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 /* @a is a power of 2 value */ 49 #define ALIGN(x, a) __ALIGN_KERNEL((x), (a)) 50 #define __ALIGN_MASK(x, mask) __ALIGN_KERNEL_MASK((x), (mask)) 51 #define PTR_ALIGN(p, a) ((typeof(p))ALIGN((unsigned long)(p), (a))) 52 #define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0) 53 54 /* generic data direction definitions */ 55 #define READ 0 56 #define WRITE 1 57 58 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr)) 59 60 #define u64_to_user_ptr(x) ( \ 61 { \ 62 typecheck(u64, x); \ 63 (void __user *)(uintptr_t)x; \ 64 } \ 65 ) 66 67 /* 68 * This looks more complex than it should be. But we need to 69 * get the type for the ~ right in round_down (it needs to be 70 * as wide as the result!), and we want to evaluate the macro 71 * arguments just once each. 72 */ 73 #define __round_mask(x, y) ((__typeof__(x))((y)-1)) 74 #define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1) 75 #define round_down(x, y) ((x) & ~__round_mask(x, y)) 76 77 #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f)) 78 #define DIV_ROUND_UP __KERNEL_DIV_ROUND_UP 79 #define DIV_ROUND_UP_ULL(ll,d) \ 80 ({ unsigned long long _tmp = (ll)+(d)-1; do_div(_tmp, d); _tmp; }) 81 82 #if BITS_PER_LONG == 32 83 # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP_ULL(ll, d) 84 #else 85 # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP(ll,d) 86 #endif 87 88 /* The `const' in roundup() prevents gcc-3.3 from calling __divdi3 */ 89 #define roundup(x, y) ( \ 90 { \ 91 const typeof(y) __y = y; \ 92 (((x) + (__y - 1)) / __y) * __y; \ 93 } \ 94 ) 95 #define rounddown(x, y) ( \ 96 { \ 97 typeof(x) __x = (x); \ 98 __x - (__x % (y)); \ 99 } \ 100 ) 101 102 /* 103 * Divide positive or negative dividend by positive divisor and round 104 * to closest integer. Result is undefined for negative divisors and 105 * for negative dividends if the divisor variable type is unsigned. 106 */ 107 #define DIV_ROUND_CLOSEST(x, divisor)( \ 108 { \ 109 typeof(x) __x = x; \ 110 typeof(divisor) __d = divisor; \ 111 (((typeof(x))-1) > 0 || \ 112 ((typeof(divisor))-1) > 0 || (__x) > 0) ? \ 113 (((__x) + ((__d) / 2)) / (__d)) : \ 114 (((__x) - ((__d) / 2)) / (__d)); \ 115 } \ 116 ) 117 /* 118 * Same as above but for u64 dividends. divisor must be a 32-bit 119 * number. 120 */ 121 #define DIV_ROUND_CLOSEST_ULL(x, divisor)( \ 122 { \ 123 typeof(divisor) __d = divisor; \ 124 unsigned long long _tmp = (x) + (__d) / 2; \ 125 do_div(_tmp, __d); \ 126 _tmp; \ 127 } \ 128 ) 129 130 /* 131 * Multiplies an integer by a fraction, while avoiding unnecessary 132 * overflow or loss of precision. 133 */ 134 #define mult_frac(x, numer, denom)( \ 135 { \ 136 typeof(x) quot = (x) / (denom); \ 137 typeof(x) rem = (x) % (denom); \ 138 (quot * (numer)) + ((rem * (numer)) / (denom)); \ 139 } \ 140 ) 141 142 143 #define _RET_IP_ (unsigned long)__builtin_return_address(0) 144 #define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; }) 145 146 #ifdef CONFIG_LBDAF 147 # include <asm/div64.h> 148 # define sector_div(a, b) do_div(a, b) 149 #else 150 # define sector_div(n, b)( \ 151 { \ 152 int _res; \ 153 _res = (n) % (b); \ 154 (n) /= (b); \ 155 _res; \ 156 } \ 157 ) 158 #endif 159 160 /** 161 * upper_32_bits - return bits 32-63 of a number 162 * @n: the number we're accessing 163 * 164 * A basic shift-right of a 64- or 32-bit quantity. Use this to suppress 165 * the "right shift count >= width of type" warning when that quantity is 166 * 32-bits. 167 */ 168 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16)) 169 170 /** 171 * lower_32_bits - return bits 0-31 of a number 172 * @n: the number we're accessing 173 */ 174 #define lower_32_bits(n) ((u32)(n)) 175 176 struct completion; 177 struct pt_regs; 178 struct user; 179 180 #ifdef CONFIG_PREEMPT_VOLUNTARY 181 extern int _cond_resched(void); 182 # define might_resched() _cond_resched() 183 #else 184 # define might_resched() do { } while (0) 185 #endif 186 187 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 188 void ___might_sleep(const char *file, int line, int preempt_offset); 189 void __might_sleep(const char *file, int line, int preempt_offset); 190 /** 191 * might_sleep - annotation for functions that can sleep 192 * 193 * this macro will print a stack trace if it is executed in an atomic 194 * context (spinlock, irq-handler, ...). 195 * 196 * This is a useful debugging help to be able to catch problems early and not 197 * be bitten later when the calling function happens to sleep when it is not 198 * supposed to. 199 */ 200 # define might_sleep() \ 201 do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0) 202 # define sched_annotate_sleep() (current->task_state_change = 0) 203 #else 204 static inline void ___might_sleep(const char *file, int line, 205 int preempt_offset) { } 206 static inline void __might_sleep(const char *file, int line, 207 int preempt_offset) { } 208 # define might_sleep() do { might_resched(); } while (0) 209 # define sched_annotate_sleep() do { } while (0) 210 #endif 211 212 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0) 213 214 /** 215 * abs - return absolute value of an argument 216 * @x: the value. If it is unsigned type, it is converted to signed type first. 217 * char is treated as if it was signed (regardless of whether it really is) 218 * but the macro's return type is preserved as char. 219 * 220 * Return: an absolute value of x. 221 */ 222 #define abs(x) __abs_choose_expr(x, long long, \ 223 __abs_choose_expr(x, long, \ 224 __abs_choose_expr(x, int, \ 225 __abs_choose_expr(x, short, \ 226 __abs_choose_expr(x, char, \ 227 __builtin_choose_expr( \ 228 __builtin_types_compatible_p(typeof(x), char), \ 229 (char)({ signed char __x = (x); __x<0?-__x:__x; }), \ 230 ((void)0))))))) 231 232 #define __abs_choose_expr(x, type, other) __builtin_choose_expr( \ 233 __builtin_types_compatible_p(typeof(x), signed type) || \ 234 __builtin_types_compatible_p(typeof(x), unsigned type), \ 235 ({ signed type __x = (x); __x < 0 ? -__x : __x; }), other) 236 237 /** 238 * reciprocal_scale - "scale" a value into range [0, ep_ro) 239 * @val: value 240 * @ep_ro: right open interval endpoint 241 * 242 * Perform a "reciprocal multiplication" in order to "scale" a value into 243 * range [0, ep_ro), where the upper interval endpoint is right-open. 244 * This is useful, e.g. for accessing a index of an array containing 245 * ep_ro elements, for example. Think of it as sort of modulus, only that 246 * the result isn't that of modulo. ;) Note that if initial input is a 247 * small value, then result will return 0. 248 * 249 * Return: a result based on val in interval [0, ep_ro). 250 */ 251 static inline u32 reciprocal_scale(u32 val, u32 ep_ro) 252 { 253 return (u32)(((u64) val * ep_ro) >> 32); 254 } 255 256 #if defined(CONFIG_MMU) && \ 257 (defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP)) 258 #define might_fault() __might_fault(__FILE__, __LINE__) 259 void __might_fault(const char *file, int line); 260 #else 261 static inline void might_fault(void) { } 262 #endif 263 264 extern struct atomic_notifier_head panic_notifier_list; 265 extern long (*panic_blink)(int state); 266 __printf(1, 2) 267 void panic(const char *fmt, ...) __noreturn __cold; 268 void nmi_panic(struct pt_regs *regs, const char *msg); 269 extern void oops_enter(void); 270 extern void oops_exit(void); 271 void print_oops_end_marker(void); 272 extern int oops_may_print(void); 273 void do_exit(long error_code) __noreturn; 274 void complete_and_exit(struct completion *, long) __noreturn; 275 276 /* Internal, do not use. */ 277 int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res); 278 int __must_check _kstrtol(const char *s, unsigned int base, long *res); 279 280 int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res); 281 int __must_check kstrtoll(const char *s, unsigned int base, long long *res); 282 283 /** 284 * kstrtoul - convert a string to an unsigned long 285 * @s: The start of the string. The string must be null-terminated, and may also 286 * include a single newline before its terminating null. The first character 287 * may also be a plus sign, but not a minus sign. 288 * @base: The number base to use. The maximum supported base is 16. If base is 289 * given as 0, then the base of the string is automatically detected with the 290 * conventional semantics - If it begins with 0x the number will be parsed as a 291 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be 292 * parsed as an octal number. Otherwise it will be parsed as a decimal. 293 * @res: Where to write the result of the conversion on success. 294 * 295 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. 296 * Used as a replacement for the obsolete simple_strtoull. Return code must 297 * be checked. 298 */ 299 static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res) 300 { 301 /* 302 * We want to shortcut function call, but 303 * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0. 304 */ 305 if (sizeof(unsigned long) == sizeof(unsigned long long) && 306 __alignof__(unsigned long) == __alignof__(unsigned long long)) 307 return kstrtoull(s, base, (unsigned long long *)res); 308 else 309 return _kstrtoul(s, base, res); 310 } 311 312 /** 313 * kstrtol - convert a string to a long 314 * @s: The start of the string. The string must be null-terminated, and may also 315 * include a single newline before its terminating null. The first character 316 * may also be a plus sign or a minus sign. 317 * @base: The number base to use. The maximum supported base is 16. If base is 318 * given as 0, then the base of the string is automatically detected with the 319 * conventional semantics - If it begins with 0x the number will be parsed as a 320 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be 321 * parsed as an octal number. Otherwise it will be parsed as a decimal. 322 * @res: Where to write the result of the conversion on success. 323 * 324 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. 325 * Used as a replacement for the obsolete simple_strtoull. Return code must 326 * be checked. 327 */ 328 static inline int __must_check kstrtol(const char *s, unsigned int base, long *res) 329 { 330 /* 331 * We want to shortcut function call, but 332 * __builtin_types_compatible_p(long, long long) = 0. 333 */ 334 if (sizeof(long) == sizeof(long long) && 335 __alignof__(long) == __alignof__(long long)) 336 return kstrtoll(s, base, (long long *)res); 337 else 338 return _kstrtol(s, base, res); 339 } 340 341 int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res); 342 int __must_check kstrtoint(const char *s, unsigned int base, int *res); 343 344 static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res) 345 { 346 return kstrtoull(s, base, res); 347 } 348 349 static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res) 350 { 351 return kstrtoll(s, base, res); 352 } 353 354 static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res) 355 { 356 return kstrtouint(s, base, res); 357 } 358 359 static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res) 360 { 361 return kstrtoint(s, base, res); 362 } 363 364 int __must_check kstrtou16(const char *s, unsigned int base, u16 *res); 365 int __must_check kstrtos16(const char *s, unsigned int base, s16 *res); 366 int __must_check kstrtou8(const char *s, unsigned int base, u8 *res); 367 int __must_check kstrtos8(const char *s, unsigned int base, s8 *res); 368 int __must_check kstrtobool(const char *s, bool *res); 369 370 int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res); 371 int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res); 372 int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res); 373 int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res); 374 int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res); 375 int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res); 376 int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res); 377 int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res); 378 int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res); 379 int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res); 380 int __must_check kstrtobool_from_user(const char __user *s, size_t count, bool *res); 381 382 static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res) 383 { 384 return kstrtoull_from_user(s, count, base, res); 385 } 386 387 static inline int __must_check kstrtos64_from_user(const char __user *s, size_t count, unsigned int base, s64 *res) 388 { 389 return kstrtoll_from_user(s, count, base, res); 390 } 391 392 static inline int __must_check kstrtou32_from_user(const char __user *s, size_t count, unsigned int base, u32 *res) 393 { 394 return kstrtouint_from_user(s, count, base, res); 395 } 396 397 static inline int __must_check kstrtos32_from_user(const char __user *s, size_t count, unsigned int base, s32 *res) 398 { 399 return kstrtoint_from_user(s, count, base, res); 400 } 401 402 /* Obsolete, do not use. Use kstrto<foo> instead */ 403 404 extern unsigned long simple_strtoul(const char *,char **,unsigned int); 405 extern long simple_strtol(const char *,char **,unsigned int); 406 extern unsigned long long simple_strtoull(const char *,char **,unsigned int); 407 extern long long simple_strtoll(const char *,char **,unsigned int); 408 409 extern int num_to_str(char *buf, int size, unsigned long long num); 410 411 /* lib/printf utilities */ 412 413 extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...); 414 extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list); 415 extern __printf(3, 4) 416 int snprintf(char *buf, size_t size, const char *fmt, ...); 417 extern __printf(3, 0) 418 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args); 419 extern __printf(3, 4) 420 int scnprintf(char *buf, size_t size, const char *fmt, ...); 421 extern __printf(3, 0) 422 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args); 423 extern __printf(2, 3) __malloc 424 char *kasprintf(gfp_t gfp, const char *fmt, ...); 425 extern __printf(2, 0) __malloc 426 char *kvasprintf(gfp_t gfp, const char *fmt, va_list args); 427 extern __printf(2, 0) 428 const char *kvasprintf_const(gfp_t gfp, const char *fmt, va_list args); 429 430 extern __scanf(2, 3) 431 int sscanf(const char *, const char *, ...); 432 extern __scanf(2, 0) 433 int vsscanf(const char *, const char *, va_list); 434 435 extern int get_option(char **str, int *pint); 436 extern char *get_options(const char *str, int nints, int *ints); 437 extern unsigned long long memparse(const char *ptr, char **retptr); 438 extern bool parse_option_str(const char *str, const char *option); 439 440 extern int core_kernel_text(unsigned long addr); 441 extern int core_kernel_data(unsigned long addr); 442 extern int __kernel_text_address(unsigned long addr); 443 extern int kernel_text_address(unsigned long addr); 444 extern int func_ptr_is_kernel_text(void *ptr); 445 446 unsigned long int_sqrt(unsigned long); 447 448 extern void bust_spinlocks(int yes); 449 extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */ 450 extern int panic_timeout; 451 extern int panic_on_oops; 452 extern int panic_on_unrecovered_nmi; 453 extern int panic_on_io_nmi; 454 extern int panic_on_warn; 455 extern int sysctl_panic_on_rcu_stall; 456 extern int sysctl_panic_on_stackoverflow; 457 458 extern bool crash_kexec_post_notifiers; 459 460 /* 461 * panic_cpu is used for synchronizing panic() and crash_kexec() execution. It 462 * holds a CPU number which is executing panic() currently. A value of 463 * PANIC_CPU_INVALID means no CPU has entered panic() or crash_kexec(). 464 */ 465 extern atomic_t panic_cpu; 466 #define PANIC_CPU_INVALID -1 467 468 /* 469 * Only to be used by arch init code. If the user over-wrote the default 470 * CONFIG_PANIC_TIMEOUT, honor it. 471 */ 472 static inline void set_arch_panic_timeout(int timeout, int arch_default_timeout) 473 { 474 if (panic_timeout == arch_default_timeout) 475 panic_timeout = timeout; 476 } 477 extern const char *print_tainted(void); 478 enum lockdep_ok { 479 LOCKDEP_STILL_OK, 480 LOCKDEP_NOW_UNRELIABLE 481 }; 482 extern void add_taint(unsigned flag, enum lockdep_ok); 483 extern int test_taint(unsigned flag); 484 extern unsigned long get_taint(void); 485 extern int root_mountflags; 486 487 extern bool early_boot_irqs_disabled; 488 489 /* Values used for system_state */ 490 extern enum system_states { 491 SYSTEM_BOOTING, 492 SYSTEM_RUNNING, 493 SYSTEM_HALT, 494 SYSTEM_POWER_OFF, 495 SYSTEM_RESTART, 496 } system_state; 497 498 #define TAINT_PROPRIETARY_MODULE 0 499 #define TAINT_FORCED_MODULE 1 500 #define TAINT_CPU_OUT_OF_SPEC 2 501 #define TAINT_FORCED_RMMOD 3 502 #define TAINT_MACHINE_CHECK 4 503 #define TAINT_BAD_PAGE 5 504 #define TAINT_USER 6 505 #define TAINT_DIE 7 506 #define TAINT_OVERRIDDEN_ACPI_TABLE 8 507 #define TAINT_WARN 9 508 #define TAINT_CRAP 10 509 #define TAINT_FIRMWARE_WORKAROUND 11 510 #define TAINT_OOT_MODULE 12 511 #define TAINT_UNSIGNED_MODULE 13 512 #define TAINT_SOFTLOCKUP 14 513 #define TAINT_LIVEPATCH 15 514 #define TAINT_FLAGS_COUNT 16 515 516 struct taint_flag { 517 char true; /* character printed when tainted */ 518 char false; /* character printed when not tainted */ 519 bool module; /* also show as a per-module taint flag */ 520 }; 521 522 extern const struct taint_flag taint_flags[TAINT_FLAGS_COUNT]; 523 524 extern const char hex_asc[]; 525 #define hex_asc_lo(x) hex_asc[((x) & 0x0f)] 526 #define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4] 527 528 static inline char *hex_byte_pack(char *buf, u8 byte) 529 { 530 *buf++ = hex_asc_hi(byte); 531 *buf++ = hex_asc_lo(byte); 532 return buf; 533 } 534 535 extern const char hex_asc_upper[]; 536 #define hex_asc_upper_lo(x) hex_asc_upper[((x) & 0x0f)] 537 #define hex_asc_upper_hi(x) hex_asc_upper[((x) & 0xf0) >> 4] 538 539 static inline char *hex_byte_pack_upper(char *buf, u8 byte) 540 { 541 *buf++ = hex_asc_upper_hi(byte); 542 *buf++ = hex_asc_upper_lo(byte); 543 return buf; 544 } 545 546 extern int hex_to_bin(char ch); 547 extern int __must_check hex2bin(u8 *dst, const char *src, size_t count); 548 extern char *bin2hex(char *dst, const void *src, size_t count); 549 550 bool mac_pton(const char *s, u8 *mac); 551 552 /* 553 * General tracing related utility functions - trace_printk(), 554 * tracing_on/tracing_off and tracing_start()/tracing_stop 555 * 556 * Use tracing_on/tracing_off when you want to quickly turn on or off 557 * tracing. It simply enables or disables the recording of the trace events. 558 * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on 559 * file, which gives a means for the kernel and userspace to interact. 560 * Place a tracing_off() in the kernel where you want tracing to end. 561 * From user space, examine the trace, and then echo 1 > tracing_on 562 * to continue tracing. 563 * 564 * tracing_stop/tracing_start has slightly more overhead. It is used 565 * by things like suspend to ram where disabling the recording of the 566 * trace is not enough, but tracing must actually stop because things 567 * like calling smp_processor_id() may crash the system. 568 * 569 * Most likely, you want to use tracing_on/tracing_off. 570 */ 571 572 enum ftrace_dump_mode { 573 DUMP_NONE, 574 DUMP_ALL, 575 DUMP_ORIG, 576 }; 577 578 #ifdef CONFIG_TRACING 579 void tracing_on(void); 580 void tracing_off(void); 581 int tracing_is_on(void); 582 void tracing_snapshot(void); 583 void tracing_snapshot_alloc(void); 584 585 extern void tracing_start(void); 586 extern void tracing_stop(void); 587 588 static inline __printf(1, 2) 589 void ____trace_printk_check_format(const char *fmt, ...) 590 { 591 } 592 #define __trace_printk_check_format(fmt, args...) \ 593 do { \ 594 if (0) \ 595 ____trace_printk_check_format(fmt, ##args); \ 596 } while (0) 597 598 /** 599 * trace_printk - printf formatting in the ftrace buffer 600 * @fmt: the printf format for printing 601 * 602 * Note: __trace_printk is an internal function for trace_printk and 603 * the @ip is passed in via the trace_printk macro. 604 * 605 * This function allows a kernel developer to debug fast path sections 606 * that printk is not appropriate for. By scattering in various 607 * printk like tracing in the code, a developer can quickly see 608 * where problems are occurring. 609 * 610 * This is intended as a debugging tool for the developer only. 611 * Please refrain from leaving trace_printks scattered around in 612 * your code. (Extra memory is used for special buffers that are 613 * allocated when trace_printk() is used) 614 * 615 * A little optization trick is done here. If there's only one 616 * argument, there's no need to scan the string for printf formats. 617 * The trace_puts() will suffice. But how can we take advantage of 618 * using trace_puts() when trace_printk() has only one argument? 619 * By stringifying the args and checking the size we can tell 620 * whether or not there are args. __stringify((__VA_ARGS__)) will 621 * turn into "()\0" with a size of 3 when there are no args, anything 622 * else will be bigger. All we need to do is define a string to this, 623 * and then take its size and compare to 3. If it's bigger, use 624 * do_trace_printk() otherwise, optimize it to trace_puts(). Then just 625 * let gcc optimize the rest. 626 */ 627 628 #define trace_printk(fmt, ...) \ 629 do { \ 630 char _______STR[] = __stringify((__VA_ARGS__)); \ 631 if (sizeof(_______STR) > 3) \ 632 do_trace_printk(fmt, ##__VA_ARGS__); \ 633 else \ 634 trace_puts(fmt); \ 635 } while (0) 636 637 #define do_trace_printk(fmt, args...) \ 638 do { \ 639 static const char *trace_printk_fmt __used \ 640 __attribute__((section("__trace_printk_fmt"))) = \ 641 __builtin_constant_p(fmt) ? fmt : NULL; \ 642 \ 643 __trace_printk_check_format(fmt, ##args); \ 644 \ 645 if (__builtin_constant_p(fmt)) \ 646 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \ 647 else \ 648 __trace_printk(_THIS_IP_, fmt, ##args); \ 649 } while (0) 650 651 extern __printf(2, 3) 652 int __trace_bprintk(unsigned long ip, const char *fmt, ...); 653 654 extern __printf(2, 3) 655 int __trace_printk(unsigned long ip, const char *fmt, ...); 656 657 /** 658 * trace_puts - write a string into the ftrace buffer 659 * @str: the string to record 660 * 661 * Note: __trace_bputs is an internal function for trace_puts and 662 * the @ip is passed in via the trace_puts macro. 663 * 664 * This is similar to trace_printk() but is made for those really fast 665 * paths that a developer wants the least amount of "Heisenbug" affects, 666 * where the processing of the print format is still too much. 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_puts scattered around in 675 * your code. (Extra memory is used for special buffers that are 676 * allocated when trace_puts() is used) 677 * 678 * Returns: 0 if nothing was written, positive # if string was. 679 * (1 when __trace_bputs is used, strlen(str) when __trace_puts is used) 680 */ 681 682 #define trace_puts(str) ({ \ 683 static const char *trace_printk_fmt __used \ 684 __attribute__((section("__trace_printk_fmt"))) = \ 685 __builtin_constant_p(str) ? str : NULL; \ 686 \ 687 if (__builtin_constant_p(str)) \ 688 __trace_bputs(_THIS_IP_, trace_printk_fmt); \ 689 else \ 690 __trace_puts(_THIS_IP_, str, strlen(str)); \ 691 }) 692 extern int __trace_bputs(unsigned long ip, const char *str); 693 extern int __trace_puts(unsigned long ip, const char *str, int size); 694 695 extern void trace_dump_stack(int skip); 696 697 /* 698 * The double __builtin_constant_p is because gcc will give us an error 699 * if we try to allocate the static variable to fmt if it is not a 700 * constant. Even with the outer if statement. 701 */ 702 #define ftrace_vprintk(fmt, vargs) \ 703 do { \ 704 if (__builtin_constant_p(fmt)) { \ 705 static const char *trace_printk_fmt __used \ 706 __attribute__((section("__trace_printk_fmt"))) = \ 707 __builtin_constant_p(fmt) ? fmt : NULL; \ 708 \ 709 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \ 710 } else \ 711 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \ 712 } while (0) 713 714 extern __printf(2, 0) int 715 __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap); 716 717 extern __printf(2, 0) int 718 __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap); 719 720 extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode); 721 #else 722 static inline void tracing_start(void) { } 723 static inline void tracing_stop(void) { } 724 static inline void trace_dump_stack(int skip) { } 725 726 static inline void tracing_on(void) { } 727 static inline void tracing_off(void) { } 728 static inline int tracing_is_on(void) { return 0; } 729 static inline void tracing_snapshot(void) { } 730 static inline void tracing_snapshot_alloc(void) { } 731 732 static inline __printf(1, 2) 733 int trace_printk(const char *fmt, ...) 734 { 735 return 0; 736 } 737 static __printf(1, 0) inline int 738 ftrace_vprintk(const char *fmt, va_list ap) 739 { 740 return 0; 741 } 742 static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { } 743 #endif /* CONFIG_TRACING */ 744 745 /* 746 * min()/max()/clamp() macros that also do 747 * strict type-checking.. See the 748 * "unnecessary" pointer comparison. 749 */ 750 #define __min(t1, t2, min1, min2, x, y) ({ \ 751 t1 min1 = (x); \ 752 t2 min2 = (y); \ 753 (void) (&min1 == &min2); \ 754 min1 < min2 ? min1 : min2; }) 755 #define min(x, y) \ 756 __min(typeof(x), typeof(y), \ 757 __UNIQUE_ID(min1_), __UNIQUE_ID(min2_), \ 758 x, y) 759 760 #define __max(t1, t2, max1, max2, x, y) ({ \ 761 t1 max1 = (x); \ 762 t2 max2 = (y); \ 763 (void) (&max1 == &max2); \ 764 max1 > max2 ? max1 : max2; }) 765 #define max(x, y) \ 766 __max(typeof(x), typeof(y), \ 767 __UNIQUE_ID(max1_), __UNIQUE_ID(max2_), \ 768 x, y) 769 770 #define min3(x, y, z) min((typeof(x))min(x, y), z) 771 #define max3(x, y, z) max((typeof(x))max(x, y), z) 772 773 /** 774 * min_not_zero - return the minimum that is _not_ zero, unless both are zero 775 * @x: value1 776 * @y: value2 777 */ 778 #define min_not_zero(x, y) ({ \ 779 typeof(x) __x = (x); \ 780 typeof(y) __y = (y); \ 781 __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); }) 782 783 /** 784 * clamp - return a value clamped to a given range with strict typechecking 785 * @val: current value 786 * @lo: lowest allowable value 787 * @hi: highest allowable value 788 * 789 * This macro does strict typechecking of lo/hi to make sure they are of the 790 * same type as val. See the unnecessary pointer comparisons. 791 */ 792 #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi) 793 794 /* 795 * ..and if you can't take the strict 796 * types, you can specify one yourself. 797 * 798 * Or not use min/max/clamp at all, of course. 799 */ 800 #define min_t(type, x, y) \ 801 __min(type, type, \ 802 __UNIQUE_ID(min1_), __UNIQUE_ID(min2_), \ 803 x, y) 804 805 #define max_t(type, x, y) \ 806 __max(type, type, \ 807 __UNIQUE_ID(min1_), __UNIQUE_ID(min2_), \ 808 x, y) 809 810 /** 811 * clamp_t - return a value clamped to a given range using a given type 812 * @type: the type of variable to use 813 * @val: current value 814 * @lo: minimum allowable value 815 * @hi: maximum allowable value 816 * 817 * This macro does no typechecking and uses temporary variables of type 818 * 'type' to make all the comparisons. 819 */ 820 #define clamp_t(type, val, lo, hi) min_t(type, max_t(type, val, lo), hi) 821 822 /** 823 * clamp_val - return a value clamped to a given range using val's type 824 * @val: current value 825 * @lo: minimum allowable value 826 * @hi: maximum allowable value 827 * 828 * This macro does no typechecking and uses temporary variables of whatever 829 * type the input argument 'val' is. This is useful when val is an unsigned 830 * type and min and max are literals that will otherwise be assigned a signed 831 * integer type. 832 */ 833 #define clamp_val(val, lo, hi) clamp_t(typeof(val), val, lo, hi) 834 835 836 /* 837 * swap - swap value of @a and @b 838 */ 839 #define swap(a, b) \ 840 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0) 841 842 /** 843 * container_of - cast a member of a structure out to the containing structure 844 * @ptr: the pointer to the member. 845 * @type: the type of the container struct this is embedded in. 846 * @member: the name of the member within the struct. 847 * 848 */ 849 #define container_of(ptr, type, member) ({ \ 850 const typeof( ((type *)0)->member ) *__mptr = (ptr); \ 851 (type *)( (char *)__mptr - offsetof(type,member) );}) 852 853 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */ 854 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 855 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD 856 #endif 857 858 /* Permissions on a sysfs file: you didn't miss the 0 prefix did you? */ 859 #define VERIFY_OCTAL_PERMISSIONS(perms) \ 860 (BUILD_BUG_ON_ZERO((perms) < 0) + \ 861 BUILD_BUG_ON_ZERO((perms) > 0777) + \ 862 /* USER_READABLE >= GROUP_READABLE >= OTHER_READABLE */ \ 863 BUILD_BUG_ON_ZERO((((perms) >> 6) & 4) < (((perms) >> 3) & 4)) + \ 864 BUILD_BUG_ON_ZERO((((perms) >> 3) & 4) < ((perms) & 4)) + \ 865 /* USER_WRITABLE >= GROUP_WRITABLE */ \ 866 BUILD_BUG_ON_ZERO((((perms) >> 6) & 2) < (((perms) >> 3) & 2)) + \ 867 /* OTHER_WRITABLE? Generally considered a bad idea. */ \ 868 BUILD_BUG_ON_ZERO((perms) & 2) + \ 869 (perms)) 870 #endif 871