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 /* 108 * Multiplies an integer by a fraction, while avoiding unnecessary 109 * overflow or loss of precision. 110 */ 111 #define mult_frac(x, numer, denom)( \ 112 { \ 113 typeof(x) quot = (x) / (denom); \ 114 typeof(x) rem = (x) % (denom); \ 115 (quot * (numer)) + ((rem * (numer)) / (denom)); \ 116 } \ 117 ) 118 119 120 #define _RET_IP_ (unsigned long)__builtin_return_address(0) 121 #define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; }) 122 123 #ifdef CONFIG_LBDAF 124 # include <asm/div64.h> 125 # define sector_div(a, b) do_div(a, b) 126 #else 127 # define sector_div(n, b)( \ 128 { \ 129 int _res; \ 130 _res = (n) % (b); \ 131 (n) /= (b); \ 132 _res; \ 133 } \ 134 ) 135 #endif 136 137 /** 138 * upper_32_bits - return bits 32-63 of a number 139 * @n: the number we're accessing 140 * 141 * A basic shift-right of a 64- or 32-bit quantity. Use this to suppress 142 * the "right shift count >= width of type" warning when that quantity is 143 * 32-bits. 144 */ 145 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16)) 146 147 /** 148 * lower_32_bits - return bits 0-31 of a number 149 * @n: the number we're accessing 150 */ 151 #define lower_32_bits(n) ((u32)(n)) 152 153 struct completion; 154 struct pt_regs; 155 struct user; 156 157 #ifdef CONFIG_PREEMPT_VOLUNTARY 158 extern int _cond_resched(void); 159 # define might_resched() _cond_resched() 160 #else 161 # define might_resched() do { } while (0) 162 #endif 163 164 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 165 void ___might_sleep(const char *file, int line, int preempt_offset); 166 void __might_sleep(const char *file, int line, int preempt_offset); 167 /** 168 * might_sleep - annotation for functions that can sleep 169 * 170 * this macro will print a stack trace if it is executed in an atomic 171 * context (spinlock, irq-handler, ...). 172 * 173 * This is a useful debugging help to be able to catch problems early and not 174 * be bitten later when the calling function happens to sleep when it is not 175 * supposed to. 176 */ 177 # define might_sleep() \ 178 do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0) 179 # define sched_annotate_sleep() (current->task_state_change = 0) 180 #else 181 static inline void ___might_sleep(const char *file, int line, 182 int preempt_offset) { } 183 static inline void __might_sleep(const char *file, int line, 184 int preempt_offset) { } 185 # define might_sleep() do { might_resched(); } while (0) 186 # define sched_annotate_sleep() do { } while (0) 187 #endif 188 189 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0) 190 191 /* 192 * abs() handles unsigned and signed longs, ints, shorts and chars. For all 193 * input types abs() returns a signed long. 194 * abs() should not be used for 64-bit types (s64, u64, long long) - use abs64() 195 * for those. 196 */ 197 #define abs(x) ({ \ 198 long ret; \ 199 if (sizeof(x) == sizeof(long)) { \ 200 long __x = (x); \ 201 ret = (__x < 0) ? -__x : __x; \ 202 } else { \ 203 int __x = (x); \ 204 ret = (__x < 0) ? -__x : __x; \ 205 } \ 206 ret; \ 207 }) 208 209 #define abs64(x) ({ \ 210 s64 __x = (x); \ 211 (__x < 0) ? -__x : __x; \ 212 }) 213 214 /** 215 * reciprocal_scale - "scale" a value into range [0, ep_ro) 216 * @val: value 217 * @ep_ro: right open interval endpoint 218 * 219 * Perform a "reciprocal multiplication" in order to "scale" a value into 220 * range [0, ep_ro), where the upper interval endpoint is right-open. 221 * This is useful, e.g. for accessing a index of an array containing 222 * ep_ro elements, for example. Think of it as sort of modulus, only that 223 * the result isn't that of modulo. ;) Note that if initial input is a 224 * small value, then result will return 0. 225 * 226 * Return: a result based on val in interval [0, ep_ro). 227 */ 228 static inline u32 reciprocal_scale(u32 val, u32 ep_ro) 229 { 230 return (u32)(((u64) val * ep_ro) >> 32); 231 } 232 233 #if defined(CONFIG_MMU) && \ 234 (defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP)) 235 void might_fault(void); 236 #else 237 static inline void might_fault(void) { } 238 #endif 239 240 extern struct atomic_notifier_head panic_notifier_list; 241 extern long (*panic_blink)(int state); 242 __printf(1, 2) 243 void panic(const char *fmt, ...) 244 __noreturn __cold; 245 extern void oops_enter(void); 246 extern void oops_exit(void); 247 void print_oops_end_marker(void); 248 extern int oops_may_print(void); 249 void do_exit(long error_code) 250 __noreturn; 251 void complete_and_exit(struct completion *, long) 252 __noreturn; 253 254 /* Internal, do not use. */ 255 int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res); 256 int __must_check _kstrtol(const char *s, unsigned int base, long *res); 257 258 int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res); 259 int __must_check kstrtoll(const char *s, unsigned int base, long long *res); 260 261 /** 262 * kstrtoul - convert a string to an unsigned long 263 * @s: The start of the string. The string must be null-terminated, and may also 264 * include a single newline before its terminating null. The first character 265 * may also be a plus sign, but not a minus sign. 266 * @base: The number base to use. The maximum supported base is 16. If base is 267 * given as 0, then the base of the string is automatically detected with the 268 * conventional semantics - If it begins with 0x the number will be parsed as a 269 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be 270 * parsed as an octal number. Otherwise it will be parsed as a decimal. 271 * @res: Where to write the result of the conversion on success. 272 * 273 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. 274 * Used as a replacement for the obsolete simple_strtoull. Return code must 275 * be checked. 276 */ 277 static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res) 278 { 279 /* 280 * We want to shortcut function call, but 281 * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0. 282 */ 283 if (sizeof(unsigned long) == sizeof(unsigned long long) && 284 __alignof__(unsigned long) == __alignof__(unsigned long long)) 285 return kstrtoull(s, base, (unsigned long long *)res); 286 else 287 return _kstrtoul(s, base, res); 288 } 289 290 /** 291 * kstrtol - convert a string to a long 292 * @s: The start of the string. The string must be null-terminated, and may also 293 * include a single newline before its terminating null. The first character 294 * may also be a plus sign or a minus sign. 295 * @base: The number base to use. The maximum supported base is 16. If base is 296 * given as 0, then the base of the string is automatically detected with the 297 * conventional semantics - If it begins with 0x the number will be parsed as a 298 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be 299 * parsed as an octal number. Otherwise it will be parsed as a decimal. 300 * @res: Where to write the result of the conversion on success. 301 * 302 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. 303 * Used as a replacement for the obsolete simple_strtoull. Return code must 304 * be checked. 305 */ 306 static inline int __must_check kstrtol(const char *s, unsigned int base, long *res) 307 { 308 /* 309 * We want to shortcut function call, but 310 * __builtin_types_compatible_p(long, long long) = 0. 311 */ 312 if (sizeof(long) == sizeof(long long) && 313 __alignof__(long) == __alignof__(long long)) 314 return kstrtoll(s, base, (long long *)res); 315 else 316 return _kstrtol(s, base, res); 317 } 318 319 int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res); 320 int __must_check kstrtoint(const char *s, unsigned int base, int *res); 321 322 static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res) 323 { 324 return kstrtoull(s, base, res); 325 } 326 327 static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res) 328 { 329 return kstrtoll(s, base, res); 330 } 331 332 static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res) 333 { 334 return kstrtouint(s, base, res); 335 } 336 337 static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res) 338 { 339 return kstrtoint(s, base, res); 340 } 341 342 int __must_check kstrtou16(const char *s, unsigned int base, u16 *res); 343 int __must_check kstrtos16(const char *s, unsigned int base, s16 *res); 344 int __must_check kstrtou8(const char *s, unsigned int base, u8 *res); 345 int __must_check kstrtos8(const char *s, unsigned int base, s8 *res); 346 347 int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res); 348 int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res); 349 int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res); 350 int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res); 351 int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res); 352 int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res); 353 int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res); 354 int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res); 355 int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res); 356 int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res); 357 358 static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res) 359 { 360 return kstrtoull_from_user(s, count, base, res); 361 } 362 363 static inline int __must_check kstrtos64_from_user(const char __user *s, size_t count, unsigned int base, s64 *res) 364 { 365 return kstrtoll_from_user(s, count, base, res); 366 } 367 368 static inline int __must_check kstrtou32_from_user(const char __user *s, size_t count, unsigned int base, u32 *res) 369 { 370 return kstrtouint_from_user(s, count, base, res); 371 } 372 373 static inline int __must_check kstrtos32_from_user(const char __user *s, size_t count, unsigned int base, s32 *res) 374 { 375 return kstrtoint_from_user(s, count, base, res); 376 } 377 378 /* Obsolete, do not use. Use kstrto<foo> instead */ 379 380 extern unsigned long simple_strtoul(const char *,char **,unsigned int); 381 extern long simple_strtol(const char *,char **,unsigned int); 382 extern unsigned long long simple_strtoull(const char *,char **,unsigned int); 383 extern long long simple_strtoll(const char *,char **,unsigned int); 384 385 extern int num_to_str(char *buf, int size, unsigned long long num); 386 387 /* lib/printf utilities */ 388 389 extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...); 390 extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list); 391 extern __printf(3, 4) 392 int snprintf(char *buf, size_t size, const char *fmt, ...); 393 extern __printf(3, 0) 394 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args); 395 extern __printf(3, 4) 396 int scnprintf(char *buf, size_t size, const char *fmt, ...); 397 extern __printf(3, 0) 398 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args); 399 extern __printf(2, 3) 400 char *kasprintf(gfp_t gfp, const char *fmt, ...); 401 extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args); 402 403 extern __scanf(2, 3) 404 int sscanf(const char *, const char *, ...); 405 extern __scanf(2, 0) 406 int vsscanf(const char *, const char *, va_list); 407 408 extern int get_option(char **str, int *pint); 409 extern char *get_options(const char *str, int nints, int *ints); 410 extern unsigned long long memparse(const char *ptr, char **retptr); 411 extern bool parse_option_str(const char *str, const char *option); 412 413 extern int core_kernel_text(unsigned long addr); 414 extern int core_kernel_data(unsigned long addr); 415 extern int __kernel_text_address(unsigned long addr); 416 extern int kernel_text_address(unsigned long addr); 417 extern int func_ptr_is_kernel_text(void *ptr); 418 419 unsigned long int_sqrt(unsigned long); 420 421 extern void bust_spinlocks(int yes); 422 extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */ 423 extern int panic_timeout; 424 extern int panic_on_oops; 425 extern int panic_on_unrecovered_nmi; 426 extern int panic_on_io_nmi; 427 extern int panic_on_warn; 428 extern int sysctl_panic_on_stackoverflow; 429 /* 430 * Only to be used by arch init code. If the user over-wrote the default 431 * CONFIG_PANIC_TIMEOUT, honor it. 432 */ 433 static inline void set_arch_panic_timeout(int timeout, int arch_default_timeout) 434 { 435 if (panic_timeout == arch_default_timeout) 436 panic_timeout = timeout; 437 } 438 extern const char *print_tainted(void); 439 enum lockdep_ok { 440 LOCKDEP_STILL_OK, 441 LOCKDEP_NOW_UNRELIABLE 442 }; 443 extern void add_taint(unsigned flag, enum lockdep_ok); 444 extern int test_taint(unsigned flag); 445 extern unsigned long get_taint(void); 446 extern int root_mountflags; 447 448 extern bool early_boot_irqs_disabled; 449 450 /* Values used for system_state */ 451 extern enum system_states { 452 SYSTEM_BOOTING, 453 SYSTEM_RUNNING, 454 SYSTEM_HALT, 455 SYSTEM_POWER_OFF, 456 SYSTEM_RESTART, 457 } system_state; 458 459 #define TAINT_PROPRIETARY_MODULE 0 460 #define TAINT_FORCED_MODULE 1 461 #define TAINT_CPU_OUT_OF_SPEC 2 462 #define TAINT_FORCED_RMMOD 3 463 #define TAINT_MACHINE_CHECK 4 464 #define TAINT_BAD_PAGE 5 465 #define TAINT_USER 6 466 #define TAINT_DIE 7 467 #define TAINT_OVERRIDDEN_ACPI_TABLE 8 468 #define TAINT_WARN 9 469 #define TAINT_CRAP 10 470 #define TAINT_FIRMWARE_WORKAROUND 11 471 #define TAINT_OOT_MODULE 12 472 #define TAINT_UNSIGNED_MODULE 13 473 #define TAINT_SOFTLOCKUP 14 474 #define TAINT_LIVEPATCH 15 475 476 extern const char hex_asc[]; 477 #define hex_asc_lo(x) hex_asc[((x) & 0x0f)] 478 #define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4] 479 480 static inline char *hex_byte_pack(char *buf, u8 byte) 481 { 482 *buf++ = hex_asc_hi(byte); 483 *buf++ = hex_asc_lo(byte); 484 return buf; 485 } 486 487 extern const char hex_asc_upper[]; 488 #define hex_asc_upper_lo(x) hex_asc_upper[((x) & 0x0f)] 489 #define hex_asc_upper_hi(x) hex_asc_upper[((x) & 0xf0) >> 4] 490 491 static inline char *hex_byte_pack_upper(char *buf, u8 byte) 492 { 493 *buf++ = hex_asc_upper_hi(byte); 494 *buf++ = hex_asc_upper_lo(byte); 495 return buf; 496 } 497 498 extern int hex_to_bin(char ch); 499 extern int __must_check hex2bin(u8 *dst, const char *src, size_t count); 500 extern char *bin2hex(char *dst, const void *src, size_t count); 501 502 bool mac_pton(const char *s, u8 *mac); 503 504 /* 505 * General tracing related utility functions - trace_printk(), 506 * tracing_on/tracing_off and tracing_start()/tracing_stop 507 * 508 * Use tracing_on/tracing_off when you want to quickly turn on or off 509 * tracing. It simply enables or disables the recording of the trace events. 510 * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on 511 * file, which gives a means for the kernel and userspace to interact. 512 * Place a tracing_off() in the kernel where you want tracing to end. 513 * From user space, examine the trace, and then echo 1 > tracing_on 514 * to continue tracing. 515 * 516 * tracing_stop/tracing_start has slightly more overhead. It is used 517 * by things like suspend to ram where disabling the recording of the 518 * trace is not enough, but tracing must actually stop because things 519 * like calling smp_processor_id() may crash the system. 520 * 521 * Most likely, you want to use tracing_on/tracing_off. 522 */ 523 #ifdef CONFIG_RING_BUFFER 524 /* trace_off_permanent stops recording with no way to bring it back */ 525 void tracing_off_permanent(void); 526 #else 527 static inline void tracing_off_permanent(void) { } 528 #endif 529 530 enum ftrace_dump_mode { 531 DUMP_NONE, 532 DUMP_ALL, 533 DUMP_ORIG, 534 }; 535 536 #ifdef CONFIG_TRACING 537 void tracing_on(void); 538 void tracing_off(void); 539 int tracing_is_on(void); 540 void tracing_snapshot(void); 541 void tracing_snapshot_alloc(void); 542 543 extern void tracing_start(void); 544 extern void tracing_stop(void); 545 546 static inline __printf(1, 2) 547 void ____trace_printk_check_format(const char *fmt, ...) 548 { 549 } 550 #define __trace_printk_check_format(fmt, args...) \ 551 do { \ 552 if (0) \ 553 ____trace_printk_check_format(fmt, ##args); \ 554 } while (0) 555 556 /** 557 * trace_printk - printf formatting in the ftrace buffer 558 * @fmt: the printf format for printing 559 * 560 * Note: __trace_printk is an internal function for trace_printk and 561 * the @ip is passed in via the trace_printk macro. 562 * 563 * This function allows a kernel developer to debug fast path sections 564 * that printk is not appropriate for. By scattering in various 565 * printk like tracing in the code, a developer can quickly see 566 * where problems are occurring. 567 * 568 * This is intended as a debugging tool for the developer only. 569 * Please refrain from leaving trace_printks scattered around in 570 * your code. (Extra memory is used for special buffers that are 571 * allocated when trace_printk() is used) 572 * 573 * A little optization trick is done here. If there's only one 574 * argument, there's no need to scan the string for printf formats. 575 * The trace_puts() will suffice. But how can we take advantage of 576 * using trace_puts() when trace_printk() has only one argument? 577 * By stringifying the args and checking the size we can tell 578 * whether or not there are args. __stringify((__VA_ARGS__)) will 579 * turn into "()\0" with a size of 3 when there are no args, anything 580 * else will be bigger. All we need to do is define a string to this, 581 * and then take its size and compare to 3. If it's bigger, use 582 * do_trace_printk() otherwise, optimize it to trace_puts(). Then just 583 * let gcc optimize the rest. 584 */ 585 586 #define trace_printk(fmt, ...) \ 587 do { \ 588 char _______STR[] = __stringify((__VA_ARGS__)); \ 589 if (sizeof(_______STR) > 3) \ 590 do_trace_printk(fmt, ##__VA_ARGS__); \ 591 else \ 592 trace_puts(fmt); \ 593 } while (0) 594 595 #define do_trace_printk(fmt, args...) \ 596 do { \ 597 static const char *trace_printk_fmt \ 598 __attribute__((section("__trace_printk_fmt"))) = \ 599 __builtin_constant_p(fmt) ? fmt : NULL; \ 600 \ 601 __trace_printk_check_format(fmt, ##args); \ 602 \ 603 if (__builtin_constant_p(fmt)) \ 604 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \ 605 else \ 606 __trace_printk(_THIS_IP_, fmt, ##args); \ 607 } while (0) 608 609 extern __printf(2, 3) 610 int __trace_bprintk(unsigned long ip, const char *fmt, ...); 611 612 extern __printf(2, 3) 613 int __trace_printk(unsigned long ip, const char *fmt, ...); 614 615 /** 616 * trace_puts - write a string into the ftrace buffer 617 * @str: the string to record 618 * 619 * Note: __trace_bputs is an internal function for trace_puts and 620 * the @ip is passed in via the trace_puts macro. 621 * 622 * This is similar to trace_printk() but is made for those really fast 623 * paths that a developer wants the least amount of "Heisenbug" affects, 624 * where the processing of the print format is still too much. 625 * 626 * This function allows a kernel developer to debug fast path sections 627 * that printk is not appropriate for. By scattering in various 628 * printk like tracing in the code, a developer can quickly see 629 * where problems are occurring. 630 * 631 * This is intended as a debugging tool for the developer only. 632 * Please refrain from leaving trace_puts scattered around in 633 * your code. (Extra memory is used for special buffers that are 634 * allocated when trace_puts() is used) 635 * 636 * Returns: 0 if nothing was written, positive # if string was. 637 * (1 when __trace_bputs is used, strlen(str) when __trace_puts is used) 638 */ 639 640 #define trace_puts(str) ({ \ 641 static const char *trace_printk_fmt \ 642 __attribute__((section("__trace_printk_fmt"))) = \ 643 __builtin_constant_p(str) ? str : NULL; \ 644 \ 645 if (__builtin_constant_p(str)) \ 646 __trace_bputs(_THIS_IP_, trace_printk_fmt); \ 647 else \ 648 __trace_puts(_THIS_IP_, str, strlen(str)); \ 649 }) 650 extern int __trace_bputs(unsigned long ip, const char *str); 651 extern int __trace_puts(unsigned long ip, const char *str, int size); 652 653 extern void trace_dump_stack(int skip); 654 655 /* 656 * The double __builtin_constant_p is because gcc will give us an error 657 * if we try to allocate the static variable to fmt if it is not a 658 * constant. Even with the outer if statement. 659 */ 660 #define ftrace_vprintk(fmt, vargs) \ 661 do { \ 662 if (__builtin_constant_p(fmt)) { \ 663 static const char *trace_printk_fmt \ 664 __attribute__((section("__trace_printk_fmt"))) = \ 665 __builtin_constant_p(fmt) ? fmt : NULL; \ 666 \ 667 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \ 668 } else \ 669 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \ 670 } while (0) 671 672 extern int 673 __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap); 674 675 extern int 676 __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap); 677 678 extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode); 679 #else 680 static inline void tracing_start(void) { } 681 static inline void tracing_stop(void) { } 682 static inline void trace_dump_stack(int skip) { } 683 684 static inline void tracing_on(void) { } 685 static inline void tracing_off(void) { } 686 static inline int tracing_is_on(void) { return 0; } 687 static inline void tracing_snapshot(void) { } 688 static inline void tracing_snapshot_alloc(void) { } 689 690 static inline __printf(1, 2) 691 int trace_printk(const char *fmt, ...) 692 { 693 return 0; 694 } 695 static inline int 696 ftrace_vprintk(const char *fmt, va_list ap) 697 { 698 return 0; 699 } 700 static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { } 701 #endif /* CONFIG_TRACING */ 702 703 /* 704 * min()/max()/clamp() macros that also do 705 * strict type-checking.. See the 706 * "unnecessary" pointer comparison. 707 */ 708 #define min(x, y) ({ \ 709 typeof(x) _min1 = (x); \ 710 typeof(y) _min2 = (y); \ 711 (void) (&_min1 == &_min2); \ 712 _min1 < _min2 ? _min1 : _min2; }) 713 714 #define max(x, y) ({ \ 715 typeof(x) _max1 = (x); \ 716 typeof(y) _max2 = (y); \ 717 (void) (&_max1 == &_max2); \ 718 _max1 > _max2 ? _max1 : _max2; }) 719 720 #define min3(x, y, z) min((typeof(x))min(x, y), z) 721 #define max3(x, y, z) max((typeof(x))max(x, y), z) 722 723 /** 724 * min_not_zero - return the minimum that is _not_ zero, unless both are zero 725 * @x: value1 726 * @y: value2 727 */ 728 #define min_not_zero(x, y) ({ \ 729 typeof(x) __x = (x); \ 730 typeof(y) __y = (y); \ 731 __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); }) 732 733 /** 734 * clamp - return a value clamped to a given range with strict typechecking 735 * @val: current value 736 * @lo: lowest allowable value 737 * @hi: highest allowable value 738 * 739 * This macro does strict typechecking of lo/hi to make sure they are of the 740 * same type as val. See the unnecessary pointer comparisons. 741 */ 742 #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi) 743 744 /* 745 * ..and if you can't take the strict 746 * types, you can specify one yourself. 747 * 748 * Or not use min/max/clamp at all, of course. 749 */ 750 #define min_t(type, x, y) ({ \ 751 type __min1 = (x); \ 752 type __min2 = (y); \ 753 __min1 < __min2 ? __min1: __min2; }) 754 755 #define max_t(type, x, y) ({ \ 756 type __max1 = (x); \ 757 type __max2 = (y); \ 758 __max1 > __max2 ? __max1: __max2; }) 759 760 /** 761 * clamp_t - return a value clamped to a given range using a given type 762 * @type: the type of variable to use 763 * @val: current value 764 * @lo: minimum allowable value 765 * @hi: maximum allowable value 766 * 767 * This macro does no typechecking and uses temporary variables of type 768 * 'type' to make all the comparisons. 769 */ 770 #define clamp_t(type, val, lo, hi) min_t(type, max_t(type, val, lo), hi) 771 772 /** 773 * clamp_val - return a value clamped to a given range using val's type 774 * @val: current value 775 * @lo: minimum allowable value 776 * @hi: maximum allowable value 777 * 778 * This macro does no typechecking and uses temporary variables of whatever 779 * type the input argument 'val' is. This is useful when val is an unsigned 780 * type and min and max are literals that will otherwise be assigned a signed 781 * integer type. 782 */ 783 #define clamp_val(val, lo, hi) clamp_t(typeof(val), val, lo, hi) 784 785 786 /* 787 * swap - swap value of @a and @b 788 */ 789 #define swap(a, b) \ 790 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0) 791 792 /** 793 * container_of - cast a member of a structure out to the containing structure 794 * @ptr: the pointer to the member. 795 * @type: the type of the container struct this is embedded in. 796 * @member: the name of the member within the struct. 797 * 798 */ 799 #define container_of(ptr, type, member) ({ \ 800 const typeof( ((type *)0)->member ) *__mptr = (ptr); \ 801 (type *)( (char *)__mptr - offsetof(type,member) );}) 802 803 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */ 804 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 805 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD 806 #endif 807 808 /* Permissions on a sysfs file: you didn't miss the 0 prefix did you? */ 809 #define VERIFY_OCTAL_PERMISSIONS(perms) \ 810 (BUILD_BUG_ON_ZERO((perms) < 0) + \ 811 BUILD_BUG_ON_ZERO((perms) > 0777) + \ 812 /* User perms >= group perms >= other perms */ \ 813 BUILD_BUG_ON_ZERO(((perms) >> 6) < (((perms) >> 3) & 7)) + \ 814 BUILD_BUG_ON_ZERO((((perms) >> 3) & 7) < ((perms) & 7)) + \ 815 /* Other writable? Generally considered a bad idea. */ \ 816 BUILD_BUG_ON_ZERO((perms) & 2) + \ 817 (perms)) 818 #endif 819