers | fb32e03 | 2008-02-02 15:10:33 -0500 | [diff] [blame] | 1 | # |
| 2 | # General architecture dependent options |
| 3 | # |
Mathieu Desnoyers | 125e564 | 2008-02-02 15:10:36 -0500 | [diff] [blame] | 4 | |
Dave Young | 2965faa | 2015-09-09 15:38:55 -0700 | [diff] [blame] | 5 | config KEXEC_CORE |
| 6 | bool |
| 7 | |
Mathieu Desnoyers | 125e564 | 2008-02-02 15:10:36 -0500 | [diff] [blame] | 8 | config OPROFILE |
Robert Richter | b309a29 | 2010-02-26 15:01:23 +0100 | [diff] [blame] | 9 | tristate "OProfile system profiling" |
Mathieu Desnoyers | 125e564 | 2008-02-02 15:10:36 -0500 | [diff] [blame] | 10 | depends on PROFILING |
| 11 | depends on HAVE_OPROFILE |
Ingo Molnar | d69d59f | 2008-12-12 09:38:57 +0100 | [diff] [blame] | 12 | select RING_BUFFER |
Christian Borntraeger | 9a5963e | 2009-09-16 21:56:49 +0200 | [diff] [blame] | 13 | select RING_BUFFER_ALLOW_SWAP |
Mathieu Desnoyers | 125e564 | 2008-02-02 15:10:36 -0500 | [diff] [blame] | 14 | help |
| 15 | OProfile is a profiling system capable of profiling the |
| 16 | whole system, include the kernel, kernel modules, libraries, |
| 17 | and applications. |
| 18 | |
| 19 | If unsure, say N. |
| 20 | |
Jason Yeh | 4d4036e | 2009-07-08 13:49:38 +0200 | [diff] [blame] | 21 | config OPROFILE_EVENT_MULTIPLEX |
| 22 | bool "OProfile multiplexing support (EXPERIMENTAL)" |
| 23 | default n |
| 24 | depends on OPROFILE && X86 |
| 25 | help |
| 26 | The number of hardware counters is limited. The multiplexing |
| 27 | feature enables OProfile to gather more events than counters |
| 28 | are provided by the hardware. This is realized by switching |
| 29 | between events at an user specified time interval. |
| 30 | |
| 31 | If unsure, say N. |
| 32 | |
Mathieu Desnoyers | 125e564 | 2008-02-02 15:10:36 -0500 | [diff] [blame] | 33 | config HAVE_OPROFILE |
Jan Beulich | 9ba1608 | 2008-10-15 22:01:38 -0700 | [diff] [blame] | 34 | bool |
Mathieu Desnoyers | 125e564 | 2008-02-02 15:10:36 -0500 | [diff] [blame] | 35 | |
Robert Richter | dcfce4a | 2011-10-11 17:11:08 +0200 | [diff] [blame] | 36 | config OPROFILE_NMI_TIMER |
| 37 | def_bool y |
Anton Blanchard | af9feeb | 2015-04-09 12:52:55 +1000 | [diff] [blame] | 38 | depends on PERF_EVENTS && HAVE_PERF_EVENTS_NMI && !PPC64 |
Robert Richter | dcfce4a | 2011-10-11 17:11:08 +0200 | [diff] [blame] | 39 | |
Mathieu Desnoyers | 125e564 | 2008-02-02 15:10:36 -0500 | [diff] [blame] | 40 | config KPROBES |
| 41 | bool "Kprobes" |
Masami Hiramatsu | 05ed160 | 2010-09-13 19:25:41 +0900 | [diff] [blame] | 42 | depends on MODULES |
Mathieu Desnoyers | 125e564 | 2008-02-02 15:10:36 -0500 | [diff] [blame] | 43 | depends on HAVE_KPROBES |
Masami Hiramatsu | 05ed160 | 2010-09-13 19:25:41 +0900 | [diff] [blame] | 44 | select KALLSYMS |
Mathieu Desnoyers | 125e564 | 2008-02-02 15:10:36 -0500 | [diff] [blame] | 45 | help |
| 46 | Kprobes allows you to trap at almost any kernel address and |
| 47 | execute a callback function. register_kprobe() establishes |
| 48 | a probepoint and specifies the callback. Kprobes is useful |
| 49 | for kernel debugging, non-intrusive instrumentation and testing. |
| 50 | If in doubt, say "N". |
| 51 | |
Steven Rostedt | 45f81b1 | 2010-10-29 12:33:43 -0400 | [diff] [blame] | 52 | config JUMP_LABEL |
Ingo Molnar | c5905af | 2012-02-24 08:31:31 +0100 | [diff] [blame] | 53 | bool "Optimize very unlikely/likely branches" |
Steven Rostedt | 45f81b1 | 2010-10-29 12:33:43 -0400 | [diff] [blame] | 54 | depends on HAVE_ARCH_JUMP_LABEL |
| 55 | help |
Ingo Molnar | c5905af | 2012-02-24 08:31:31 +0100 | [diff] [blame] | 56 | This option enables a transparent branch optimization that |
| 57 | makes certain almost-always-true or almost-always-false branch |
| 58 | conditions even cheaper to execute within the kernel. |
Steven Rostedt | 45f81b1 | 2010-10-29 12:33:43 -0400 | [diff] [blame] | 59 | |
Ingo Molnar | c5905af | 2012-02-24 08:31:31 +0100 | [diff] [blame] | 60 | Certain performance-sensitive kernel code, such as trace points, |
| 61 | scheduler functionality, networking code and KVM have such |
| 62 | branches and include support for this optimization technique. |
| 63 | |
| 64 | If it is detected that the compiler has support for "asm goto", |
| 65 | the kernel will compile such branches with just a nop |
| 66 | instruction. When the condition flag is toggled to true, the |
| 67 | nop will be converted to a jump instruction to execute the |
| 68 | conditional block of instructions. |
| 69 | |
| 70 | This technique lowers overhead and stress on the branch prediction |
| 71 | of the processor and generally makes the kernel faster. The update |
| 72 | of the condition is slower, but those are always very rare. |
| 73 | |
| 74 | ( On 32-bit x86, the necessary options added to the compiler |
| 75 | flags may increase the size of the kernel slightly. ) |
Steven Rostedt | 45f81b1 | 2010-10-29 12:33:43 -0400 | [diff] [blame] | 76 | |
Peter Zijlstra | 1987c94 | 2015-07-27 18:32:09 +0200 | [diff] [blame] | 77 | config STATIC_KEYS_SELFTEST |
| 78 | bool "Static key selftest" |
| 79 | depends on JUMP_LABEL |
| 80 | help |
| 81 | Boot time self-test of the branch patching code. |
| 82 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 83 | config OPTPROBES |
Masami Hiramatsu | 5cc718b | 2010-03-15 13:00:54 -0400 | [diff] [blame] | 84 | def_bool y |
| 85 | depends on KPROBES && HAVE_OPTPROBES |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 86 | depends on !PREEMPT |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 87 | |
Masami Hiramatsu | e7dbfe3 | 2012-09-28 17:15:20 +0900 | [diff] [blame] | 88 | config KPROBES_ON_FTRACE |
| 89 | def_bool y |
| 90 | depends on KPROBES && HAVE_KPROBES_ON_FTRACE |
| 91 | depends on DYNAMIC_FTRACE_WITH_REGS |
| 92 | help |
| 93 | If function tracer is enabled and the arch supports full |
| 94 | passing of pt_regs to function tracing, then kprobes can |
| 95 | optimize on top of function tracing. |
| 96 | |
Srikar Dronamraju | 2b14449 | 2012-02-09 14:56:42 +0530 | [diff] [blame] | 97 | config UPROBES |
David A. Long | 09294e3 | 2014-03-07 10:32:22 -0500 | [diff] [blame] | 98 | def_bool n |
Srikar Dronamraju | 2b14449 | 2012-02-09 14:56:42 +0530 | [diff] [blame] | 99 | help |
Ingo Molnar | 7b2d81d | 2012-02-17 09:27:41 +0100 | [diff] [blame] | 100 | Uprobes is the user-space counterpart to kprobes: they |
| 101 | enable instrumentation applications (such as 'perf probe') |
| 102 | to establish unintrusive probes in user-space binaries and |
| 103 | libraries, by executing handler functions when the probes |
| 104 | are hit by user-space applications. |
| 105 | |
| 106 | ( These probes come in the form of single-byte breakpoints, |
| 107 | managed by the kernel and kept transparent to the probed |
| 108 | application. ) |
Srikar Dronamraju | 2b14449 | 2012-02-09 14:56:42 +0530 | [diff] [blame] | 109 | |
James Hogan | c19fa94 | 2012-05-30 11:23:23 +0100 | [diff] [blame] | 110 | config HAVE_64BIT_ALIGNED_ACCESS |
| 111 | def_bool 64BIT && !HAVE_EFFICIENT_UNALIGNED_ACCESS |
| 112 | help |
| 113 | Some architectures require 64 bit accesses to be 64 bit |
| 114 | aligned, which also requires structs containing 64 bit values |
| 115 | to be 64 bit aligned too. This includes some 32 bit |
| 116 | architectures which can do 64 bit accesses, as well as 64 bit |
| 117 | architectures without unaligned access. |
| 118 | |
| 119 | This symbol should be selected by an architecture if 64 bit |
| 120 | accesses are required to be 64 bit aligned in this way even |
| 121 | though it is not a 64 bit architecture. |
| 122 | |
| 123 | See Documentation/unaligned-memory-access.txt for more |
| 124 | information on the topic of unaligned memory accesses. |
| 125 | |
Johannes Berg | 58340a0 | 2008-07-25 01:45:33 -0700 | [diff] [blame] | 126 | config HAVE_EFFICIENT_UNALIGNED_ACCESS |
Jan Beulich | 9ba1608 | 2008-10-15 22:01:38 -0700 | [diff] [blame] | 127 | bool |
Johannes Berg | 58340a0 | 2008-07-25 01:45:33 -0700 | [diff] [blame] | 128 | help |
| 129 | Some architectures are unable to perform unaligned accesses |
| 130 | without the use of get_unaligned/put_unaligned. Others are |
| 131 | unable to perform such accesses efficiently (e.g. trap on |
| 132 | unaligned access and require fixing it up in the exception |
| 133 | handler.) |
| 134 | |
| 135 | This symbol should be selected by an architecture if it can |
| 136 | perform unaligned accesses efficiently to allow different |
| 137 | code paths to be selected for these cases. Some network |
| 138 | drivers, for example, could opt to not fix up alignment |
| 139 | problems with received packets if doing so would not help |
| 140 | much. |
| 141 | |
| 142 | See Documentation/unaligned-memory-access.txt for more |
| 143 | information on the topic of unaligned memory accesses. |
| 144 | |
David Woodhouse | cf66bb9 | 2012-12-03 16:25:40 +0000 | [diff] [blame] | 145 | config ARCH_USE_BUILTIN_BSWAP |
| 146 | bool |
| 147 | help |
| 148 | Modern versions of GCC (since 4.4) have builtin functions |
| 149 | for handling byte-swapping. Using these, instead of the old |
| 150 | inline assembler that the architecture code provides in the |
| 151 | __arch_bswapXX() macros, allows the compiler to see what's |
| 152 | happening and offers more opportunity for optimisation. In |
| 153 | particular, the compiler will be able to combine the byteswap |
| 154 | with a nearby load or store and use load-and-swap or |
| 155 | store-and-swap instructions if the architecture has them. It |
| 156 | should almost *never* result in code which is worse than the |
| 157 | hand-coded assembler in <asm/swab.h>. But just in case it |
| 158 | does, the use of the builtins is optional. |
| 159 | |
| 160 | Any architecture with load-and-swap or store-and-swap |
| 161 | instructions should set this. And it shouldn't hurt to set it |
| 162 | on architectures that don't have such instructions. |
| 163 | |
Ananth N Mavinakayanahalli | 9edddaa | 2008-03-04 14:28:37 -0800 | [diff] [blame] | 164 | config KRETPROBES |
| 165 | def_bool y |
| 166 | depends on KPROBES && HAVE_KRETPROBES |
| 167 | |
Avi Kivity | 7c68af6 | 2009-09-19 09:40:22 +0300 | [diff] [blame] | 168 | config USER_RETURN_NOTIFIER |
| 169 | bool |
| 170 | depends on HAVE_USER_RETURN_NOTIFIER |
| 171 | help |
| 172 | Provide a kernel-internal notification when a cpu is about to |
| 173 | switch to user mode. |
| 174 | |
Rik van Riel | 28b2ee2 | 2008-07-23 21:27:05 -0700 | [diff] [blame] | 175 | config HAVE_IOREMAP_PROT |
Jan Beulich | 9ba1608 | 2008-10-15 22:01:38 -0700 | [diff] [blame] | 176 | bool |
Rik van Riel | 28b2ee2 | 2008-07-23 21:27:05 -0700 | [diff] [blame] | 177 | |
Mathieu Desnoyers | 125e564 | 2008-02-02 15:10:36 -0500 | [diff] [blame] | 178 | config HAVE_KPROBES |
Jan Beulich | 9ba1608 | 2008-10-15 22:01:38 -0700 | [diff] [blame] | 179 | bool |
Ananth N Mavinakayanahalli | 9edddaa | 2008-03-04 14:28:37 -0800 | [diff] [blame] | 180 | |
| 181 | config HAVE_KRETPROBES |
Jan Beulich | 9ba1608 | 2008-10-15 22:01:38 -0700 | [diff] [blame] | 182 | bool |
Arthur Kepner | 74bc7ce | 2008-04-29 01:00:30 -0700 | [diff] [blame] | 183 | |
Masami Hiramatsu | afd6625 | 2010-02-25 08:34:07 -0500 | [diff] [blame] | 184 | config HAVE_OPTPROBES |
| 185 | bool |
Cong Wang | d314d74 | 2012-03-23 15:01:51 -0700 | [diff] [blame] | 186 | |
Masami Hiramatsu | e7dbfe3 | 2012-09-28 17:15:20 +0900 | [diff] [blame] | 187 | config HAVE_KPROBES_ON_FTRACE |
| 188 | bool |
| 189 | |
Cong Wang | d314d74 | 2012-03-23 15:01:51 -0700 | [diff] [blame] | 190 | config HAVE_NMI_WATCHDOG |
| 191 | bool |
Roland McGrath | 1f5a4ad | 2008-07-25 19:45:57 -0700 | [diff] [blame] | 192 | # |
| 193 | # An arch should select this if it provides all these things: |
| 194 | # |
| 195 | # task_pt_regs() in asm/processor.h or asm/ptrace.h |
| 196 | # arch_has_single_step() if there is hardware single-step support |
| 197 | # arch_has_block_step() if there is hardware block-step support |
Roland McGrath | 1f5a4ad | 2008-07-25 19:45:57 -0700 | [diff] [blame] | 198 | # asm/syscall.h supplying asm-generic/syscall.h interface |
| 199 | # linux/regset.h user_regset interfaces |
| 200 | # CORE_DUMP_USE_REGSET #define'd in linux/elf.h |
| 201 | # TIF_SYSCALL_TRACE calls tracehook_report_syscall_{entry,exit} |
| 202 | # TIF_NOTIFY_RESUME calls tracehook_notify_resume() |
| 203 | # signal delivery calls tracehook_signal_handler() |
| 204 | # |
| 205 | config HAVE_ARCH_TRACEHOOK |
Jan Beulich | 9ba1608 | 2008-10-15 22:01:38 -0700 | [diff] [blame] | 206 | bool |
Roland McGrath | 1f5a4ad | 2008-07-25 19:45:57 -0700 | [diff] [blame] | 207 | |
Marek Szyprowski | c64be2b | 2011-12-29 13:09:51 +0100 | [diff] [blame] | 208 | config HAVE_DMA_CONTIGUOUS |
| 209 | bool |
| 210 | |
Thomas Gleixner | 29d5e04 | 2012-04-20 13:05:45 +0000 | [diff] [blame] | 211 | config GENERIC_SMP_IDLE_THREAD |
| 212 | bool |
| 213 | |
Kevin Hilman | 485cf5d | 2013-04-24 17:19:13 -0700 | [diff] [blame] | 214 | config GENERIC_IDLE_POLL_SETUP |
| 215 | bool |
| 216 | |
Thomas Gleixner | a6359d1 | 2012-05-03 09:03:02 +0000 | [diff] [blame] | 217 | # Select if arch init_task initializer is different to init/init_task.c |
| 218 | config ARCH_INIT_TASK |
Thomas Gleixner | a4a2eb4 | 2012-05-03 09:02:48 +0000 | [diff] [blame] | 219 | bool |
| 220 | |
Thomas Gleixner | f5e1028 | 2012-05-05 15:05:48 +0000 | [diff] [blame] | 221 | # Select if arch has its private alloc_task_struct() function |
| 222 | config ARCH_TASK_STRUCT_ALLOCATOR |
| 223 | bool |
| 224 | |
| 225 | # Select if arch has its private alloc_thread_info() function |
| 226 | config ARCH_THREAD_INFO_ALLOCATOR |
| 227 | bool |
| 228 | |
Ingo Molnar | 5aaeb5c | 2015-07-17 12:28:12 +0200 | [diff] [blame] | 229 | # Select if arch wants to size task_struct dynamically via arch_task_struct_size: |
| 230 | config ARCH_WANTS_DYNAMIC_TASK_STRUCT |
| 231 | bool |
| 232 | |
Heiko Carstens | f850c30c | 2010-02-10 17:25:17 +0100 | [diff] [blame] | 233 | config HAVE_REGS_AND_STACK_ACCESS_API |
| 234 | bool |
Heiko Carstens | e01292b | 2010-02-18 14:25:21 +0100 | [diff] [blame] | 235 | help |
| 236 | This symbol should be selected by an architecure if it supports |
| 237 | the API needed to access registers and stack entries from pt_regs, |
| 238 | declared in asm/ptrace.h |
| 239 | For example the kprobes-based event tracer needs this API. |
Heiko Carstens | f850c30c | 2010-02-10 17:25:17 +0100 | [diff] [blame] | 240 | |
David Brownell | 9483a57 | 2008-07-23 21:26:48 -0700 | [diff] [blame] | 241 | config HAVE_CLK |
Jan Beulich | 9ba1608 | 2008-10-15 22:01:38 -0700 | [diff] [blame] | 242 | bool |
David Brownell | 9483a57 | 2008-07-23 21:26:48 -0700 | [diff] [blame] | 243 | help |
| 244 | The <linux/clk.h> calls support software clock gating and |
| 245 | thus are a key power management tool on many systems. |
| 246 | |
Joerg Roedel | 5ee00bd | 2009-01-09 12:14:24 +0100 | [diff] [blame] | 247 | config HAVE_DMA_API_DEBUG |
| 248 | bool |
Heiko Carstens | 36cd3c9 | 2009-04-09 18:48:34 +0200 | [diff] [blame] | 249 | |
K.Prasad | 62a038d | 2009-06-01 23:43:33 +0530 | [diff] [blame] | 250 | config HAVE_HW_BREAKPOINT |
| 251 | bool |
Frederic Weisbecker | 99e8c5a | 2009-12-17 01:33:54 +0100 | [diff] [blame] | 252 | depends on PERF_EVENTS |
K.Prasad | 62a038d | 2009-06-01 23:43:33 +0530 | [diff] [blame] | 253 | |
Frederic Weisbecker | 0102752 | 2010-04-11 18:55:56 +0200 | [diff] [blame] | 254 | config HAVE_MIXED_BREAKPOINTS_REGS |
| 255 | bool |
| 256 | depends on HAVE_HW_BREAKPOINT |
| 257 | help |
| 258 | Depending on the arch implementation of hardware breakpoints, |
| 259 | some of them have separate registers for data and instruction |
| 260 | breakpoints addresses, others have mixed registers to store |
| 261 | them but define the access type in a control register. |
| 262 | Select this option if your arch implements breakpoints under the |
| 263 | latter fashion. |
| 264 | |
Avi Kivity | 7c68af6 | 2009-09-19 09:40:22 +0300 | [diff] [blame] | 265 | config HAVE_USER_RETURN_NOTIFIER |
| 266 | bool |
Ingo Molnar | a1922ed | 2009-09-07 08:19:51 +0200 | [diff] [blame] | 267 | |
Frederic Weisbecker | c01d432 | 2010-05-15 22:57:48 +0200 | [diff] [blame] | 268 | config HAVE_PERF_EVENTS_NMI |
| 269 | bool |
Frederic Weisbecker | 23637d4 | 2010-05-15 23:15:20 +0200 | [diff] [blame] | 270 | help |
| 271 | System hardware can generate an NMI using the perf event |
| 272 | subsystem. Also has support for calculating CPU cycle events |
| 273 | to determine how many clock cycles in a given period. |
Frederic Weisbecker | c01d432 | 2010-05-15 22:57:48 +0200 | [diff] [blame] | 274 | |
Jiri Olsa | c5e6319 | 2012-08-07 15:20:36 +0200 | [diff] [blame] | 275 | config HAVE_PERF_REGS |
| 276 | bool |
| 277 | help |
| 278 | Support selective register dumps for perf events. This includes |
| 279 | bit-mapping of each registers and a unique architecture id. |
| 280 | |
Jiri Olsa | c5ebced | 2012-08-07 15:20:40 +0200 | [diff] [blame] | 281 | config HAVE_PERF_USER_STACK_DUMP |
| 282 | bool |
| 283 | help |
| 284 | Support user stack dumps for perf event samples. This needs |
| 285 | access to the user stack pointer which is not unified across |
| 286 | architectures. |
| 287 | |
Jason Baron | bf5438fc | 2010-09-17 11:09:00 -0400 | [diff] [blame] | 288 | config HAVE_ARCH_JUMP_LABEL |
| 289 | bool |
| 290 | |
Peter Zijlstra | 2672391 | 2011-05-24 17:12:00 -0700 | [diff] [blame] | 291 | config HAVE_RCU_TABLE_FREE |
| 292 | bool |
| 293 | |
Huang Ying | df013ff | 2011-07-13 13:14:22 +0800 | [diff] [blame] | 294 | config ARCH_HAVE_NMI_SAFE_CMPXCHG |
| 295 | bool |
| 296 | |
Heiko Carstens | 43570fd | 2012-01-12 17:17:27 -0800 | [diff] [blame] | 297 | config HAVE_ALIGNED_STRUCT_PAGE |
| 298 | bool |
| 299 | help |
| 300 | This makes sure that struct pages are double word aligned and that |
| 301 | e.g. the SLUB allocator can perform double word atomic operations |
| 302 | on a struct page for better performance. However selecting this |
| 303 | might increase the size of a struct page by a word. |
| 304 | |
Heiko Carstens | 4156153 | 2012-01-12 17:17:30 -0800 | [diff] [blame] | 305 | config HAVE_CMPXCHG_LOCAL |
| 306 | bool |
| 307 | |
Heiko Carstens | 2565409 | 2012-01-12 17:17:33 -0800 | [diff] [blame] | 308 | config HAVE_CMPXCHG_DOUBLE |
| 309 | bool |
| 310 | |
Will Deacon | c1d7e01 | 2012-07-30 14:42:46 -0700 | [diff] [blame] | 311 | config ARCH_WANT_IPC_PARSE_VERSION |
| 312 | bool |
| 313 | |
| 314 | config ARCH_WANT_COMPAT_IPC_PARSE_VERSION |
| 315 | bool |
| 316 | |
Chris Metcalf | 48b25c4 | 2012-03-15 13:13:38 -0400 | [diff] [blame] | 317 | config ARCH_WANT_OLD_COMPAT_IPC |
Will Deacon | c1d7e01 | 2012-07-30 14:42:46 -0700 | [diff] [blame] | 318 | select ARCH_WANT_COMPAT_IPC_PARSE_VERSION |
Chris Metcalf | 48b25c4 | 2012-03-15 13:13:38 -0400 | [diff] [blame] | 319 | bool |
| 320 | |
Will Drewry | e2cfabdf | 2012-04-12 16:47:57 -0500 | [diff] [blame] | 321 | config HAVE_ARCH_SECCOMP_FILTER |
| 322 | bool |
| 323 | help |
Will Drewry | fb0fadf | 2012-04-12 16:48:02 -0500 | [diff] [blame] | 324 | An arch should select this symbol if it provides all of these things: |
Will Drewry | bb6ea43 | 2012-04-12 16:48:01 -0500 | [diff] [blame] | 325 | - syscall_get_arch() |
| 326 | - syscall_get_arguments() |
| 327 | - syscall_rollback() |
| 328 | - syscall_set_return_value() |
Will Drewry | fb0fadf | 2012-04-12 16:48:02 -0500 | [diff] [blame] | 329 | - SIGSYS siginfo_t support |
| 330 | - secure_computing is called from a ptrace_event()-safe context |
| 331 | - secure_computing return value is checked and a return value of -1 |
| 332 | results in the system call being skipped immediately. |
Kees Cook | 48dc92b | 2014-06-25 16:08:24 -0700 | [diff] [blame] | 333 | - seccomp syscall wired up |
Will Drewry | e2cfabdf | 2012-04-12 16:47:57 -0500 | [diff] [blame] | 334 | |
Andy Lutomirski | ff27f38 | 2014-07-21 18:49:17 -0700 | [diff] [blame] | 335 | For best performance, an arch should use seccomp_phase1 and |
| 336 | seccomp_phase2 directly. It should call seccomp_phase1 for all |
| 337 | syscalls if TIF_SECCOMP is set, but seccomp_phase1 does not |
| 338 | need to be called from a ptrace-safe context. It must then |
| 339 | call seccomp_phase2 if seccomp_phase1 returns anything other |
| 340 | than SECCOMP_PHASE1_OK or SECCOMP_PHASE1_SKIP. |
| 341 | |
| 342 | As an additional optimization, an arch may provide seccomp_data |
| 343 | directly to seccomp_phase1; this avoids multiple calls |
| 344 | to the syscall_xyz helpers for every syscall. |
| 345 | |
Will Drewry | e2cfabdf | 2012-04-12 16:47:57 -0500 | [diff] [blame] | 346 | config SECCOMP_FILTER |
| 347 | def_bool y |
| 348 | depends on HAVE_ARCH_SECCOMP_FILTER && SECCOMP && NET |
| 349 | help |
| 350 | Enable tasks to build secure computing environments defined |
| 351 | in terms of Berkeley Packet Filter programs which implement |
| 352 | task-defined system call filtering polices. |
| 353 | |
| 354 | See Documentation/prctl/seccomp_filter.txt for details. |
| 355 | |
Kees Cook | 19952a9 | 2013-12-19 11:35:58 -0800 | [diff] [blame] | 356 | config HAVE_CC_STACKPROTECTOR |
| 357 | bool |
| 358 | help |
| 359 | An arch should select this symbol if: |
| 360 | - its compiler supports the -fstack-protector option |
| 361 | - it has implemented a stack canary (e.g. __stack_chk_guard) |
| 362 | |
| 363 | config CC_STACKPROTECTOR |
Kees Cook | 8779657 | 2013-12-19 11:35:59 -0800 | [diff] [blame] | 364 | def_bool n |
Kees Cook | 19952a9 | 2013-12-19 11:35:58 -0800 | [diff] [blame] | 365 | help |
Kees Cook | 8779657 | 2013-12-19 11:35:59 -0800 | [diff] [blame] | 366 | Set when a stack-protector mode is enabled, so that the build |
| 367 | can enable kernel-side support for the GCC feature. |
| 368 | |
| 369 | choice |
| 370 | prompt "Stack Protector buffer overflow detection" |
| 371 | depends on HAVE_CC_STACKPROTECTOR |
| 372 | default CC_STACKPROTECTOR_NONE |
| 373 | help |
| 374 | This option turns on the "stack-protector" GCC feature. This |
Kees Cook | 19952a9 | 2013-12-19 11:35:58 -0800 | [diff] [blame] | 375 | feature puts, at the beginning of functions, a canary value on |
| 376 | the stack just before the return address, and validates |
| 377 | the value just before actually returning. Stack based buffer |
| 378 | overflows (that need to overwrite this return address) now also |
| 379 | overwrite the canary, which gets detected and the attack is then |
| 380 | neutralized via a kernel panic. |
| 381 | |
Kees Cook | 8779657 | 2013-12-19 11:35:59 -0800 | [diff] [blame] | 382 | config CC_STACKPROTECTOR_NONE |
| 383 | bool "None" |
| 384 | help |
| 385 | Disable "stack-protector" GCC feature. |
| 386 | |
| 387 | config CC_STACKPROTECTOR_REGULAR |
| 388 | bool "Regular" |
| 389 | select CC_STACKPROTECTOR |
| 390 | help |
| 391 | Functions will have the stack-protector canary logic added if they |
| 392 | have an 8-byte or larger character array on the stack. |
| 393 | |
Kees Cook | 19952a9 | 2013-12-19 11:35:58 -0800 | [diff] [blame] | 394 | This feature requires gcc version 4.2 or above, or a distribution |
Kees Cook | 8779657 | 2013-12-19 11:35:59 -0800 | [diff] [blame] | 395 | gcc with the feature backported ("-fstack-protector"). |
| 396 | |
| 397 | On an x86 "defconfig" build, this feature adds canary checks to |
| 398 | about 3% of all kernel functions, which increases kernel code size |
| 399 | by about 0.3%. |
| 400 | |
| 401 | config CC_STACKPROTECTOR_STRONG |
| 402 | bool "Strong" |
| 403 | select CC_STACKPROTECTOR |
| 404 | help |
| 405 | Functions will have the stack-protector canary logic added in any |
| 406 | of the following conditions: |
| 407 | |
| 408 | - local variable's address used as part of the right hand side of an |
| 409 | assignment or function argument |
| 410 | - local variable is an array (or union containing an array), |
| 411 | regardless of array type or length |
| 412 | - uses register local variables |
| 413 | |
| 414 | This feature requires gcc version 4.9 or above, or a distribution |
| 415 | gcc with the feature backported ("-fstack-protector-strong"). |
| 416 | |
| 417 | On an x86 "defconfig" build, this feature adds canary checks to |
| 418 | about 20% of all kernel functions, which increases the kernel code |
| 419 | size by about 2%. |
| 420 | |
| 421 | endchoice |
Kees Cook | 19952a9 | 2013-12-19 11:35:58 -0800 | [diff] [blame] | 422 | |
Frederic Weisbecker | 91d1aa43 | 2012-11-27 19:33:25 +0100 | [diff] [blame] | 423 | config HAVE_CONTEXT_TRACKING |
Frederic Weisbecker | 2b1d502 | 2012-07-11 20:26:30 +0200 | [diff] [blame] | 424 | bool |
| 425 | help |
Frederic Weisbecker | 91d1aa43 | 2012-11-27 19:33:25 +0100 | [diff] [blame] | 426 | Provide kernel/user boundaries probes necessary for subsystems |
| 427 | that need it, such as userspace RCU extended quiescent state. |
| 428 | Syscalls need to be wrapped inside user_exit()-user_enter() through |
| 429 | the slow path using TIF_NOHZ flag. Exceptions handlers must be |
| 430 | wrapped as well. Irqs are already protected inside |
| 431 | rcu_irq_enter/rcu_irq_exit() but preemption or signal handling on |
| 432 | irq exit still need to be protected. |
Frederic Weisbecker | 2b1d502 | 2012-07-11 20:26:30 +0200 | [diff] [blame] | 433 | |
Frederic Weisbecker | b952741 | 2012-06-16 15:39:34 +0200 | [diff] [blame] | 434 | config HAVE_VIRT_CPU_ACCOUNTING |
| 435 | bool |
| 436 | |
Kevin Hilman | 554b000 | 2013-09-16 15:28:21 -0700 | [diff] [blame] | 437 | config HAVE_VIRT_CPU_ACCOUNTING_GEN |
| 438 | bool |
| 439 | default y if 64BIT |
| 440 | help |
| 441 | With VIRT_CPU_ACCOUNTING_GEN, cputime_t becomes 64-bit. |
| 442 | Before enabling this option, arch code must be audited |
| 443 | to ensure there are no races in concurrent read/write of |
| 444 | cputime_t. For example, reading/writing 64-bit cputime_t on |
| 445 | some 32-bit arches may require multiple accesses, so proper |
| 446 | locking is needed to protect against concurrent accesses. |
| 447 | |
| 448 | |
Frederic Weisbecker | fdf9c35 | 2012-09-09 14:56:31 +0200 | [diff] [blame] | 449 | config HAVE_IRQ_TIME_ACCOUNTING |
| 450 | bool |
| 451 | help |
| 452 | Archs need to ensure they use a high enough resolution clock to |
| 453 | support irq time accounting and then call enable_sched_clock_irqtime(). |
| 454 | |
Gerald Schaefer | 1562606 | 2012-10-08 16:30:04 -0700 | [diff] [blame] | 455 | config HAVE_ARCH_TRANSPARENT_HUGEPAGE |
| 456 | bool |
| 457 | |
Toshi Kani | 0ddab1d | 2015-04-14 15:47:20 -0700 | [diff] [blame] | 458 | config HAVE_ARCH_HUGE_VMAP |
| 459 | bool |
| 460 | |
Pavel Emelyanov | 0f8975e | 2013-07-03 15:01:20 -0700 | [diff] [blame] | 461 | config HAVE_ARCH_SOFT_DIRTY |
| 462 | bool |
| 463 | |
David Howells | 786d35d | 2012-09-28 14:31:03 +0930 | [diff] [blame] | 464 | config HAVE_MOD_ARCH_SPECIFIC |
| 465 | bool |
| 466 | help |
| 467 | The arch uses struct mod_arch_specific to store data. Many arches |
| 468 | just need a simple module loader without arch specific data - those |
| 469 | should not enable this. |
| 470 | |
| 471 | config MODULES_USE_ELF_RELA |
| 472 | bool |
| 473 | help |
| 474 | Modules only use ELF RELA relocations. Modules with ELF REL |
| 475 | relocations will give an error. |
| 476 | |
| 477 | config MODULES_USE_ELF_REL |
| 478 | bool |
| 479 | help |
| 480 | Modules only use ELF REL relocations. Modules with ELF RELA |
| 481 | relocations will give an error. |
| 482 | |
Rusty Russell | b92021b | 2013-03-15 15:04:17 +1030 | [diff] [blame] | 483 | config HAVE_UNDERSCORE_SYMBOL_PREFIX |
| 484 | bool |
| 485 | help |
| 486 | Some architectures generate an _ in front of C symbols; things like |
| 487 | module loading and assembly files need to know about this. |
| 488 | |
Frederic Weisbecker | cc1f027 | 2013-09-24 17:17:47 +0200 | [diff] [blame] | 489 | config HAVE_IRQ_EXIT_ON_IRQ_STACK |
| 490 | bool |
| 491 | help |
| 492 | Architecture doesn't only execute the irq handler on the irq stack |
| 493 | but also irq_exit(). This way we can process softirqs on this irq |
| 494 | stack instead of switching to a new one when we call __do_softirq() |
| 495 | in the end of an hardirq. |
| 496 | This spares a stack switch and improves cache usage on softirq |
| 497 | processing. |
| 498 | |
Kirill A. Shutemov | 235a8f0 | 2015-04-14 15:46:17 -0700 | [diff] [blame] | 499 | config PGTABLE_LEVELS |
| 500 | int |
| 501 | default 2 |
| 502 | |
Kees Cook | 2b68f6c | 2015-04-14 15:48:00 -0700 | [diff] [blame] | 503 | config ARCH_HAS_ELF_RANDOMIZE |
| 504 | bool |
| 505 | help |
| 506 | An architecture supports choosing randomized locations for |
| 507 | stack, mmap, brk, and ET_DYN. Defined functions: |
| 508 | - arch_mmap_rnd() |
Kees Cook | 204db6e | 2015-04-14 15:48:12 -0700 | [diff] [blame] | 509 | - arch_randomize_brk() |
Kees Cook | 2b68f6c | 2015-04-14 15:48:00 -0700 | [diff] [blame] | 510 | |
Daniel Cashman | d07e225 | 2016-01-14 15:19:53 -0800 | [diff] [blame] | 511 | config HAVE_ARCH_MMAP_RND_BITS |
| 512 | bool |
| 513 | help |
| 514 | An arch should select this symbol if it supports setting a variable |
| 515 | number of bits for use in establishing the base address for mmap |
| 516 | allocations, has MMU enabled and provides values for both: |
| 517 | - ARCH_MMAP_RND_BITS_MIN |
| 518 | - ARCH_MMAP_RND_BITS_MAX |
| 519 | |
Jiri Slaby | 5f56a5d | 2016-05-20 17:00:16 -0700 | [diff] [blame^] | 520 | config HAVE_EXIT_THREAD |
| 521 | bool |
| 522 | help |
| 523 | An architecture implements exit_thread. |
| 524 | |
Daniel Cashman | d07e225 | 2016-01-14 15:19:53 -0800 | [diff] [blame] | 525 | config ARCH_MMAP_RND_BITS_MIN |
| 526 | int |
| 527 | |
| 528 | config ARCH_MMAP_RND_BITS_MAX |
| 529 | int |
| 530 | |
| 531 | config ARCH_MMAP_RND_BITS_DEFAULT |
| 532 | int |
| 533 | |
| 534 | config ARCH_MMAP_RND_BITS |
| 535 | int "Number of bits to use for ASLR of mmap base address" if EXPERT |
| 536 | range ARCH_MMAP_RND_BITS_MIN ARCH_MMAP_RND_BITS_MAX |
| 537 | default ARCH_MMAP_RND_BITS_DEFAULT if ARCH_MMAP_RND_BITS_DEFAULT |
| 538 | default ARCH_MMAP_RND_BITS_MIN |
| 539 | depends on HAVE_ARCH_MMAP_RND_BITS |
| 540 | help |
| 541 | This value can be used to select the number of bits to use to |
| 542 | determine the random offset to the base address of vma regions |
| 543 | resulting from mmap allocations. This value will be bounded |
| 544 | by the architecture's minimum and maximum supported values. |
| 545 | |
| 546 | This value can be changed after boot using the |
| 547 | /proc/sys/vm/mmap_rnd_bits tunable |
| 548 | |
| 549 | config HAVE_ARCH_MMAP_RND_COMPAT_BITS |
| 550 | bool |
| 551 | help |
| 552 | An arch should select this symbol if it supports running applications |
| 553 | in compatibility mode, supports setting a variable number of bits for |
| 554 | use in establishing the base address for mmap allocations, has MMU |
| 555 | enabled and provides values for both: |
| 556 | - ARCH_MMAP_RND_COMPAT_BITS_MIN |
| 557 | - ARCH_MMAP_RND_COMPAT_BITS_MAX |
| 558 | |
| 559 | config ARCH_MMAP_RND_COMPAT_BITS_MIN |
| 560 | int |
| 561 | |
| 562 | config ARCH_MMAP_RND_COMPAT_BITS_MAX |
| 563 | int |
| 564 | |
| 565 | config ARCH_MMAP_RND_COMPAT_BITS_DEFAULT |
| 566 | int |
| 567 | |
| 568 | config ARCH_MMAP_RND_COMPAT_BITS |
| 569 | int "Number of bits to use for ASLR of mmap base address for compatible applications" if EXPERT |
| 570 | range ARCH_MMAP_RND_COMPAT_BITS_MIN ARCH_MMAP_RND_COMPAT_BITS_MAX |
| 571 | default ARCH_MMAP_RND_COMPAT_BITS_DEFAULT if ARCH_MMAP_RND_COMPAT_BITS_DEFAULT |
| 572 | default ARCH_MMAP_RND_COMPAT_BITS_MIN |
| 573 | depends on HAVE_ARCH_MMAP_RND_COMPAT_BITS |
| 574 | help |
| 575 | This value can be used to select the number of bits to use to |
| 576 | determine the random offset to the base address of vma regions |
| 577 | resulting from mmap allocations for compatible applications This |
| 578 | value will be bounded by the architecture's minimum and maximum |
| 579 | supported values. |
| 580 | |
| 581 | This value can be changed after boot using the |
| 582 | /proc/sys/vm/mmap_rnd_compat_bits tunable |
| 583 | |
Josh Triplett | 3033f14a | 2015-06-25 15:01:19 -0700 | [diff] [blame] | 584 | config HAVE_COPY_THREAD_TLS |
| 585 | bool |
| 586 | help |
| 587 | Architecture provides copy_thread_tls to accept tls argument via |
| 588 | normal C parameter passing, rather than extracting the syscall |
| 589 | argument from pt_regs. |
| 590 | |
Josh Poimboeuf | b9ab5eb | 2016-02-28 22:22:42 -0600 | [diff] [blame] | 591 | config HAVE_STACK_VALIDATION |
| 592 | bool |
| 593 | help |
| 594 | Architecture supports the 'objtool check' host tool command, which |
| 595 | performs compile-time stack metadata validation. |
| 596 | |
Al Viro | d212504 | 2012-10-23 13:17:59 -0400 | [diff] [blame] | 597 | # |
| 598 | # ABI hall of shame |
| 599 | # |
| 600 | config CLONE_BACKWARDS |
| 601 | bool |
| 602 | help |
| 603 | Architecture has tls passed as the 4th argument of clone(2), |
| 604 | not the 5th one. |
| 605 | |
| 606 | config CLONE_BACKWARDS2 |
| 607 | bool |
| 608 | help |
| 609 | Architecture has the first two arguments of clone(2) swapped. |
| 610 | |
Michal Simek | dfa9771 | 2013-08-13 16:00:53 -0700 | [diff] [blame] | 611 | config CLONE_BACKWARDS3 |
| 612 | bool |
| 613 | help |
| 614 | Architecture has tls passed as the 3rd argument of clone(2), |
| 615 | not the 5th one. |
| 616 | |
Al Viro | eaca6ea | 2012-11-25 23:12:10 -0500 | [diff] [blame] | 617 | config ODD_RT_SIGACTION |
| 618 | bool |
| 619 | help |
| 620 | Architecture has unusual rt_sigaction(2) arguments |
| 621 | |
Al Viro | 0a0e8cd | 2012-12-25 16:04:12 -0500 | [diff] [blame] | 622 | config OLD_SIGSUSPEND |
| 623 | bool |
| 624 | help |
| 625 | Architecture has old sigsuspend(2) syscall, of one-argument variety |
| 626 | |
| 627 | config OLD_SIGSUSPEND3 |
| 628 | bool |
| 629 | help |
| 630 | Even weirder antique ABI - three-argument sigsuspend(2) |
| 631 | |
Al Viro | 495dfbf | 2012-12-25 19:09:45 -0500 | [diff] [blame] | 632 | config OLD_SIGACTION |
| 633 | bool |
| 634 | help |
| 635 | Architecture has old sigaction(2) syscall. Nope, not the same |
| 636 | as OLD_SIGSUSPEND | OLD_SIGSUSPEND3 - alpha has sigsuspend(2), |
| 637 | but fairly different variant of sigaction(2), thanks to OSF/1 |
| 638 | compatibility... |
| 639 | |
| 640 | config COMPAT_OLD_SIGACTION |
| 641 | bool |
| 642 | |
Christoph Hellwig | 0d4a619 | 2016-01-20 15:01:22 -0800 | [diff] [blame] | 643 | config ARCH_NO_COHERENT_DMA_MMAP |
| 644 | bool |
| 645 | |
Peter Oberparleiter | 2521f2c | 2009-06-17 16:28:08 -0700 | [diff] [blame] | 646 | source "kernel/gcov/Kconfig" |