1 #ifndef _LINUX_KERNEL_H 2 #define _LINUX_KERNEL_H 3 4 5 #include <stdarg.h> 6 #include <linux/linkage.h> 7 #include <linux/stddef.h> 8 #include <linux/types.h> 9 #include <linux/compiler.h> 10 #include <linux/bitops.h> 11 #include <linux/log2.h> 12 #include <linux/typecheck.h> 13 #include <linux/printk.h> 14 #include <asm/byteorder.h> 15 #include <uapi/linux/kernel.h> 16 17 #define USHRT_MAX ((u16)(~0U)) 18 #define SHRT_MAX ((s16)(USHRT_MAX>>1)) 19 #define SHRT_MIN ((s16)(-SHRT_MAX - 1)) 20 #define INT_MAX ((int)(~0U>>1)) 21 #define INT_MIN (-INT_MAX - 1) 22 #define UINT_MAX (~0U) 23 #define LONG_MAX ((long)(~0UL>>1)) 24 #define LONG_MIN (-LONG_MAX - 1) 25 #define ULONG_MAX (~0UL) 26 #define LLONG_MAX ((long long)(~0ULL>>1)) 27 #define LLONG_MIN (-LLONG_MAX - 1) 28 #define ULLONG_MAX (~0ULL) 29 #define SIZE_MAX (~(size_t)0) 30 31 #define U8_MAX ((u8)~0U) 32 #define S8_MAX ((s8)(U8_MAX>>1)) 33 #define S8_MIN ((s8)(-S8_MAX - 1)) 34 #define U16_MAX ((u16)~0U) 35 #define S16_MAX ((s16)(U16_MAX>>1)) 36 #define S16_MIN ((s16)(-S16_MAX - 1)) 37 #define U32_MAX ((u32)~0U) 38 #define S32_MAX ((s32)(U32_MAX>>1)) 39 #define S32_MIN ((s32)(-S32_MAX - 1)) 40 #define U64_MAX ((u64)~0ULL) 41 #define S64_MAX ((s64)(U64_MAX>>1)) 42 #define S64_MIN ((s64)(-S64_MAX - 1)) 43 44 #define STACK_MAGIC 0xdeadbeef 45 46 #define REPEAT_BYTE(x) ((~0ul / 0xff) * (x)) 47 48 #define ALIGN(x, a) __ALIGN_KERNEL((x), (a)) 49 #define __ALIGN_MASK(x, mask) __ALIGN_KERNEL_MASK((x), (mask)) 50 #define PTR_ALIGN(p, a) ((typeof(p))ALIGN((unsigned long)(p), (a))) 51 #define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0) 52 53 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr)) 54 55 #define u64_to_user_ptr(x) ( \ 56 { \ 57 typecheck(u64, x); \ 58 (void __user *)(uintptr_t)x; \ 59 } \ 60 ) 61 62 /* 63 * This looks more complex than it should be. But we need to 64 * get the type for the ~ right in round_down (it needs to be 65 * as wide as the result!), and we want to evaluate the macro 66 * arguments just once each. 67 */ 68 #define __round_mask(x, y) ((__typeof__(x))((y)-1)) 69 #define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1) 70 #define round_down(x, y) ((x) & ~__round_mask(x, y)) 71 72 #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f)) 73 #define DIV_ROUND_UP __KERNEL_DIV_ROUND_UP 74 #define DIV_ROUND_UP_ULL(ll,d) \ 75 ({ unsigned long long _tmp = (ll)+(d)-1; do_div(_tmp, d); _tmp; }) 76 77 #if BITS_PER_LONG == 32 78 # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP_ULL(ll, d) 79 #else 80 # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP(ll,d) 81 #endif 82 83 /* The `const' in roundup() prevents gcc-3.3 from calling __divdi3 */ 84 #define roundup(x, y) ( \ 85 { \ 86 const typeof(y) __y = y; \ 87 (((x) + (__y - 1)) / __y) * __y; \ 88 } \ 89 ) 90 #define rounddown(x, y) ( \ 91 { \ 92 typeof(x) __x = (x); \ 93 __x - (__x % (y)); \ 94 } \ 95 ) 96 97 /* 98 * Divide positive or negative dividend by positive divisor and round 99 * to closest integer. Result is undefined for negative divisors and 100 * for negative dividends if the divisor variable type is unsigned. 101 */ 102 #define DIV_ROUND_CLOSEST(x, divisor)( \ 103 { \ 104 typeof(x) __x = x; \ 105 typeof(divisor) __d = divisor; \ 106 (((typeof(x))-1) > 0 || \ 107 ((typeof(divisor))-1) > 0 || (__x) > 0) ? \ 108 (((__x) + ((__d) / 2)) / (__d)) : \ 109 (((__x) - ((__d) / 2)) / (__d)); \ 110 } \ 111 ) 112 /* 113 * Same as above but for u64 dividends. divisor must be a 32-bit 114 * number. 115 */ 116 #define DIV_ROUND_CLOSEST_ULL(x, divisor)( \ 117 { \ 118 typeof(divisor) __d = divisor; \ 119 unsigned long long _tmp = (x) + (__d) / 2; \ 120 do_div(_tmp, __d); \ 121 _tmp; \ 122 } \ 123 ) 124 125 /* 126 * Multiplies an integer by a fraction, while avoiding unnecessary 127 * overflow or loss of precision. 128 */ 129 #define mult_frac(x, numer, denom)( \ 130 { \ 131 typeof(x) quot = (x) / (denom); \ 132 typeof(x) rem = (x) % (denom); \ 133 (quot * (numer)) + ((rem * (numer)) / (denom)); \ 134 } \ 135 ) 136 137 138 #define _RET_IP_ (unsigned long)__builtin_return_address(0) 139 #define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; }) 140 141 #ifdef CONFIG_LBDAF 142 # include <asm/div64.h> 143 # define sector_div(a, b) do_div(a, b) 144 #else 145 # define sector_div(n, b)( \ 146 { \ 147 int _res; \ 148 _res = (n) % (b); \ 149 (n) /= (b); \ 150 _res; \ 151 } \ 152 ) 153 #endif 154 155 /** 156 * upper_32_bits - return bits 32-63 of a number 157 * @n: the number we're accessing 158 * 159 * A basic shift-right of a 64- or 32-bit quantity. Use this to suppress 160 * the "right shift count >= width of type" warning when that quantity is 161 * 32-bits. 162 */ 163 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16)) 164 165 /** 166 * lower_32_bits - return bits 0-31 of a number 167 * @n: the number we're accessing 168 */ 169 #define lower_32_bits(n) ((u32)(n)) 170 171 struct completion; 172 struct pt_regs; 173 struct user; 174 175 #ifdef CONFIG_PREEMPT_VOLUNTARY 176 extern int _cond_resched(void); 177 # define might_resched() _cond_resched() 178 #else 179 # define might_resched() do { } while (0) 180 #endif 181 182 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 183 void ___might_sleep(const char *file, int line, int preempt_offset); 184 void __might_sleep(const char *file, int line, int preempt_offset); 185 /** 186 * might_sleep - annotation for functions that can sleep 187 * 188 * this macro will print a stack trace if it is executed in an atomic 189 * context (spinlock, irq-handler, ...). 190 * 191 * This is a useful debugging help to be able to catch problems early and not 192 * be bitten later when the calling function happens to sleep when it is not 193 * supposed to. 194 */ 195 # define might_sleep() \ 196 do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0) 197 # define sched_annotate_sleep() (current->task_state_change = 0) 198 #else 199 static inline void ___might_sleep(const char *file, int line, 200 int preempt_offset) { } 201 static inline void __might_sleep(const char *file, int line, 202 int preempt_offset) { } 203 # define might_sleep() do { might_resched(); } while (0) 204 # define sched_annotate_sleep() do { } while (0) 205 #endif 206 207 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0) 208 209 /** 210 * abs - return absolute value of an argument 211 * @x: the value. If it is unsigned type, it is converted to signed type first. 212 * char is treated as if it was signed (regardless of whether it really is) 213 * but the macro's return type is preserved as char. 214 * 215 * Return: an absolute value of x. 216 */ 217 #define abs(x) __abs_choose_expr(x, long long, \ 218 __abs_choose_expr(x, long, \ 219 __abs_choose_expr(x, int, \ 220 __abs_choose_expr(x, short, \ 221 __abs_choose_expr(x, char, \ 222 __builtin_choose_expr( \ 223 __builtin_types_compatible_p(typeof(x), char), \ 224 (char)({ signed char __x = (x); __x<0?-__x:__x; }), \ 225 ((void)0))))))) 226 227 #define __abs_choose_expr(x, type, other) __builtin_choose_expr( \ 228 __builtin_types_compatible_p(typeof(x), signed type) || \ 229 __builtin_types_compatible_p(typeof(x), unsigned type), \ 230 ({ signed type __x = (x); __x < 0 ? -__x : __x; }), other) 231 232 /** 233 * reciprocal_scale - "scale" a value into range [0, ep_ro) 234 * @val: value 235 * @ep_ro: right open interval endpoint 236 * 237 * Perform a "reciprocal multiplication" in order to "scale" a value into 238 * range [0, ep_ro), where the upper interval endpoint is right-open. 239 * This is useful, e.g. for accessing a index of an array containing 240 * ep_ro elements, for example. Think of it as sort of modulus, only that 241 * the result isn't that of modulo. ;) Note that if initial input is a 242 * small value, then result will return 0. 243 * 244 * Return: a result based on val in interval [0, ep_ro). 245 */ 246 static inline u32 reciprocal_scale(u32 val, u32 ep_ro) 247 { 248 return (u32)(((u64) val * ep_ro) >> 32); 249 } 250 251 #if defined(CONFIG_MMU) && \ 252 (defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP)) 253 #define might_fault() __might_fault(__FILE__, __LINE__) 254 void __might_fault(const char *file, int line); 255 #else 256 static inline void might_fault(void) { } 257 #endif 258 259 extern struct atomic_notifier_head panic_notifier_list; 260 extern long (*panic_blink)(int state); 261 __printf(1, 2) 262 void panic(const char *fmt, ...) __noreturn __cold; 263 void nmi_panic(struct pt_regs *regs, const char *msg); 264 extern void oops_enter(void); 265 extern void oops_exit(void); 266 void print_oops_end_marker(void); 267 extern int oops_may_print(void); 268 void do_exit(long error_code) __noreturn; 269 void complete_and_exit(struct completion *, long) __noreturn; 270 271 /* Internal, do not use. */ 272 int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res); 273 int __must_check _kstrtol(const char *s, unsigned int base, long *res); 274 275 int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res); 276 int __must_check kstrtoll(const char *s, unsigned int base, long long *res); 277 278 /** 279 * kstrtoul - convert a string to an unsigned long 280 * @s: The start of the string. The string must be null-terminated, and may also 281 * include a single newline before its terminating null. The first character 282 * may also be a plus sign, but not a minus sign. 283 * @base: The number base to use. The maximum supported base is 16. If base is 284 * given as 0, then the base of the string is automatically detected with the 285 * conventional semantics - If it begins with 0x the number will be parsed as a 286 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be 287 * parsed as an octal number. Otherwise it will be parsed as a decimal. 288 * @res: Where to write the result of the conversion on success. 289 * 290 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. 291 * Used as a replacement for the obsolete simple_strtoull. Return code must 292 * be checked. 293 */ 294 static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res) 295 { 296 /* 297 * We want to shortcut function call, but 298 * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0. 299 */ 300 if (sizeof(unsigned long) == sizeof(unsigned long long) && 301 __alignof__(unsigned long) == __alignof__(unsigned long long)) 302 return kstrtoull(s, base, (unsigned long long *)res); 303 else 304 return _kstrtoul(s, base, res); 305 } 306 307 /** 308 * kstrtol - convert a string to a long 309 * @s: The start of the string. The string must be null-terminated, and may also 310 * include a single newline before its terminating null. The first character 311 * may also be a plus sign or a minus sign. 312 * @base: The number base to use. The maximum supported base is 16. If base is 313 * given as 0, then the base of the string is automatically detected with the 314 * conventional semantics - If it begins with 0x the number will be parsed as a 315 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be 316 * parsed as an octal number. Otherwise it will be parsed as a decimal. 317 * @res: Where to write the result of the conversion on success. 318 * 319 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. 320 * Used as a replacement for the obsolete simple_strtoull. Return code must 321 * be checked. 322 */ 323 static inline int __must_check kstrtol(const char *s, unsigned int base, long *res) 324 { 325 /* 326 * We want to shortcut function call, but 327 * __builtin_types_compatible_p(long, long long) = 0. 328 */ 329 if (sizeof(long) == sizeof(long long) && 330 __alignof__(long) == __alignof__(long long)) 331 return kstrtoll(s, base, (long long *)res); 332 else 333 return _kstrtol(s, base, res); 334 } 335 336 int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res); 337 int __must_check kstrtoint(const char *s, unsigned int base, int *res); 338 339 static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res) 340 { 341 return kstrtoull(s, base, res); 342 } 343 344 static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res) 345 { 346 return kstrtoll(s, base, res); 347 } 348 349 static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res) 350 { 351 return kstrtouint(s, base, res); 352 } 353 354 static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res) 355 { 356 return kstrtoint(s, base, res); 357 } 358 359 int __must_check kstrtou16(const char *s, unsigned int base, u16 *res); 360 int __must_check kstrtos16(const char *s, unsigned int base, s16 *res); 361 int __must_check kstrtou8(const char *s, unsigned int base, u8 *res); 362 int __must_check kstrtos8(const char *s, unsigned int base, s8 *res); 363 int __must_check kstrtobool(const char *s, bool *res); 364 365 int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res); 366 int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res); 367 int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res); 368 int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res); 369 int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res); 370 int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res); 371 int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res); 372 int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res); 373 int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res); 374 int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res); 375 int __must_check kstrtobool_from_user(const char __user *s, size_t count, bool *res); 376 377 static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res) 378 { 379 return kstrtoull_from_user(s, count, base, res); 380 } 381 382 static inline int __must_check kstrtos64_from_user(const char __user *s, size_t count, unsigned int base, s64 *res) 383 { 384 return kstrtoll_from_user(s, count, base, res); 385 } 386 387 static inline int __must_check kstrtou32_from_user(const char __user *s, size_t count, unsigned int base, u32 *res) 388 { 389 return kstrtouint_from_user(s, count, base, res); 390 } 391 392 static inline int __must_check kstrtos32_from_user(const char __user *s, size_t count, unsigned int base, s32 *res) 393 { 394 return kstrtoint_from_user(s, count, base, res); 395 } 396 397 /* Obsolete, do not use. Use kstrto<foo> instead */ 398 399 extern unsigned long simple_strtoul(const char *,char **,unsigned int); 400 extern long simple_strtol(const char *,char **,unsigned int); 401 extern unsigned long long simple_strtoull(const char *,char **,unsigned int); 402 extern long long simple_strtoll(const char *,char **,unsigned int); 403 404 extern int num_to_str(char *buf, int size, unsigned long long num); 405 406 /* lib/printf utilities */ 407 408 extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...); 409 extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list); 410 extern __printf(3, 4) 411 int snprintf(char *buf, size_t size, const char *fmt, ...); 412 extern __printf(3, 0) 413 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args); 414 extern __printf(3, 4) 415 int scnprintf(char *buf, size_t size, const char *fmt, ...); 416 extern __printf(3, 0) 417 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args); 418 extern __printf(2, 3) __malloc 419 char *kasprintf(gfp_t gfp, const char *fmt, ...); 420 extern __printf(2, 0) __malloc 421 char *kvasprintf(gfp_t gfp, const char *fmt, va_list args); 422 extern __printf(2, 0) 423 const char *kvasprintf_const(gfp_t gfp, const char *fmt, va_list args); 424 425 extern __scanf(2, 3) 426 int sscanf(const char *, const char *, ...); 427 extern __scanf(2, 0) 428 int vsscanf(const char *, const char *, va_list); 429 430 extern int get_option(char **str, int *pint); 431 extern char *get_options(const char *str, int nints, int *ints); 432 extern unsigned long long memparse(const char *ptr, char **retptr); 433 extern bool parse_option_str(const char *str, const char *option); 434 435 extern int core_kernel_text(unsigned long addr); 436 extern int core_kernel_data(unsigned long addr); 437 extern int __kernel_text_address(unsigned long addr); 438 extern int kernel_text_address(unsigned long addr); 439 extern int func_ptr_is_kernel_text(void *ptr); 440 441 unsigned long int_sqrt(unsigned long); 442 443 extern void bust_spinlocks(int yes); 444 extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */ 445 extern int panic_timeout; 446 extern int panic_on_oops; 447 extern int panic_on_unrecovered_nmi; 448 extern int panic_on_io_nmi; 449 extern int panic_on_warn; 450 extern int sysctl_panic_on_rcu_stall; 451 extern int sysctl_panic_on_stackoverflow; 452 453 extern bool crash_kexec_post_notifiers; 454 455 /* 456 * panic_cpu is used for synchronizing panic() and crash_kexec() execution. It 457 * holds a CPU number which is executing panic() currently. A value of 458 * PANIC_CPU_INVALID means no CPU has entered panic() or crash_kexec(). 459 */ 460 extern atomic_t panic_cpu; 461 #define PANIC_CPU_INVALID -1 462 463 /* 464 * Only to be used by arch init code. If the user over-wrote the default 465 * CONFIG_PANIC_TIMEOUT, honor it. 466 */ 467 static inline void set_arch_panic_timeout(int timeout, int arch_default_timeout) 468 { 469 if (panic_timeout == arch_default_timeout) 470 panic_timeout = timeout; 471 } 472 extern const char *print_tainted(void); 473 enum lockdep_ok { 474 LOCKDEP_STILL_OK, 475 LOCKDEP_NOW_UNRELIABLE 476 }; 477 extern void add_taint(unsigned flag, enum lockdep_ok); 478 extern int test_taint(unsigned flag); 479 extern unsigned long get_taint(void); 480 extern int root_mountflags; 481 482 extern bool early_boot_irqs_disabled; 483 484 /* Values used for system_state */ 485 extern enum system_states { 486 SYSTEM_BOOTING, 487 SYSTEM_RUNNING, 488 SYSTEM_HALT, 489 SYSTEM_POWER_OFF, 490 SYSTEM_RESTART, 491 } system_state; 492 493 #define TAINT_PROPRIETARY_MODULE 0 494 #define TAINT_FORCED_MODULE 1 495 #define TAINT_CPU_OUT_OF_SPEC 2 496 #define TAINT_FORCED_RMMOD 3 497 #define TAINT_MACHINE_CHECK 4 498 #define TAINT_BAD_PAGE 5 499 #define TAINT_USER 6 500 #define TAINT_DIE 7 501 #define TAINT_OVERRIDDEN_ACPI_TABLE 8 502 #define TAINT_WARN 9 503 #define TAINT_CRAP 10 504 #define TAINT_FIRMWARE_WORKAROUND 11 505 #define TAINT_OOT_MODULE 12 506 #define TAINT_UNSIGNED_MODULE 13 507 #define TAINT_SOFTLOCKUP 14 508 #define TAINT_LIVEPATCH 15 509 510 extern const char hex_asc[]; 511 #define hex_asc_lo(x) hex_asc[((x) & 0x0f)] 512 #define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4] 513 514 static inline char *hex_byte_pack(char *buf, u8 byte) 515 { 516 *buf++ = hex_asc_hi(byte); 517 *buf++ = hex_asc_lo(byte); 518 return buf; 519 } 520 521 extern const char hex_asc_upper[]; 522 #define hex_asc_upper_lo(x) hex_asc_upper[((x) & 0x0f)] 523 #define hex_asc_upper_hi(x) hex_asc_upper[((x) & 0xf0) >> 4] 524 525 static inline char *hex_byte_pack_upper(char *buf, u8 byte) 526 { 527 *buf++ = hex_asc_upper_hi(byte); 528 *buf++ = hex_asc_upper_lo(byte); 529 return buf; 530 } 531 532 extern int hex_to_bin(char ch); 533 extern int __must_check hex2bin(u8 *dst, const char *src, size_t count); 534 extern char *bin2hex(char *dst, const void *src, size_t count); 535 536 bool mac_pton(const char *s, u8 *mac); 537 538 /* 539 * General tracing related utility functions - trace_printk(), 540 * tracing_on/tracing_off and tracing_start()/tracing_stop 541 * 542 * Use tracing_on/tracing_off when you want to quickly turn on or off 543 * tracing. It simply enables or disables the recording of the trace events. 544 * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on 545 * file, which gives a means for the kernel and userspace to interact. 546 * Place a tracing_off() in the kernel where you want tracing to end. 547 * From user space, examine the trace, and then echo 1 > tracing_on 548 * to continue tracing. 549 * 550 * tracing_stop/tracing_start has slightly more overhead. It is used 551 * by things like suspend to ram where disabling the recording of the 552 * trace is not enough, but tracing must actually stop because things 553 * like calling smp_processor_id() may crash the system. 554 * 555 * Most likely, you want to use tracing_on/tracing_off. 556 */ 557 558 enum ftrace_dump_mode { 559 DUMP_NONE, 560 DUMP_ALL, 561 DUMP_ORIG, 562 }; 563 564 #ifdef CONFIG_TRACING 565 void tracing_on(void); 566 void tracing_off(void); 567 int tracing_is_on(void); 568 void tracing_snapshot(void); 569 void tracing_snapshot_alloc(void); 570 571 extern void tracing_start(void); 572 extern void tracing_stop(void); 573 574 static inline __printf(1, 2) 575 void ____trace_printk_check_format(const char *fmt, ...) 576 { 577 } 578 #define __trace_printk_check_format(fmt, args...) \ 579 do { \ 580 if (0) \ 581 ____trace_printk_check_format(fmt, ##args); \ 582 } while (0) 583 584 /** 585 * trace_printk - printf formatting in the ftrace buffer 586 * @fmt: the printf format for printing 587 * 588 * Note: __trace_printk is an internal function for trace_printk and 589 * the @ip is passed in via the trace_printk macro. 590 * 591 * This function allows a kernel developer to debug fast path sections 592 * that printk is not appropriate for. By scattering in various 593 * printk like tracing in the code, a developer can quickly see 594 * where problems are occurring. 595 * 596 * This is intended as a debugging tool for the developer only. 597 * Please refrain from leaving trace_printks scattered around in 598 * your code. (Extra memory is used for special buffers that are 599 * allocated when trace_printk() is used) 600 * 601 * A little optization trick is done here. If there's only one 602 * argument, there's no need to scan the string for printf formats. 603 * The trace_puts() will suffice. But how can we take advantage of 604 * using trace_puts() when trace_printk() has only one argument? 605 * By stringifying the args and checking the size we can tell 606 * whether or not there are args. __stringify((__VA_ARGS__)) will 607 * turn into "()\0" with a size of 3 when there are no args, anything 608 * else will be bigger. All we need to do is define a string to this, 609 * and then take its size and compare to 3. If it's bigger, use 610 * do_trace_printk() otherwise, optimize it to trace_puts(). Then just 611 * let gcc optimize the rest. 612 */ 613 614 #define trace_printk(fmt, ...) \ 615 do { \ 616 char _______STR[] = __stringify((__VA_ARGS__)); \ 617 if (sizeof(_______STR) > 3) \ 618 do_trace_printk(fmt, ##__VA_ARGS__); \ 619 else \ 620 trace_puts(fmt); \ 621 } while (0) 622 623 #define do_trace_printk(fmt, args...) \ 624 do { \ 625 static const char *trace_printk_fmt __used \ 626 __attribute__((section("__trace_printk_fmt"))) = \ 627 __builtin_constant_p(fmt) ? fmt : NULL; \ 628 \ 629 __trace_printk_check_format(fmt, ##args); \ 630 \ 631 if (__builtin_constant_p(fmt)) \ 632 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \ 633 else \ 634 __trace_printk(_THIS_IP_, fmt, ##args); \ 635 } while (0) 636 637 extern __printf(2, 3) 638 int __trace_bprintk(unsigned long ip, const char *fmt, ...); 639 640 extern __printf(2, 3) 641 int __trace_printk(unsigned long ip, const char *fmt, ...); 642 643 /** 644 * trace_puts - write a string into the ftrace buffer 645 * @str: the string to record 646 * 647 * Note: __trace_bputs is an internal function for trace_puts and 648 * the @ip is passed in via the trace_puts macro. 649 * 650 * This is similar to trace_printk() but is made for those really fast 651 * paths that a developer wants the least amount of "Heisenbug" affects, 652 * where the processing of the print format is still too much. 653 * 654 * This function allows a kernel developer to debug fast path sections 655 * that printk is not appropriate for. By scattering in various 656 * printk like tracing in the code, a developer can quickly see 657 * where problems are occurring. 658 * 659 * This is intended as a debugging tool for the developer only. 660 * Please refrain from leaving trace_puts scattered around in 661 * your code. (Extra memory is used for special buffers that are 662 * allocated when trace_puts() is used) 663 * 664 * Returns: 0 if nothing was written, positive # if string was. 665 * (1 when __trace_bputs is used, strlen(str) when __trace_puts is used) 666 */ 667 668 #define trace_puts(str) ({ \ 669 static const char *trace_printk_fmt __used \ 670 __attribute__((section("__trace_printk_fmt"))) = \ 671 __builtin_constant_p(str) ? str : NULL; \ 672 \ 673 if (__builtin_constant_p(str)) \ 674 __trace_bputs(_THIS_IP_, trace_printk_fmt); \ 675 else \ 676 __trace_puts(_THIS_IP_, str, strlen(str)); \ 677 }) 678 extern int __trace_bputs(unsigned long ip, const char *str); 679 extern int __trace_puts(unsigned long ip, const char *str, int size); 680 681 extern void trace_dump_stack(int skip); 682 683 /* 684 * The double __builtin_constant_p is because gcc will give us an error 685 * if we try to allocate the static variable to fmt if it is not a 686 * constant. Even with the outer if statement. 687 */ 688 #define ftrace_vprintk(fmt, vargs) \ 689 do { \ 690 if (__builtin_constant_p(fmt)) { \ 691 static const char *trace_printk_fmt __used \ 692 __attribute__((section("__trace_printk_fmt"))) = \ 693 __builtin_constant_p(fmt) ? fmt : NULL; \ 694 \ 695 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \ 696 } else \ 697 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \ 698 } while (0) 699 700 extern __printf(2, 0) int 701 __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap); 702 703 extern __printf(2, 0) int 704 __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap); 705 706 extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode); 707 #else 708 static inline void tracing_start(void) { } 709 static inline void tracing_stop(void) { } 710 static inline void trace_dump_stack(int skip) { } 711 712 static inline void tracing_on(void) { } 713 static inline void tracing_off(void) { } 714 static inline int tracing_is_on(void) { return 0; } 715 static inline void tracing_snapshot(void) { } 716 static inline void tracing_snapshot_alloc(void) { } 717 718 static inline __printf(1, 2) 719 int trace_printk(const char *fmt, ...) 720 { 721 return 0; 722 } 723 static __printf(1, 0) inline int 724 ftrace_vprintk(const char *fmt, va_list ap) 725 { 726 return 0; 727 } 728 static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { } 729 #endif /* CONFIG_TRACING */ 730 731 /* 732 * min()/max()/clamp() macros that also do 733 * strict type-checking.. See the 734 * "unnecessary" pointer comparison. 735 */ 736 #define __min(t1, t2, min1, min2, x, y) ({ \ 737 t1 min1 = (x); \ 738 t2 min2 = (y); \ 739 (void) (&min1 == &min2); \ 740 min1 < min2 ? min1 : min2; }) 741 #define min(x, y) \ 742 __min(typeof(x), typeof(y), \ 743 __UNIQUE_ID(min1_), __UNIQUE_ID(min2_), \ 744 x, y) 745 746 #define __max(t1, t2, max1, max2, x, y) ({ \ 747 t1 max1 = (x); \ 748 t2 max2 = (y); \ 749 (void) (&max1 == &max2); \ 750 max1 > max2 ? max1 : max2; }) 751 #define max(x, y) \ 752 __max(typeof(x), typeof(y), \ 753 __UNIQUE_ID(max1_), __UNIQUE_ID(max2_), \ 754 x, y) 755 756 #define min3(x, y, z) min((typeof(x))min(x, y), z) 757 #define max3(x, y, z) max((typeof(x))max(x, y), z) 758 759 /** 760 * min_not_zero - return the minimum that is _not_ zero, unless both are zero 761 * @x: value1 762 * @y: value2 763 */ 764 #define min_not_zero(x, y) ({ \ 765 typeof(x) __x = (x); \ 766 typeof(y) __y = (y); \ 767 __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); }) 768 769 /** 770 * clamp - return a value clamped to a given range with strict typechecking 771 * @val: current value 772 * @lo: lowest allowable value 773 * @hi: highest allowable value 774 * 775 * This macro does strict typechecking of lo/hi to make sure they are of the 776 * same type as val. See the unnecessary pointer comparisons. 777 */ 778 #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi) 779 780 /* 781 * ..and if you can't take the strict 782 * types, you can specify one yourself. 783 * 784 * Or not use min/max/clamp at all, of course. 785 */ 786 #define min_t(type, x, y) \ 787 __min(type, type, \ 788 __UNIQUE_ID(min1_), __UNIQUE_ID(min2_), \ 789 x, y) 790 791 #define max_t(type, x, y) \ 792 __max(type, type, \ 793 __UNIQUE_ID(min1_), __UNIQUE_ID(min2_), \ 794 x, y) 795 796 /** 797 * clamp_t - return a value clamped to a given range using a given type 798 * @type: the type of variable to use 799 * @val: current value 800 * @lo: minimum allowable value 801 * @hi: maximum allowable value 802 * 803 * This macro does no typechecking and uses temporary variables of type 804 * 'type' to make all the comparisons. 805 */ 806 #define clamp_t(type, val, lo, hi) min_t(type, max_t(type, val, lo), hi) 807 808 /** 809 * clamp_val - return a value clamped to a given range using val's type 810 * @val: current value 811 * @lo: minimum allowable value 812 * @hi: maximum allowable value 813 * 814 * This macro does no typechecking and uses temporary variables of whatever 815 * type the input argument 'val' is. This is useful when val is an unsigned 816 * type and min and max are literals that will otherwise be assigned a signed 817 * integer type. 818 */ 819 #define clamp_val(val, lo, hi) clamp_t(typeof(val), val, lo, hi) 820 821 822 /* 823 * swap - swap value of @a and @b 824 */ 825 #define swap(a, b) \ 826 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0) 827 828 /** 829 * container_of - cast a member of a structure out to the containing structure 830 * @ptr: the pointer to the member. 831 * @type: the type of the container struct this is embedded in. 832 * @member: the name of the member within the struct. 833 * 834 */ 835 #define container_of(ptr, type, member) ({ \ 836 const typeof( ((type *)0)->member ) *__mptr = (ptr); \ 837 (type *)( (char *)__mptr - offsetof(type,member) );}) 838 839 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */ 840 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 841 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD 842 #endif 843 844 /* Permissions on a sysfs file: you didn't miss the 0 prefix did you? */ 845 #define VERIFY_OCTAL_PERMISSIONS(perms) \ 846 (BUILD_BUG_ON_ZERO((perms) < 0) + \ 847 BUILD_BUG_ON_ZERO((perms) > 0777) + \ 848 /* USER_READABLE >= GROUP_READABLE >= OTHER_READABLE */ \ 849 BUILD_BUG_ON_ZERO((((perms) >> 6) & 4) < (((perms) >> 3) & 4)) + \ 850 BUILD_BUG_ON_ZERO((((perms) >> 3) & 4) < ((perms) & 4)) + \ 851 /* USER_WRITABLE >= GROUP_WRITABLE */ \ 852 BUILD_BUG_ON_ZERO((((perms) >> 6) & 2) < (((perms) >> 3) & 2)) + \ 853 /* OTHER_WRITABLE? Generally considered a bad idea. */ \ 854 BUILD_BUG_ON_ZERO((perms) & 2) + \ 855 (perms)) 856 #endif 857