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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 <asm/byteorder.h>
15 #include <uapi/linux/kernel.h>
16
17 #define USHRT_MAX ((u16)(~0U))
18 #define SHRT_MAX ((s16)(USHRT_MAX>>1))
19 #define SHRT_MIN ((s16)(-SHRT_MAX - 1))
20 #define INT_MAX ((int)(~0U>>1))
21 #define INT_MIN (-INT_MAX - 1)
22 #define UINT_MAX (~0U)
23 #define LONG_MAX ((long)(~0UL>>1))
24 #define LONG_MIN (-LONG_MAX - 1)
25 #define ULONG_MAX (~0UL)
26 #define LLONG_MAX ((long long)(~0ULL>>1))
27 #define LLONG_MIN (-LLONG_MAX - 1)
28 #define ULLONG_MAX (~0ULL)
29 #define SIZE_MAX (~(size_t)0)
30
31 #define U8_MAX ((u8)~0U)
32 #define S8_MAX ((s8)(U8_MAX>>1))
33 #define S8_MIN ((s8)(-S8_MAX - 1))
34 #define U16_MAX ((u16)~0U)
35 #define S16_MAX ((s16)(U16_MAX>>1))
36 #define S16_MIN ((s16)(-S16_MAX - 1))
37 #define U32_MAX ((u32)~0U)
38 #define S32_MAX ((s32)(U32_MAX>>1))
39 #define S32_MIN ((s32)(-S32_MAX - 1))
40 #define U64_MAX ((u64)~0ULL)
41 #define S64_MAX ((s64)(U64_MAX>>1))
42 #define S64_MIN ((s64)(-S64_MAX - 1))
43
44 #define STACK_MAGIC 0xdeadbeef
45
46 #define REPEAT_BYTE(x) ((~0ul / 0xff) * (x))
47
48 /* @a is a power of 2 value */
49 #define ALIGN(x, a) __ALIGN_KERNEL((x), (a))
50 #define __ALIGN_MASK(x, mask) __ALIGN_KERNEL_MASK((x), (mask))
51 #define PTR_ALIGN(p, a) ((typeof(p))ALIGN((unsigned long)(p), (a)))
52 #define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0)
53
54 /* generic data direction definitions */
55 #define READ 0
56 #define WRITE 1
57
58 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
59
60 #define u64_to_user_ptr(x) ( \
61 { \
62 typecheck(u64, x); \
63 (void __user *)(uintptr_t)x; \
64 } \
65 )
66
67 /*
68 * This looks more complex than it should be. But we need to
69 * get the type for the ~ right in round_down (it needs to be
70 * as wide as the result!), and we want to evaluate the macro
71 * arguments just once each.
72 */
73 #define __round_mask(x, y) ((__typeof__(x))((y)-1))
74 #define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
75 #define round_down(x, y) ((x) & ~__round_mask(x, y))
76
77 #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
78 #define DIV_ROUND_UP __KERNEL_DIV_ROUND_UP
79 #define DIV_ROUND_UP_ULL(ll,d) \
80 ({ unsigned long long _tmp = (ll)+(d)-1; do_div(_tmp, d); _tmp; })
81
82 #if BITS_PER_LONG == 32
83 # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP_ULL(ll, d)
84 #else
85 # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP(ll,d)
86 #endif
87
88 /* The `const' in roundup() prevents gcc-3.3 from calling __divdi3 */
89 #define roundup(x, y) ( \
90 { \
91 const typeof(y) __y = y; \
92 (((x) + (__y - 1)) / __y) * __y; \
93 } \
94 )
95 #define rounddown(x, y) ( \
96 { \
97 typeof(x) __x = (x); \
98 __x - (__x % (y)); \
99 } \
100 )
101
102 /*
103 * Divide positive or negative dividend by positive divisor and round
104 * to closest integer. Result is undefined for negative divisors and
105 * for negative dividends if the divisor variable type is unsigned.
106 */
107 #define DIV_ROUND_CLOSEST(x, divisor)( \
108 { \
109 typeof(x) __x = x; \
110 typeof(divisor) __d = divisor; \
111 (((typeof(x))-1) > 0 || \
112 ((typeof(divisor))-1) > 0 || (__x) > 0) ? \
113 (((__x) + ((__d) / 2)) / (__d)) : \
114 (((__x) - ((__d) / 2)) / (__d)); \
115 } \
116 )
117 /*
118 * Same as above but for u64 dividends. divisor must be a 32-bit
119 * number.
120 */
121 #define DIV_ROUND_CLOSEST_ULL(x, divisor)( \
122 { \
123 typeof(divisor) __d = divisor; \
124 unsigned long long _tmp = (x) + (__d) / 2; \
125 do_div(_tmp, __d); \
126 _tmp; \
127 } \
128 )
129
130 /*
131 * Multiplies an integer by a fraction, while avoiding unnecessary
132 * overflow or loss of precision.
133 */
134 #define mult_frac(x, numer, denom)( \
135 { \
136 typeof(x) quot = (x) / (denom); \
137 typeof(x) rem = (x) % (denom); \
138 (quot * (numer)) + ((rem * (numer)) / (denom)); \
139 } \
140 )
141
142
143 #define _RET_IP_ (unsigned long)__builtin_return_address(0)
144 #define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; })
145
146 #ifdef CONFIG_LBDAF
147 # include <asm/div64.h>
148 # define sector_div(a, b) do_div(a, b)
149 #else
150 # define sector_div(n, b)( \
151 { \
152 int _res; \
153 _res = (n) % (b); \
154 (n) /= (b); \
155 _res; \
156 } \
157 )
158 #endif
159
160 /**
161 * upper_32_bits - return bits 32-63 of a number
162 * @n: the number we're accessing
163 *
164 * A basic shift-right of a 64- or 32-bit quantity. Use this to suppress
165 * the "right shift count >= width of type" warning when that quantity is
166 * 32-bits.
167 */
168 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
169
170 /**
171 * lower_32_bits - return bits 0-31 of a number
172 * @n: the number we're accessing
173 */
174 #define lower_32_bits(n) ((u32)(n))
175
176 struct completion;
177 struct pt_regs;
178 struct user;
179
180 #ifdef CONFIG_PREEMPT_VOLUNTARY
181 extern int _cond_resched(void);
182 # define might_resched() _cond_resched()
183 #else
184 # define might_resched() do { } while (0)
185 #endif
186
187 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
188 void ___might_sleep(const char *file, int line, int preempt_offset);
189 void __might_sleep(const char *file, int line, int preempt_offset);
190 /**
191 * might_sleep - annotation for functions that can sleep
192 *
193 * this macro will print a stack trace if it is executed in an atomic
194 * context (spinlock, irq-handler, ...).
195 *
196 * This is a useful debugging help to be able to catch problems early and not
197 * be bitten later when the calling function happens to sleep when it is not
198 * supposed to.
199 */
200 # define might_sleep() \
201 do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
202 # define sched_annotate_sleep() (current->task_state_change = 0)
203 #else
204 static inline void ___might_sleep(const char *file, int line,
205 int preempt_offset) { }
206 static inline void __might_sleep(const char *file, int line,
207 int preempt_offset) { }
208 # define might_sleep() do { might_resched(); } while (0)
209 # define sched_annotate_sleep() do { } while (0)
210 #endif
211
212 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
213
214 /**
215 * abs - return absolute value of an argument
216 * @x: the value. If it is unsigned type, it is converted to signed type first.
217 * char is treated as if it was signed (regardless of whether it really is)
218 * but the macro's return type is preserved as char.
219 *
220 * Return: an absolute value of x.
221 */
222 #define abs(x) __abs_choose_expr(x, long long, \
223 __abs_choose_expr(x, long, \
224 __abs_choose_expr(x, int, \
225 __abs_choose_expr(x, short, \
226 __abs_choose_expr(x, char, \
227 __builtin_choose_expr( \
228 __builtin_types_compatible_p(typeof(x), char), \
229 (char)({ signed char __x = (x); __x<0?-__x:__x; }), \
230 ((void)0)))))))
231
232 #define __abs_choose_expr(x, type, other) __builtin_choose_expr( \
233 __builtin_types_compatible_p(typeof(x), signed type) || \
234 __builtin_types_compatible_p(typeof(x), unsigned type), \
235 ({ signed type __x = (x); __x < 0 ? -__x : __x; }), other)
236
237 /**
238 * reciprocal_scale - "scale" a value into range [0, ep_ro)
239 * @val: value
240 * @ep_ro: right open interval endpoint
241 *
242 * Perform a "reciprocal multiplication" in order to "scale" a value into
243 * range [0, ep_ro), where the upper interval endpoint is right-open.
244 * This is useful, e.g. for accessing a index of an array containing
245 * ep_ro elements, for example. Think of it as sort of modulus, only that
246 * the result isn't that of modulo. ;) Note that if initial input is a
247 * small value, then result will return 0.
248 *
249 * Return: a result based on val in interval [0, ep_ro).
250 */
251 static inline u32 reciprocal_scale(u32 val, u32 ep_ro)
252 {
253 return (u32)(((u64) val * ep_ro) >> 32);
254 }
255
256 #if defined(CONFIG_MMU) && \
257 (defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP))
258 #define might_fault() __might_fault(__FILE__, __LINE__)
259 void __might_fault(const char *file, int line);
260 #else
261 static inline void might_fault(void) { }
262 #endif
263
264 extern struct atomic_notifier_head panic_notifier_list;
265 extern long (*panic_blink)(int state);
266 __printf(1, 2)
267 void panic(const char *fmt, ...) __noreturn __cold;
268 void nmi_panic(struct pt_regs *regs, const char *msg);
269 extern void oops_enter(void);
270 extern void oops_exit(void);
271 void print_oops_end_marker(void);
272 extern int oops_may_print(void);
273 void do_exit(long error_code) __noreturn;
274 void complete_and_exit(struct completion *, long) __noreturn;
275
276 /* Internal, do not use. */
277 int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res);
278 int __must_check _kstrtol(const char *s, unsigned int base, long *res);
279
280 int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res);
281 int __must_check kstrtoll(const char *s, unsigned int base, long long *res);
282
283 /**
284 * kstrtoul - convert a string to an unsigned long
285 * @s: The start of the string. The string must be null-terminated, and may also
286 * include a single newline before its terminating null. The first character
287 * may also be a plus sign, but not a minus sign.
288 * @base: The number base to use. The maximum supported base is 16. If base is
289 * given as 0, then the base of the string is automatically detected with the
290 * conventional semantics - If it begins with 0x the number will be parsed as a
291 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be
292 * parsed as an octal number. Otherwise it will be parsed as a decimal.
293 * @res: Where to write the result of the conversion on success.
294 *
295 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
296 * Used as a replacement for the obsolete simple_strtoull. Return code must
297 * be checked.
298 */
299 static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res)
300 {
301 /*
302 * We want to shortcut function call, but
303 * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0.
304 */
305 if (sizeof(unsigned long) == sizeof(unsigned long long) &&
306 __alignof__(unsigned long) == __alignof__(unsigned long long))
307 return kstrtoull(s, base, (unsigned long long *)res);
308 else
309 return _kstrtoul(s, base, res);
310 }
311
312 /**
313 * kstrtol - convert a string to a long
314 * @s: The start of the string. The string must be null-terminated, and may also
315 * include a single newline before its terminating null. The first character
316 * may also be a plus sign or a minus sign.
317 * @base: The number base to use. The maximum supported base is 16. If base is
318 * given as 0, then the base of the string is automatically detected with the
319 * conventional semantics - If it begins with 0x the number will be parsed as a
320 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be
321 * parsed as an octal number. Otherwise it will be parsed as a decimal.
322 * @res: Where to write the result of the conversion on success.
323 *
324 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
325 * Used as a replacement for the obsolete simple_strtoull. Return code must
326 * be checked.
327 */
328 static inline int __must_check kstrtol(const char *s, unsigned int base, long *res)
329 {
330 /*
331 * We want to shortcut function call, but
332 * __builtin_types_compatible_p(long, long long) = 0.
333 */
334 if (sizeof(long) == sizeof(long long) &&
335 __alignof__(long) == __alignof__(long long))
336 return kstrtoll(s, base, (long long *)res);
337 else
338 return _kstrtol(s, base, res);
339 }
340
341 int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res);
342 int __must_check kstrtoint(const char *s, unsigned int base, int *res);
343
344 static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res)
345 {
346 return kstrtoull(s, base, res);
347 }
348
349 static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res)
350 {
351 return kstrtoll(s, base, res);
352 }
353
354 static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res)
355 {
356 return kstrtouint(s, base, res);
357 }
358
359 static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res)
360 {
361 return kstrtoint(s, base, res);
362 }
363
364 int __must_check kstrtou16(const char *s, unsigned int base, u16 *res);
365 int __must_check kstrtos16(const char *s, unsigned int base, s16 *res);
366 int __must_check kstrtou8(const char *s, unsigned int base, u8 *res);
367 int __must_check kstrtos8(const char *s, unsigned int base, s8 *res);
368 int __must_check kstrtobool(const char *s, bool *res);
369
370 int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res);
371 int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res);
372 int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res);
373 int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res);
374 int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res);
375 int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res);
376 int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res);
377 int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res);
378 int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res);
379 int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res);
380 int __must_check kstrtobool_from_user(const char __user *s, size_t count, bool *res);
381
382 static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res)
383 {
384 return kstrtoull_from_user(s, count, base, res);
385 }
386
387 static inline int __must_check kstrtos64_from_user(const char __user *s, size_t count, unsigned int base, s64 *res)
388 {
389 return kstrtoll_from_user(s, count, base, res);
390 }
391
392 static inline int __must_check kstrtou32_from_user(const char __user *s, size_t count, unsigned int base, u32 *res)
393 {
394 return kstrtouint_from_user(s, count, base, res);
395 }
396
397 static inline int __must_check kstrtos32_from_user(const char __user *s, size_t count, unsigned int base, s32 *res)
398 {
399 return kstrtoint_from_user(s, count, base, res);
400 }
401
402 /* Obsolete, do not use. Use kstrto<foo> instead */
403
404 extern unsigned long simple_strtoul(const char *,char **,unsigned int);
405 extern long simple_strtol(const char *,char **,unsigned int);
406 extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
407 extern long long simple_strtoll(const char *,char **,unsigned int);
408
409 extern int num_to_str(char *buf, int size, unsigned long long num);
410
411 /* lib/printf utilities */
412
413 extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...);
414 extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list);
415 extern __printf(3, 4)
416 int snprintf(char *buf, size_t size, const char *fmt, ...);
417 extern __printf(3, 0)
418 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args);
419 extern __printf(3, 4)
420 int scnprintf(char *buf, size_t size, const char *fmt, ...);
421 extern __printf(3, 0)
422 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args);
423 extern __printf(2, 3) __malloc
424 char *kasprintf(gfp_t gfp, const char *fmt, ...);
425 extern __printf(2, 0) __malloc
426 char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
427 extern __printf(2, 0)
428 const char *kvasprintf_const(gfp_t gfp, const char *fmt, va_list args);
429
430 extern __scanf(2, 3)
431 int sscanf(const char *, const char *, ...);
432 extern __scanf(2, 0)
433 int vsscanf(const char *, const char *, va_list);
434
435 extern int get_option(char **str, int *pint);
436 extern char *get_options(const char *str, int nints, int *ints);
437 extern unsigned long long memparse(const char *ptr, char **retptr);
438 extern bool parse_option_str(const char *str, const char *option);
439
440 extern int core_kernel_text(unsigned long addr);
441 extern int core_kernel_data(unsigned long addr);
442 extern int __kernel_text_address(unsigned long addr);
443 extern int kernel_text_address(unsigned long addr);
444 extern int func_ptr_is_kernel_text(void *ptr);
445
446 unsigned long int_sqrt(unsigned long);
447
448 extern void bust_spinlocks(int yes);
449 extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */
450 extern int panic_timeout;
451 extern int panic_on_oops;
452 extern int panic_on_unrecovered_nmi;
453 extern int panic_on_io_nmi;
454 extern int panic_on_warn;
455 extern int sysctl_panic_on_rcu_stall;
456 extern int sysctl_panic_on_stackoverflow;
457
458 extern bool crash_kexec_post_notifiers;
459
460 /*
461 * panic_cpu is used for synchronizing panic() and crash_kexec() execution. It
462 * holds a CPU number which is executing panic() currently. A value of
463 * PANIC_CPU_INVALID means no CPU has entered panic() or crash_kexec().
464 */
465 extern atomic_t panic_cpu;
466 #define PANIC_CPU_INVALID -1
467
468 /*
469 * Only to be used by arch init code. If the user over-wrote the default
470 * CONFIG_PANIC_TIMEOUT, honor it.
471 */
472 static inline void set_arch_panic_timeout(int timeout, int arch_default_timeout)
473 {
474 if (panic_timeout == arch_default_timeout)
475 panic_timeout = timeout;
476 }
477 extern const char *print_tainted(void);
478 enum lockdep_ok {
479 LOCKDEP_STILL_OK,
480 LOCKDEP_NOW_UNRELIABLE
481 };
482 extern void add_taint(unsigned flag, enum lockdep_ok);
483 extern int test_taint(unsigned flag);
484 extern unsigned long get_taint(void);
485 extern int root_mountflags;
486
487 extern bool early_boot_irqs_disabled;
488
489 /* Values used for system_state */
490 extern enum system_states {
491 SYSTEM_BOOTING,
492 SYSTEM_RUNNING,
493 SYSTEM_HALT,
494 SYSTEM_POWER_OFF,
495 SYSTEM_RESTART,
496 } system_state;
497
498 #define TAINT_PROPRIETARY_MODULE 0
499 #define TAINT_FORCED_MODULE 1
500 #define TAINT_CPU_OUT_OF_SPEC 2
501 #define TAINT_FORCED_RMMOD 3
502 #define TAINT_MACHINE_CHECK 4
503 #define TAINT_BAD_PAGE 5
504 #define TAINT_USER 6
505 #define TAINT_DIE 7
506 #define TAINT_OVERRIDDEN_ACPI_TABLE 8
507 #define TAINT_WARN 9
508 #define TAINT_CRAP 10
509 #define TAINT_FIRMWARE_WORKAROUND 11
510 #define TAINT_OOT_MODULE 12
511 #define TAINT_UNSIGNED_MODULE 13
512 #define TAINT_SOFTLOCKUP 14
513 #define TAINT_LIVEPATCH 15
514 #define TAINT_FLAGS_COUNT 16
515
516 struct taint_flag {
517 char c_true; /* character printed when tainted */
518 char c_false; /* character printed when not tainted */
519 bool module; /* also show as a per-module taint flag */
520 };
521
522 extern const struct taint_flag taint_flags[TAINT_FLAGS_COUNT];
523
524 extern const char hex_asc[];
525 #define hex_asc_lo(x) hex_asc[((x) & 0x0f)]
526 #define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4]
527
528 static inline char *hex_byte_pack(char *buf, u8 byte)
529 {
530 *buf++ = hex_asc_hi(byte);
531 *buf++ = hex_asc_lo(byte);
532 return buf;
533 }
534
535 extern const char hex_asc_upper[];
536 #define hex_asc_upper_lo(x) hex_asc_upper[((x) & 0x0f)]
537 #define hex_asc_upper_hi(x) hex_asc_upper[((x) & 0xf0) >> 4]
538
539 static inline char *hex_byte_pack_upper(char *buf, u8 byte)
540 {
541 *buf++ = hex_asc_upper_hi(byte);
542 *buf++ = hex_asc_upper_lo(byte);
543 return buf;
544 }
545
546 extern int hex_to_bin(char ch);
547 extern int __must_check hex2bin(u8 *dst, const char *src, size_t count);
548 extern char *bin2hex(char *dst, const void *src, size_t count);
549
550 bool mac_pton(const char *s, u8 *mac);
551
552 /*
553 * General tracing related utility functions - trace_printk(),
554 * tracing_on/tracing_off and tracing_start()/tracing_stop
555 *
556 * Use tracing_on/tracing_off when you want to quickly turn on or off
557 * tracing. It simply enables or disables the recording of the trace events.
558 * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on
559 * file, which gives a means for the kernel and userspace to interact.
560 * Place a tracing_off() in the kernel where you want tracing to end.
561 * From user space, examine the trace, and then echo 1 > tracing_on
562 * to continue tracing.
563 *
564 * tracing_stop/tracing_start has slightly more overhead. It is used
565 * by things like suspend to ram where disabling the recording of the
566 * trace is not enough, but tracing must actually stop because things
567 * like calling smp_processor_id() may crash the system.
568 *
569 * Most likely, you want to use tracing_on/tracing_off.
570 */
571
572 enum ftrace_dump_mode {
573 DUMP_NONE,
574 DUMP_ALL,
575 DUMP_ORIG,
576 };
577
578 #ifdef CONFIG_TRACING
579 void tracing_on(void);
580 void tracing_off(void);
581 int tracing_is_on(void);
582 void tracing_snapshot(void);
583 void tracing_snapshot_alloc(void);
584
585 extern void tracing_start(void);
586 extern void tracing_stop(void);
587
588 static inline __printf(1, 2)
589 void ____trace_printk_check_format(const char *fmt, ...)
590 {
591 }
592 #define __trace_printk_check_format(fmt, args...) \
593 do { \
594 if (0) \
595 ____trace_printk_check_format(fmt, ##args); \
596 } while (0)
597
598 /**
599 * trace_printk - printf formatting in the ftrace buffer
600 * @fmt: the printf format for printing
601 *
602 * Note: __trace_printk is an internal function for trace_printk and
603 * the @ip is passed in via the trace_printk macro.
604 *
605 * This function allows a kernel developer to debug fast path sections
606 * that printk is not appropriate for. By scattering in various
607 * printk like tracing in the code, a developer can quickly see
608 * where problems are occurring.
609 *
610 * This is intended as a debugging tool for the developer only.
611 * Please refrain from leaving trace_printks scattered around in
612 * your code. (Extra memory is used for special buffers that are
613 * allocated when trace_printk() is used)
614 *
615 * A little optization trick is done here. If there's only one
616 * argument, there's no need to scan the string for printf formats.
617 * The trace_puts() will suffice. But how can we take advantage of
618 * using trace_puts() when trace_printk() has only one argument?
619 * By stringifying the args and checking the size we can tell
620 * whether or not there are args. __stringify((__VA_ARGS__)) will
621 * turn into "()\0" with a size of 3 when there are no args, anything
622 * else will be bigger. All we need to do is define a string to this,
623 * and then take its size and compare to 3. If it's bigger, use
624 * do_trace_printk() otherwise, optimize it to trace_puts(). Then just
625 * let gcc optimize the rest.
626 */
627
628 #define trace_printk(fmt, ...) \
629 do { \
630 char _______STR[] = __stringify((__VA_ARGS__)); \
631 if (sizeof(_______STR) > 3) \
632 do_trace_printk(fmt, ##__VA_ARGS__); \
633 else \
634 trace_puts(fmt); \
635 } while (0)
636
637 #define do_trace_printk(fmt, args...) \
638 do { \
639 static const char *trace_printk_fmt __used \
640 __attribute__((section("__trace_printk_fmt"))) = \
641 __builtin_constant_p(fmt) ? fmt : NULL; \
642 \
643 __trace_printk_check_format(fmt, ##args); \
644 \
645 if (__builtin_constant_p(fmt)) \
646 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \
647 else \
648 __trace_printk(_THIS_IP_, fmt, ##args); \
649 } while (0)
650
651 extern __printf(2, 3)
652 int __trace_bprintk(unsigned long ip, const char *fmt, ...);
653
654 extern __printf(2, 3)
655 int __trace_printk(unsigned long ip, const char *fmt, ...);
656
657 /**
658 * trace_puts - write a string into the ftrace buffer
659 * @str: the string to record
660 *
661 * Note: __trace_bputs is an internal function for trace_puts and
662 * the @ip is passed in via the trace_puts macro.
663 *
664 * This is similar to trace_printk() but is made for those really fast
665 * paths that a developer wants the least amount of "Heisenbug" affects,
666 * where the processing of the print format is still too much.
667 *
668 * This function allows a kernel developer to debug fast path sections
669 * that printk is not appropriate for. By scattering in various
670 * printk like tracing in the code, a developer can quickly see
671 * where problems are occurring.
672 *
673 * This is intended as a debugging tool for the developer only.
674 * Please refrain from leaving trace_puts scattered around in
675 * your code. (Extra memory is used for special buffers that are
676 * allocated when trace_puts() is used)
677 *
678 * Returns: 0 if nothing was written, positive # if string was.
679 * (1 when __trace_bputs is used, strlen(str) when __trace_puts is used)
680 */
681
682 #define trace_puts(str) ({ \
683 static const char *trace_printk_fmt __used \
684 __attribute__((section("__trace_printk_fmt"))) = \
685 __builtin_constant_p(str) ? str : NULL; \
686 \
687 if (__builtin_constant_p(str)) \
688 __trace_bputs(_THIS_IP_, trace_printk_fmt); \
689 else \
690 __trace_puts(_THIS_IP_, str, strlen(str)); \
691 })
692 extern int __trace_bputs(unsigned long ip, const char *str);
693 extern int __trace_puts(unsigned long ip, const char *str, int size);
694
695 extern void trace_dump_stack(int skip);
696
697 /*
698 * The double __builtin_constant_p is because gcc will give us an error
699 * if we try to allocate the static variable to fmt if it is not a
700 * constant. Even with the outer if statement.
701 */
702 #define ftrace_vprintk(fmt, vargs) \
703 do { \
704 if (__builtin_constant_p(fmt)) { \
705 static const char *trace_printk_fmt __used \
706 __attribute__((section("__trace_printk_fmt"))) = \
707 __builtin_constant_p(fmt) ? fmt : NULL; \
708 \
709 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \
710 } else \
711 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \
712 } while (0)
713
714 extern __printf(2, 0) int
715 __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
716
717 extern __printf(2, 0) int
718 __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
719
720 extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode);
721 #else
722 static inline void tracing_start(void) { }
723 static inline void tracing_stop(void) { }
724 static inline void trace_dump_stack(int skip) { }
725
726 static inline void tracing_on(void) { }
727 static inline void tracing_off(void) { }
728 static inline int tracing_is_on(void) { return 0; }
729 static inline void tracing_snapshot(void) { }
730 static inline void tracing_snapshot_alloc(void) { }
731
732 static inline __printf(1, 2)
733 int trace_printk(const char *fmt, ...)
734 {
735 return 0;
736 }
737 static __printf(1, 0) inline int
738 ftrace_vprintk(const char *fmt, va_list ap)
739 {
740 return 0;
741 }
742 static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
743 #endif /* CONFIG_TRACING */
744
745 /*
746 * min()/max()/clamp() macros that also do
747 * strict type-checking.. See the
748 * "unnecessary" pointer comparison.
749 */
750 #define __min(t1, t2, min1, min2, x, y) ({ \
751 t1 min1 = (x); \
752 t2 min2 = (y); \
753 (void) (&min1 == &min2); \
754 min1 < min2 ? min1 : min2; })
755 #define min(x, y) \
756 __min(typeof(x), typeof(y), \
757 __UNIQUE_ID(min1_), __UNIQUE_ID(min2_), \
758 x, y)
759
760 #define __max(t1, t2, max1, max2, x, y) ({ \
761 t1 max1 = (x); \
762 t2 max2 = (y); \
763 (void) (&max1 == &max2); \
764 max1 > max2 ? max1 : max2; })
765 #define max(x, y) \
766 __max(typeof(x), typeof(y), \
767 __UNIQUE_ID(max1_), __UNIQUE_ID(max2_), \
768 x, y)
769
770 #define min3(x, y, z) min((typeof(x))min(x, y), z)
771 #define max3(x, y, z) max((typeof(x))max(x, y), z)
772
773 /**
774 * min_not_zero - return the minimum that is _not_ zero, unless both are zero
775 * @x: value1
776 * @y: value2
777 */
778 #define min_not_zero(x, y) ({ \
779 typeof(x) __x = (x); \
780 typeof(y) __y = (y); \
781 __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); })
782
783 /**
784 * clamp - return a value clamped to a given range with strict typechecking
785 * @val: current value
786 * @lo: lowest allowable value
787 * @hi: highest allowable value
788 *
789 * This macro does strict typechecking of lo/hi to make sure they are of the
790 * same type as val. See the unnecessary pointer comparisons.
791 */
792 #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi)
793
794 /*
795 * ..and if you can't take the strict
796 * types, you can specify one yourself.
797 *
798 * Or not use min/max/clamp at all, of course.
799 */
800 #define min_t(type, x, y) \
801 __min(type, type, \
802 __UNIQUE_ID(min1_), __UNIQUE_ID(min2_), \
803 x, y)
804
805 #define max_t(type, x, y) \
806 __max(type, type, \
807 __UNIQUE_ID(min1_), __UNIQUE_ID(min2_), \
808 x, y)
809
810 /**
811 * clamp_t - return a value clamped to a given range using a given type
812 * @type: the type of variable to use
813 * @val: current value
814 * @lo: minimum allowable value
815 * @hi: maximum allowable value
816 *
817 * This macro does no typechecking and uses temporary variables of type
818 * 'type' to make all the comparisons.
819 */
820 #define clamp_t(type, val, lo, hi) min_t(type, max_t(type, val, lo), hi)
821
822 /**
823 * clamp_val - return a value clamped to a given range using val's type
824 * @val: current value
825 * @lo: minimum allowable value
826 * @hi: maximum allowable value
827 *
828 * This macro does no typechecking and uses temporary variables of whatever
829 * type the input argument 'val' is. This is useful when val is an unsigned
830 * type and min and max are literals that will otherwise be assigned a signed
831 * integer type.
832 */
833 #define clamp_val(val, lo, hi) clamp_t(typeof(val), val, lo, hi)
834
835
836 /*
837 * swap - swap value of @a and @b
838 */
839 #define swap(a, b) \
840 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
841
842 /**
843 * container_of - cast a member of a structure out to the containing structure
844 * @ptr: the pointer to the member.
845 * @type: the type of the container struct this is embedded in.
846 * @member: the name of the member within the struct.
847 *
848 */
849 #define container_of(ptr, type, member) ({ \
850 const typeof( ((type *)0)->member ) *__mptr = (ptr); \
851 (type *)( (char *)__mptr - offsetof(type,member) );})
852
853 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
854 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
855 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
856 #endif
857
858 /* Permissions on a sysfs file: you didn't miss the 0 prefix did you? */
859 #define VERIFY_OCTAL_PERMISSIONS(perms) \
860 (BUILD_BUG_ON_ZERO((perms) < 0) + \
861 BUILD_BUG_ON_ZERO((perms) > 0777) + \
862 /* USER_READABLE >= GROUP_READABLE >= OTHER_READABLE */ \
863 BUILD_BUG_ON_ZERO((((perms) >> 6) & 4) < (((perms) >> 3) & 4)) + \
864 BUILD_BUG_ON_ZERO((((perms) >> 3) & 4) < ((perms) & 4)) + \
865 /* USER_WRITABLE >= GROUP_WRITABLE */ \
866 BUILD_BUG_ON_ZERO((((perms) >> 6) & 2) < (((perms) >> 3) & 2)) + \
867 /* OTHER_WRITABLE? Generally considered a bad idea. */ \
868 BUILD_BUG_ON_ZERO((perms) & 2) + \
869 (perms))
870 #endif