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 or negative divisor 104 * and round to closest integer. Result is undefined for negative 105 * divisors if he dividend variable type is unsigned and for negative 106 * dividends if the divisor variable type is unsigned. 107 */ 108 #define DIV_ROUND_CLOSEST(x, divisor)( \ 109 { \ 110 typeof(x) __x = x; \ 111 typeof(divisor) __d = divisor; \ 112 (((typeof(x))-1) > 0 || \ 113 ((typeof(divisor))-1) > 0 || \ 114 (((__x) > 0) == ((__d) > 0))) ? \ 115 (((__x) + ((__d) / 2)) / (__d)) : \ 116 (((__x) - ((__d) / 2)) / (__d)); \ 117 } \ 118 ) 119 /* 120 * Same as above but for u64 dividends. divisor must be a 32-bit 121 * number. 122 */ 123 #define DIV_ROUND_CLOSEST_ULL(x, divisor)( \ 124 { \ 125 typeof(divisor) __d = divisor; \ 126 unsigned long long _tmp = (x) + (__d) / 2; \ 127 do_div(_tmp, __d); \ 128 _tmp; \ 129 } \ 130 ) 131 132 /* 133 * Multiplies an integer by a fraction, while avoiding unnecessary 134 * overflow or loss of precision. 135 */ 136 #define mult_frac(x, numer, denom)( \ 137 { \ 138 typeof(x) quot = (x) / (denom); \ 139 typeof(x) rem = (x) % (denom); \ 140 (quot * (numer)) + ((rem * (numer)) / (denom)); \ 141 } \ 142 ) 143 144 145 #define _RET_IP_ (unsigned long)__builtin_return_address(0) 146 #define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; }) 147 148 #ifdef CONFIG_LBDAF 149 # include <asm/div64.h> 150 # define sector_div(a, b) do_div(a, b) 151 #else 152 # define sector_div(n, b)( \ 153 { \ 154 int _res; \ 155 _res = (n) % (b); \ 156 (n) /= (b); \ 157 _res; \ 158 } \ 159 ) 160 #endif 161 162 /** 163 * upper_32_bits - return bits 32-63 of a number 164 * @n: the number we're accessing 165 * 166 * A basic shift-right of a 64- or 32-bit quantity. Use this to suppress 167 * the "right shift count >= width of type" warning when that quantity is 168 * 32-bits. 169 */ 170 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16)) 171 172 /** 173 * lower_32_bits - return bits 0-31 of a number 174 * @n: the number we're accessing 175 */ 176 #define lower_32_bits(n) ((u32)(n)) 177 178 struct completion; 179 struct pt_regs; 180 struct user; 181 182 #ifdef CONFIG_PREEMPT_VOLUNTARY 183 extern int _cond_resched(void); 184 # define might_resched() _cond_resched() 185 #else 186 # define might_resched() do { } while (0) 187 #endif 188 189 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 190 void ___might_sleep(const char *file, int line, int preempt_offset); 191 void __might_sleep(const char *file, int line, int preempt_offset); 192 /** 193 * might_sleep - annotation for functions that can sleep 194 * 195 * this macro will print a stack trace if it is executed in an atomic 196 * context (spinlock, irq-handler, ...). 197 * 198 * This is a useful debugging help to be able to catch problems early and not 199 * be bitten later when the calling function happens to sleep when it is not 200 * supposed to. 201 */ 202 # define might_sleep() \ 203 do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0) 204 # define sched_annotate_sleep() (current->task_state_change = 0) 205 #else 206 static inline void ___might_sleep(const char *file, int line, 207 int preempt_offset) { } 208 static inline void __might_sleep(const char *file, int line, 209 int preempt_offset) { } 210 # define might_sleep() do { might_resched(); } while (0) 211 # define sched_annotate_sleep() do { } while (0) 212 #endif 213 214 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0) 215 216 /** 217 * abs - return absolute value of an argument 218 * @x: the value. If it is unsigned type, it is converted to signed type first. 219 * char is treated as if it was signed (regardless of whether it really is) 220 * but the macro's return type is preserved as char. 221 * 222 * Return: an absolute value of x. 223 */ 224 #define abs(x) __abs_choose_expr(x, long long, \ 225 __abs_choose_expr(x, long, \ 226 __abs_choose_expr(x, int, \ 227 __abs_choose_expr(x, short, \ 228 __abs_choose_expr(x, char, \ 229 __builtin_choose_expr( \ 230 __builtin_types_compatible_p(typeof(x), char), \ 231 (char)({ signed char __x = (x); __x<0?-__x:__x; }), \ 232 ((void)0))))))) 233 234 #define __abs_choose_expr(x, type, other) __builtin_choose_expr( \ 235 __builtin_types_compatible_p(typeof(x), signed type) || \ 236 __builtin_types_compatible_p(typeof(x), unsigned type), \ 237 ({ signed type __x = (x); __x < 0 ? -__x : __x; }), other) 238 239 /** 240 * reciprocal_scale - "scale" a value into range [0, ep_ro) 241 * @val: value 242 * @ep_ro: right open interval endpoint 243 * 244 * Perform a "reciprocal multiplication" in order to "scale" a value into 245 * range [0, ep_ro), where the upper interval endpoint is right-open. 246 * This is useful, e.g. for accessing a index of an array containing 247 * ep_ro elements, for example. Think of it as sort of modulus, only that 248 * the result isn't that of modulo. ;) Note that if initial input is a 249 * small value, then result will return 0. 250 * 251 * Return: a result based on val in interval [0, ep_ro). 252 */ 253 static inline u32 reciprocal_scale(u32 val, u32 ep_ro) 254 { 255 return (u32)(((u64) val * ep_ro) >> 32); 256 } 257 258 #if defined(CONFIG_MMU) && \ 259 (defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP)) 260 #define might_fault() __might_fault(__FILE__, __LINE__) 261 void __might_fault(const char *file, int line); 262 #else 263 static inline void might_fault(void) { } 264 #endif 265 266 extern struct atomic_notifier_head panic_notifier_list; 267 extern long (*panic_blink)(int state); 268 __printf(1, 2) 269 void panic(const char *fmt, ...) __noreturn __cold; 270 void nmi_panic(struct pt_regs *regs, const char *msg); 271 extern void oops_enter(void); 272 extern void oops_exit(void); 273 void print_oops_end_marker(void); 274 extern int oops_may_print(void); 275 void do_exit(long error_code) __noreturn; 276 void complete_and_exit(struct completion *, long) __noreturn; 277 278 /* Internal, do not use. */ 279 int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res); 280 int __must_check _kstrtol(const char *s, unsigned int base, long *res); 281 282 int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res); 283 int __must_check kstrtoll(const char *s, unsigned int base, long long *res); 284 285 /** 286 * kstrtoul - convert a string to an unsigned long 287 * @s: The start of the string. The string must be null-terminated, and may also 288 * include a single newline before its terminating null. The first character 289 * may also be a plus sign, but not a minus sign. 290 * @base: The number base to use. The maximum supported base is 16. If base is 291 * given as 0, then the base of the string is automatically detected with the 292 * conventional semantics - If it begins with 0x the number will be parsed as a 293 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be 294 * parsed as an octal number. Otherwise it will be parsed as a decimal. 295 * @res: Where to write the result of the conversion on success. 296 * 297 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. 298 * Used as a replacement for the obsolete simple_strtoull. Return code must 299 * be checked. 300 */ 301 static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res) 302 { 303 /* 304 * We want to shortcut function call, but 305 * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0. 306 */ 307 if (sizeof(unsigned long) == sizeof(unsigned long long) && 308 __alignof__(unsigned long) == __alignof__(unsigned long long)) 309 return kstrtoull(s, base, (unsigned long long *)res); 310 else 311 return _kstrtoul(s, base, res); 312 } 313 314 /** 315 * kstrtol - convert a string to a long 316 * @s: The start of the string. The string must be null-terminated, and may also 317 * include a single newline before its terminating null. The first character 318 * may also be a plus sign or a minus sign. 319 * @base: The number base to use. The maximum supported base is 16. If base is 320 * given as 0, then the base of the string is automatically detected with the 321 * conventional semantics - If it begins with 0x the number will be parsed as a 322 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be 323 * parsed as an octal number. Otherwise it will be parsed as a decimal. 324 * @res: Where to write the result of the conversion on success. 325 * 326 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. 327 * Used as a replacement for the obsolete simple_strtoull. Return code must 328 * be checked. 329 */ 330 static inline int __must_check kstrtol(const char *s, unsigned int base, long *res) 331 { 332 /* 333 * We want to shortcut function call, but 334 * __builtin_types_compatible_p(long, long long) = 0. 335 */ 336 if (sizeof(long) == sizeof(long long) && 337 __alignof__(long) == __alignof__(long long)) 338 return kstrtoll(s, base, (long long *)res); 339 else 340 return _kstrtol(s, base, res); 341 } 342 343 int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res); 344 int __must_check kstrtoint(const char *s, unsigned int base, int *res); 345 346 static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res) 347 { 348 return kstrtoull(s, base, res); 349 } 350 351 static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res) 352 { 353 return kstrtoll(s, base, res); 354 } 355 356 static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res) 357 { 358 return kstrtouint(s, base, res); 359 } 360 361 static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res) 362 { 363 return kstrtoint(s, base, res); 364 } 365 366 int __must_check kstrtou16(const char *s, unsigned int base, u16 *res); 367 int __must_check kstrtos16(const char *s, unsigned int base, s16 *res); 368 int __must_check kstrtou8(const char *s, unsigned int base, u8 *res); 369 int __must_check kstrtos8(const char *s, unsigned int base, s8 *res); 370 int __must_check kstrtobool(const char *s, bool *res); 371 372 int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res); 373 int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res); 374 int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res); 375 int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res); 376 int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res); 377 int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res); 378 int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res); 379 int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res); 380 int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res); 381 int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res); 382 int __must_check kstrtobool_from_user(const char __user *s, size_t count, bool *res); 383 384 static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res) 385 { 386 return kstrtoull_from_user(s, count, base, res); 387 } 388 389 static inline int __must_check kstrtos64_from_user(const char __user *s, size_t count, unsigned int base, s64 *res) 390 { 391 return kstrtoll_from_user(s, count, base, res); 392 } 393 394 static inline int __must_check kstrtou32_from_user(const char __user *s, size_t count, unsigned int base, u32 *res) 395 { 396 return kstrtouint_from_user(s, count, base, res); 397 } 398 399 static inline int __must_check kstrtos32_from_user(const char __user *s, size_t count, unsigned int base, s32 *res) 400 { 401 return kstrtoint_from_user(s, count, base, res); 402 } 403 404 /* Obsolete, do not use. Use kstrto<foo> instead */ 405 406 extern unsigned long simple_strtoul(const char *,char **,unsigned int); 407 extern long simple_strtol(const char *,char **,unsigned int); 408 extern unsigned long long simple_strtoull(const char *,char **,unsigned int); 409 extern long long simple_strtoll(const char *,char **,unsigned int); 410 411 extern int num_to_str(char *buf, int size, unsigned long long num); 412 413 /* lib/printf utilities */ 414 415 extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...); 416 extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list); 417 extern __printf(3, 4) 418 int snprintf(char *buf, size_t size, const char *fmt, ...); 419 extern __printf(3, 0) 420 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args); 421 extern __printf(3, 4) 422 int scnprintf(char *buf, size_t size, const char *fmt, ...); 423 extern __printf(3, 0) 424 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args); 425 extern __printf(2, 3) __malloc 426 char *kasprintf(gfp_t gfp, const char *fmt, ...); 427 extern __printf(2, 0) __malloc 428 char *kvasprintf(gfp_t gfp, const char *fmt, va_list args); 429 extern __printf(2, 0) 430 const char *kvasprintf_const(gfp_t gfp, const char *fmt, va_list args); 431 432 extern __scanf(2, 3) 433 int sscanf(const char *, const char *, ...); 434 extern __scanf(2, 0) 435 int vsscanf(const char *, const char *, va_list); 436 437 extern int get_option(char **str, int *pint); 438 extern char *get_options(const char *str, int nints, int *ints); 439 extern unsigned long long memparse(const char *ptr, char **retptr); 440 extern bool parse_option_str(const char *str, const char *option); 441 442 extern int core_kernel_text(unsigned long addr); 443 extern int core_kernel_data(unsigned long addr); 444 extern int __kernel_text_address(unsigned long addr); 445 extern int kernel_text_address(unsigned long addr); 446 extern int func_ptr_is_kernel_text(void *ptr); 447 448 unsigned long int_sqrt(unsigned long); 449 450 extern void bust_spinlocks(int yes); 451 extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */ 452 extern int panic_timeout; 453 extern int panic_on_oops; 454 extern int panic_on_unrecovered_nmi; 455 extern int panic_on_io_nmi; 456 extern int panic_on_warn; 457 extern int sysctl_panic_on_rcu_stall; 458 extern int sysctl_panic_on_stackoverflow; 459 460 extern bool crash_kexec_post_notifiers; 461 462 /* 463 * panic_cpu is used for synchronizing panic() and crash_kexec() execution. It 464 * holds a CPU number which is executing panic() currently. A value of 465 * PANIC_CPU_INVALID means no CPU has entered panic() or crash_kexec(). 466 */ 467 extern atomic_t panic_cpu; 468 #define PANIC_CPU_INVALID -1 469 470 /* 471 * Only to be used by arch init code. If the user over-wrote the default 472 * CONFIG_PANIC_TIMEOUT, honor it. 473 */ 474 static inline void set_arch_panic_timeout(int timeout, int arch_default_timeout) 475 { 476 if (panic_timeout == arch_default_timeout) 477 panic_timeout = timeout; 478 } 479 extern const char *print_tainted(void); 480 enum lockdep_ok { 481 LOCKDEP_STILL_OK, 482 LOCKDEP_NOW_UNRELIABLE 483 }; 484 extern void add_taint(unsigned flag, enum lockdep_ok); 485 extern int test_taint(unsigned flag); 486 extern unsigned long get_taint(void); 487 extern int root_mountflags; 488 489 extern bool early_boot_irqs_disabled; 490 491 /* Values used for system_state */ 492 extern enum system_states { 493 SYSTEM_BOOTING, 494 SYSTEM_RUNNING, 495 SYSTEM_HALT, 496 SYSTEM_POWER_OFF, 497 SYSTEM_RESTART, 498 } system_state; 499 500 #define TAINT_PROPRIETARY_MODULE 0 501 #define TAINT_FORCED_MODULE 1 502 #define TAINT_CPU_OUT_OF_SPEC 2 503 #define TAINT_FORCED_RMMOD 3 504 #define TAINT_MACHINE_CHECK 4 505 #define TAINT_BAD_PAGE 5 506 #define TAINT_USER 6 507 #define TAINT_DIE 7 508 #define TAINT_OVERRIDDEN_ACPI_TABLE 8 509 #define TAINT_WARN 9 510 #define TAINT_CRAP 10 511 #define TAINT_FIRMWARE_WORKAROUND 11 512 #define TAINT_OOT_MODULE 12 513 #define TAINT_UNSIGNED_MODULE 13 514 #define TAINT_SOFTLOCKUP 14 515 #define TAINT_LIVEPATCH 15 516 #define TAINT_FLAGS_COUNT 16 517 518 struct taint_flag { 519 char c_true; /* character printed when tainted */ 520 char c_false; /* character printed when not tainted */ 521 bool module; /* also show as a per-module taint flag */ 522 }; 523 524 extern const struct taint_flag taint_flags[TAINT_FLAGS_COUNT]; 525 526 extern const char hex_asc[]; 527 #define hex_asc_lo(x) hex_asc[((x) & 0x0f)] 528 #define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4] 529 530 static inline char *hex_byte_pack(char *buf, u8 byte) 531 { 532 *buf++ = hex_asc_hi(byte); 533 *buf++ = hex_asc_lo(byte); 534 return buf; 535 } 536 537 extern const char hex_asc_upper[]; 538 #define hex_asc_upper_lo(x) hex_asc_upper[((x) & 0x0f)] 539 #define hex_asc_upper_hi(x) hex_asc_upper[((x) & 0xf0) >> 4] 540 541 static inline char *hex_byte_pack_upper(char *buf, u8 byte) 542 { 543 *buf++ = hex_asc_upper_hi(byte); 544 *buf++ = hex_asc_upper_lo(byte); 545 return buf; 546 } 547 548 extern int hex_to_bin(char ch); 549 extern int __must_check hex2bin(u8 *dst, const char *src, size_t count); 550 extern char *bin2hex(char *dst, const void *src, size_t count); 551 552 bool mac_pton(const char *s, u8 *mac); 553 554 /* 555 * General tracing related utility functions - trace_printk(), 556 * tracing_on/tracing_off and tracing_start()/tracing_stop 557 * 558 * Use tracing_on/tracing_off when you want to quickly turn on or off 559 * tracing. It simply enables or disables the recording of the trace events. 560 * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on 561 * file, which gives a means for the kernel and userspace to interact. 562 * Place a tracing_off() in the kernel where you want tracing to end. 563 * From user space, examine the trace, and then echo 1 > tracing_on 564 * to continue tracing. 565 * 566 * tracing_stop/tracing_start has slightly more overhead. It is used 567 * by things like suspend to ram where disabling the recording of the 568 * trace is not enough, but tracing must actually stop because things 569 * like calling smp_processor_id() may crash the system. 570 * 571 * Most likely, you want to use tracing_on/tracing_off. 572 */ 573 574 enum ftrace_dump_mode { 575 DUMP_NONE, 576 DUMP_ALL, 577 DUMP_ORIG, 578 }; 579 580 #ifdef CONFIG_TRACING 581 void tracing_on(void); 582 void tracing_off(void); 583 int tracing_is_on(void); 584 void tracing_snapshot(void); 585 void tracing_snapshot_alloc(void); 586 587 extern void tracing_start(void); 588 extern void tracing_stop(void); 589 590 static inline __printf(1, 2) 591 void ____trace_printk_check_format(const char *fmt, ...) 592 { 593 } 594 #define __trace_printk_check_format(fmt, args...) \ 595 do { \ 596 if (0) \ 597 ____trace_printk_check_format(fmt, ##args); \ 598 } while (0) 599 600 /** 601 * trace_printk - printf formatting in the ftrace buffer 602 * @fmt: the printf format for printing 603 * 604 * Note: __trace_printk is an internal function for trace_printk and 605 * the @ip is passed in via the trace_printk macro. 606 * 607 * This function allows a kernel developer to debug fast path sections 608 * that printk is not appropriate for. By scattering in various 609 * printk like tracing in the code, a developer can quickly see 610 * where problems are occurring. 611 * 612 * This is intended as a debugging tool for the developer only. 613 * Please refrain from leaving trace_printks scattered around in 614 * your code. (Extra memory is used for special buffers that are 615 * allocated when trace_printk() is used) 616 * 617 * A little optization trick is done here. If there's only one 618 * argument, there's no need to scan the string for printf formats. 619 * The trace_puts() will suffice. But how can we take advantage of 620 * using trace_puts() when trace_printk() has only one argument? 621 * By stringifying the args and checking the size we can tell 622 * whether or not there are args. __stringify((__VA_ARGS__)) will 623 * turn into "()\0" with a size of 3 when there are no args, anything 624 * else will be bigger. All we need to do is define a string to this, 625 * and then take its size and compare to 3. If it's bigger, use 626 * do_trace_printk() otherwise, optimize it to trace_puts(). Then just 627 * let gcc optimize the rest. 628 */ 629 630 #define trace_printk(fmt, ...) \ 631 do { \ 632 char _______STR[] = __stringify((__VA_ARGS__)); \ 633 if (sizeof(_______STR) > 3) \ 634 do_trace_printk(fmt, ##__VA_ARGS__); \ 635 else \ 636 trace_puts(fmt); \ 637 } while (0) 638 639 #define do_trace_printk(fmt, args...) \ 640 do { \ 641 static const char *trace_printk_fmt __used \ 642 __attribute__((section("__trace_printk_fmt"))) = \ 643 __builtin_constant_p(fmt) ? fmt : NULL; \ 644 \ 645 __trace_printk_check_format(fmt, ##args); \ 646 \ 647 if (__builtin_constant_p(fmt)) \ 648 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \ 649 else \ 650 __trace_printk(_THIS_IP_, fmt, ##args); \ 651 } while (0) 652 653 extern __printf(2, 3) 654 int __trace_bprintk(unsigned long ip, const char *fmt, ...); 655 656 extern __printf(2, 3) 657 int __trace_printk(unsigned long ip, const char *fmt, ...); 658 659 /** 660 * trace_puts - write a string into the ftrace buffer 661 * @str: the string to record 662 * 663 * Note: __trace_bputs is an internal function for trace_puts and 664 * the @ip is passed in via the trace_puts macro. 665 * 666 * This is similar to trace_printk() but is made for those really fast 667 * paths that a developer wants the least amount of "Heisenbug" affects, 668 * where the processing of the print format is still too much. 669 * 670 * This function allows a kernel developer to debug fast path sections 671 * that printk is not appropriate for. By scattering in various 672 * printk like tracing in the code, a developer can quickly see 673 * where problems are occurring. 674 * 675 * This is intended as a debugging tool for the developer only. 676 * Please refrain from leaving trace_puts scattered around in 677 * your code. (Extra memory is used for special buffers that are 678 * allocated when trace_puts() is used) 679 * 680 * Returns: 0 if nothing was written, positive # if string was. 681 * (1 when __trace_bputs is used, strlen(str) when __trace_puts is used) 682 */ 683 684 #define trace_puts(str) ({ \ 685 static const char *trace_printk_fmt __used \ 686 __attribute__((section("__trace_printk_fmt"))) = \ 687 __builtin_constant_p(str) ? str : NULL; \ 688 \ 689 if (__builtin_constant_p(str)) \ 690 __trace_bputs(_THIS_IP_, trace_printk_fmt); \ 691 else \ 692 __trace_puts(_THIS_IP_, str, strlen(str)); \ 693 }) 694 extern int __trace_bputs(unsigned long ip, const char *str); 695 extern int __trace_puts(unsigned long ip, const char *str, int size); 696 697 extern void trace_dump_stack(int skip); 698 699 /* 700 * The double __builtin_constant_p is because gcc will give us an error 701 * if we try to allocate the static variable to fmt if it is not a 702 * constant. Even with the outer if statement. 703 */ 704 #define ftrace_vprintk(fmt, vargs) \ 705 do { \ 706 if (__builtin_constant_p(fmt)) { \ 707 static const char *trace_printk_fmt __used \ 708 __attribute__((section("__trace_printk_fmt"))) = \ 709 __builtin_constant_p(fmt) ? fmt : NULL; \ 710 \ 711 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \ 712 } else \ 713 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \ 714 } while (0) 715 716 extern __printf(2, 0) int 717 __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap); 718 719 extern __printf(2, 0) int 720 __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap); 721 722 extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode); 723 #else 724 static inline void tracing_start(void) { } 725 static inline void tracing_stop(void) { } 726 static inline void trace_dump_stack(int skip) { } 727 728 static inline void tracing_on(void) { } 729 static inline void tracing_off(void) { } 730 static inline int tracing_is_on(void) { return 0; } 731 static inline void tracing_snapshot(void) { } 732 static inline void tracing_snapshot_alloc(void) { } 733 734 static inline __printf(1, 2) 735 int trace_printk(const char *fmt, ...) 736 { 737 return 0; 738 } 739 static __printf(1, 0) inline int 740 ftrace_vprintk(const char *fmt, va_list ap) 741 { 742 return 0; 743 } 744 static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { } 745 #endif /* CONFIG_TRACING */ 746 747 /* 748 * min()/max()/clamp() macros that also do 749 * strict type-checking.. See the 750 * "unnecessary" pointer comparison. 751 */ 752 #define __min(t1, t2, min1, min2, x, y) ({ \ 753 t1 min1 = (x); \ 754 t2 min2 = (y); \ 755 (void) (&min1 == &min2); \ 756 min1 < min2 ? min1 : min2; }) 757 #define min(x, y) \ 758 __min(typeof(x), typeof(y), \ 759 __UNIQUE_ID(min1_), __UNIQUE_ID(min2_), \ 760 x, y) 761 762 #define __max(t1, t2, max1, max2, x, y) ({ \ 763 t1 max1 = (x); \ 764 t2 max2 = (y); \ 765 (void) (&max1 == &max2); \ 766 max1 > max2 ? max1 : max2; }) 767 #define max(x, y) \ 768 __max(typeof(x), typeof(y), \ 769 __UNIQUE_ID(max1_), __UNIQUE_ID(max2_), \ 770 x, y) 771 772 #define min3(x, y, z) min((typeof(x))min(x, y), z) 773 #define max3(x, y, z) max((typeof(x))max(x, y), z) 774 775 /** 776 * min_not_zero - return the minimum that is _not_ zero, unless both are zero 777 * @x: value1 778 * @y: value2 779 */ 780 #define min_not_zero(x, y) ({ \ 781 typeof(x) __x = (x); \ 782 typeof(y) __y = (y); \ 783 __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); }) 784 785 /** 786 * clamp - return a value clamped to a given range with strict typechecking 787 * @val: current value 788 * @lo: lowest allowable value 789 * @hi: highest allowable value 790 * 791 * This macro does strict typechecking of lo/hi to make sure they are of the 792 * same type as val. See the unnecessary pointer comparisons. 793 */ 794 #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi) 795 796 /* 797 * ..and if you can't take the strict 798 * types, you can specify one yourself. 799 * 800 * Or not use min/max/clamp at all, of course. 801 */ 802 #define min_t(type, x, y) \ 803 __min(type, type, \ 804 __UNIQUE_ID(min1_), __UNIQUE_ID(min2_), \ 805 x, y) 806 807 #define max_t(type, x, y) \ 808 __max(type, type, \ 809 __UNIQUE_ID(min1_), __UNIQUE_ID(min2_), \ 810 x, y) 811 812 /** 813 * clamp_t - return a value clamped to a given range using a given type 814 * @type: the type of variable to use 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 type 820 * 'type' to make all the comparisons. 821 */ 822 #define clamp_t(type, val, lo, hi) min_t(type, max_t(type, val, lo), hi) 823 824 /** 825 * clamp_val - return a value clamped to a given range using val's type 826 * @val: current value 827 * @lo: minimum allowable value 828 * @hi: maximum allowable value 829 * 830 * This macro does no typechecking and uses temporary variables of whatever 831 * type the input argument 'val' is. This is useful when val is an unsigned 832 * type and min and max are literals that will otherwise be assigned a signed 833 * integer type. 834 */ 835 #define clamp_val(val, lo, hi) clamp_t(typeof(val), val, lo, hi) 836 837 838 /* 839 * swap - swap value of @a and @b 840 */ 841 #define swap(a, b) \ 842 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0) 843 844 /** 845 * container_of - cast a member of a structure out to the containing structure 846 * @ptr: the pointer to the member. 847 * @type: the type of the container struct this is embedded in. 848 * @member: the name of the member within the struct. 849 * 850 */ 851 #define container_of(ptr, type, member) ({ \ 852 const typeof( ((type *)0)->member ) *__mptr = (ptr); \ 853 (type *)( (char *)__mptr - offsetof(type,member) );}) 854 855 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */ 856 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 857 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD 858 #endif 859 860 /* Permissions on a sysfs file: you didn't miss the 0 prefix did you? */ 861 #define VERIFY_OCTAL_PERMISSIONS(perms) \ 862 (BUILD_BUG_ON_ZERO((perms) < 0) + \ 863 BUILD_BUG_ON_ZERO((perms) > 0777) + \ 864 /* USER_READABLE >= GROUP_READABLE >= OTHER_READABLE */ \ 865 BUILD_BUG_ON_ZERO((((perms) >> 6) & 4) < (((perms) >> 3) & 4)) + \ 866 BUILD_BUG_ON_ZERO((((perms) >> 3) & 4) < ((perms) & 4)) + \ 867 /* USER_WRITABLE >= GROUP_WRITABLE */ \ 868 BUILD_BUG_ON_ZERO((((perms) >> 6) & 2) < (((perms) >> 3) & 2)) + \ 869 /* OTHER_WRITABLE? Generally considered a bad idea. */ \ 870 BUILD_BUG_ON_ZERO((perms) & 2) + \ 871 (perms)) 872 #endif 873