kernel.h 26 KB

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  1. #ifndef _LINUX_KERNEL_H
  2. #define _LINUX_KERNEL_H
  3. #include <stdarg.h>
  4. #include <linux/linkage.h>
  5. #include <linux/stddef.h>
  6. #include <linux/types.h>
  7. #include <linux/compiler.h>
  8. #include <linux/bitops.h>
  9. #include <linux/log2.h>
  10. #include <linux/typecheck.h>
  11. #include <linux/printk.h>
  12. #include <linux/dynamic_debug.h>
  13. #include <asm/byteorder.h>
  14. #include <uapi/linux/kernel.h>
  15. #define USHRT_MAX ((u16)(~0U))
  16. #define SHRT_MAX ((s16)(USHRT_MAX>>1))
  17. #define SHRT_MIN ((s16)(-SHRT_MAX - 1))
  18. #define INT_MAX ((int)(~0U>>1))
  19. #define INT_MIN (-INT_MAX - 1)
  20. #define UINT_MAX (~0U)
  21. #define LONG_MAX ((long)(~0UL>>1))
  22. #define LONG_MIN (-LONG_MAX - 1)
  23. #define ULONG_MAX (~0UL)
  24. #define LLONG_MAX ((long long)(~0ULL>>1))
  25. #define LLONG_MIN (-LLONG_MAX - 1)
  26. #define ULLONG_MAX (~0ULL)
  27. #define SIZE_MAX (~(size_t)0)
  28. #define STACK_MAGIC 0xdeadbeef
  29. #define REPEAT_BYTE(x) ((~0ul / 0xff) * (x))
  30. #define ALIGN(x, a) __ALIGN_KERNEL((x), (a))
  31. #define __ALIGN_MASK(x, mask) __ALIGN_KERNEL_MASK((x), (mask))
  32. #define PTR_ALIGN(p, a) ((typeof(p))ALIGN((unsigned long)(p), (a)))
  33. #define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0)
  34. #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
  35. /*
  36. * This looks more complex than it should be. But we need to
  37. * get the type for the ~ right in round_down (it needs to be
  38. * as wide as the result!), and we want to evaluate the macro
  39. * arguments just once each.
  40. */
  41. #define __round_mask(x, y) ((__typeof__(x))((y)-1))
  42. #define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
  43. #define round_down(x, y) ((x) & ~__round_mask(x, y))
  44. #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
  45. #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
  46. #define DIV_ROUND_UP_ULL(ll,d) \
  47. ({ unsigned long long _tmp = (ll)+(d)-1; do_div(_tmp, d); _tmp; })
  48. #if BITS_PER_LONG == 32
  49. # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP_ULL(ll, d)
  50. #else
  51. # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP(ll,d)
  52. #endif
  53. /* The `const' in roundup() prevents gcc-3.3 from calling __divdi3 */
  54. #define roundup(x, y) ( \
  55. { \
  56. const typeof(y) __y = y; \
  57. (((x) + (__y - 1)) / __y) * __y; \
  58. } \
  59. )
  60. #define rounddown(x, y) ( \
  61. { \
  62. typeof(x) __x = (x); \
  63. __x - (__x % (y)); \
  64. } \
  65. )
  66. /*
  67. * Divide positive or negative dividend by positive divisor and round
  68. * to closest integer. Result is undefined for negative divisors and
  69. * for negative dividends if the divisor variable type is unsigned.
  70. */
  71. #define DIV_ROUND_CLOSEST(x, divisor)( \
  72. { \
  73. typeof(x) __x = x; \
  74. typeof(divisor) __d = divisor; \
  75. (((typeof(x))-1) > 0 || \
  76. ((typeof(divisor))-1) > 0 || (__x) > 0) ? \
  77. (((__x) + ((__d) / 2)) / (__d)) : \
  78. (((__x) - ((__d) / 2)) / (__d)); \
  79. } \
  80. )
  81. /*
  82. * Multiplies an integer by a fraction, while avoiding unnecessary
  83. * overflow or loss of precision.
  84. */
  85. #define mult_frac(x, numer, denom)( \
  86. { \
  87. typeof(x) quot = (x) / (denom); \
  88. typeof(x) rem = (x) % (denom); \
  89. (quot * (numer)) + ((rem * (numer)) / (denom)); \
  90. } \
  91. )
  92. #define _RET_IP_ (unsigned long)__builtin_return_address(0)
  93. #define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; })
  94. #ifdef CONFIG_LBDAF
  95. # include <asm/div64.h>
  96. # define sector_div(a, b) do_div(a, b)
  97. #else
  98. # define sector_div(n, b)( \
  99. { \
  100. int _res; \
  101. _res = (n) % (b); \
  102. (n) /= (b); \
  103. _res; \
  104. } \
  105. )
  106. #endif
  107. /**
  108. * upper_32_bits - return bits 32-63 of a number
  109. * @n: the number we're accessing
  110. *
  111. * A basic shift-right of a 64- or 32-bit quantity. Use this to suppress
  112. * the "right shift count >= width of type" warning when that quantity is
  113. * 32-bits.
  114. */
  115. #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
  116. /**
  117. * lower_32_bits - return bits 0-31 of a number
  118. * @n: the number we're accessing
  119. */
  120. #define lower_32_bits(n) ((u32)(n))
  121. struct completion;
  122. struct pt_regs;
  123. struct user;
  124. #ifdef CONFIG_PREEMPT_VOLUNTARY
  125. extern int _cond_resched(void);
  126. # define might_resched() _cond_resched()
  127. #else
  128. # define might_resched() do { } while (0)
  129. #endif
  130. #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
  131. void __might_sleep(const char *file, int line, int preempt_offset);
  132. /**
  133. * might_sleep - annotation for functions that can sleep
  134. *
  135. * this macro will print a stack trace if it is executed in an atomic
  136. * context (spinlock, irq-handler, ...).
  137. *
  138. * This is a useful debugging help to be able to catch problems early and not
  139. * be bitten later when the calling function happens to sleep when it is not
  140. * supposed to.
  141. */
  142. # define might_sleep() \
  143. do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
  144. #else
  145. static inline void __might_sleep(const char *file, int line,
  146. int preempt_offset) { }
  147. # define might_sleep() do { might_resched(); } while (0)
  148. #endif
  149. #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
  150. /*
  151. * abs() handles unsigned and signed longs, ints, shorts and chars. For all
  152. * input types abs() returns a signed long.
  153. * abs() should not be used for 64-bit types (s64, u64, long long) - use abs64()
  154. * for those.
  155. */
  156. #define abs(x) ({ \
  157. long ret; \
  158. if (sizeof(x) == sizeof(long)) { \
  159. long __x = (x); \
  160. ret = (__x < 0) ? -__x : __x; \
  161. } else { \
  162. int __x = (x); \
  163. ret = (__x < 0) ? -__x : __x; \
  164. } \
  165. ret; \
  166. })
  167. #define abs64(x) ({ \
  168. s64 __x = (x); \
  169. (__x < 0) ? -__x : __x; \
  170. })
  171. #if defined(CONFIG_MMU) && \
  172. (defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP))
  173. void might_fault(void);
  174. #else
  175. static inline void might_fault(void) { }
  176. #endif
  177. extern struct atomic_notifier_head panic_notifier_list;
  178. extern long (*panic_blink)(int state);
  179. __printf(1, 2)
  180. void panic(const char *fmt, ...)
  181. __noreturn __cold;
  182. extern void oops_enter(void);
  183. extern void oops_exit(void);
  184. void print_oops_end_marker(void);
  185. extern int oops_may_print(void);
  186. void do_exit(long error_code)
  187. __noreturn;
  188. void complete_and_exit(struct completion *, long)
  189. __noreturn;
  190. /* Internal, do not use. */
  191. int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res);
  192. int __must_check _kstrtol(const char *s, unsigned int base, long *res);
  193. int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res);
  194. int __must_check kstrtoll(const char *s, unsigned int base, long long *res);
  195. /**
  196. * kstrtoul - convert a string to an unsigned long
  197. * @s: The start of the string. The string must be null-terminated, and may also
  198. * include a single newline before its terminating null. The first character
  199. * may also be a plus sign, but not a minus sign.
  200. * @base: The number base to use. The maximum supported base is 16. If base is
  201. * given as 0, then the base of the string is automatically detected with the
  202. * conventional semantics - If it begins with 0x the number will be parsed as a
  203. * hexadecimal (case insensitive), if it otherwise begins with 0, it will be
  204. * parsed as an octal number. Otherwise it will be parsed as a decimal.
  205. * @res: Where to write the result of the conversion on success.
  206. *
  207. * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
  208. * Used as a replacement for the obsolete simple_strtoull. Return code must
  209. * be checked.
  210. */
  211. static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res)
  212. {
  213. /*
  214. * We want to shortcut function call, but
  215. * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0.
  216. */
  217. if (sizeof(unsigned long) == sizeof(unsigned long long) &&
  218. __alignof__(unsigned long) == __alignof__(unsigned long long))
  219. return kstrtoull(s, base, (unsigned long long *)res);
  220. else
  221. return _kstrtoul(s, base, res);
  222. }
  223. /**
  224. * kstrtol - convert a string to a long
  225. * @s: The start of the string. The string must be null-terminated, and may also
  226. * include a single newline before its terminating null. The first character
  227. * may also be a plus sign or a minus sign.
  228. * @base: The number base to use. The maximum supported base is 16. If base is
  229. * given as 0, then the base of the string is automatically detected with the
  230. * conventional semantics - If it begins with 0x the number will be parsed as a
  231. * hexadecimal (case insensitive), if it otherwise begins with 0, it will be
  232. * parsed as an octal number. Otherwise it will be parsed as a decimal.
  233. * @res: Where to write the result of the conversion on success.
  234. *
  235. * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
  236. * Used as a replacement for the obsolete simple_strtoull. Return code must
  237. * be checked.
  238. */
  239. static inline int __must_check kstrtol(const char *s, unsigned int base, long *res)
  240. {
  241. /*
  242. * We want to shortcut function call, but
  243. * __builtin_types_compatible_p(long, long long) = 0.
  244. */
  245. if (sizeof(long) == sizeof(long long) &&
  246. __alignof__(long) == __alignof__(long long))
  247. return kstrtoll(s, base, (long long *)res);
  248. else
  249. return _kstrtol(s, base, res);
  250. }
  251. int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res);
  252. int __must_check kstrtoint(const char *s, unsigned int base, int *res);
  253. static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res)
  254. {
  255. return kstrtoull(s, base, res);
  256. }
  257. static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res)
  258. {
  259. return kstrtoll(s, base, res);
  260. }
  261. static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res)
  262. {
  263. return kstrtouint(s, base, res);
  264. }
  265. static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res)
  266. {
  267. return kstrtoint(s, base, res);
  268. }
  269. int __must_check kstrtou16(const char *s, unsigned int base, u16 *res);
  270. int __must_check kstrtos16(const char *s, unsigned int base, s16 *res);
  271. int __must_check kstrtou8(const char *s, unsigned int base, u8 *res);
  272. int __must_check kstrtos8(const char *s, unsigned int base, s8 *res);
  273. int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res);
  274. int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res);
  275. int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res);
  276. int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res);
  277. int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res);
  278. int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res);
  279. int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res);
  280. int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res);
  281. int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res);
  282. int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res);
  283. static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res)
  284. {
  285. return kstrtoull_from_user(s, count, base, res);
  286. }
  287. static inline int __must_check kstrtos64_from_user(const char __user *s, size_t count, unsigned int base, s64 *res)
  288. {
  289. return kstrtoll_from_user(s, count, base, res);
  290. }
  291. static inline int __must_check kstrtou32_from_user(const char __user *s, size_t count, unsigned int base, u32 *res)
  292. {
  293. return kstrtouint_from_user(s, count, base, res);
  294. }
  295. static inline int __must_check kstrtos32_from_user(const char __user *s, size_t count, unsigned int base, s32 *res)
  296. {
  297. return kstrtoint_from_user(s, count, base, res);
  298. }
  299. /* Obsolete, do not use. Use kstrto<foo> instead */
  300. extern unsigned long simple_strtoul(const char *,char **,unsigned int);
  301. extern long simple_strtol(const char *,char **,unsigned int);
  302. extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
  303. extern long long simple_strtoll(const char *,char **,unsigned int);
  304. #define strict_strtoul kstrtoul
  305. #define strict_strtol kstrtol
  306. #define strict_strtoull kstrtoull
  307. #define strict_strtoll kstrtoll
  308. extern int num_to_str(char *buf, int size, unsigned long long num);
  309. /* lib/printf utilities */
  310. extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...);
  311. extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list);
  312. extern __printf(3, 4)
  313. int snprintf(char *buf, size_t size, const char *fmt, ...);
  314. extern __printf(3, 0)
  315. int vsnprintf(char *buf, size_t size, const char *fmt, va_list args);
  316. extern __printf(3, 4)
  317. int scnprintf(char *buf, size_t size, const char *fmt, ...);
  318. extern __printf(3, 0)
  319. int vscnprintf(char *buf, size_t size, const char *fmt, va_list args);
  320. extern __printf(2, 3)
  321. char *kasprintf(gfp_t gfp, const char *fmt, ...);
  322. extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
  323. extern __scanf(2, 3)
  324. int sscanf(const char *, const char *, ...);
  325. extern __scanf(2, 0)
  326. int vsscanf(const char *, const char *, va_list);
  327. extern int get_option(char **str, int *pint);
  328. extern char *get_options(const char *str, int nints, int *ints);
  329. extern unsigned long long memparse(const char *ptr, char **retptr);
  330. extern int core_kernel_text(unsigned long addr);
  331. extern int core_kernel_data(unsigned long addr);
  332. extern int __kernel_text_address(unsigned long addr);
  333. extern int kernel_text_address(unsigned long addr);
  334. extern int func_ptr_is_kernel_text(void *ptr);
  335. struct pid;
  336. extern struct pid *session_of_pgrp(struct pid *pgrp);
  337. unsigned long int_sqrt(unsigned long);
  338. extern void bust_spinlocks(int yes);
  339. extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */
  340. extern int panic_timeout;
  341. extern int panic_on_oops;
  342. extern int panic_on_unrecovered_nmi;
  343. extern int panic_on_io_nmi;
  344. extern int sysctl_panic_on_stackoverflow;
  345. extern const char *print_tainted(void);
  346. enum lockdep_ok {
  347. LOCKDEP_STILL_OK,
  348. LOCKDEP_NOW_UNRELIABLE
  349. };
  350. extern void add_taint(unsigned flag, enum lockdep_ok);
  351. extern int test_taint(unsigned flag);
  352. extern unsigned long get_taint(void);
  353. extern int root_mountflags;
  354. extern bool early_boot_irqs_disabled;
  355. /* Values used for system_state */
  356. extern enum system_states {
  357. SYSTEM_BOOTING,
  358. SYSTEM_RUNNING,
  359. SYSTEM_HALT,
  360. SYSTEM_POWER_OFF,
  361. SYSTEM_RESTART,
  362. } system_state;
  363. #define TAINT_PROPRIETARY_MODULE 0
  364. #define TAINT_FORCED_MODULE 1
  365. #define TAINT_UNSAFE_SMP 2
  366. #define TAINT_FORCED_RMMOD 3
  367. #define TAINT_MACHINE_CHECK 4
  368. #define TAINT_BAD_PAGE 5
  369. #define TAINT_USER 6
  370. #define TAINT_DIE 7
  371. #define TAINT_OVERRIDDEN_ACPI_TABLE 8
  372. #define TAINT_WARN 9
  373. #define TAINT_CRAP 10
  374. #define TAINT_FIRMWARE_WORKAROUND 11
  375. #define TAINT_OOT_MODULE 12
  376. extern const char hex_asc[];
  377. #define hex_asc_lo(x) hex_asc[((x) & 0x0f)]
  378. #define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4]
  379. static inline char *hex_byte_pack(char *buf, u8 byte)
  380. {
  381. *buf++ = hex_asc_hi(byte);
  382. *buf++ = hex_asc_lo(byte);
  383. return buf;
  384. }
  385. extern const char hex_asc_upper[];
  386. #define hex_asc_upper_lo(x) hex_asc_upper[((x) & 0x0f)]
  387. #define hex_asc_upper_hi(x) hex_asc_upper[((x) & 0xf0) >> 4]
  388. static inline char *hex_byte_pack_upper(char *buf, u8 byte)
  389. {
  390. *buf++ = hex_asc_upper_hi(byte);
  391. *buf++ = hex_asc_upper_lo(byte);
  392. return buf;
  393. }
  394. static inline char * __deprecated pack_hex_byte(char *buf, u8 byte)
  395. {
  396. return hex_byte_pack(buf, byte);
  397. }
  398. extern int hex_to_bin(char ch);
  399. extern int __must_check hex2bin(u8 *dst, const char *src, size_t count);
  400. int mac_pton(const char *s, u8 *mac);
  401. /*
  402. * General tracing related utility functions - trace_printk(),
  403. * tracing_on/tracing_off and tracing_start()/tracing_stop
  404. *
  405. * Use tracing_on/tracing_off when you want to quickly turn on or off
  406. * tracing. It simply enables or disables the recording of the trace events.
  407. * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on
  408. * file, which gives a means for the kernel and userspace to interact.
  409. * Place a tracing_off() in the kernel where you want tracing to end.
  410. * From user space, examine the trace, and then echo 1 > tracing_on
  411. * to continue tracing.
  412. *
  413. * tracing_stop/tracing_start has slightly more overhead. It is used
  414. * by things like suspend to ram where disabling the recording of the
  415. * trace is not enough, but tracing must actually stop because things
  416. * like calling smp_processor_id() may crash the system.
  417. *
  418. * Most likely, you want to use tracing_on/tracing_off.
  419. */
  420. #ifdef CONFIG_RING_BUFFER
  421. /* trace_off_permanent stops recording with no way to bring it back */
  422. void tracing_off_permanent(void);
  423. #else
  424. static inline void tracing_off_permanent(void) { }
  425. #endif
  426. enum ftrace_dump_mode {
  427. DUMP_NONE,
  428. DUMP_ALL,
  429. DUMP_ORIG,
  430. };
  431. #ifdef CONFIG_TRACING
  432. void tracing_on(void);
  433. void tracing_off(void);
  434. int tracing_is_on(void);
  435. void tracing_snapshot(void);
  436. void tracing_snapshot_alloc(void);
  437. extern void tracing_start(void);
  438. extern void tracing_stop(void);
  439. static inline __printf(1, 2)
  440. void ____trace_printk_check_format(const char *fmt, ...)
  441. {
  442. }
  443. #define __trace_printk_check_format(fmt, args...) \
  444. do { \
  445. if (0) \
  446. ____trace_printk_check_format(fmt, ##args); \
  447. } while (0)
  448. /**
  449. * trace_printk - printf formatting in the ftrace buffer
  450. * @fmt: the printf format for printing
  451. *
  452. * Note: __trace_printk is an internal function for trace_printk and
  453. * the @ip is passed in via the trace_printk macro.
  454. *
  455. * This function allows a kernel developer to debug fast path sections
  456. * that printk is not appropriate for. By scattering in various
  457. * printk like tracing in the code, a developer can quickly see
  458. * where problems are occurring.
  459. *
  460. * This is intended as a debugging tool for the developer only.
  461. * Please refrain from leaving trace_printks scattered around in
  462. * your code. (Extra memory is used for special buffers that are
  463. * allocated when trace_printk() is used)
  464. *
  465. * A little optization trick is done here. If there's only one
  466. * argument, there's no need to scan the string for printf formats.
  467. * The trace_puts() will suffice. But how can we take advantage of
  468. * using trace_puts() when trace_printk() has only one argument?
  469. * By stringifying the args and checking the size we can tell
  470. * whether or not there are args. __stringify((__VA_ARGS__)) will
  471. * turn into "()\0" with a size of 3 when there are no args, anything
  472. * else will be bigger. All we need to do is define a string to this,
  473. * and then take its size and compare to 3. If it's bigger, use
  474. * do_trace_printk() otherwise, optimize it to trace_puts(). Then just
  475. * let gcc optimize the rest.
  476. */
  477. #define trace_printk(fmt, ...) \
  478. do { \
  479. char _______STR[] = __stringify((__VA_ARGS__)); \
  480. if (sizeof(_______STR) > 3) \
  481. do_trace_printk(fmt, ##__VA_ARGS__); \
  482. else \
  483. trace_puts(fmt); \
  484. } while (0)
  485. #define do_trace_printk(fmt, args...) \
  486. do { \
  487. static const char *trace_printk_fmt \
  488. __attribute__((section("__trace_printk_fmt"))) = \
  489. __builtin_constant_p(fmt) ? fmt : NULL; \
  490. \
  491. __trace_printk_check_format(fmt, ##args); \
  492. \
  493. if (__builtin_constant_p(fmt)) \
  494. __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \
  495. else \
  496. __trace_printk(_THIS_IP_, fmt, ##args); \
  497. } while (0)
  498. extern __printf(2, 3)
  499. int __trace_bprintk(unsigned long ip, const char *fmt, ...);
  500. extern __printf(2, 3)
  501. int __trace_printk(unsigned long ip, const char *fmt, ...);
  502. /**
  503. * trace_puts - write a string into the ftrace buffer
  504. * @str: the string to record
  505. *
  506. * Note: __trace_bputs is an internal function for trace_puts and
  507. * the @ip is passed in via the trace_puts macro.
  508. *
  509. * This is similar to trace_printk() but is made for those really fast
  510. * paths that a developer wants the least amount of "Heisenbug" affects,
  511. * where the processing of the print format is still too much.
  512. *
  513. * This function allows a kernel developer to debug fast path sections
  514. * that printk is not appropriate for. By scattering in various
  515. * printk like tracing in the code, a developer can quickly see
  516. * where problems are occurring.
  517. *
  518. * This is intended as a debugging tool for the developer only.
  519. * Please refrain from leaving trace_puts scattered around in
  520. * your code. (Extra memory is used for special buffers that are
  521. * allocated when trace_puts() is used)
  522. *
  523. * Returns: 0 if nothing was written, positive # if string was.
  524. * (1 when __trace_bputs is used, strlen(str) when __trace_puts is used)
  525. */
  526. #define trace_puts(str) ({ \
  527. static const char *trace_printk_fmt \
  528. __attribute__((section("__trace_printk_fmt"))) = \
  529. __builtin_constant_p(str) ? str : NULL; \
  530. \
  531. if (__builtin_constant_p(str)) \
  532. __trace_bputs(_THIS_IP_, trace_printk_fmt); \
  533. else \
  534. __trace_puts(_THIS_IP_, str, strlen(str)); \
  535. })
  536. extern int __trace_bputs(unsigned long ip, const char *str);
  537. extern int __trace_puts(unsigned long ip, const char *str, int size);
  538. extern void trace_dump_stack(int skip);
  539. /*
  540. * The double __builtin_constant_p is because gcc will give us an error
  541. * if we try to allocate the static variable to fmt if it is not a
  542. * constant. Even with the outer if statement.
  543. */
  544. #define ftrace_vprintk(fmt, vargs) \
  545. do { \
  546. if (__builtin_constant_p(fmt)) { \
  547. static const char *trace_printk_fmt \
  548. __attribute__((section("__trace_printk_fmt"))) = \
  549. __builtin_constant_p(fmt) ? fmt : NULL; \
  550. \
  551. __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \
  552. } else \
  553. __ftrace_vprintk(_THIS_IP_, fmt, vargs); \
  554. } while (0)
  555. extern int
  556. __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
  557. extern int
  558. __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
  559. extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode);
  560. #else
  561. static inline void tracing_start(void) { }
  562. static inline void tracing_stop(void) { }
  563. static inline void trace_dump_stack(int skip) { }
  564. static inline void tracing_on(void) { }
  565. static inline void tracing_off(void) { }
  566. static inline int tracing_is_on(void) { return 0; }
  567. static inline void tracing_snapshot(void) { }
  568. static inline void tracing_snapshot_alloc(void) { }
  569. static inline __printf(1, 2)
  570. int trace_printk(const char *fmt, ...)
  571. {
  572. return 0;
  573. }
  574. static inline int
  575. ftrace_vprintk(const char *fmt, va_list ap)
  576. {
  577. return 0;
  578. }
  579. static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
  580. #endif /* CONFIG_TRACING */
  581. /*
  582. * min()/max()/clamp() macros that also do
  583. * strict type-checking.. See the
  584. * "unnecessary" pointer comparison.
  585. */
  586. #define min(x, y) ({ \
  587. typeof(x) _min1 = (x); \
  588. typeof(y) _min2 = (y); \
  589. (void) (&_min1 == &_min2); \
  590. _min1 < _min2 ? _min1 : _min2; })
  591. #define max(x, y) ({ \
  592. typeof(x) _max1 = (x); \
  593. typeof(y) _max2 = (y); \
  594. (void) (&_max1 == &_max2); \
  595. _max1 > _max2 ? _max1 : _max2; })
  596. #define min3(x, y, z) ({ \
  597. typeof(x) _min1 = (x); \
  598. typeof(y) _min2 = (y); \
  599. typeof(z) _min3 = (z); \
  600. (void) (&_min1 == &_min2); \
  601. (void) (&_min1 == &_min3); \
  602. _min1 < _min2 ? (_min1 < _min3 ? _min1 : _min3) : \
  603. (_min2 < _min3 ? _min2 : _min3); })
  604. #define max3(x, y, z) ({ \
  605. typeof(x) _max1 = (x); \
  606. typeof(y) _max2 = (y); \
  607. typeof(z) _max3 = (z); \
  608. (void) (&_max1 == &_max2); \
  609. (void) (&_max1 == &_max3); \
  610. _max1 > _max2 ? (_max1 > _max3 ? _max1 : _max3) : \
  611. (_max2 > _max3 ? _max2 : _max3); })
  612. /**
  613. * min_not_zero - return the minimum that is _not_ zero, unless both are zero
  614. * @x: value1
  615. * @y: value2
  616. */
  617. #define min_not_zero(x, y) ({ \
  618. typeof(x) __x = (x); \
  619. typeof(y) __y = (y); \
  620. __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); })
  621. /**
  622. * clamp - return a value clamped to a given range with strict typechecking
  623. * @val: current value
  624. * @min: minimum allowable value
  625. * @max: maximum allowable value
  626. *
  627. * This macro does strict typechecking of min/max to make sure they are of the
  628. * same type as val. See the unnecessary pointer comparisons.
  629. */
  630. #define clamp(val, min, max) ({ \
  631. typeof(val) __val = (val); \
  632. typeof(min) __min = (min); \
  633. typeof(max) __max = (max); \
  634. (void) (&__val == &__min); \
  635. (void) (&__val == &__max); \
  636. __val = __val < __min ? __min: __val; \
  637. __val > __max ? __max: __val; })
  638. /*
  639. * ..and if you can't take the strict
  640. * types, you can specify one yourself.
  641. *
  642. * Or not use min/max/clamp at all, of course.
  643. */
  644. #define min_t(type, x, y) ({ \
  645. type __min1 = (x); \
  646. type __min2 = (y); \
  647. __min1 < __min2 ? __min1: __min2; })
  648. #define max_t(type, x, y) ({ \
  649. type __max1 = (x); \
  650. type __max2 = (y); \
  651. __max1 > __max2 ? __max1: __max2; })
  652. /**
  653. * clamp_t - return a value clamped to a given range using a given type
  654. * @type: the type of variable to use
  655. * @val: current value
  656. * @min: minimum allowable value
  657. * @max: maximum allowable value
  658. *
  659. * This macro does no typechecking and uses temporary variables of type
  660. * 'type' to make all the comparisons.
  661. */
  662. #define clamp_t(type, val, min, max) ({ \
  663. type __val = (val); \
  664. type __min = (min); \
  665. type __max = (max); \
  666. __val = __val < __min ? __min: __val; \
  667. __val > __max ? __max: __val; })
  668. /**
  669. * clamp_val - return a value clamped to a given range using val's type
  670. * @val: current value
  671. * @min: minimum allowable value
  672. * @max: maximum allowable value
  673. *
  674. * This macro does no typechecking and uses temporary variables of whatever
  675. * type the input argument 'val' is. This is useful when val is an unsigned
  676. * type and min and max are literals that will otherwise be assigned a signed
  677. * integer type.
  678. */
  679. #define clamp_val(val, min, max) ({ \
  680. typeof(val) __val = (val); \
  681. typeof(val) __min = (min); \
  682. typeof(val) __max = (max); \
  683. __val = __val < __min ? __min: __val; \
  684. __val > __max ? __max: __val; })
  685. /*
  686. * swap - swap value of @a and @b
  687. */
  688. #define swap(a, b) \
  689. do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
  690. /**
  691. * container_of - cast a member of a structure out to the containing structure
  692. * @ptr: the pointer to the member.
  693. * @type: the type of the container struct this is embedded in.
  694. * @member: the name of the member within the struct.
  695. *
  696. */
  697. #define container_of(ptr, type, member) ({ \
  698. const typeof( ((type *)0)->member ) *__mptr = (ptr); \
  699. (type *)( (char *)__mptr - offsetof(type,member) );})
  700. /* Trap pasters of __FUNCTION__ at compile-time */
  701. #define __FUNCTION__ (__func__)
  702. /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
  703. #ifdef CONFIG_FTRACE_MCOUNT_RECORD
  704. # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
  705. #endif
  706. #endif