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