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() handles unsigned and signed longs, ints, shorts and chars. For all 205 * input types abs() returns a signed long. 206 * abs() should not be used for 64-bit types (s64, u64, long long) - use abs64() 207 * for those. 208 */ 209 #define abs(x) ({ \ 210 long ret; \ 211 if (sizeof(x) == sizeof(long)) { \ 212 long __x = (x); \ 213 ret = (__x < 0) ? -__x : __x; \ 214 } else { \ 215 int __x = (x); \ 216 ret = (__x < 0) ? -__x : __x; \ 217 } \ 218 ret; \ 219 }) 220 221 #define abs64(x) ({ \ 222 s64 __x = (x); \ 223 (__x < 0) ? -__x : __x; \ 224 }) 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 extern void oops_enter(void); 259 extern void oops_exit(void); 260 void print_oops_end_marker(void); 261 extern int oops_may_print(void); 262 void do_exit(long error_code) 263 __noreturn; 264 void complete_and_exit(struct completion *, long) 265 __noreturn; 266 267 /* Internal, do not use. */ 268 int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res); 269 int __must_check _kstrtol(const char *s, unsigned int base, long *res); 270 271 int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res); 272 int __must_check kstrtoll(const char *s, unsigned int base, long long *res); 273 274 /** 275 * kstrtoul - convert a string to an unsigned long 276 * @s: The start of the string. The string must be null-terminated, and may also 277 * include a single newline before its terminating null. The first character 278 * may also be a plus sign, but not a minus sign. 279 * @base: The number base to use. The maximum supported base is 16. If base is 280 * given as 0, then the base of the string is automatically detected with the 281 * conventional semantics - If it begins with 0x the number will be parsed as a 282 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be 283 * parsed as an octal number. Otherwise it will be parsed as a decimal. 284 * @res: Where to write the result of the conversion on success. 285 * 286 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. 287 * Used as a replacement for the obsolete simple_strtoull. Return code must 288 * be checked. 289 */ 290 static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res) 291 { 292 /* 293 * We want to shortcut function call, but 294 * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0. 295 */ 296 if (sizeof(unsigned long) == sizeof(unsigned long long) && 297 __alignof__(unsigned long) == __alignof__(unsigned long long)) 298 return kstrtoull(s, base, (unsigned long long *)res); 299 else 300 return _kstrtoul(s, base, res); 301 } 302 303 /** 304 * kstrtol - convert a string to a long 305 * @s: The start of the string. The string must be null-terminated, and may also 306 * include a single newline before its terminating null. The first character 307 * may also be a plus sign or a minus sign. 308 * @base: The number base to use. The maximum supported base is 16. If base is 309 * given as 0, then the base of the string is automatically detected with the 310 * conventional semantics - If it begins with 0x the number will be parsed as a 311 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be 312 * parsed as an octal number. Otherwise it will be parsed as a decimal. 313 * @res: Where to write the result of the conversion on success. 314 * 315 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. 316 * Used as a replacement for the obsolete simple_strtoull. Return code must 317 * be checked. 318 */ 319 static inline int __must_check kstrtol(const char *s, unsigned int base, long *res) 320 { 321 /* 322 * We want to shortcut function call, but 323 * __builtin_types_compatible_p(long, long long) = 0. 324 */ 325 if (sizeof(long) == sizeof(long long) && 326 __alignof__(long) == __alignof__(long long)) 327 return kstrtoll(s, base, (long long *)res); 328 else 329 return _kstrtol(s, base, res); 330 } 331 332 int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res); 333 int __must_check kstrtoint(const char *s, unsigned int base, int *res); 334 335 static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res) 336 { 337 return kstrtoull(s, base, res); 338 } 339 340 static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res) 341 { 342 return kstrtoll(s, base, res); 343 } 344 345 static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res) 346 { 347 return kstrtouint(s, base, res); 348 } 349 350 static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res) 351 { 352 return kstrtoint(s, base, res); 353 } 354 355 int __must_check kstrtou16(const char *s, unsigned int base, u16 *res); 356 int __must_check kstrtos16(const char *s, unsigned int base, s16 *res); 357 int __must_check kstrtou8(const char *s, unsigned int base, u8 *res); 358 int __must_check kstrtos8(const char *s, unsigned int base, s8 *res); 359 360 int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res); 361 int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res); 362 int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res); 363 int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res); 364 int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res); 365 int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res); 366 int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res); 367 int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res); 368 int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res); 369 int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res); 370 371 static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res) 372 { 373 return kstrtoull_from_user(s, count, base, res); 374 } 375 376 static inline int __must_check kstrtos64_from_user(const char __user *s, size_t count, unsigned int base, s64 *res) 377 { 378 return kstrtoll_from_user(s, count, base, res); 379 } 380 381 static inline int __must_check kstrtou32_from_user(const char __user *s, size_t count, unsigned int base, u32 *res) 382 { 383 return kstrtouint_from_user(s, count, base, res); 384 } 385 386 static inline int __must_check kstrtos32_from_user(const char __user *s, size_t count, unsigned int base, s32 *res) 387 { 388 return kstrtoint_from_user(s, count, base, res); 389 } 390 391 /* Obsolete, do not use. Use kstrto<foo> instead */ 392 393 extern unsigned long simple_strtoul(const char *,char **,unsigned int); 394 extern long simple_strtol(const char *,char **,unsigned int); 395 extern unsigned long long simple_strtoull(const char *,char **,unsigned int); 396 extern long long simple_strtoll(const char *,char **,unsigned int); 397 398 extern int num_to_str(char *buf, int size, unsigned long long num); 399 400 /* lib/printf utilities */ 401 402 extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...); 403 extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list); 404 extern __printf(3, 4) 405 int snprintf(char *buf, size_t size, const char *fmt, ...); 406 extern __printf(3, 0) 407 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args); 408 extern __printf(3, 4) 409 int scnprintf(char *buf, size_t size, const char *fmt, ...); 410 extern __printf(3, 0) 411 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args); 412 extern __printf(2, 3) 413 char *kasprintf(gfp_t gfp, const char *fmt, ...); 414 extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args); 415 416 extern __scanf(2, 3) 417 int sscanf(const char *, const char *, ...); 418 extern __scanf(2, 0) 419 int vsscanf(const char *, const char *, va_list); 420 421 extern int get_option(char **str, int *pint); 422 extern char *get_options(const char *str, int nints, int *ints); 423 extern unsigned long long memparse(const char *ptr, char **retptr); 424 extern bool parse_option_str(const char *str, const char *option); 425 426 extern int core_kernel_text(unsigned long addr); 427 extern int core_kernel_data(unsigned long addr); 428 extern int __kernel_text_address(unsigned long addr); 429 extern int kernel_text_address(unsigned long addr); 430 extern int func_ptr_is_kernel_text(void *ptr); 431 432 unsigned long int_sqrt(unsigned long); 433 434 extern void bust_spinlocks(int yes); 435 extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */ 436 extern int panic_timeout; 437 extern int panic_on_oops; 438 extern int panic_on_unrecovered_nmi; 439 extern int panic_on_io_nmi; 440 extern int panic_on_warn; 441 extern int sysctl_panic_on_stackoverflow; 442 443 extern bool crash_kexec_post_notifiers; 444 445 /* 446 * Only to be used by arch init code. If the user over-wrote the default 447 * CONFIG_PANIC_TIMEOUT, honor it. 448 */ 449 static inline void set_arch_panic_timeout(int timeout, int arch_default_timeout) 450 { 451 if (panic_timeout == arch_default_timeout) 452 panic_timeout = timeout; 453 } 454 extern const char *print_tainted(void); 455 enum lockdep_ok { 456 LOCKDEP_STILL_OK, 457 LOCKDEP_NOW_UNRELIABLE 458 }; 459 extern void add_taint(unsigned flag, enum lockdep_ok); 460 extern int test_taint(unsigned flag); 461 extern unsigned long get_taint(void); 462 extern int root_mountflags; 463 464 extern bool early_boot_irqs_disabled; 465 466 /* Values used for system_state */ 467 extern enum system_states { 468 SYSTEM_BOOTING, 469 SYSTEM_RUNNING, 470 SYSTEM_HALT, 471 SYSTEM_POWER_OFF, 472 SYSTEM_RESTART, 473 } system_state; 474 475 #define TAINT_PROPRIETARY_MODULE 0 476 #define TAINT_FORCED_MODULE 1 477 #define TAINT_CPU_OUT_OF_SPEC 2 478 #define TAINT_FORCED_RMMOD 3 479 #define TAINT_MACHINE_CHECK 4 480 #define TAINT_BAD_PAGE 5 481 #define TAINT_USER 6 482 #define TAINT_DIE 7 483 #define TAINT_OVERRIDDEN_ACPI_TABLE 8 484 #define TAINT_WARN 9 485 #define TAINT_CRAP 10 486 #define TAINT_FIRMWARE_WORKAROUND 11 487 #define TAINT_OOT_MODULE 12 488 #define TAINT_UNSIGNED_MODULE 13 489 #define TAINT_SOFTLOCKUP 14 490 #define TAINT_LIVEPATCH 15 491 492 extern const char hex_asc[]; 493 #define hex_asc_lo(x) hex_asc[((x) & 0x0f)] 494 #define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4] 495 496 static inline char *hex_byte_pack(char *buf, u8 byte) 497 { 498 *buf++ = hex_asc_hi(byte); 499 *buf++ = hex_asc_lo(byte); 500 return buf; 501 } 502 503 extern const char hex_asc_upper[]; 504 #define hex_asc_upper_lo(x) hex_asc_upper[((x) & 0x0f)] 505 #define hex_asc_upper_hi(x) hex_asc_upper[((x) & 0xf0) >> 4] 506 507 static inline char *hex_byte_pack_upper(char *buf, u8 byte) 508 { 509 *buf++ = hex_asc_upper_hi(byte); 510 *buf++ = hex_asc_upper_lo(byte); 511 return buf; 512 } 513 514 extern int hex_to_bin(char ch); 515 extern int __must_check hex2bin(u8 *dst, const char *src, size_t count); 516 extern char *bin2hex(char *dst, const void *src, size_t count); 517 518 bool mac_pton(const char *s, u8 *mac); 519 520 /* 521 * General tracing related utility functions - trace_printk(), 522 * tracing_on/tracing_off and tracing_start()/tracing_stop 523 * 524 * Use tracing_on/tracing_off when you want to quickly turn on or off 525 * tracing. It simply enables or disables the recording of the trace events. 526 * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on 527 * file, which gives a means for the kernel and userspace to interact. 528 * Place a tracing_off() in the kernel where you want tracing to end. 529 * From user space, examine the trace, and then echo 1 > tracing_on 530 * to continue tracing. 531 * 532 * tracing_stop/tracing_start has slightly more overhead. It is used 533 * by things like suspend to ram where disabling the recording of the 534 * trace is not enough, but tracing must actually stop because things 535 * like calling smp_processor_id() may crash the system. 536 * 537 * Most likely, you want to use tracing_on/tracing_off. 538 */ 539 540 enum ftrace_dump_mode { 541 DUMP_NONE, 542 DUMP_ALL, 543 DUMP_ORIG, 544 }; 545 546 #ifdef CONFIG_TRACING 547 void tracing_on(void); 548 void tracing_off(void); 549 int tracing_is_on(void); 550 void tracing_snapshot(void); 551 void tracing_snapshot_alloc(void); 552 553 extern void tracing_start(void); 554 extern void tracing_stop(void); 555 556 static inline __printf(1, 2) 557 void ____trace_printk_check_format(const char *fmt, ...) 558 { 559 } 560 #define __trace_printk_check_format(fmt, args...) \ 561 do { \ 562 if (0) \ 563 ____trace_printk_check_format(fmt, ##args); \ 564 } while (0) 565 566 /** 567 * trace_printk - printf formatting in the ftrace buffer 568 * @fmt: the printf format for printing 569 * 570 * Note: __trace_printk is an internal function for trace_printk and 571 * the @ip is passed in via the trace_printk macro. 572 * 573 * This function allows a kernel developer to debug fast path sections 574 * that printk is not appropriate for. By scattering in various 575 * printk like tracing in the code, a developer can quickly see 576 * where problems are occurring. 577 * 578 * This is intended as a debugging tool for the developer only. 579 * Please refrain from leaving trace_printks scattered around in 580 * your code. (Extra memory is used for special buffers that are 581 * allocated when trace_printk() is used) 582 * 583 * A little optization trick is done here. If there's only one 584 * argument, there's no need to scan the string for printf formats. 585 * The trace_puts() will suffice. But how can we take advantage of 586 * using trace_puts() when trace_printk() has only one argument? 587 * By stringifying the args and checking the size we can tell 588 * whether or not there are args. __stringify((__VA_ARGS__)) will 589 * turn into "()\0" with a size of 3 when there are no args, anything 590 * else will be bigger. All we need to do is define a string to this, 591 * and then take its size and compare to 3. If it's bigger, use 592 * do_trace_printk() otherwise, optimize it to trace_puts(). Then just 593 * let gcc optimize the rest. 594 */ 595 596 #define trace_printk(fmt, ...) \ 597 do { \ 598 char _______STR[] = __stringify((__VA_ARGS__)); \ 599 if (sizeof(_______STR) > 3) \ 600 do_trace_printk(fmt, ##__VA_ARGS__); \ 601 else \ 602 trace_puts(fmt); \ 603 } while (0) 604 605 #define do_trace_printk(fmt, args...) \ 606 do { \ 607 static const char *trace_printk_fmt \ 608 __attribute__((section("__trace_printk_fmt"))) = \ 609 __builtin_constant_p(fmt) ? fmt : NULL; \ 610 \ 611 __trace_printk_check_format(fmt, ##args); \ 612 \ 613 if (__builtin_constant_p(fmt)) \ 614 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \ 615 else \ 616 __trace_printk(_THIS_IP_, fmt, ##args); \ 617 } while (0) 618 619 extern __printf(2, 3) 620 int __trace_bprintk(unsigned long ip, const char *fmt, ...); 621 622 extern __printf(2, 3) 623 int __trace_printk(unsigned long ip, const char *fmt, ...); 624 625 /** 626 * trace_puts - write a string into the ftrace buffer 627 * @str: the string to record 628 * 629 * Note: __trace_bputs is an internal function for trace_puts and 630 * the @ip is passed in via the trace_puts macro. 631 * 632 * This is similar to trace_printk() but is made for those really fast 633 * paths that a developer wants the least amount of "Heisenbug" affects, 634 * where the processing of the print format is still too much. 635 * 636 * This function allows a kernel developer to debug fast path sections 637 * that printk is not appropriate for. By scattering in various 638 * printk like tracing in the code, a developer can quickly see 639 * where problems are occurring. 640 * 641 * This is intended as a debugging tool for the developer only. 642 * Please refrain from leaving trace_puts scattered around in 643 * your code. (Extra memory is used for special buffers that are 644 * allocated when trace_puts() is used) 645 * 646 * Returns: 0 if nothing was written, positive # if string was. 647 * (1 when __trace_bputs is used, strlen(str) when __trace_puts is used) 648 */ 649 650 #define trace_puts(str) ({ \ 651 static const char *trace_printk_fmt \ 652 __attribute__((section("__trace_printk_fmt"))) = \ 653 __builtin_constant_p(str) ? str : NULL; \ 654 \ 655 if (__builtin_constant_p(str)) \ 656 __trace_bputs(_THIS_IP_, trace_printk_fmt); \ 657 else \ 658 __trace_puts(_THIS_IP_, str, strlen(str)); \ 659 }) 660 extern int __trace_bputs(unsigned long ip, const char *str); 661 extern int __trace_puts(unsigned long ip, const char *str, int size); 662 663 extern void trace_dump_stack(int skip); 664 665 /* 666 * The double __builtin_constant_p is because gcc will give us an error 667 * if we try to allocate the static variable to fmt if it is not a 668 * constant. Even with the outer if statement. 669 */ 670 #define ftrace_vprintk(fmt, vargs) \ 671 do { \ 672 if (__builtin_constant_p(fmt)) { \ 673 static const char *trace_printk_fmt \ 674 __attribute__((section("__trace_printk_fmt"))) = \ 675 __builtin_constant_p(fmt) ? fmt : NULL; \ 676 \ 677 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \ 678 } else \ 679 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \ 680 } while (0) 681 682 extern int 683 __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap); 684 685 extern int 686 __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap); 687 688 extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode); 689 #else 690 static inline void tracing_start(void) { } 691 static inline void tracing_stop(void) { } 692 static inline void trace_dump_stack(int skip) { } 693 694 static inline void tracing_on(void) { } 695 static inline void tracing_off(void) { } 696 static inline int tracing_is_on(void) { return 0; } 697 static inline void tracing_snapshot(void) { } 698 static inline void tracing_snapshot_alloc(void) { } 699 700 static inline __printf(1, 2) 701 int trace_printk(const char *fmt, ...) 702 { 703 return 0; 704 } 705 static inline int 706 ftrace_vprintk(const char *fmt, va_list ap) 707 { 708 return 0; 709 } 710 static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { } 711 #endif /* CONFIG_TRACING */ 712 713 /* 714 * min()/max()/clamp() macros that also do 715 * strict type-checking.. See the 716 * "unnecessary" pointer comparison. 717 */ 718 #define min(x, y) ({ \ 719 typeof(x) _min1 = (x); \ 720 typeof(y) _min2 = (y); \ 721 (void) (&_min1 == &_min2); \ 722 _min1 < _min2 ? _min1 : _min2; }) 723 724 #define max(x, y) ({ \ 725 typeof(x) _max1 = (x); \ 726 typeof(y) _max2 = (y); \ 727 (void) (&_max1 == &_max2); \ 728 _max1 > _max2 ? _max1 : _max2; }) 729 730 #define min3(x, y, z) min((typeof(x))min(x, y), z) 731 #define max3(x, y, z) max((typeof(x))max(x, y), z) 732 733 /** 734 * min_not_zero - return the minimum that is _not_ zero, unless both are zero 735 * @x: value1 736 * @y: value2 737 */ 738 #define min_not_zero(x, y) ({ \ 739 typeof(x) __x = (x); \ 740 typeof(y) __y = (y); \ 741 __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); }) 742 743 /** 744 * clamp - return a value clamped to a given range with strict typechecking 745 * @val: current value 746 * @lo: lowest allowable value 747 * @hi: highest allowable value 748 * 749 * This macro does strict typechecking of lo/hi to make sure they are of the 750 * same type as val. See the unnecessary pointer comparisons. 751 */ 752 #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi) 753 754 /* 755 * ..and if you can't take the strict 756 * types, you can specify one yourself. 757 * 758 * Or not use min/max/clamp at all, of course. 759 */ 760 #define min_t(type, x, y) ({ \ 761 type __min1 = (x); \ 762 type __min2 = (y); \ 763 __min1 < __min2 ? __min1: __min2; }) 764 765 #define max_t(type, x, y) ({ \ 766 type __max1 = (x); \ 767 type __max2 = (y); \ 768 __max1 > __max2 ? __max1: __max2; }) 769 770 /** 771 * clamp_t - return a value clamped to a given range using a given type 772 * @type: the type of variable to use 773 * @val: current value 774 * @lo: minimum allowable value 775 * @hi: maximum allowable value 776 * 777 * This macro does no typechecking and uses temporary variables of type 778 * 'type' to make all the comparisons. 779 */ 780 #define clamp_t(type, val, lo, hi) min_t(type, max_t(type, val, lo), hi) 781 782 /** 783 * clamp_val - return a value clamped to a given range using val's type 784 * @val: current value 785 * @lo: minimum allowable value 786 * @hi: maximum allowable value 787 * 788 * This macro does no typechecking and uses temporary variables of whatever 789 * type the input argument 'val' is. This is useful when val is an unsigned 790 * type and min and max are literals that will otherwise be assigned a signed 791 * integer type. 792 */ 793 #define clamp_val(val, lo, hi) clamp_t(typeof(val), val, lo, hi) 794 795 796 /* 797 * swap - swap value of @a and @b 798 */ 799 #define swap(a, b) \ 800 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0) 801 802 /** 803 * container_of - cast a member of a structure out to the containing structure 804 * @ptr: the pointer to the member. 805 * @type: the type of the container struct this is embedded in. 806 * @member: the name of the member within the struct. 807 * 808 */ 809 #define container_of(ptr, type, member) ({ \ 810 const typeof( ((type *)0)->member ) *__mptr = (ptr); \ 811 (type *)( (char *)__mptr - offsetof(type,member) );}) 812 813 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */ 814 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 815 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD 816 #endif 817 818 /* Permissions on a sysfs file: you didn't miss the 0 prefix did you? */ 819 #define VERIFY_OCTAL_PERMISSIONS(perms) \ 820 (BUILD_BUG_ON_ZERO((perms) < 0) + \ 821 BUILD_BUG_ON_ZERO((perms) > 0777) + \ 822 /* USER_READABLE >= GROUP_READABLE >= OTHER_READABLE */ \ 823 BUILD_BUG_ON_ZERO((((perms) >> 6) & 4) < (((perms) >> 3) & 4)) + \ 824 BUILD_BUG_ON_ZERO((((perms) >> 3) & 4) < ((perms) & 4)) + \ 825 /* USER_WRITABLE >= GROUP_WRITABLE */ \ 826 BUILD_BUG_ON_ZERO((((perms) >> 6) & 2) < (((perms) >> 3) & 2)) + \ 827 /* OTHER_WRITABLE? Generally considered a bad idea. */ \ 828 BUILD_BUG_ON_ZERO((perms) & 2) + \ 829 (perms)) 830 #endif 831