1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _LINUX_KERNEL_H 3 #define _LINUX_KERNEL_H 4 5 #include <stdarg.h> 6 #include <linux/limits.h> 7 #include <linux/linkage.h> 8 #include <linux/stddef.h> 9 #include <linux/types.h> 10 #include <linux/compiler.h> 11 #include <linux/bitops.h> 12 #include <linux/log2.h> 13 #include <linux/math.h> 14 #include <linux/minmax.h> 15 #include <linux/typecheck.h> 16 #include <linux/printk.h> 17 #include <linux/build_bug.h> 18 #include <linux/static_call_types.h> 19 #include <asm/byteorder.h> 20 21 #include <uapi/linux/kernel.h> 22 23 #define STACK_MAGIC 0xdeadbeef 24 25 /** 26 * REPEAT_BYTE - repeat the value @x multiple times as an unsigned long value 27 * @x: value to repeat 28 * 29 * NOTE: @x is not checked for > 0xff; larger values produce odd results. 30 */ 31 #define REPEAT_BYTE(x) ((~0ul / 0xff) * (x)) 32 33 /* @a is a power of 2 value */ 34 #define ALIGN(x, a) __ALIGN_KERNEL((x), (a)) 35 #define ALIGN_DOWN(x, a) __ALIGN_KERNEL((x) - ((a) - 1), (a)) 36 #define __ALIGN_MASK(x, mask) __ALIGN_KERNEL_MASK((x), (mask)) 37 #define PTR_ALIGN(p, a) ((typeof(p))ALIGN((unsigned long)(p), (a))) 38 #define PTR_ALIGN_DOWN(p, a) ((typeof(p))ALIGN_DOWN((unsigned long)(p), (a))) 39 #define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0) 40 41 /* generic data direction definitions */ 42 #define READ 0 43 #define WRITE 1 44 45 /** 46 * ARRAY_SIZE - get the number of elements in array @arr 47 * @arr: array to be sized 48 */ 49 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr)) 50 51 #define u64_to_user_ptr(x) ( \ 52 { \ 53 typecheck(u64, (x)); \ 54 (void __user *)(uintptr_t)(x); \ 55 } \ 56 ) 57 58 #define typeof_member(T, m) typeof(((T*)0)->m) 59 60 #define _RET_IP_ (unsigned long)__builtin_return_address(0) 61 #define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; }) 62 63 /** 64 * upper_32_bits - return bits 32-63 of a number 65 * @n: the number we're accessing 66 * 67 * A basic shift-right of a 64- or 32-bit quantity. Use this to suppress 68 * the "right shift count >= width of type" warning when that quantity is 69 * 32-bits. 70 */ 71 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16)) 72 73 /** 74 * lower_32_bits - return bits 0-31 of a number 75 * @n: the number we're accessing 76 */ 77 #define lower_32_bits(n) ((u32)((n) & 0xffffffff)) 78 79 struct completion; 80 struct pt_regs; 81 struct user; 82 83 #ifdef CONFIG_PREEMPT_VOLUNTARY 84 85 extern int __cond_resched(void); 86 # define might_resched() __cond_resched() 87 88 #elif defined(CONFIG_PREEMPT_DYNAMIC) 89 90 extern int __cond_resched(void); 91 92 DECLARE_STATIC_CALL(might_resched, __cond_resched); 93 94 static __always_inline void might_resched(void) 95 { 96 static_call_mod(might_resched)(); 97 } 98 99 #else 100 101 # define might_resched() do { } while (0) 102 103 #endif /* CONFIG_PREEMPT_* */ 104 105 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 106 extern void ___might_sleep(const char *file, int line, int preempt_offset); 107 extern void __might_sleep(const char *file, int line, int preempt_offset); 108 extern void __cant_sleep(const char *file, int line, int preempt_offset); 109 extern void __cant_migrate(const char *file, int line); 110 111 /** 112 * might_sleep - annotation for functions that can sleep 113 * 114 * this macro will print a stack trace if it is executed in an atomic 115 * context (spinlock, irq-handler, ...). Additional sections where blocking is 116 * not allowed can be annotated with non_block_start() and non_block_end() 117 * pairs. 118 * 119 * This is a useful debugging help to be able to catch problems early and not 120 * be bitten later when the calling function happens to sleep when it is not 121 * supposed to. 122 */ 123 # define might_sleep() \ 124 do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0) 125 /** 126 * cant_sleep - annotation for functions that cannot sleep 127 * 128 * this macro will print a stack trace if it is executed with preemption enabled 129 */ 130 # define cant_sleep() \ 131 do { __cant_sleep(__FILE__, __LINE__, 0); } while (0) 132 # define sched_annotate_sleep() (current->task_state_change = 0) 133 134 /** 135 * cant_migrate - annotation for functions that cannot migrate 136 * 137 * Will print a stack trace if executed in code which is migratable 138 */ 139 # define cant_migrate() \ 140 do { \ 141 if (IS_ENABLED(CONFIG_SMP)) \ 142 __cant_migrate(__FILE__, __LINE__); \ 143 } while (0) 144 145 /** 146 * non_block_start - annotate the start of section where sleeping is prohibited 147 * 148 * This is on behalf of the oom reaper, specifically when it is calling the mmu 149 * notifiers. The problem is that if the notifier were to block on, for example, 150 * mutex_lock() and if the process which holds that mutex were to perform a 151 * sleeping memory allocation, the oom reaper is now blocked on completion of 152 * that memory allocation. Other blocking calls like wait_event() pose similar 153 * issues. 154 */ 155 # define non_block_start() (current->non_block_count++) 156 /** 157 * non_block_end - annotate the end of section where sleeping is prohibited 158 * 159 * Closes a section opened by non_block_start(). 160 */ 161 # define non_block_end() WARN_ON(current->non_block_count-- == 0) 162 #else 163 static inline void ___might_sleep(const char *file, int line, 164 int preempt_offset) { } 165 static inline void __might_sleep(const char *file, int line, 166 int preempt_offset) { } 167 # define might_sleep() do { might_resched(); } while (0) 168 # define cant_sleep() do { } while (0) 169 # define cant_migrate() do { } while (0) 170 # define sched_annotate_sleep() do { } while (0) 171 # define non_block_start() do { } while (0) 172 # define non_block_end() do { } while (0) 173 #endif 174 175 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0) 176 177 #if defined(CONFIG_MMU) && \ 178 (defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP)) 179 #define might_fault() __might_fault(__FILE__, __LINE__) 180 void __might_fault(const char *file, int line); 181 #else 182 static inline void might_fault(void) { } 183 #endif 184 185 extern struct atomic_notifier_head panic_notifier_list; 186 extern long (*panic_blink)(int state); 187 __printf(1, 2) 188 void panic(const char *fmt, ...) __noreturn __cold; 189 void nmi_panic(struct pt_regs *regs, const char *msg); 190 extern void oops_enter(void); 191 extern void oops_exit(void); 192 extern bool oops_may_print(void); 193 void do_exit(long error_code) __noreturn; 194 void complete_and_exit(struct completion *, long) __noreturn; 195 196 /* Internal, do not use. */ 197 int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res); 198 int __must_check _kstrtol(const char *s, unsigned int base, long *res); 199 200 int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res); 201 int __must_check kstrtoll(const char *s, unsigned int base, long long *res); 202 203 /** 204 * kstrtoul - convert a string to an unsigned long 205 * @s: The start of the string. The string must be null-terminated, and may also 206 * include a single newline before its terminating null. The first character 207 * may also be a plus sign, but not a minus sign. 208 * @base: The number base to use. The maximum supported base is 16. If base is 209 * given as 0, then the base of the string is automatically detected with the 210 * conventional semantics - If it begins with 0x the number will be parsed as a 211 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be 212 * parsed as an octal number. Otherwise it will be parsed as a decimal. 213 * @res: Where to write the result of the conversion on success. 214 * 215 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. 216 * Preferred over simple_strtoul(). Return code must be checked. 217 */ 218 static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res) 219 { 220 /* 221 * We want to shortcut function call, but 222 * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0. 223 */ 224 if (sizeof(unsigned long) == sizeof(unsigned long long) && 225 __alignof__(unsigned long) == __alignof__(unsigned long long)) 226 return kstrtoull(s, base, (unsigned long long *)res); 227 else 228 return _kstrtoul(s, base, res); 229 } 230 231 /** 232 * kstrtol - convert a string to a long 233 * @s: The start of the string. The string must be null-terminated, and may also 234 * include a single newline before its terminating null. The first character 235 * may also be a plus sign or a minus sign. 236 * @base: The number base to use. The maximum supported base is 16. If base is 237 * given as 0, then the base of the string is automatically detected with the 238 * conventional semantics - If it begins with 0x the number will be parsed as a 239 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be 240 * parsed as an octal number. Otherwise it will be parsed as a decimal. 241 * @res: Where to write the result of the conversion on success. 242 * 243 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. 244 * Preferred over simple_strtol(). Return code must be checked. 245 */ 246 static inline int __must_check kstrtol(const char *s, unsigned int base, long *res) 247 { 248 /* 249 * We want to shortcut function call, but 250 * __builtin_types_compatible_p(long, long long) = 0. 251 */ 252 if (sizeof(long) == sizeof(long long) && 253 __alignof__(long) == __alignof__(long long)) 254 return kstrtoll(s, base, (long long *)res); 255 else 256 return _kstrtol(s, base, res); 257 } 258 259 int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res); 260 int __must_check kstrtoint(const char *s, unsigned int base, int *res); 261 262 static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res) 263 { 264 return kstrtoull(s, base, res); 265 } 266 267 static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res) 268 { 269 return kstrtoll(s, base, res); 270 } 271 272 static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res) 273 { 274 return kstrtouint(s, base, res); 275 } 276 277 static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res) 278 { 279 return kstrtoint(s, base, res); 280 } 281 282 int __must_check kstrtou16(const char *s, unsigned int base, u16 *res); 283 int __must_check kstrtos16(const char *s, unsigned int base, s16 *res); 284 int __must_check kstrtou8(const char *s, unsigned int base, u8 *res); 285 int __must_check kstrtos8(const char *s, unsigned int base, s8 *res); 286 int __must_check kstrtobool(const char *s, bool *res); 287 288 int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res); 289 int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res); 290 int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res); 291 int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res); 292 int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res); 293 int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res); 294 int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res); 295 int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res); 296 int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res); 297 int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res); 298 int __must_check kstrtobool_from_user(const char __user *s, size_t count, bool *res); 299 300 static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res) 301 { 302 return kstrtoull_from_user(s, count, base, res); 303 } 304 305 static inline int __must_check kstrtos64_from_user(const char __user *s, size_t count, unsigned int base, s64 *res) 306 { 307 return kstrtoll_from_user(s, count, base, res); 308 } 309 310 static inline int __must_check kstrtou32_from_user(const char __user *s, size_t count, unsigned int base, u32 *res) 311 { 312 return kstrtouint_from_user(s, count, base, res); 313 } 314 315 static inline int __must_check kstrtos32_from_user(const char __user *s, size_t count, unsigned int base, s32 *res) 316 { 317 return kstrtoint_from_user(s, count, base, res); 318 } 319 320 /* 321 * Use kstrto<foo> instead. 322 * 323 * NOTE: simple_strto<foo> does not check for the range overflow and, 324 * depending on the input, may give interesting results. 325 * 326 * Use these functions if and only if you cannot use kstrto<foo>, because 327 * the conversion ends on the first non-digit character, which may be far 328 * beyond the supported range. It might be useful to parse the strings like 329 * 10x50 or 12:21 without altering original string or temporary buffer in use. 330 * Keep in mind above caveat. 331 */ 332 333 extern unsigned long simple_strtoul(const char *,char **,unsigned int); 334 extern long simple_strtol(const char *,char **,unsigned int); 335 extern unsigned long long simple_strtoull(const char *,char **,unsigned int); 336 extern long long simple_strtoll(const char *,char **,unsigned int); 337 338 extern int num_to_str(char *buf, int size, 339 unsigned long long num, unsigned int width); 340 341 /* lib/printf utilities */ 342 343 extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...); 344 extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list); 345 extern __printf(3, 4) 346 int snprintf(char *buf, size_t size, const char *fmt, ...); 347 extern __printf(3, 0) 348 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args); 349 extern __printf(3, 4) 350 int scnprintf(char *buf, size_t size, const char *fmt, ...); 351 extern __printf(3, 0) 352 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args); 353 extern __printf(2, 3) __malloc 354 char *kasprintf(gfp_t gfp, const char *fmt, ...); 355 extern __printf(2, 0) __malloc 356 char *kvasprintf(gfp_t gfp, const char *fmt, va_list args); 357 extern __printf(2, 0) 358 const char *kvasprintf_const(gfp_t gfp, const char *fmt, va_list args); 359 360 extern __scanf(2, 3) 361 int sscanf(const char *, const char *, ...); 362 extern __scanf(2, 0) 363 int vsscanf(const char *, const char *, va_list); 364 365 extern int get_option(char **str, int *pint); 366 extern char *get_options(const char *str, int nints, int *ints); 367 extern unsigned long long memparse(const char *ptr, char **retptr); 368 extern bool parse_option_str(const char *str, const char *option); 369 extern char *next_arg(char *args, char **param, char **val); 370 371 extern int core_kernel_text(unsigned long addr); 372 extern int init_kernel_text(unsigned long addr); 373 extern int core_kernel_data(unsigned long addr); 374 extern int __kernel_text_address(unsigned long addr); 375 extern int kernel_text_address(unsigned long addr); 376 extern int func_ptr_is_kernel_text(void *ptr); 377 378 #ifdef CONFIG_SMP 379 extern unsigned int sysctl_oops_all_cpu_backtrace; 380 #else 381 #define sysctl_oops_all_cpu_backtrace 0 382 #endif /* CONFIG_SMP */ 383 384 extern void bust_spinlocks(int yes); 385 extern int panic_timeout; 386 extern unsigned long panic_print; 387 extern int panic_on_oops; 388 extern int panic_on_unrecovered_nmi; 389 extern int panic_on_io_nmi; 390 extern int panic_on_warn; 391 extern unsigned long panic_on_taint; 392 extern bool panic_on_taint_nousertaint; 393 extern int sysctl_panic_on_rcu_stall; 394 extern int sysctl_max_rcu_stall_to_panic; 395 extern int sysctl_panic_on_stackoverflow; 396 397 extern bool crash_kexec_post_notifiers; 398 399 /* 400 * panic_cpu is used for synchronizing panic() and crash_kexec() execution. It 401 * holds a CPU number which is executing panic() currently. A value of 402 * PANIC_CPU_INVALID means no CPU has entered panic() or crash_kexec(). 403 */ 404 extern atomic_t panic_cpu; 405 #define PANIC_CPU_INVALID -1 406 407 /* 408 * Only to be used by arch init code. If the user over-wrote the default 409 * CONFIG_PANIC_TIMEOUT, honor it. 410 */ 411 static inline void set_arch_panic_timeout(int timeout, int arch_default_timeout) 412 { 413 if (panic_timeout == arch_default_timeout) 414 panic_timeout = timeout; 415 } 416 extern const char *print_tainted(void); 417 enum lockdep_ok { 418 LOCKDEP_STILL_OK, 419 LOCKDEP_NOW_UNRELIABLE 420 }; 421 extern void add_taint(unsigned flag, enum lockdep_ok); 422 extern int test_taint(unsigned flag); 423 extern unsigned long get_taint(void); 424 extern int root_mountflags; 425 426 extern bool early_boot_irqs_disabled; 427 428 /* 429 * Values used for system_state. Ordering of the states must not be changed 430 * as code checks for <, <=, >, >= STATE. 431 */ 432 extern enum system_states { 433 SYSTEM_BOOTING, 434 SYSTEM_SCHEDULING, 435 SYSTEM_RUNNING, 436 SYSTEM_HALT, 437 SYSTEM_POWER_OFF, 438 SYSTEM_RESTART, 439 SYSTEM_SUSPEND, 440 } system_state; 441 442 /* This cannot be an enum because some may be used in assembly source. */ 443 #define TAINT_PROPRIETARY_MODULE 0 444 #define TAINT_FORCED_MODULE 1 445 #define TAINT_CPU_OUT_OF_SPEC 2 446 #define TAINT_FORCED_RMMOD 3 447 #define TAINT_MACHINE_CHECK 4 448 #define TAINT_BAD_PAGE 5 449 #define TAINT_USER 6 450 #define TAINT_DIE 7 451 #define TAINT_OVERRIDDEN_ACPI_TABLE 8 452 #define TAINT_WARN 9 453 #define TAINT_CRAP 10 454 #define TAINT_FIRMWARE_WORKAROUND 11 455 #define TAINT_OOT_MODULE 12 456 #define TAINT_UNSIGNED_MODULE 13 457 #define TAINT_SOFTLOCKUP 14 458 #define TAINT_LIVEPATCH 15 459 #define TAINT_AUX 16 460 #define TAINT_RANDSTRUCT 17 461 #define TAINT_FLAGS_COUNT 18 462 #define TAINT_FLAGS_MAX ((1UL << TAINT_FLAGS_COUNT) - 1) 463 464 struct taint_flag { 465 char c_true; /* character printed when tainted */ 466 char c_false; /* character printed when not tainted */ 467 bool module; /* also show as a per-module taint flag */ 468 }; 469 470 extern const struct taint_flag taint_flags[TAINT_FLAGS_COUNT]; 471 472 extern const char hex_asc[]; 473 #define hex_asc_lo(x) hex_asc[((x) & 0x0f)] 474 #define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4] 475 476 static inline char *hex_byte_pack(char *buf, u8 byte) 477 { 478 *buf++ = hex_asc_hi(byte); 479 *buf++ = hex_asc_lo(byte); 480 return buf; 481 } 482 483 extern const char hex_asc_upper[]; 484 #define hex_asc_upper_lo(x) hex_asc_upper[((x) & 0x0f)] 485 #define hex_asc_upper_hi(x) hex_asc_upper[((x) & 0xf0) >> 4] 486 487 static inline char *hex_byte_pack_upper(char *buf, u8 byte) 488 { 489 *buf++ = hex_asc_upper_hi(byte); 490 *buf++ = hex_asc_upper_lo(byte); 491 return buf; 492 } 493 494 extern int hex_to_bin(char ch); 495 extern int __must_check hex2bin(u8 *dst, const char *src, size_t count); 496 extern char *bin2hex(char *dst, const void *src, size_t count); 497 498 bool mac_pton(const char *s, u8 *mac); 499 500 /* 501 * General tracing related utility functions - trace_printk(), 502 * tracing_on/tracing_off and tracing_start()/tracing_stop 503 * 504 * Use tracing_on/tracing_off when you want to quickly turn on or off 505 * tracing. It simply enables or disables the recording of the trace events. 506 * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on 507 * file, which gives a means for the kernel and userspace to interact. 508 * Place a tracing_off() in the kernel where you want tracing to end. 509 * From user space, examine the trace, and then echo 1 > tracing_on 510 * to continue tracing. 511 * 512 * tracing_stop/tracing_start has slightly more overhead. It is used 513 * by things like suspend to ram where disabling the recording of the 514 * trace is not enough, but tracing must actually stop because things 515 * like calling smp_processor_id() may crash the system. 516 * 517 * Most likely, you want to use tracing_on/tracing_off. 518 */ 519 520 enum ftrace_dump_mode { 521 DUMP_NONE, 522 DUMP_ALL, 523 DUMP_ORIG, 524 }; 525 526 #ifdef CONFIG_TRACING 527 void tracing_on(void); 528 void tracing_off(void); 529 int tracing_is_on(void); 530 void tracing_snapshot(void); 531 void tracing_snapshot_alloc(void); 532 533 extern void tracing_start(void); 534 extern void tracing_stop(void); 535 536 static inline __printf(1, 2) 537 void ____trace_printk_check_format(const char *fmt, ...) 538 { 539 } 540 #define __trace_printk_check_format(fmt, args...) \ 541 do { \ 542 if (0) \ 543 ____trace_printk_check_format(fmt, ##args); \ 544 } while (0) 545 546 /** 547 * trace_printk - printf formatting in the ftrace buffer 548 * @fmt: the printf format for printing 549 * 550 * Note: __trace_printk is an internal function for trace_printk() and 551 * the @ip is passed in via the trace_printk() macro. 552 * 553 * This function allows a kernel developer to debug fast path sections 554 * that printk is not appropriate for. By scattering in various 555 * printk like tracing in the code, a developer can quickly see 556 * where problems are occurring. 557 * 558 * This is intended as a debugging tool for the developer only. 559 * Please refrain from leaving trace_printks scattered around in 560 * your code. (Extra memory is used for special buffers that are 561 * allocated when trace_printk() is used.) 562 * 563 * A little optimization trick is done here. If there's only one 564 * argument, there's no need to scan the string for printf formats. 565 * The trace_puts() will suffice. But how can we take advantage of 566 * using trace_puts() when trace_printk() has only one argument? 567 * By stringifying the args and checking the size we can tell 568 * whether or not there are args. __stringify((__VA_ARGS__)) will 569 * turn into "()\0" with a size of 3 when there are no args, anything 570 * else will be bigger. All we need to do is define a string to this, 571 * and then take its size and compare to 3. If it's bigger, use 572 * do_trace_printk() otherwise, optimize it to trace_puts(). Then just 573 * let gcc optimize the rest. 574 */ 575 576 #define trace_printk(fmt, ...) \ 577 do { \ 578 char _______STR[] = __stringify((__VA_ARGS__)); \ 579 if (sizeof(_______STR) > 3) \ 580 do_trace_printk(fmt, ##__VA_ARGS__); \ 581 else \ 582 trace_puts(fmt); \ 583 } while (0) 584 585 #define do_trace_printk(fmt, args...) \ 586 do { \ 587 static const char *trace_printk_fmt __used \ 588 __section("__trace_printk_fmt") = \ 589 __builtin_constant_p(fmt) ? fmt : NULL; \ 590 \ 591 __trace_printk_check_format(fmt, ##args); \ 592 \ 593 if (__builtin_constant_p(fmt)) \ 594 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \ 595 else \ 596 __trace_printk(_THIS_IP_, fmt, ##args); \ 597 } while (0) 598 599 extern __printf(2, 3) 600 int __trace_bprintk(unsigned long ip, const char *fmt, ...); 601 602 extern __printf(2, 3) 603 int __trace_printk(unsigned long ip, const char *fmt, ...); 604 605 /** 606 * trace_puts - write a string into the ftrace buffer 607 * @str: the string to record 608 * 609 * Note: __trace_bputs is an internal function for trace_puts and 610 * the @ip is passed in via the trace_puts macro. 611 * 612 * This is similar to trace_printk() but is made for those really fast 613 * paths that a developer wants the least amount of "Heisenbug" effects, 614 * where the processing of the print format is still too much. 615 * 616 * This function allows a kernel developer to debug fast path sections 617 * that printk is not appropriate for. By scattering in various 618 * printk like tracing in the code, a developer can quickly see 619 * where problems are occurring. 620 * 621 * This is intended as a debugging tool for the developer only. 622 * Please refrain from leaving trace_puts scattered around in 623 * your code. (Extra memory is used for special buffers that are 624 * allocated when trace_puts() is used.) 625 * 626 * Returns: 0 if nothing was written, positive # if string was. 627 * (1 when __trace_bputs is used, strlen(str) when __trace_puts is used) 628 */ 629 630 #define trace_puts(str) ({ \ 631 static const char *trace_printk_fmt __used \ 632 __section("__trace_printk_fmt") = \ 633 __builtin_constant_p(str) ? str : NULL; \ 634 \ 635 if (__builtin_constant_p(str)) \ 636 __trace_bputs(_THIS_IP_, trace_printk_fmt); \ 637 else \ 638 __trace_puts(_THIS_IP_, str, strlen(str)); \ 639 }) 640 extern int __trace_bputs(unsigned long ip, const char *str); 641 extern int __trace_puts(unsigned long ip, const char *str, int size); 642 643 extern void trace_dump_stack(int skip); 644 645 /* 646 * The double __builtin_constant_p is because gcc will give us an error 647 * if we try to allocate the static variable to fmt if it is not a 648 * constant. Even with the outer if statement. 649 */ 650 #define ftrace_vprintk(fmt, vargs) \ 651 do { \ 652 if (__builtin_constant_p(fmt)) { \ 653 static const char *trace_printk_fmt __used \ 654 __section("__trace_printk_fmt") = \ 655 __builtin_constant_p(fmt) ? fmt : NULL; \ 656 \ 657 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \ 658 } else \ 659 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \ 660 } while (0) 661 662 extern __printf(2, 0) int 663 __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap); 664 665 extern __printf(2, 0) int 666 __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap); 667 668 extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode); 669 #else 670 static inline void tracing_start(void) { } 671 static inline void tracing_stop(void) { } 672 static inline void trace_dump_stack(int skip) { } 673 674 static inline void tracing_on(void) { } 675 static inline void tracing_off(void) { } 676 static inline int tracing_is_on(void) { return 0; } 677 static inline void tracing_snapshot(void) { } 678 static inline void tracing_snapshot_alloc(void) { } 679 680 static inline __printf(1, 2) 681 int trace_printk(const char *fmt, ...) 682 { 683 return 0; 684 } 685 static __printf(1, 0) inline int 686 ftrace_vprintk(const char *fmt, va_list ap) 687 { 688 return 0; 689 } 690 static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { } 691 #endif /* CONFIG_TRACING */ 692 693 /* This counts to 12. Any more, it will return 13th argument. */ 694 #define __COUNT_ARGS(_0, _1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11, _12, _n, X...) _n 695 #define COUNT_ARGS(X...) __COUNT_ARGS(, ##X, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0) 696 697 #define __CONCAT(a, b) a ## b 698 #define CONCATENATE(a, b) __CONCAT(a, b) 699 700 /** 701 * container_of - cast a member of a structure out to the containing structure 702 * @ptr: the pointer to the member. 703 * @type: the type of the container struct this is embedded in. 704 * @member: the name of the member within the struct. 705 * 706 */ 707 #define container_of(ptr, type, member) ({ \ 708 void *__mptr = (void *)(ptr); \ 709 BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \ 710 !__same_type(*(ptr), void), \ 711 "pointer type mismatch in container_of()"); \ 712 ((type *)(__mptr - offsetof(type, member))); }) 713 714 /** 715 * container_of_safe - cast a member of a structure out to the containing structure 716 * @ptr: the pointer to the member. 717 * @type: the type of the container struct this is embedded in. 718 * @member: the name of the member within the struct. 719 * 720 * If IS_ERR_OR_NULL(ptr), ptr is returned unchanged. 721 */ 722 #define container_of_safe(ptr, type, member) ({ \ 723 void *__mptr = (void *)(ptr); \ 724 BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \ 725 !__same_type(*(ptr), void), \ 726 "pointer type mismatch in container_of()"); \ 727 IS_ERR_OR_NULL(__mptr) ? ERR_CAST(__mptr) : \ 728 ((type *)(__mptr - offsetof(type, member))); }) 729 730 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */ 731 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 732 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD 733 #endif 734 735 /* Permissions on a sysfs file: you didn't miss the 0 prefix did you? */ 736 #define VERIFY_OCTAL_PERMISSIONS(perms) \ 737 (BUILD_BUG_ON_ZERO((perms) < 0) + \ 738 BUILD_BUG_ON_ZERO((perms) > 0777) + \ 739 /* USER_READABLE >= GROUP_READABLE >= OTHER_READABLE */ \ 740 BUILD_BUG_ON_ZERO((((perms) >> 6) & 4) < (((perms) >> 3) & 4)) + \ 741 BUILD_BUG_ON_ZERO((((perms) >> 3) & 4) < ((perms) & 4)) + \ 742 /* USER_WRITABLE >= GROUP_WRITABLE */ \ 743 BUILD_BUG_ON_ZERO((((perms) >> 6) & 2) < (((perms) >> 3) & 2)) + \ 744 /* OTHER_WRITABLE? Generally considered a bad idea. */ \ 745 BUILD_BUG_ON_ZERO((perms) & 2) + \ 746 (perms)) 747 #endif 748