1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _LINUX_KERNEL_H 3 #define _LINUX_KERNEL_H 4 5 6 #include <stdarg.h> 7 #include <linux/limits.h> 8 #include <linux/linkage.h> 9 #include <linux/stddef.h> 10 #include <linux/types.h> 11 #include <linux/compiler.h> 12 #include <linux/bitops.h> 13 #include <linux/log2.h> 14 #include <linux/typecheck.h> 15 #include <linux/printk.h> 16 #include <linux/build_bug.h> 17 #include <asm/byteorder.h> 18 #include <asm/div64.h> 19 #include <uapi/linux/kernel.h> 20 21 #define STACK_MAGIC 0xdeadbeef 22 23 /** 24 * REPEAT_BYTE - repeat the value @x multiple times as an unsigned long value 25 * @x: value to repeat 26 * 27 * NOTE: @x is not checked for > 0xff; larger values produce odd results. 28 */ 29 #define REPEAT_BYTE(x) ((~0ul / 0xff) * (x)) 30 31 /* @a is a power of 2 value */ 32 #define ALIGN(x, a) __ALIGN_KERNEL((x), (a)) 33 #define ALIGN_DOWN(x, a) __ALIGN_KERNEL((x) - ((a) - 1), (a)) 34 #define __ALIGN_MASK(x, mask) __ALIGN_KERNEL_MASK((x), (mask)) 35 #define PTR_ALIGN(p, a) ((typeof(p))ALIGN((unsigned long)(p), (a))) 36 #define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0) 37 38 /* generic data direction definitions */ 39 #define READ 0 40 #define WRITE 1 41 42 /** 43 * ARRAY_SIZE - get the number of elements in array @arr 44 * @arr: array to be sized 45 */ 46 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr)) 47 48 #define u64_to_user_ptr(x) ( \ 49 { \ 50 typecheck(u64, (x)); \ 51 (void __user *)(uintptr_t)(x); \ 52 } \ 53 ) 54 55 /* 56 * This looks more complex than it should be. But we need to 57 * get the type for the ~ right in round_down (it needs to be 58 * as wide as the result!), and we want to evaluate the macro 59 * arguments just once each. 60 */ 61 #define __round_mask(x, y) ((__typeof__(x))((y)-1)) 62 /** 63 * round_up - round up to next specified power of 2 64 * @x: the value to round 65 * @y: multiple to round up to (must be a power of 2) 66 * 67 * Rounds @x up to next multiple of @y (which must be a power of 2). 68 * To perform arbitrary rounding up, use roundup() below. 69 */ 70 #define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1) 71 /** 72 * round_down - round down to next specified power of 2 73 * @x: the value to round 74 * @y: multiple to round down to (must be a power of 2) 75 * 76 * Rounds @x down to next multiple of @y (which must be a power of 2). 77 * To perform arbitrary rounding down, use rounddown() below. 78 */ 79 #define round_down(x, y) ((x) & ~__round_mask(x, y)) 80 81 /** 82 * FIELD_SIZEOF - get the size of a struct's field 83 * @t: the target struct 84 * @f: the target struct's field 85 * Return: the size of @f in the struct definition without having a 86 * declared instance of @t. 87 */ 88 #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f)) 89 90 #define DIV_ROUND_UP __KERNEL_DIV_ROUND_UP 91 92 #define DIV_ROUND_DOWN_ULL(ll, d) \ 93 ({ unsigned long long _tmp = (ll); do_div(_tmp, d); _tmp; }) 94 95 #define DIV_ROUND_UP_ULL(ll, d) DIV_ROUND_DOWN_ULL((ll) + (d) - 1, (d)) 96 97 #if BITS_PER_LONG == 32 98 # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP_ULL(ll, d) 99 #else 100 # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP(ll,d) 101 #endif 102 103 /** 104 * roundup - round up to the next specified multiple 105 * @x: the value to up 106 * @y: multiple to round up to 107 * 108 * Rounds @x up to next multiple of @y. If @y will always be a power 109 * of 2, consider using the faster round_up(). 110 */ 111 #define roundup(x, y) ( \ 112 { \ 113 typeof(y) __y = y; \ 114 (((x) + (__y - 1)) / __y) * __y; \ 115 } \ 116 ) 117 /** 118 * rounddown - round down to next specified multiple 119 * @x: the value to round 120 * @y: multiple to round down to 121 * 122 * Rounds @x down to next multiple of @y. If @y will always be a power 123 * of 2, consider using the faster round_down(). 124 */ 125 #define rounddown(x, y) ( \ 126 { \ 127 typeof(x) __x = (x); \ 128 __x - (__x % (y)); \ 129 } \ 130 ) 131 132 /* 133 * Divide positive or negative dividend by positive or negative divisor 134 * and round to closest integer. Result is undefined for negative 135 * divisors if the dividend variable type is unsigned and for negative 136 * dividends if the divisor variable type is unsigned. 137 */ 138 #define DIV_ROUND_CLOSEST(x, divisor)( \ 139 { \ 140 typeof(x) __x = x; \ 141 typeof(divisor) __d = divisor; \ 142 (((typeof(x))-1) > 0 || \ 143 ((typeof(divisor))-1) > 0 || \ 144 (((__x) > 0) == ((__d) > 0))) ? \ 145 (((__x) + ((__d) / 2)) / (__d)) : \ 146 (((__x) - ((__d) / 2)) / (__d)); \ 147 } \ 148 ) 149 /* 150 * Same as above but for u64 dividends. divisor must be a 32-bit 151 * number. 152 */ 153 #define DIV_ROUND_CLOSEST_ULL(x, divisor)( \ 154 { \ 155 typeof(divisor) __d = divisor; \ 156 unsigned long long _tmp = (x) + (__d) / 2; \ 157 do_div(_tmp, __d); \ 158 _tmp; \ 159 } \ 160 ) 161 162 /* 163 * Multiplies an integer by a fraction, while avoiding unnecessary 164 * overflow or loss of precision. 165 */ 166 #define mult_frac(x, numer, denom)( \ 167 { \ 168 typeof(x) quot = (x) / (denom); \ 169 typeof(x) rem = (x) % (denom); \ 170 (quot * (numer)) + ((rem * (numer)) / (denom)); \ 171 } \ 172 ) 173 174 175 #define _RET_IP_ (unsigned long)__builtin_return_address(0) 176 #define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; }) 177 178 #ifdef CONFIG_LBDAF 179 # define sector_div(a, b) do_div(a, b) 180 #else 181 # define sector_div(n, b)( \ 182 { \ 183 int _res; \ 184 _res = (n) % (b); \ 185 (n) /= (b); \ 186 _res; \ 187 } \ 188 ) 189 #endif 190 191 /** 192 * upper_32_bits - return bits 32-63 of a number 193 * @n: the number we're accessing 194 * 195 * A basic shift-right of a 64- or 32-bit quantity. Use this to suppress 196 * the "right shift count >= width of type" warning when that quantity is 197 * 32-bits. 198 */ 199 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16)) 200 201 /** 202 * lower_32_bits - return bits 0-31 of a number 203 * @n: the number we're accessing 204 */ 205 #define lower_32_bits(n) ((u32)(n)) 206 207 struct completion; 208 struct pt_regs; 209 struct user; 210 211 #ifdef CONFIG_PREEMPT_VOLUNTARY 212 extern int _cond_resched(void); 213 # define might_resched() _cond_resched() 214 #else 215 # define might_resched() do { } while (0) 216 #endif 217 218 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 219 extern void ___might_sleep(const char *file, int line, int preempt_offset); 220 extern void __might_sleep(const char *file, int line, int preempt_offset); 221 extern void __cant_sleep(const char *file, int line, int preempt_offset); 222 223 /** 224 * might_sleep - annotation for functions that can sleep 225 * 226 * this macro will print a stack trace if it is executed in an atomic 227 * context (spinlock, irq-handler, ...). 228 * 229 * This is a useful debugging help to be able to catch problems early and not 230 * be bitten later when the calling function happens to sleep when it is not 231 * supposed to. 232 */ 233 # define might_sleep() \ 234 do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0) 235 /** 236 * cant_sleep - annotation for functions that cannot sleep 237 * 238 * this macro will print a stack trace if it is executed with preemption enabled 239 */ 240 # define cant_sleep() \ 241 do { __cant_sleep(__FILE__, __LINE__, 0); } while (0) 242 # define sched_annotate_sleep() (current->task_state_change = 0) 243 #else 244 static inline void ___might_sleep(const char *file, int line, 245 int preempt_offset) { } 246 static inline void __might_sleep(const char *file, int line, 247 int preempt_offset) { } 248 # define might_sleep() do { might_resched(); } while (0) 249 # define cant_sleep() do { } while (0) 250 # define sched_annotate_sleep() do { } while (0) 251 #endif 252 253 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0) 254 255 /** 256 * abs - return absolute value of an argument 257 * @x: the value. If it is unsigned type, it is converted to signed type first. 258 * char is treated as if it was signed (regardless of whether it really is) 259 * but the macro's return type is preserved as char. 260 * 261 * Return: an absolute value of x. 262 */ 263 #define abs(x) __abs_choose_expr(x, long long, \ 264 __abs_choose_expr(x, long, \ 265 __abs_choose_expr(x, int, \ 266 __abs_choose_expr(x, short, \ 267 __abs_choose_expr(x, char, \ 268 __builtin_choose_expr( \ 269 __builtin_types_compatible_p(typeof(x), char), \ 270 (char)({ signed char __x = (x); __x<0?-__x:__x; }), \ 271 ((void)0))))))) 272 273 #define __abs_choose_expr(x, type, other) __builtin_choose_expr( \ 274 __builtin_types_compatible_p(typeof(x), signed type) || \ 275 __builtin_types_compatible_p(typeof(x), unsigned type), \ 276 ({ signed type __x = (x); __x < 0 ? -__x : __x; }), other) 277 278 /** 279 * reciprocal_scale - "scale" a value into range [0, ep_ro) 280 * @val: value 281 * @ep_ro: right open interval endpoint 282 * 283 * Perform a "reciprocal multiplication" in order to "scale" a value into 284 * range [0, @ep_ro), where the upper interval endpoint is right-open. 285 * This is useful, e.g. for accessing a index of an array containing 286 * @ep_ro elements, for example. Think of it as sort of modulus, only that 287 * the result isn't that of modulo. ;) Note that if initial input is a 288 * small value, then result will return 0. 289 * 290 * Return: a result based on @val in interval [0, @ep_ro). 291 */ 292 static inline u32 reciprocal_scale(u32 val, u32 ep_ro) 293 { 294 return (u32)(((u64) val * ep_ro) >> 32); 295 } 296 297 #if defined(CONFIG_MMU) && \ 298 (defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP)) 299 #define might_fault() __might_fault(__FILE__, __LINE__) 300 void __might_fault(const char *file, int line); 301 #else 302 static inline void might_fault(void) { } 303 #endif 304 305 extern struct atomic_notifier_head panic_notifier_list; 306 extern long (*panic_blink)(int state); 307 __printf(1, 2) 308 void panic(const char *fmt, ...) __noreturn __cold; 309 void nmi_panic(struct pt_regs *regs, const char *msg); 310 extern void oops_enter(void); 311 extern void oops_exit(void); 312 void print_oops_end_marker(void); 313 extern int oops_may_print(void); 314 void do_exit(long error_code) __noreturn; 315 void complete_and_exit(struct completion *, long) __noreturn; 316 317 #ifdef CONFIG_ARCH_HAS_REFCOUNT 318 void refcount_error_report(struct pt_regs *regs, const char *err); 319 #else 320 static inline void refcount_error_report(struct pt_regs *regs, const char *err) 321 { } 322 #endif 323 324 /* Internal, do not use. */ 325 int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res); 326 int __must_check _kstrtol(const char *s, unsigned int base, long *res); 327 328 int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res); 329 int __must_check kstrtoll(const char *s, unsigned int base, long long *res); 330 331 /** 332 * kstrtoul - convert a string to an unsigned long 333 * @s: The start of the string. The string must be null-terminated, and may also 334 * include a single newline before its terminating null. The first character 335 * may also be a plus sign, but not a minus sign. 336 * @base: The number base to use. The maximum supported base is 16. If base is 337 * given as 0, then the base of the string is automatically detected with the 338 * conventional semantics - If it begins with 0x the number will be parsed as a 339 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be 340 * parsed as an octal number. Otherwise it will be parsed as a decimal. 341 * @res: Where to write the result of the conversion on success. 342 * 343 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. 344 * Used as a replacement for the obsolete simple_strtoull. Return code must 345 * be checked. 346 */ 347 static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res) 348 { 349 /* 350 * We want to shortcut function call, but 351 * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0. 352 */ 353 if (sizeof(unsigned long) == sizeof(unsigned long long) && 354 __alignof__(unsigned long) == __alignof__(unsigned long long)) 355 return kstrtoull(s, base, (unsigned long long *)res); 356 else 357 return _kstrtoul(s, base, res); 358 } 359 360 /** 361 * kstrtol - convert a string to a long 362 * @s: The start of the string. The string must be null-terminated, and may also 363 * include a single newline before its terminating null. The first character 364 * may also be a plus sign or a minus sign. 365 * @base: The number base to use. The maximum supported base is 16. If base is 366 * given as 0, then the base of the string is automatically detected with the 367 * conventional semantics - If it begins with 0x the number will be parsed as a 368 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be 369 * parsed as an octal number. Otherwise it will be parsed as a decimal. 370 * @res: Where to write the result of the conversion on success. 371 * 372 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. 373 * Used as a replacement for the obsolete simple_strtoull. Return code must 374 * be checked. 375 */ 376 static inline int __must_check kstrtol(const char *s, unsigned int base, long *res) 377 { 378 /* 379 * We want to shortcut function call, but 380 * __builtin_types_compatible_p(long, long long) = 0. 381 */ 382 if (sizeof(long) == sizeof(long long) && 383 __alignof__(long) == __alignof__(long long)) 384 return kstrtoll(s, base, (long long *)res); 385 else 386 return _kstrtol(s, base, res); 387 } 388 389 int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res); 390 int __must_check kstrtoint(const char *s, unsigned int base, int *res); 391 392 static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res) 393 { 394 return kstrtoull(s, base, res); 395 } 396 397 static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res) 398 { 399 return kstrtoll(s, base, res); 400 } 401 402 static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res) 403 { 404 return kstrtouint(s, base, res); 405 } 406 407 static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res) 408 { 409 return kstrtoint(s, base, res); 410 } 411 412 int __must_check kstrtou16(const char *s, unsigned int base, u16 *res); 413 int __must_check kstrtos16(const char *s, unsigned int base, s16 *res); 414 int __must_check kstrtou8(const char *s, unsigned int base, u8 *res); 415 int __must_check kstrtos8(const char *s, unsigned int base, s8 *res); 416 int __must_check kstrtobool(const char *s, bool *res); 417 418 int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res); 419 int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res); 420 int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res); 421 int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res); 422 int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res); 423 int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res); 424 int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res); 425 int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res); 426 int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res); 427 int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res); 428 int __must_check kstrtobool_from_user(const char __user *s, size_t count, bool *res); 429 430 static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res) 431 { 432 return kstrtoull_from_user(s, count, base, res); 433 } 434 435 static inline int __must_check kstrtos64_from_user(const char __user *s, size_t count, unsigned int base, s64 *res) 436 { 437 return kstrtoll_from_user(s, count, base, res); 438 } 439 440 static inline int __must_check kstrtou32_from_user(const char __user *s, size_t count, unsigned int base, u32 *res) 441 { 442 return kstrtouint_from_user(s, count, base, res); 443 } 444 445 static inline int __must_check kstrtos32_from_user(const char __user *s, size_t count, unsigned int base, s32 *res) 446 { 447 return kstrtoint_from_user(s, count, base, res); 448 } 449 450 /* Obsolete, do not use. Use kstrto<foo> instead */ 451 452 extern unsigned long simple_strtoul(const char *,char **,unsigned int); 453 extern long simple_strtol(const char *,char **,unsigned int); 454 extern unsigned long long simple_strtoull(const char *,char **,unsigned int); 455 extern long long simple_strtoll(const char *,char **,unsigned int); 456 457 extern int num_to_str(char *buf, int size, 458 unsigned long long num, unsigned int width); 459 460 /* lib/printf utilities */ 461 462 extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...); 463 extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list); 464 extern __printf(3, 4) 465 int snprintf(char *buf, size_t size, const char *fmt, ...); 466 extern __printf(3, 0) 467 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args); 468 extern __printf(3, 4) 469 int scnprintf(char *buf, size_t size, const char *fmt, ...); 470 extern __printf(3, 0) 471 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args); 472 extern __printf(2, 3) __malloc 473 char *kasprintf(gfp_t gfp, const char *fmt, ...); 474 extern __printf(2, 0) __malloc 475 char *kvasprintf(gfp_t gfp, const char *fmt, va_list args); 476 extern __printf(2, 0) 477 const char *kvasprintf_const(gfp_t gfp, const char *fmt, va_list args); 478 479 extern __scanf(2, 3) 480 int sscanf(const char *, const char *, ...); 481 extern __scanf(2, 0) 482 int vsscanf(const char *, const char *, va_list); 483 484 extern int get_option(char **str, int *pint); 485 extern char *get_options(const char *str, int nints, int *ints); 486 extern unsigned long long memparse(const char *ptr, char **retptr); 487 extern bool parse_option_str(const char *str, const char *option); 488 extern char *next_arg(char *args, char **param, char **val); 489 490 extern int core_kernel_text(unsigned long addr); 491 extern int init_kernel_text(unsigned long addr); 492 extern int core_kernel_data(unsigned long addr); 493 extern int __kernel_text_address(unsigned long addr); 494 extern int kernel_text_address(unsigned long addr); 495 extern int func_ptr_is_kernel_text(void *ptr); 496 497 unsigned long int_sqrt(unsigned long); 498 499 #if BITS_PER_LONG < 64 500 u32 int_sqrt64(u64 x); 501 #else 502 static inline u32 int_sqrt64(u64 x) 503 { 504 return (u32)int_sqrt(x); 505 } 506 #endif 507 508 extern void bust_spinlocks(int yes); 509 extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */ 510 extern int panic_timeout; 511 extern unsigned long panic_print; 512 extern int panic_on_oops; 513 extern int panic_on_unrecovered_nmi; 514 extern int panic_on_io_nmi; 515 extern int panic_on_warn; 516 extern int sysctl_panic_on_rcu_stall; 517 extern int sysctl_panic_on_stackoverflow; 518 519 extern bool crash_kexec_post_notifiers; 520 521 /* 522 * panic_cpu is used for synchronizing panic() and crash_kexec() execution. It 523 * holds a CPU number which is executing panic() currently. A value of 524 * PANIC_CPU_INVALID means no CPU has entered panic() or crash_kexec(). 525 */ 526 extern atomic_t panic_cpu; 527 #define PANIC_CPU_INVALID -1 528 529 /* 530 * Only to be used by arch init code. If the user over-wrote the default 531 * CONFIG_PANIC_TIMEOUT, honor it. 532 */ 533 static inline void set_arch_panic_timeout(int timeout, int arch_default_timeout) 534 { 535 if (panic_timeout == arch_default_timeout) 536 panic_timeout = timeout; 537 } 538 extern const char *print_tainted(void); 539 enum lockdep_ok { 540 LOCKDEP_STILL_OK, 541 LOCKDEP_NOW_UNRELIABLE 542 }; 543 extern void add_taint(unsigned flag, enum lockdep_ok); 544 extern int test_taint(unsigned flag); 545 extern unsigned long get_taint(void); 546 extern int root_mountflags; 547 548 extern bool early_boot_irqs_disabled; 549 550 /* 551 * Values used for system_state. Ordering of the states must not be changed 552 * as code checks for <, <=, >, >= STATE. 553 */ 554 extern enum system_states { 555 SYSTEM_BOOTING, 556 SYSTEM_SCHEDULING, 557 SYSTEM_RUNNING, 558 SYSTEM_HALT, 559 SYSTEM_POWER_OFF, 560 SYSTEM_RESTART, 561 SYSTEM_SUSPEND, 562 } system_state; 563 564 /* This cannot be an enum because some may be used in assembly source. */ 565 #define TAINT_PROPRIETARY_MODULE 0 566 #define TAINT_FORCED_MODULE 1 567 #define TAINT_CPU_OUT_OF_SPEC 2 568 #define TAINT_FORCED_RMMOD 3 569 #define TAINT_MACHINE_CHECK 4 570 #define TAINT_BAD_PAGE 5 571 #define TAINT_USER 6 572 #define TAINT_DIE 7 573 #define TAINT_OVERRIDDEN_ACPI_TABLE 8 574 #define TAINT_WARN 9 575 #define TAINT_CRAP 10 576 #define TAINT_FIRMWARE_WORKAROUND 11 577 #define TAINT_OOT_MODULE 12 578 #define TAINT_UNSIGNED_MODULE 13 579 #define TAINT_SOFTLOCKUP 14 580 #define TAINT_LIVEPATCH 15 581 #define TAINT_AUX 16 582 #define TAINT_RANDSTRUCT 17 583 #define TAINT_FLAGS_COUNT 18 584 585 struct taint_flag { 586 char c_true; /* character printed when tainted */ 587 char c_false; /* character printed when not tainted */ 588 bool module; /* also show as a per-module taint flag */ 589 }; 590 591 extern const struct taint_flag taint_flags[TAINT_FLAGS_COUNT]; 592 593 extern const char hex_asc[]; 594 #define hex_asc_lo(x) hex_asc[((x) & 0x0f)] 595 #define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4] 596 597 static inline char *hex_byte_pack(char *buf, u8 byte) 598 { 599 *buf++ = hex_asc_hi(byte); 600 *buf++ = hex_asc_lo(byte); 601 return buf; 602 } 603 604 extern const char hex_asc_upper[]; 605 #define hex_asc_upper_lo(x) hex_asc_upper[((x) & 0x0f)] 606 #define hex_asc_upper_hi(x) hex_asc_upper[((x) & 0xf0) >> 4] 607 608 static inline char *hex_byte_pack_upper(char *buf, u8 byte) 609 { 610 *buf++ = hex_asc_upper_hi(byte); 611 *buf++ = hex_asc_upper_lo(byte); 612 return buf; 613 } 614 615 extern int hex_to_bin(char ch); 616 extern int __must_check hex2bin(u8 *dst, const char *src, size_t count); 617 extern char *bin2hex(char *dst, const void *src, size_t count); 618 619 bool mac_pton(const char *s, u8 *mac); 620 621 /* 622 * General tracing related utility functions - trace_printk(), 623 * tracing_on/tracing_off and tracing_start()/tracing_stop 624 * 625 * Use tracing_on/tracing_off when you want to quickly turn on or off 626 * tracing. It simply enables or disables the recording of the trace events. 627 * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on 628 * file, which gives a means for the kernel and userspace to interact. 629 * Place a tracing_off() in the kernel where you want tracing to end. 630 * From user space, examine the trace, and then echo 1 > tracing_on 631 * to continue tracing. 632 * 633 * tracing_stop/tracing_start has slightly more overhead. It is used 634 * by things like suspend to ram where disabling the recording of the 635 * trace is not enough, but tracing must actually stop because things 636 * like calling smp_processor_id() may crash the system. 637 * 638 * Most likely, you want to use tracing_on/tracing_off. 639 */ 640 641 enum ftrace_dump_mode { 642 DUMP_NONE, 643 DUMP_ALL, 644 DUMP_ORIG, 645 }; 646 647 #ifdef CONFIG_TRACING 648 void tracing_on(void); 649 void tracing_off(void); 650 int tracing_is_on(void); 651 void tracing_snapshot(void); 652 void tracing_snapshot_alloc(void); 653 654 extern void tracing_start(void); 655 extern void tracing_stop(void); 656 657 static inline __printf(1, 2) 658 void ____trace_printk_check_format(const char *fmt, ...) 659 { 660 } 661 #define __trace_printk_check_format(fmt, args...) \ 662 do { \ 663 if (0) \ 664 ____trace_printk_check_format(fmt, ##args); \ 665 } while (0) 666 667 /** 668 * trace_printk - printf formatting in the ftrace buffer 669 * @fmt: the printf format for printing 670 * 671 * Note: __trace_printk is an internal function for trace_printk() and 672 * the @ip is passed in via the trace_printk() macro. 673 * 674 * This function allows a kernel developer to debug fast path sections 675 * that printk is not appropriate for. By scattering in various 676 * printk like tracing in the code, a developer can quickly see 677 * where problems are occurring. 678 * 679 * This is intended as a debugging tool for the developer only. 680 * Please refrain from leaving trace_printks scattered around in 681 * your code. (Extra memory is used for special buffers that are 682 * allocated when trace_printk() is used.) 683 * 684 * A little optimization trick is done here. If there's only one 685 * argument, there's no need to scan the string for printf formats. 686 * The trace_puts() will suffice. But how can we take advantage of 687 * using trace_puts() when trace_printk() has only one argument? 688 * By stringifying the args and checking the size we can tell 689 * whether or not there are args. __stringify((__VA_ARGS__)) will 690 * turn into "()\0" with a size of 3 when there are no args, anything 691 * else will be bigger. All we need to do is define a string to this, 692 * and then take its size and compare to 3. If it's bigger, use 693 * do_trace_printk() otherwise, optimize it to trace_puts(). Then just 694 * let gcc optimize the rest. 695 */ 696 697 #define trace_printk(fmt, ...) \ 698 do { \ 699 char _______STR[] = __stringify((__VA_ARGS__)); \ 700 if (sizeof(_______STR) > 3) \ 701 do_trace_printk(fmt, ##__VA_ARGS__); \ 702 else \ 703 trace_puts(fmt); \ 704 } while (0) 705 706 #define do_trace_printk(fmt, args...) \ 707 do { \ 708 static const char *trace_printk_fmt __used \ 709 __attribute__((section("__trace_printk_fmt"))) = \ 710 __builtin_constant_p(fmt) ? fmt : NULL; \ 711 \ 712 __trace_printk_check_format(fmt, ##args); \ 713 \ 714 if (__builtin_constant_p(fmt)) \ 715 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \ 716 else \ 717 __trace_printk(_THIS_IP_, fmt, ##args); \ 718 } while (0) 719 720 extern __printf(2, 3) 721 int __trace_bprintk(unsigned long ip, const char *fmt, ...); 722 723 extern __printf(2, 3) 724 int __trace_printk(unsigned long ip, const char *fmt, ...); 725 726 /** 727 * trace_puts - write a string into the ftrace buffer 728 * @str: the string to record 729 * 730 * Note: __trace_bputs is an internal function for trace_puts and 731 * the @ip is passed in via the trace_puts macro. 732 * 733 * This is similar to trace_printk() but is made for those really fast 734 * paths that a developer wants the least amount of "Heisenbug" effects, 735 * where the processing of the print format is still too much. 736 * 737 * This function allows a kernel developer to debug fast path sections 738 * that printk is not appropriate for. By scattering in various 739 * printk like tracing in the code, a developer can quickly see 740 * where problems are occurring. 741 * 742 * This is intended as a debugging tool for the developer only. 743 * Please refrain from leaving trace_puts scattered around in 744 * your code. (Extra memory is used for special buffers that are 745 * allocated when trace_puts() is used.) 746 * 747 * Returns: 0 if nothing was written, positive # if string was. 748 * (1 when __trace_bputs is used, strlen(str) when __trace_puts is used) 749 */ 750 751 #define trace_puts(str) ({ \ 752 static const char *trace_printk_fmt __used \ 753 __attribute__((section("__trace_printk_fmt"))) = \ 754 __builtin_constant_p(str) ? str : NULL; \ 755 \ 756 if (__builtin_constant_p(str)) \ 757 __trace_bputs(_THIS_IP_, trace_printk_fmt); \ 758 else \ 759 __trace_puts(_THIS_IP_, str, strlen(str)); \ 760 }) 761 extern int __trace_bputs(unsigned long ip, const char *str); 762 extern int __trace_puts(unsigned long ip, const char *str, int size); 763 764 extern void trace_dump_stack(int skip); 765 766 /* 767 * The double __builtin_constant_p is because gcc will give us an error 768 * if we try to allocate the static variable to fmt if it is not a 769 * constant. Even with the outer if statement. 770 */ 771 #define ftrace_vprintk(fmt, vargs) \ 772 do { \ 773 if (__builtin_constant_p(fmt)) { \ 774 static const char *trace_printk_fmt __used \ 775 __attribute__((section("__trace_printk_fmt"))) = \ 776 __builtin_constant_p(fmt) ? fmt : NULL; \ 777 \ 778 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \ 779 } else \ 780 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \ 781 } while (0) 782 783 extern __printf(2, 0) int 784 __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap); 785 786 extern __printf(2, 0) int 787 __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap); 788 789 extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode); 790 #else 791 static inline void tracing_start(void) { } 792 static inline void tracing_stop(void) { } 793 static inline void trace_dump_stack(int skip) { } 794 795 static inline void tracing_on(void) { } 796 static inline void tracing_off(void) { } 797 static inline int tracing_is_on(void) { return 0; } 798 static inline void tracing_snapshot(void) { } 799 static inline void tracing_snapshot_alloc(void) { } 800 801 static inline __printf(1, 2) 802 int trace_printk(const char *fmt, ...) 803 { 804 return 0; 805 } 806 static __printf(1, 0) inline int 807 ftrace_vprintk(const char *fmt, va_list ap) 808 { 809 return 0; 810 } 811 static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { } 812 #endif /* CONFIG_TRACING */ 813 814 /* 815 * min()/max()/clamp() macros must accomplish three things: 816 * 817 * - avoid multiple evaluations of the arguments (so side-effects like 818 * "x++" happen only once) when non-constant. 819 * - perform strict type-checking (to generate warnings instead of 820 * nasty runtime surprises). See the "unnecessary" pointer comparison 821 * in __typecheck(). 822 * - retain result as a constant expressions when called with only 823 * constant expressions (to avoid tripping VLA warnings in stack 824 * allocation usage). 825 */ 826 #define __typecheck(x, y) \ 827 (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1))) 828 829 /* 830 * This returns a constant expression while determining if an argument is 831 * a constant expression, most importantly without evaluating the argument. 832 * Glory to Martin Uecker <Martin.Uecker@med.uni-goettingen.de> 833 */ 834 #define __is_constexpr(x) \ 835 (sizeof(int) == sizeof(*(8 ? ((void *)((long)(x) * 0l)) : (int *)8))) 836 837 #define __no_side_effects(x, y) \ 838 (__is_constexpr(x) && __is_constexpr(y)) 839 840 #define __safe_cmp(x, y) \ 841 (__typecheck(x, y) && __no_side_effects(x, y)) 842 843 #define __cmp(x, y, op) ((x) op (y) ? (x) : (y)) 844 845 #define __cmp_once(x, y, unique_x, unique_y, op) ({ \ 846 typeof(x) unique_x = (x); \ 847 typeof(y) unique_y = (y); \ 848 __cmp(unique_x, unique_y, op); }) 849 850 #define __careful_cmp(x, y, op) \ 851 __builtin_choose_expr(__safe_cmp(x, y), \ 852 __cmp(x, y, op), \ 853 __cmp_once(x, y, __UNIQUE_ID(__x), __UNIQUE_ID(__y), op)) 854 855 /** 856 * min - return minimum of two values of the same or compatible types 857 * @x: first value 858 * @y: second value 859 */ 860 #define min(x, y) __careful_cmp(x, y, <) 861 862 /** 863 * max - return maximum of two values of the same or compatible types 864 * @x: first value 865 * @y: second value 866 */ 867 #define max(x, y) __careful_cmp(x, y, >) 868 869 /** 870 * min3 - return minimum of three values 871 * @x: first value 872 * @y: second value 873 * @z: third value 874 */ 875 #define min3(x, y, z) min((typeof(x))min(x, y), z) 876 877 /** 878 * max3 - return maximum of three values 879 * @x: first value 880 * @y: second value 881 * @z: third value 882 */ 883 #define max3(x, y, z) max((typeof(x))max(x, y), z) 884 885 /** 886 * min_not_zero - return the minimum that is _not_ zero, unless both are zero 887 * @x: value1 888 * @y: value2 889 */ 890 #define min_not_zero(x, y) ({ \ 891 typeof(x) __x = (x); \ 892 typeof(y) __y = (y); \ 893 __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); }) 894 895 /** 896 * clamp - return a value clamped to a given range with strict typechecking 897 * @val: current value 898 * @lo: lowest allowable value 899 * @hi: highest allowable value 900 * 901 * This macro does strict typechecking of @lo/@hi to make sure they are of the 902 * same type as @val. See the unnecessary pointer comparisons. 903 */ 904 #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi) 905 906 /* 907 * ..and if you can't take the strict 908 * types, you can specify one yourself. 909 * 910 * Or not use min/max/clamp at all, of course. 911 */ 912 913 /** 914 * min_t - return minimum of two values, using the specified type 915 * @type: data type to use 916 * @x: first value 917 * @y: second value 918 */ 919 #define min_t(type, x, y) __careful_cmp((type)(x), (type)(y), <) 920 921 /** 922 * max_t - return maximum of two values, using the specified type 923 * @type: data type to use 924 * @x: first value 925 * @y: second value 926 */ 927 #define max_t(type, x, y) __careful_cmp((type)(x), (type)(y), >) 928 929 /** 930 * clamp_t - return a value clamped to a given range using a given type 931 * @type: the type of variable to use 932 * @val: current value 933 * @lo: minimum allowable value 934 * @hi: maximum allowable value 935 * 936 * This macro does no typechecking and uses temporary variables of type 937 * @type to make all the comparisons. 938 */ 939 #define clamp_t(type, val, lo, hi) min_t(type, max_t(type, val, lo), hi) 940 941 /** 942 * clamp_val - return a value clamped to a given range using val's type 943 * @val: current value 944 * @lo: minimum allowable value 945 * @hi: maximum allowable value 946 * 947 * This macro does no typechecking and uses temporary variables of whatever 948 * type the input argument @val is. This is useful when @val is an unsigned 949 * type and @lo and @hi are literals that will otherwise be assigned a signed 950 * integer type. 951 */ 952 #define clamp_val(val, lo, hi) clamp_t(typeof(val), val, lo, hi) 953 954 955 /** 956 * swap - swap values of @a and @b 957 * @a: first value 958 * @b: second value 959 */ 960 #define swap(a, b) \ 961 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0) 962 963 /* This counts to 12. Any more, it will return 13th argument. */ 964 #define __COUNT_ARGS(_0, _1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11, _12, _n, X...) _n 965 #define COUNT_ARGS(X...) __COUNT_ARGS(, ##X, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0) 966 967 #define __CONCAT(a, b) a ## b 968 #define CONCATENATE(a, b) __CONCAT(a, b) 969 970 /** 971 * container_of - cast a member of a structure out to the containing structure 972 * @ptr: the pointer to the member. 973 * @type: the type of the container struct this is embedded in. 974 * @member: the name of the member within the struct. 975 * 976 */ 977 #define container_of(ptr, type, member) ({ \ 978 void *__mptr = (void *)(ptr); \ 979 BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \ 980 !__same_type(*(ptr), void), \ 981 "pointer type mismatch in container_of()"); \ 982 ((type *)(__mptr - offsetof(type, member))); }) 983 984 /** 985 * container_of_safe - cast a member of a structure out to the containing structure 986 * @ptr: the pointer to the member. 987 * @type: the type of the container struct this is embedded in. 988 * @member: the name of the member within the struct. 989 * 990 * If IS_ERR_OR_NULL(ptr), ptr is returned unchanged. 991 */ 992 #define container_of_safe(ptr, type, member) ({ \ 993 void *__mptr = (void *)(ptr); \ 994 BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \ 995 !__same_type(*(ptr), void), \ 996 "pointer type mismatch in container_of()"); \ 997 IS_ERR_OR_NULL(__mptr) ? ERR_CAST(__mptr) : \ 998 ((type *)(__mptr - offsetof(type, member))); }) 999 1000 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */ 1001 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 1002 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD 1003 #endif 1004 1005 /* Permissions on a sysfs file: you didn't miss the 0 prefix did you? */ 1006 #define VERIFY_OCTAL_PERMISSIONS(perms) \ 1007 (BUILD_BUG_ON_ZERO((perms) < 0) + \ 1008 BUILD_BUG_ON_ZERO((perms) > 0777) + \ 1009 /* USER_READABLE >= GROUP_READABLE >= OTHER_READABLE */ \ 1010 BUILD_BUG_ON_ZERO((((perms) >> 6) & 4) < (((perms) >> 3) & 4)) + \ 1011 BUILD_BUG_ON_ZERO((((perms) >> 3) & 4) < ((perms) & 4)) + \ 1012 /* USER_WRITABLE >= GROUP_WRITABLE */ \ 1013 BUILD_BUG_ON_ZERO((((perms) >> 6) & 2) < (((perms) >> 3) & 2)) + \ 1014 /* OTHER_WRITABLE? Generally considered a bad idea. */ \ 1015 BUILD_BUG_ON_ZERO((perms) & 2) + \ 1016 (perms)) 1017 #endif 1018