tree: https://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild.git kconfig-shell-v3 head: cab76bbc77d9c585f35b5b9289850a3ae64bb879 commit: 403c3fc6b2e7499e92eafe0ab82b18172cd495f6 [21/30] stack-protector: test compiler capability in Kconfig and drop AUTO mode config: um-x86_64_defconfig compiler: gcc-7 (Debian 7.3.0-1) 7.3.0 reproduce: git checkout 403c3fc6b2e7499e92eafe0ab82b18172cd495f6 make ARCH=um SUBARCH=x86_64 defconfig make ARCH=um SUBARCH=x86_64 All errors (new ones prefixed by >>): >> arch/Kconfig:542: syntax error >> arch/Kconfig:541: invalid option arch/Kconfig:547: syntax error arch/Kconfig:546: invalid option arch/Kconfig:571: syntax error arch/Kconfig:570: invalid option make[2]: *** [defconfig] Error 1 make[1]: *** [defconfig] Error 2 make: *** [sub-make] Error 2 -- >> arch/Kconfig:542: syntax error >> arch/Kconfig:541: invalid option arch/Kconfig:547: syntax error arch/Kconfig:546: invalid option arch/Kconfig:571: syntax error arch/Kconfig:570: invalid option make[2]: *** [oldconfig] Error 1 make[1]: *** [oldconfig] Error 2 make: *** [sub-make] Error 2 -- >> arch/Kconfig:542: syntax error >> arch/Kconfig:541: invalid option arch/Kconfig:547: syntax error arch/Kconfig:546: invalid option arch/Kconfig:571: syntax error arch/Kconfig:570: invalid option make[2]: *** [olddefconfig] Error 1 make[2]: Target 'oldnoconfig' not remade because of errors. make[1]: *** [oldnoconfig] Error 2 make: *** [sub-make] Error 2 vim +542 arch/Kconfig 5 6 config CRASH_CORE 7 bool 8 9 config KEXEC_CORE 10 select CRASH_CORE 11 bool 12 13 config HAVE_IMA_KEXEC 14 bool 15 16 config OPROFILE 17 tristate "OProfile system profiling" 18 depends on PROFILING 19 depends on HAVE_OPROFILE 20 select RING_BUFFER 21 select RING_BUFFER_ALLOW_SWAP 22 help 23 OProfile is a profiling system capable of profiling the 24 whole system, include the kernel, kernel modules, libraries, 25 and applications. 26 27 If unsure, say N. 28 29 config OPROFILE_EVENT_MULTIPLEX 30 bool "OProfile multiplexing support (EXPERIMENTAL)" 31 default n 32 depends on OPROFILE && X86 33 help 34 The number of hardware counters is limited. The multiplexing 35 feature enables OProfile to gather more events than counters 36 are provided by the hardware. This is realized by switching 37 between events at a user specified time interval. 38 39 If unsure, say N. 40 41 config HAVE_OPROFILE 42 bool 43 44 config OPROFILE_NMI_TIMER 45 def_bool y 46 depends on PERF_EVENTS && HAVE_PERF_EVENTS_NMI && !PPC64 47 48 config KPROBES 49 bool "Kprobes" 50 depends on MODULES 51 depends on HAVE_KPROBES 52 select KALLSYMS 53 help 54 Kprobes allows you to trap at almost any kernel address and 55 execute a callback function. register_kprobe() establishes 56 a probepoint and specifies the callback. Kprobes is useful 57 for kernel debugging, non-intrusive instrumentation and testing. 58 If in doubt, say "N". 59 60 config JUMP_LABEL 61 bool "Optimize very unlikely/likely branches" 62 depends on HAVE_ARCH_JUMP_LABEL 63 help 64 This option enables a transparent branch optimization that 65 makes certain almost-always-true or almost-always-false branch 66 conditions even cheaper to execute within the kernel. 67 68 Certain performance-sensitive kernel code, such as trace points, 69 scheduler functionality, networking code and KVM have such 70 branches and include support for this optimization technique. 71 72 If it is detected that the compiler has support for "asm goto", 73 the kernel will compile such branches with just a nop 74 instruction. When the condition flag is toggled to true, the 75 nop will be converted to a jump instruction to execute the 76 conditional block of instructions. 77 78 This technique lowers overhead and stress on the branch prediction 79 of the processor and generally makes the kernel faster. The update 80 of the condition is slower, but those are always very rare. 81 82 ( On 32-bit x86, the necessary options added to the compiler 83 flags may increase the size of the kernel slightly. ) 84 85 config STATIC_KEYS_SELFTEST 86 bool "Static key selftest" 87 depends on JUMP_LABEL 88 help 89 Boot time self-test of the branch patching code. 90 91 config OPTPROBES 92 def_bool y 93 depends on KPROBES && HAVE_OPTPROBES 94 select TASKS_RCU if PREEMPT 95 96 config KPROBES_ON_FTRACE 97 def_bool y 98 depends on KPROBES && HAVE_KPROBES_ON_FTRACE 99 depends on DYNAMIC_FTRACE_WITH_REGS 100 help 101 If function tracer is enabled and the arch supports full 102 passing of pt_regs to function tracing, then kprobes can 103 optimize on top of function tracing. 104 105 config UPROBES 106 def_bool n 107 depends on ARCH_SUPPORTS_UPROBES 108 help 109 Uprobes is the user-space counterpart to kprobes: they 110 enable instrumentation applications (such as 'perf probe') 111 to establish unintrusive probes in user-space binaries and 112 libraries, by executing handler functions when the probes 113 are hit by user-space applications. 114 115 ( These probes come in the form of single-byte breakpoints, 116 managed by the kernel and kept transparent to the probed 117 application. ) 118 119 config HAVE_64BIT_ALIGNED_ACCESS 120 def_bool 64BIT && !HAVE_EFFICIENT_UNALIGNED_ACCESS 121 help 122 Some architectures require 64 bit accesses to be 64 bit 123 aligned, which also requires structs containing 64 bit values 124 to be 64 bit aligned too. This includes some 32 bit 125 architectures which can do 64 bit accesses, as well as 64 bit 126 architectures without unaligned access. 127 128 This symbol should be selected by an architecture if 64 bit 129 accesses are required to be 64 bit aligned in this way even 130 though it is not a 64 bit architecture. 131 132 See Documentation/unaligned-memory-access.txt for more 133 information on the topic of unaligned memory accesses. 134 135 config HAVE_EFFICIENT_UNALIGNED_ACCESS 136 bool 137 help 138 Some architectures are unable to perform unaligned accesses 139 without the use of get_unaligned/put_unaligned. Others are 140 unable to perform such accesses efficiently (e.g. trap on 141 unaligned access and require fixing it up in the exception 142 handler.) 143 144 This symbol should be selected by an architecture if it can 145 perform unaligned accesses efficiently to allow different 146 code paths to be selected for these cases. Some network 147 drivers, for example, could opt to not fix up alignment 148 problems with received packets if doing so would not help 149 much. 150 151 See Documentation/unaligned-memory-access.txt for more 152 information on the topic of unaligned memory accesses. 153 154 config ARCH_USE_BUILTIN_BSWAP 155 bool 156 help 157 Modern versions of GCC (since 4.4) have builtin functions 158 for handling byte-swapping. Using these, instead of the old 159 inline assembler that the architecture code provides in the 160 __arch_bswapXX() macros, allows the compiler to see what's 161 happening and offers more opportunity for optimisation. In 162 particular, the compiler will be able to combine the byteswap 163 with a nearby load or store and use load-and-swap or 164 store-and-swap instructions if the architecture has them. It 165 should almost *never* result in code which is worse than the 166 hand-coded assembler in <asm/swab.h>. But just in case it 167 does, the use of the builtins is optional. 168 169 Any architecture with load-and-swap or store-and-swap 170 instructions should set this. And it shouldn't hurt to set it 171 on architectures that don't have such instructions. 172 173 config KRETPROBES 174 def_bool y 175 depends on KPROBES && HAVE_KRETPROBES 176 177 config USER_RETURN_NOTIFIER 178 bool 179 depends on HAVE_USER_RETURN_NOTIFIER 180 help 181 Provide a kernel-internal notification when a cpu is about to 182 switch to user mode. 183 184 config HAVE_IOREMAP_PROT 185 bool 186 187 config HAVE_KPROBES 188 bool 189 190 config HAVE_KRETPROBES 191 bool 192 193 config HAVE_OPTPROBES 194 bool 195 196 config HAVE_KPROBES_ON_FTRACE 197 bool 198 199 config HAVE_FUNCTION_ERROR_INJECTION 200 bool 201 202 config HAVE_NMI 203 bool 204 205 # 206 # An arch should select this if it provides all these things: 207 # 208 # task_pt_regs() in asm/processor.h or asm/ptrace.h 209 # arch_has_single_step() if there is hardware single-step support 210 # arch_has_block_step() if there is hardware block-step support 211 # asm/syscall.h supplying asm-generic/syscall.h interface 212 # linux/regset.h user_regset interfaces 213 # CORE_DUMP_USE_REGSET #define'd in linux/elf.h 214 # TIF_SYSCALL_TRACE calls tracehook_report_syscall_{entry,exit} 215 # TIF_NOTIFY_RESUME calls tracehook_notify_resume() 216 # signal delivery calls tracehook_signal_handler() 217 # 218 config HAVE_ARCH_TRACEHOOK 219 bool 220 221 config HAVE_DMA_CONTIGUOUS 222 bool 223 224 config GENERIC_SMP_IDLE_THREAD 225 bool 226 227 config GENERIC_IDLE_POLL_SETUP 228 bool 229 230 config ARCH_HAS_FORTIFY_SOURCE 231 bool 232 help 233 An architecture should select this when it can successfully 234 build and run with CONFIG_FORTIFY_SOURCE. 235 236 # Select if arch has all set_memory_ro/rw/x/nx() functions in asm/cacheflush.h 237 config ARCH_HAS_SET_MEMORY 238 bool 239 240 # Select if arch init_task must go in the __init_task_data section 241 config ARCH_TASK_STRUCT_ON_STACK 242 bool 243 244 # Select if arch has its private alloc_task_struct() function 245 config ARCH_TASK_STRUCT_ALLOCATOR 246 bool 247 248 config HAVE_ARCH_THREAD_STRUCT_WHITELIST 249 bool 250 depends on !ARCH_TASK_STRUCT_ALLOCATOR 251 help 252 An architecture should select this to provide hardened usercopy 253 knowledge about what region of the thread_struct should be 254 whitelisted for copying to userspace. Normally this is only the 255 FPU registers. Specifically, arch_thread_struct_whitelist() 256 should be implemented. Without this, the entire thread_struct 257 field in task_struct will be left whitelisted. 258 259 # Select if arch has its private alloc_thread_stack() function 260 config ARCH_THREAD_STACK_ALLOCATOR 261 bool 262 263 # Select if arch wants to size task_struct dynamically via arch_task_struct_size: 264 config ARCH_WANTS_DYNAMIC_TASK_STRUCT 265 bool 266 267 config HAVE_REGS_AND_STACK_ACCESS_API 268 bool 269 help 270 This symbol should be selected by an architecure if it supports 271 the API needed to access registers and stack entries from pt_regs, 272 declared in asm/ptrace.h 273 For example the kprobes-based event tracer needs this API. 274 275 config HAVE_CLK 276 bool 277 help 278 The <linux/clk.h> calls support software clock gating and 279 thus are a key power management tool on many systems. 280 281 config HAVE_DMA_API_DEBUG 282 bool 283 284 config HAVE_HW_BREAKPOINT 285 bool 286 depends on PERF_EVENTS 287 288 config HAVE_MIXED_BREAKPOINTS_REGS 289 bool 290 depends on HAVE_HW_BREAKPOINT 291 help 292 Depending on the arch implementation of hardware breakpoints, 293 some of them have separate registers for data and instruction 294 breakpoints addresses, others have mixed registers to store 295 them but define the access type in a control register. 296 Select this option if your arch implements breakpoints under the 297 latter fashion. 298 299 config HAVE_USER_RETURN_NOTIFIER 300 bool 301 302 config HAVE_PERF_EVENTS_NMI 303 bool 304 help 305 System hardware can generate an NMI using the perf event 306 subsystem. Also has support for calculating CPU cycle events 307 to determine how many clock cycles in a given period. 308 309 config HAVE_HARDLOCKUP_DETECTOR_PERF 310 bool 311 depends on HAVE_PERF_EVENTS_NMI 312 help 313 The arch chooses to use the generic perf-NMI-based hardlockup 314 detector. Must define HAVE_PERF_EVENTS_NMI. 315 316 config HAVE_NMI_WATCHDOG 317 depends on HAVE_NMI 318 bool 319 help 320 The arch provides a low level NMI watchdog. It provides 321 asm/nmi.h, and defines its own arch_touch_nmi_watchdog(). 322 323 config HAVE_HARDLOCKUP_DETECTOR_ARCH 324 bool 325 select HAVE_NMI_WATCHDOG 326 help 327 The arch chooses to provide its own hardlockup detector, which is 328 a superset of the HAVE_NMI_WATCHDOG. It also conforms to config 329 interfaces and parameters provided by hardlockup detector subsystem. 330 331 config HAVE_PERF_REGS 332 bool 333 help 334 Support selective register dumps for perf events. This includes 335 bit-mapping of each registers and a unique architecture id. 336 337 config HAVE_PERF_USER_STACK_DUMP 338 bool 339 help 340 Support user stack dumps for perf event samples. This needs 341 access to the user stack pointer which is not unified across 342 architectures. 343 344 config HAVE_ARCH_JUMP_LABEL 345 bool 346 347 config HAVE_RCU_TABLE_FREE 348 bool 349 350 config ARCH_HAVE_NMI_SAFE_CMPXCHG 351 bool 352 353 config HAVE_ALIGNED_STRUCT_PAGE 354 bool 355 help 356 This makes sure that struct pages are double word aligned and that 357 e.g. the SLUB allocator can perform double word atomic operations 358 on a struct page for better performance. However selecting this 359 might increase the size of a struct page by a word. 360 361 config HAVE_CMPXCHG_LOCAL 362 bool 363 364 config HAVE_CMPXCHG_DOUBLE 365 bool 366 367 config ARCH_WEAK_RELEASE_ACQUIRE 368 bool 369 370 config ARCH_WANT_IPC_PARSE_VERSION 371 bool 372 373 config ARCH_WANT_COMPAT_IPC_PARSE_VERSION 374 bool 375 376 config ARCH_WANT_OLD_COMPAT_IPC 377 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION 378 bool 379 380 config HAVE_ARCH_SECCOMP_FILTER 381 bool 382 help 383 An arch should select this symbol if it provides all of these things: 384 - syscall_get_arch() 385 - syscall_get_arguments() 386 - syscall_rollback() 387 - syscall_set_return_value() 388 - SIGSYS siginfo_t support 389 - secure_computing is called from a ptrace_event()-safe context 390 - secure_computing return value is checked and a return value of -1 391 results in the system call being skipped immediately. 392 - seccomp syscall wired up 393 394 config SECCOMP_FILTER 395 def_bool y 396 depends on HAVE_ARCH_SECCOMP_FILTER && SECCOMP && NET 397 help 398 Enable tasks to build secure computing environments defined 399 in terms of Berkeley Packet Filter programs which implement 400 task-defined system call filtering polices. 401 402 See Documentation/prctl/seccomp_filter.txt for details. 403 404 config HAVE_GCC_PLUGINS 405 bool 406 help 407 An arch should select this symbol if it supports building with 408 GCC plugins. 409 410 menuconfig GCC_PLUGINS 411 bool "GCC plugins" 412 depends on HAVE_GCC_PLUGINS 413 depends on !COMPILE_TEST 414 help 415 GCC plugins are loadable modules that provide extra features to the 416 compiler. They are useful for runtime instrumentation and static analysis. 417 418 See Documentation/gcc-plugins.txt for details. 419 420 config GCC_PLUGIN_CYC_COMPLEXITY 421 bool "Compute the cyclomatic complexity of a function" if EXPERT 422 depends on GCC_PLUGINS 423 depends on !COMPILE_TEST 424 help 425 The complexity M of a function's control flow graph is defined as: 426 M = E - N + 2P 427 where 428 429 E = the number of edges 430 N = the number of nodes 431 P = the number of connected components (exit nodes). 432 433 Enabling this plugin reports the complexity to stderr during the 434 build. It mainly serves as a simple example of how to create a 435 gcc plugin for the kernel. 436 437 config GCC_PLUGIN_SANCOV 438 bool 439 depends on GCC_PLUGINS 440 help 441 This plugin inserts a __sanitizer_cov_trace_pc() call at the start of 442 basic blocks. It supports all gcc versions with plugin support (from 443 gcc-4.5 on). It is based on the commit "Add fuzzing coverage support" 444 by Dmitry Vyukov <dvyukov@xxxxxxxxxx>. 445 446 config GCC_PLUGIN_LATENT_ENTROPY 447 bool "Generate some entropy during boot and runtime" 448 depends on GCC_PLUGINS 449 help 450 By saying Y here the kernel will instrument some kernel code to 451 extract some entropy from both original and artificially created 452 program state. This will help especially embedded systems where 453 there is little 'natural' source of entropy normally. The cost 454 is some slowdown of the boot process (about 0.5%) and fork and 455 irq processing. 456 457 Note that entropy extracted this way is not cryptographically 458 secure! 459 460 This plugin was ported from grsecurity/PaX. More information at: 461 * https://grsecurity.net/ 462 * https://pax.grsecurity.net/ 463 464 config GCC_PLUGIN_STRUCTLEAK 465 bool "Force initialization of variables containing userspace addresses" 466 depends on GCC_PLUGINS 467 help 468 This plugin zero-initializes any structures containing a 469 __user attribute. This can prevent some classes of information 470 exposures. 471 472 This plugin was ported from grsecurity/PaX. More information at: 473 * https://grsecurity.net/ 474 * https://pax.grsecurity.net/ 475 476 config GCC_PLUGIN_STRUCTLEAK_BYREF_ALL 477 bool "Force initialize all struct type variables passed by reference" 478 depends on GCC_PLUGIN_STRUCTLEAK 479 help 480 Zero initialize any struct type local variable that may be passed by 481 reference without having been initialized. 482 483 config GCC_PLUGIN_STRUCTLEAK_VERBOSE 484 bool "Report forcefully initialized variables" 485 depends on GCC_PLUGIN_STRUCTLEAK 486 depends on !COMPILE_TEST 487 help 488 This option will cause a warning to be printed each time the 489 structleak plugin finds a variable it thinks needs to be 490 initialized. Since not all existing initializers are detected 491 by the plugin, this can produce false positive warnings. 492 493 config GCC_PLUGIN_RANDSTRUCT 494 bool "Randomize layout of sensitive kernel structures" 495 depends on GCC_PLUGINS 496 select MODVERSIONS if MODULES 497 help 498 If you say Y here, the layouts of structures that are entirely 499 function pointers (and have not been manually annotated with 500 __no_randomize_layout), or structures that have been explicitly 501 marked with __randomize_layout, will be randomized at compile-time. 502 This can introduce the requirement of an additional information 503 exposure vulnerability for exploits targeting these structure 504 types. 505 506 Enabling this feature will introduce some performance impact, 507 slightly increase memory usage, and prevent the use of forensic 508 tools like Volatility against the system (unless the kernel 509 source tree isn't cleaned after kernel installation). 510 511 The seed used for compilation is located at 512 scripts/gcc-plgins/randomize_layout_seed.h. It remains after 513 a make clean to allow for external modules to be compiled with 514 the existing seed and will be removed by a make mrproper or 515 make distclean. 516 517 Note that the implementation requires gcc 4.7 or newer. 518 519 This plugin was ported from grsecurity/PaX. More information at: 520 * https://grsecurity.net/ 521 * https://pax.grsecurity.net/ 522 523 config GCC_PLUGIN_RANDSTRUCT_PERFORMANCE 524 bool "Use cacheline-aware structure randomization" 525 depends on GCC_PLUGIN_RANDSTRUCT 526 depends on !COMPILE_TEST 527 help 528 If you say Y here, the RANDSTRUCT randomization will make a 529 best effort at restricting randomization to cacheline-sized 530 groups of elements. It will further not randomize bitfields 531 in structures. This reduces the performance hit of RANDSTRUCT 532 at the cost of weakened randomization. 533 534 config HAVE_CC_STACKPROTECTOR 535 bool 536 help 537 An arch should select this symbol if: 538 - it has implemented a stack canary (e.g. __stack_chk_guard) 539 540 config CC_HAS_STACKPROTECTOR_NONE > 541 def_bool $(cc-option -fno-stack-protector) > 542 --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
