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 <linux/dynamic_debug.h> 15 #include <asm/byteorder.h> 16 #include <uapi/linux/kernel.h> 17 18 #define USHRT_MAX ((u16)(~0U)) 19 #define SHRT_MAX ((s16)(USHRT_MAX>>1)) 20 #define SHRT_MIN ((s16)(-SHRT_MAX - 1)) 21 #define INT_MAX ((int)(~0U>>1)) 22 #define INT_MIN (-INT_MAX - 1) 23 #define UINT_MAX (~0U) 24 #define LONG_MAX ((long)(~0UL>>1)) 25 #define LONG_MIN (-LONG_MAX - 1) 26 #define ULONG_MAX (~0UL) 27 #define LLONG_MAX ((long long)(~0ULL>>1)) 28 #define LLONG_MIN (-LLONG_MAX - 1) 29 #define ULLONG_MAX (~0ULL) 30 #define SIZE_MAX (~(size_t)0) 31 32 #define U8_MAX ((u8)~0U) 33 #define S8_MAX ((s8)(U8_MAX>>1)) 34 #define S8_MIN ((s8)(-S8_MAX - 1)) 35 #define U16_MAX ((u16)~0U) 36 #define S16_MAX ((s16)(U16_MAX>>1)) 37 #define S16_MIN ((s16)(-S16_MAX - 1)) 38 #define U32_MAX ((u32)~0U) 39 #define S32_MAX ((s32)(U32_MAX>>1)) 40 #define S32_MIN ((s32)(-S32_MAX - 1)) 41 #define U64_MAX ((u64)~0ULL) 42 #define S64_MAX ((s64)(U64_MAX>>1)) 43 #define S64_MIN ((s64)(-S64_MAX - 1)) 44 45 #define STACK_MAGIC 0xdeadbeef 46 47 #define REPEAT_BYTE(x) ((~0ul / 0xff) * (x)) 48 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 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr)) 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 #define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1) 64 #define round_down(x, y) ((x) & ~__round_mask(x, y)) 65 66 #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f)) 67 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d)) 68 #define DIV_ROUND_UP_ULL(ll,d) \ 69 ({ unsigned long long _tmp = (ll)+(d)-1; do_div(_tmp, d); _tmp; }) 70 71 #if BITS_PER_LONG == 32 72 # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP_ULL(ll, d) 73 #else 74 # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP(ll,d) 75 #endif 76 77 /* The `const' in roundup() prevents gcc-3.3 from calling __divdi3 */ 78 #define roundup(x, y) ( \ 79 { \ 80 const typeof(y) __y = y; \ 81 (((x) + (__y - 1)) / __y) * __y; \ 82 } \ 83 ) 84 #define rounddown(x, y) ( \ 85 { \ 86 typeof(x) __x = (x); \ 87 __x - (__x % (y)); \ 88 } \ 89 ) 90 91 /* 92 * Divide positive or negative dividend by positive divisor and round 93 * to closest integer. Result is undefined for negative divisors and 94 * for negative dividends if the divisor variable type is unsigned. 95 */ 96 #define DIV_ROUND_CLOSEST(x, divisor)( \ 97 { \ 98 typeof(x) __x = x; \ 99 typeof(divisor) __d = divisor; \ 100 (((typeof(x))-1) > 0 || \ 101 ((typeof(divisor))-1) > 0 || (__x) > 0) ? \ 102 (((__x) + ((__d) / 2)) / (__d)) : \ 103 (((__x) - ((__d) / 2)) / (__d)); \ 104 } \ 105 ) 106 /* 107 * Same as above but for u64 dividends. divisor must be a 32-bit 108 * number. 109 */ 110 #define DIV_ROUND_CLOSEST_ULL(x, divisor)( \ 111 { \ 112 typeof(divisor) __d = divisor; \ 113 unsigned long long _tmp = (x) + (__d) / 2; \ 114 do_div(_tmp, __d); \ 115 _tmp; \ 116 } \ 117 ) 118 119 /* 120 * Multiplies an integer by a fraction, while avoiding unnecessary 121 * overflow or loss of precision. 122 */ 123 #define mult_frac(x, numer, denom)( \ 124 { \ 125 typeof(x) quot = (x) / (denom); \ 126 typeof(x) rem = (x) % (denom); \ 127 (quot * (numer)) + ((rem * (numer)) / (denom)); \ 128 } \ 129 ) 130 131 132 #define _RET_IP_ (unsigned long)__builtin_return_address(0) 133 #define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; }) 134 135 #ifdef CONFIG_LBDAF 136 # include <asm/div64.h> 137 # define sector_div(a, b) do_div(a, b) 138 #else 139 # define sector_div(n, b)( \ 140 { \ 141 int _res; \ 142 _res = (n) % (b); \ 143 (n) /= (b); \ 144 _res; \ 145 } \ 146 ) 147 #endif 148 149 /** 150 * upper_32_bits - return bits 32-63 of a number 151 * @n: the number we're accessing 152 * 153 * A basic shift-right of a 64- or 32-bit quantity. Use this to suppress 154 * the "right shift count >= width of type" warning when that quantity is 155 * 32-bits. 156 */ 157 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16)) 158 159 /** 160 * lower_32_bits - return bits 0-31 of a number 161 * @n: the number we're accessing 162 */ 163 #define lower_32_bits(n) ((u32)(n)) 164 165 struct completion; 166 struct pt_regs; 167 struct user; 168 169 #ifdef CONFIG_PREEMPT_VOLUNTARY 170 extern int _cond_resched(void); 171 # define might_resched() _cond_resched() 172 #else 173 # define might_resched() do { } while (0) 174 #endif 175 176 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 177 void ___might_sleep(const char *file, int line, int preempt_offset); 178 void __might_sleep(const char *file, int line, int preempt_offset); 179 /** 180 * might_sleep - annotation for functions that can sleep 181 * 182 * this macro will print a stack trace if it is executed in an atomic 183 * context (spinlock, irq-handler, ...). 184 * 185 * This is a useful debugging help to be able to catch problems early and not 186 * be bitten later when the calling function happens to sleep when it is not 187 * supposed to. 188 */ 189 # define might_sleep() \ 190 do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0) 191 # define sched_annotate_sleep() (current->task_state_change = 0) 192 #else 193 static inline void ___might_sleep(const char *file, int line, 194 int preempt_offset) { } 195 static inline void __might_sleep(const char *file, int line, 196 int preempt_offset) { } 197 # define might_sleep() do { might_resched(); } while (0) 198 # define sched_annotate_sleep() do { } while (0) 199 #endif 200 201 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0) 202 203 /** 204 * abs - return absolute value of an argument 205 * @x: the value. If it is unsigned type, it is converted to signed type first. 206 * char is treated as if it was signed (regardless of whether it really is) 207 * but the macro's return type is preserved as char. 208 * 209 * Return: an absolute value of x. 210 */ 211 #define abs(x) __abs_choose_expr(x, long long, \ 212 __abs_choose_expr(x, long, \ 213 __abs_choose_expr(x, int, \ 214 __abs_choose_expr(x, short, \ 215 __abs_choose_expr(x, char, \ 216 __builtin_choose_expr( \ 217 __builtin_types_compatible_p(typeof(x), char), \ 218 (char)({ signed char __x = (x); __x<0?-__x:__x; }), \ 219 ((void)0))))))) 220 221 #define __abs_choose_expr(x, type, other) __builtin_choose_expr( \ 222 __builtin_types_compatible_p(typeof(x), signed type) || \ 223 __builtin_types_compatible_p(typeof(x), unsigned type), \ 224 ({ signed type __x = (x); __x < 0 ? -__x : __x; }), other) 225 226 /** 227 * reciprocal_scale - "scale" a value into range [0, ep_ro) 228 * @val: value 229 * @ep_ro: right open interval endpoint 230 * 231 * Perform a "reciprocal multiplication" in order to "scale" a value into 232 * range [0, ep_ro), where the upper interval endpoint is right-open. 233 * This is useful, e.g. for accessing a index of an array containing 234 * ep_ro elements, for example. Think of it as sort of modulus, only that 235 * the result isn't that of modulo. ;) Note that if initial input is a 236 * small value, then result will return 0. 237 * 238 * Return: a result based on val in interval [0, ep_ro). 239 */ 240 static inline u32 reciprocal_scale(u32 val, u32 ep_ro) 241 { 242 return (u32)(((u64) val * ep_ro) >> 32); 243 } 244 245 #if defined(CONFIG_MMU) && \ 246 (defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP)) 247 #define might_fault() __might_fault(__FILE__, __LINE__) 248 void __might_fault(const char *file, int line); 249 #else 250 static inline void might_fault(void) { } 251 #endif 252 253 extern struct atomic_notifier_head panic_notifier_list; 254 extern long (*panic_blink)(int state); 255 __printf(1, 2) 256 void panic(const char *fmt, ...) 257 __noreturn __cold; 258 void nmi_panic_self_stop(struct pt_regs *); 259 extern void oops_enter(void); 260 extern void oops_exit(void); 261 void print_oops_end_marker(void); 262 extern int oops_may_print(void); 263 void do_exit(long error_code) 264 __noreturn; 265 void complete_and_exit(struct completion *, long) 266 __noreturn; 267 268 /* Internal, do not use. */ 269 int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res); 270 int __must_check _kstrtol(const char *s, unsigned int base, long *res); 271 272 int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res); 273 int __must_check kstrtoll(const char *s, unsigned int base, long long *res); 274 275 /** 276 * kstrtoul - convert a string to an unsigned long 277 * @s: The start of the string. The string must be null-terminated, and may also 278 * include a single newline before its terminating null. The first character 279 * may also be a plus sign, but not a minus sign. 280 * @base: The number base to use. The maximum supported base is 16. If base is 281 * given as 0, then the base of the string is automatically detected with the 282 * conventional semantics - If it begins with 0x the number will be parsed as a 283 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be 284 * parsed as an octal number. Otherwise it will be parsed as a decimal. 285 * @res: Where to write the result of the conversion on success. 286 * 287 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. 288 * Used as a replacement for the obsolete simple_strtoull. Return code must 289 * be checked. 290 */ 291 static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res) 292 { 293 /* 294 * We want to shortcut function call, but 295 * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0. 296 */ 297 if (sizeof(unsigned long) == sizeof(unsigned long long) && 298 __alignof__(unsigned long) == __alignof__(unsigned long long)) 299 return kstrtoull(s, base, (unsigned long long *)res); 300 else 301 return _kstrtoul(s, base, res); 302 } 303 304 /** 305 * kstrtol - convert a string to a long 306 * @s: The start of the string. The string must be null-terminated, and may also 307 * include a single newline before its terminating null. The first character 308 * may also be a plus sign or a minus sign. 309 * @base: The number base to use. The maximum supported base is 16. If base is 310 * given as 0, then the base of the string is automatically detected with the 311 * conventional semantics - If it begins with 0x the number will be parsed as a 312 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be 313 * parsed as an octal number. Otherwise it will be parsed as a decimal. 314 * @res: Where to write the result of the conversion on success. 315 * 316 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. 317 * Used as a replacement for the obsolete simple_strtoull. Return code must 318 * be checked. 319 */ 320 static inline int __must_check kstrtol(const char *s, unsigned int base, long *res) 321 { 322 /* 323 * We want to shortcut function call, but 324 * __builtin_types_compatible_p(long, long long) = 0. 325 */ 326 if (sizeof(long) == sizeof(long long) && 327 __alignof__(long) == __alignof__(long long)) 328 return kstrtoll(s, base, (long long *)res); 329 else 330 return _kstrtol(s, base, res); 331 } 332 333 int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res); 334 int __must_check kstrtoint(const char *s, unsigned int base, int *res); 335 336 static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res) 337 { 338 return kstrtoull(s, base, res); 339 } 340 341 static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res) 342 { 343 return kstrtoll(s, base, res); 344 } 345 346 static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res) 347 { 348 return kstrtouint(s, base, res); 349 } 350 351 static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res) 352 { 353 return kstrtoint(s, base, res); 354 } 355 356 int __must_check kstrtou16(const char *s, unsigned int base, u16 *res); 357 int __must_check kstrtos16(const char *s, unsigned int base, s16 *res); 358 int __must_check kstrtou8(const char *s, unsigned int base, u8 *res); 359 int __must_check kstrtos8(const char *s, unsigned int base, s8 *res); 360 361 int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res); 362 int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res); 363 int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res); 364 int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res); 365 int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res); 366 int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res); 367 int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res); 368 int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res); 369 int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res); 370 int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res); 371 372 static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res) 373 { 374 return kstrtoull_from_user(s, count, base, res); 375 } 376 377 static inline int __must_check kstrtos64_from_user(const char __user *s, size_t count, unsigned int base, s64 *res) 378 { 379 return kstrtoll_from_user(s, count, base, res); 380 } 381 382 static inline int __must_check kstrtou32_from_user(const char __user *s, size_t count, unsigned int base, u32 *res) 383 { 384 return kstrtouint_from_user(s, count, base, res); 385 } 386 387 static inline int __must_check kstrtos32_from_user(const char __user *s, size_t count, unsigned int base, s32 *res) 388 { 389 return kstrtoint_from_user(s, count, base, res); 390 } 391 392 /* Obsolete, do not use. Use kstrto<foo> instead */ 393 394 extern unsigned long simple_strtoul(const char *,char **,unsigned int); 395 extern long simple_strtol(const char *,char **,unsigned int); 396 extern unsigned long long simple_strtoull(const char *,char **,unsigned int); 397 extern long long simple_strtoll(const char *,char **,unsigned int); 398 399 extern int num_to_str(char *buf, int size, unsigned long long num); 400 401 /* lib/printf utilities */ 402 403 extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...); 404 extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list); 405 extern __printf(3, 4) 406 int snprintf(char *buf, size_t size, const char *fmt, ...); 407 extern __printf(3, 0) 408 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args); 409 extern __printf(3, 4) 410 int scnprintf(char *buf, size_t size, const char *fmt, ...); 411 extern __printf(3, 0) 412 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args); 413 extern __printf(2, 3) 414 char *kasprintf(gfp_t gfp, const char *fmt, ...); 415 extern __printf(2, 0) 416 char *kvasprintf(gfp_t gfp, const char *fmt, va_list args); 417 extern __printf(2, 0) 418 const char *kvasprintf_const(gfp_t gfp, const char *fmt, va_list args); 419 420 extern __scanf(2, 3) 421 int sscanf(const char *, const char *, ...); 422 extern __scanf(2, 0) 423 int vsscanf(const char *, const char *, va_list); 424 425 extern int get_option(char **str, int *pint); 426 extern char *get_options(const char *str, int nints, int *ints); 427 extern unsigned long long memparse(const char *ptr, char **retptr); 428 extern bool parse_option_str(const char *str, const char *option); 429 430 extern int core_kernel_text(unsigned long addr); 431 extern int core_kernel_data(unsigned long addr); 432 extern int __kernel_text_address(unsigned long addr); 433 extern int kernel_text_address(unsigned long addr); 434 extern int func_ptr_is_kernel_text(void *ptr); 435 436 unsigned long int_sqrt(unsigned long); 437 438 extern void bust_spinlocks(int yes); 439 extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */ 440 extern int panic_timeout; 441 extern int panic_on_oops; 442 extern int panic_on_unrecovered_nmi; 443 extern int panic_on_io_nmi; 444 extern int panic_on_warn; 445 extern int sysctl_panic_on_stackoverflow; 446 447 extern bool crash_kexec_post_notifiers; 448 449 /* 450 * panic_cpu is used for synchronizing panic() and crash_kexec() execution. It 451 * holds a CPU number which is executing panic() currently. A value of 452 * PANIC_CPU_INVALID means no CPU has entered panic() or crash_kexec(). 453 */ 454 extern atomic_t panic_cpu; 455 #define PANIC_CPU_INVALID -1 456 457 /* 458 * A variant of panic() called from NMI context. We return if we've already 459 * panicked on this CPU. If another CPU already panicked, loop in 460 * nmi_panic_self_stop() which can provide architecture dependent code such 461 * as saving register state for crash dump. 462 */ 463 #define nmi_panic(regs, fmt, ...) \ 464 do { \ 465 int old_cpu, cpu; \ 466 \ 467 cpu = raw_smp_processor_id(); \ 468 old_cpu = atomic_cmpxchg(&panic_cpu, PANIC_CPU_INVALID, cpu); \ 469 \ 470 if (old_cpu == PANIC_CPU_INVALID) \ 471 panic(fmt, ##__VA_ARGS__); \ 472 else if (old_cpu != cpu) \ 473 nmi_panic_self_stop(regs); \ 474 } while (0) 475 476 /* 477 * Only to be used by arch init code. If the user over-wrote the default 478 * CONFIG_PANIC_TIMEOUT, honor it. 479 */ 480 static inline void set_arch_panic_timeout(int timeout, int arch_default_timeout) 481 { 482 if (panic_timeout == arch_default_timeout) 483 panic_timeout = timeout; 484 } 485 extern const char *print_tainted(void); 486 enum lockdep_ok { 487 LOCKDEP_STILL_OK, 488 LOCKDEP_NOW_UNRELIABLE 489 }; 490 extern void add_taint(unsigned flag, enum lockdep_ok); 491 extern int test_taint(unsigned flag); 492 extern unsigned long get_taint(void); 493 extern int root_mountflags; 494 495 extern bool early_boot_irqs_disabled; 496 497 /* Values used for system_state */ 498 extern enum system_states { 499 SYSTEM_BOOTING, 500 SYSTEM_RUNNING, 501 SYSTEM_HALT, 502 SYSTEM_POWER_OFF, 503 SYSTEM_RESTART, 504 } system_state; 505 506 #define TAINT_PROPRIETARY_MODULE 0 507 #define TAINT_FORCED_MODULE 1 508 #define TAINT_CPU_OUT_OF_SPEC 2 509 #define TAINT_FORCED_RMMOD 3 510 #define TAINT_MACHINE_CHECK 4 511 #define TAINT_BAD_PAGE 5 512 #define TAINT_USER 6 513 #define TAINT_DIE 7 514 #define TAINT_OVERRIDDEN_ACPI_TABLE 8 515 #define TAINT_WARN 9 516 #define TAINT_CRAP 10 517 #define TAINT_FIRMWARE_WORKAROUND 11 518 #define TAINT_OOT_MODULE 12 519 #define TAINT_UNSIGNED_MODULE 13 520 #define TAINT_SOFTLOCKUP 14 521 #define TAINT_LIVEPATCH 15 522 523 extern const char hex_asc[]; 524 #define hex_asc_lo(x) hex_asc[((x) & 0x0f)] 525 #define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4] 526 527 static inline char *hex_byte_pack(char *buf, u8 byte) 528 { 529 *buf++ = hex_asc_hi(byte); 530 *buf++ = hex_asc_lo(byte); 531 return buf; 532 } 533 534 extern const char hex_asc_upper[]; 535 #define hex_asc_upper_lo(x) hex_asc_upper[((x) & 0x0f)] 536 #define hex_asc_upper_hi(x) hex_asc_upper[((x) & 0xf0) >> 4] 537 538 static inline char *hex_byte_pack_upper(char *buf, u8 byte) 539 { 540 *buf++ = hex_asc_upper_hi(byte); 541 *buf++ = hex_asc_upper_lo(byte); 542 return buf; 543 } 544 545 extern int hex_to_bin(char ch); 546 extern int __must_check hex2bin(u8 *dst, const char *src, size_t count); 547 extern char *bin2hex(char *dst, const void *src, size_t count); 548 549 bool mac_pton(const char *s, u8 *mac); 550 551 /* 552 * General tracing related utility functions - trace_printk(), 553 * tracing_on/tracing_off and tracing_start()/tracing_stop 554 * 555 * Use tracing_on/tracing_off when you want to quickly turn on or off 556 * tracing. It simply enables or disables the recording of the trace events. 557 * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on 558 * file, which gives a means for the kernel and userspace to interact. 559 * Place a tracing_off() in the kernel where you want tracing to end. 560 * From user space, examine the trace, and then echo 1 > tracing_on 561 * to continue tracing. 562 * 563 * tracing_stop/tracing_start has slightly more overhead. It is used 564 * by things like suspend to ram where disabling the recording of the 565 * trace is not enough, but tracing must actually stop because things 566 * like calling smp_processor_id() may crash the system. 567 * 568 * Most likely, you want to use tracing_on/tracing_off. 569 */ 570 571 enum ftrace_dump_mode { 572 DUMP_NONE, 573 DUMP_ALL, 574 DUMP_ORIG, 575 }; 576 577 #ifdef CONFIG_TRACING 578 void tracing_on(void); 579 void tracing_off(void); 580 int tracing_is_on(void); 581 void tracing_snapshot(void); 582 void tracing_snapshot_alloc(void); 583 584 extern void tracing_start(void); 585 extern void tracing_stop(void); 586 587 static inline __printf(1, 2) 588 void ____trace_printk_check_format(const char *fmt, ...) 589 { 590 } 591 #define __trace_printk_check_format(fmt, args...) \ 592 do { \ 593 if (0) \ 594 ____trace_printk_check_format(fmt, ##args); \ 595 } while (0) 596 597 /** 598 * trace_printk - printf formatting in the ftrace buffer 599 * @fmt: the printf format for printing 600 * 601 * Note: __trace_printk is an internal function for trace_printk and 602 * the @ip is passed in via the trace_printk macro. 603 * 604 * This function allows a kernel developer to debug fast path sections 605 * that printk is not appropriate for. By scattering in various 606 * printk like tracing in the code, a developer can quickly see 607 * where problems are occurring. 608 * 609 * This is intended as a debugging tool for the developer only. 610 * Please refrain from leaving trace_printks scattered around in 611 * your code. (Extra memory is used for special buffers that are 612 * allocated when trace_printk() is used) 613 * 614 * A little optization trick is done here. If there's only one 615 * argument, there's no need to scan the string for printf formats. 616 * The trace_puts() will suffice. But how can we take advantage of 617 * using trace_puts() when trace_printk() has only one argument? 618 * By stringifying the args and checking the size we can tell 619 * whether or not there are args. __stringify((__VA_ARGS__)) will 620 * turn into "()\0" with a size of 3 when there are no args, anything 621 * else will be bigger. All we need to do is define a string to this, 622 * and then take its size and compare to 3. If it's bigger, use 623 * do_trace_printk() otherwise, optimize it to trace_puts(). Then just 624 * let gcc optimize the rest. 625 */ 626 627 #define trace_printk(fmt, ...) \ 628 do { \ 629 char _______STR[] = __stringify((__VA_ARGS__)); \ 630 if (sizeof(_______STR) > 3) \ 631 do_trace_printk(fmt, ##__VA_ARGS__); \ 632 else \ 633 trace_puts(fmt); \ 634 } while (0) 635 636 #define do_trace_printk(fmt, args...) \ 637 do { \ 638 static const char *trace_printk_fmt \ 639 __attribute__((section("__trace_printk_fmt"))) = \ 640 __builtin_constant_p(fmt) ? fmt : NULL; \ 641 \ 642 __trace_printk_check_format(fmt, ##args); \ 643 \ 644 if (__builtin_constant_p(fmt)) \ 645 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \ 646 else \ 647 __trace_printk(_THIS_IP_, fmt, ##args); \ 648 } while (0) 649 650 extern __printf(2, 3) 651 int __trace_bprintk(unsigned long ip, const char *fmt, ...); 652 653 extern __printf(2, 3) 654 int __trace_printk(unsigned long ip, const char *fmt, ...); 655 656 /** 657 * trace_puts - write a string into the ftrace buffer 658 * @str: the string to record 659 * 660 * Note: __trace_bputs is an internal function for trace_puts and 661 * the @ip is passed in via the trace_puts macro. 662 * 663 * This is similar to trace_printk() but is made for those really fast 664 * paths that a developer wants the least amount of "Heisenbug" affects, 665 * where the processing of the print format is still too much. 666 * 667 * This function allows a kernel developer to debug fast path sections 668 * that printk is not appropriate for. By scattering in various 669 * printk like tracing in the code, a developer can quickly see 670 * where problems are occurring. 671 * 672 * This is intended as a debugging tool for the developer only. 673 * Please refrain from leaving trace_puts scattered around in 674 * your code. (Extra memory is used for special buffers that are 675 * allocated when trace_puts() is used) 676 * 677 * Returns: 0 if nothing was written, positive # if string was. 678 * (1 when __trace_bputs is used, strlen(str) when __trace_puts is used) 679 */ 680 681 #define trace_puts(str) ({ \ 682 static const char *trace_printk_fmt \ 683 __attribute__((section("__trace_printk_fmt"))) = \ 684 __builtin_constant_p(str) ? str : NULL; \ 685 \ 686 if (__builtin_constant_p(str)) \ 687 __trace_bputs(_THIS_IP_, trace_printk_fmt); \ 688 else \ 689 __trace_puts(_THIS_IP_, str, strlen(str)); \ 690 }) 691 extern int __trace_bputs(unsigned long ip, const char *str); 692 extern int __trace_puts(unsigned long ip, const char *str, int size); 693 694 extern void trace_dump_stack(int skip); 695 696 /* 697 * The double __builtin_constant_p is because gcc will give us an error 698 * if we try to allocate the static variable to fmt if it is not a 699 * constant. Even with the outer if statement. 700 */ 701 #define ftrace_vprintk(fmt, vargs) \ 702 do { \ 703 if (__builtin_constant_p(fmt)) { \ 704 static const char *trace_printk_fmt \ 705 __attribute__((section("__trace_printk_fmt"))) = \ 706 __builtin_constant_p(fmt) ? fmt : NULL; \ 707 \ 708 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \ 709 } else \ 710 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \ 711 } while (0) 712 713 extern __printf(2, 0) int 714 __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap); 715 716 extern __printf(2, 0) int 717 __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap); 718 719 extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode); 720 #else 721 static inline void tracing_start(void) { } 722 static inline void tracing_stop(void) { } 723 static inline void trace_dump_stack(int skip) { } 724 725 static inline void tracing_on(void) { } 726 static inline void tracing_off(void) { } 727 static inline int tracing_is_on(void) { return 0; } 728 static inline void tracing_snapshot(void) { } 729 static inline void tracing_snapshot_alloc(void) { } 730 731 static inline __printf(1, 2) 732 int trace_printk(const char *fmt, ...) 733 { 734 return 0; 735 } 736 static __printf(1, 0) inline int 737 ftrace_vprintk(const char *fmt, va_list ap) 738 { 739 return 0; 740 } 741 static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { } 742 #endif /* CONFIG_TRACING */ 743 744 /* 745 * min()/max()/clamp() macros that also do 746 * strict type-checking.. See the 747 * "unnecessary" pointer comparison. 748 */ 749 #define min(x, y) ({ \ 750 typeof(x) _min1 = (x); \ 751 typeof(y) _min2 = (y); \ 752 (void) (&_min1 == &_min2); \ 753 _min1 < _min2 ? _min1 : _min2; }) 754 755 #define max(x, y) ({ \ 756 typeof(x) _max1 = (x); \ 757 typeof(y) _max2 = (y); \ 758 (void) (&_max1 == &_max2); \ 759 _max1 > _max2 ? _max1 : _max2; }) 760 761 #define min3(x, y, z) min((typeof(x))min(x, y), z) 762 #define max3(x, y, z) max((typeof(x))max(x, y), z) 763 764 /** 765 * min_not_zero - return the minimum that is _not_ zero, unless both are zero 766 * @x: value1 767 * @y: value2 768 */ 769 #define min_not_zero(x, y) ({ \ 770 typeof(x) __x = (x); \ 771 typeof(y) __y = (y); \ 772 __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); }) 773 774 /** 775 * clamp - return a value clamped to a given range with strict typechecking 776 * @val: current value 777 * @lo: lowest allowable value 778 * @hi: highest allowable value 779 * 780 * This macro does strict typechecking of lo/hi to make sure they are of the 781 * same type as val. See the unnecessary pointer comparisons. 782 */ 783 #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi) 784 785 /* 786 * ..and if you can't take the strict 787 * types, you can specify one yourself. 788 * 789 * Or not use min/max/clamp at all, of course. 790 */ 791 #define min_t(type, x, y) ({ \ 792 type __min1 = (x); \ 793 type __min2 = (y); \ 794 __min1 < __min2 ? __min1: __min2; }) 795 796 #define max_t(type, x, y) ({ \ 797 type __max1 = (x); \ 798 type __max2 = (y); \ 799 __max1 > __max2 ? __max1: __max2; }) 800 801 /** 802 * clamp_t - return a value clamped to a given range using a given type 803 * @type: the type of variable to use 804 * @val: current value 805 * @lo: minimum allowable value 806 * @hi: maximum allowable value 807 * 808 * This macro does no typechecking and uses temporary variables of type 809 * 'type' to make all the comparisons. 810 */ 811 #define clamp_t(type, val, lo, hi) min_t(type, max_t(type, val, lo), hi) 812 813 /** 814 * clamp_val - return a value clamped to a given range using val's type 815 * @val: current value 816 * @lo: minimum allowable value 817 * @hi: maximum allowable value 818 * 819 * This macro does no typechecking and uses temporary variables of whatever 820 * type the input argument 'val' is. This is useful when val is an unsigned 821 * type and min and max are literals that will otherwise be assigned a signed 822 * integer type. 823 */ 824 #define clamp_val(val, lo, hi) clamp_t(typeof(val), val, lo, hi) 825 826 827 /* 828 * swap - swap value of @a and @b 829 */ 830 #define swap(a, b) \ 831 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0) 832 833 /** 834 * container_of - cast a member of a structure out to the containing structure 835 * @ptr: the pointer to the member. 836 * @type: the type of the container struct this is embedded in. 837 * @member: the name of the member within the struct. 838 * 839 */ 840 #define container_of(ptr, type, member) ({ \ 841 const typeof( ((type *)0)->member ) *__mptr = (ptr); \ 842 (type *)( (char *)__mptr - offsetof(type,member) );}) 843 844 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */ 845 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 846 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD 847 #endif 848 849 /* Permissions on a sysfs file: you didn't miss the 0 prefix did you? */ 850 #define VERIFY_OCTAL_PERMISSIONS(perms) \ 851 (BUILD_BUG_ON_ZERO((perms) < 0) + \ 852 BUILD_BUG_ON_ZERO((perms) > 0777) + \ 853 /* USER_READABLE >= GROUP_READABLE >= OTHER_READABLE */ \ 854 BUILD_BUG_ON_ZERO((((perms) >> 6) & 4) < (((perms) >> 3) & 4)) + \ 855 BUILD_BUG_ON_ZERO((((perms) >> 3) & 4) < ((perms) & 4)) + \ 856 /* USER_WRITABLE >= GROUP_WRITABLE */ \ 857 BUILD_BUG_ON_ZERO((((perms) >> 6) & 2) < (((perms) >> 3) & 2)) + \ 858 /* OTHER_WRITABLE? Generally considered a bad idea. */ \ 859 BUILD_BUG_ON_ZERO((perms) & 2) + \ 860 (perms)) 861 #endif 862