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