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