1 #ifndef _LINUX_KERNEL_H
2 #define _LINUX_KERNEL_H
3
4
5 #include <stdarg.h>
6 #include <linux/linkage.h>
7 #include <linux/stddef.h>
8 #include <linux/types.h>
9 #include <linux/compiler.h>
10 #include <linux/bitops.h>
11 #include <linux/log2.h>
12 #include <linux/typecheck.h>
13 #include <linux/printk.h>
14 #include <linux/dynamic_debug.h>
15 #include <asm/byteorder.h>
16 #include <uapi/linux/kernel.h>
17
18 #define USHRT_MAX ((u16)(~0U))
19 #define SHRT_MAX ((s16)(USHRT_MAX>>1))
20 #define SHRT_MIN ((s16)(-SHRT_MAX - 1))
21 #define INT_MAX ((int)(~0U>>1))
22 #define INT_MIN (-INT_MAX - 1)
23 #define UINT_MAX (~0U)
24 #define LONG_MAX ((long)(~0UL>>1))
25 #define LONG_MIN (-LONG_MAX - 1)
26 #define ULONG_MAX (~0UL)
27 #define LLONG_MAX ((long long)(~0ULL>>1))
28 #define LLONG_MIN (-LLONG_MAX - 1)
29 #define ULLONG_MAX (~0ULL)
30 #define SIZE_MAX (~(size_t)0)
31
32 #define U8_MAX ((u8)~0U)
33 #define S8_MAX ((s8)(U8_MAX>>1))
34 #define S8_MIN ((s8)(-S8_MAX - 1))
35 #define U16_MAX ((u16)~0U)
36 #define S16_MAX ((s16)(U16_MAX>>1))
37 #define S16_MIN ((s16)(-S16_MAX - 1))
38 #define U32_MAX ((u32)~0U)
39 #define S32_MAX ((s32)(U32_MAX>>1))
40 #define S32_MIN ((s32)(-S32_MAX - 1))
41 #define U64_MAX ((u64)~0ULL)
42 #define S64_MAX ((s64)(U64_MAX>>1))
43 #define S64_MIN ((s64)(-S64_MAX - 1))
44
45 #define STACK_MAGIC 0xdeadbeef
46
47 #define REPEAT_BYTE(x) ((~0ul / 0xff) * (x))
48
49 #define ALIGN(x, a) __ALIGN_KERNEL((x), (a))
50 #define __ALIGN_MASK(x, mask) __ALIGN_KERNEL_MASK((x), (mask))
51 #define PTR_ALIGN(p, a) ((typeof(p))ALIGN((unsigned long)(p), (a)))
52 #define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0)
53
54 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
55
56 /*
57 * This looks more complex than it should be. But we need to
58 * get the type for the ~ right in round_down (it needs to be
59 * as wide as the result!), and we want to evaluate the macro
60 * arguments just once each.
61 */
62 #define __round_mask(x, y) ((__typeof__(x))((y)-1))
63 #define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
64 #define round_down(x, y) ((x) & ~__round_mask(x, y))
65
66 #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
67 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
68 #define DIV_ROUND_UP_ULL(ll,d) \
69 ({ unsigned long long _tmp = (ll)+(d)-1; do_div(_tmp, d); _tmp; })
70
71 #if BITS_PER_LONG == 32
72 # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP_ULL(ll, d)
73 #else
74 # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP(ll,d)
75 #endif
76
77 /* The `const' in roundup() prevents gcc-3.3 from calling __divdi3 */
78 #define roundup(x, y) ( \
79 { \
80 const typeof(y) __y = y; \
81 (((x) + (__y - 1)) / __y) * __y; \
82 } \
83 )
84 #define rounddown(x, y) ( \
85 { \
86 typeof(x) __x = (x); \
87 __x - (__x % (y)); \
88 } \
89 )
90
91 /*
92 * Divide positive or negative dividend by positive divisor and round
93 * to closest integer. Result is undefined for negative divisors and
94 * for negative dividends if the divisor variable type is unsigned.
95 */
96 #define DIV_ROUND_CLOSEST(x, divisor)( \
97 { \
98 typeof(x) __x = x; \
99 typeof(divisor) __d = divisor; \
100 (((typeof(x))-1) > 0 || \
101 ((typeof(divisor))-1) > 0 || (__x) > 0) ? \
102 (((__x) + ((__d) / 2)) / (__d)) : \
103 (((__x) - ((__d) / 2)) / (__d)); \
104 } \
105 )
106 /*
107 * Same as above but for u64 dividends. divisor must be a 32-bit
108 * number.
109 */
110 #define DIV_ROUND_CLOSEST_ULL(x, divisor)( \
111 { \
112 typeof(divisor) __d = divisor; \
113 unsigned long long _tmp = (x) + (__d) / 2; \
114 do_div(_tmp, __d); \
115 _tmp; \
116 } \
117 )
118
119 /*
120 * Multiplies an integer by a fraction, while avoiding unnecessary
121 * overflow or loss of precision.
122 */
123 #define mult_frac(x, numer, denom)( \
124 { \
125 typeof(x) quot = (x) / (denom); \
126 typeof(x) rem = (x) % (denom); \
127 (quot * (numer)) + ((rem * (numer)) / (denom)); \
128 } \
129 )
130
131
132 #define _RET_IP_ (unsigned long)__builtin_return_address(0)
133 #define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; })
134
135 #ifdef CONFIG_LBDAF
136 # include <asm/div64.h>
137 # define sector_div(a, b) do_div(a, b)
138 #else
139 # define sector_div(n, b)( \
140 { \
141 int _res; \
142 _res = (n) % (b); \
143 (n) /= (b); \
144 _res; \
145 } \
146 )
147 #endif
148
149 /**
150 * upper_32_bits - return bits 32-63 of a number
151 * @n: the number we're accessing
152 *
153 * A basic shift-right of a 64- or 32-bit quantity. Use this to suppress
154 * the "right shift count >= width of type" warning when that quantity is
155 * 32-bits.
156 */
157 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
158
159 /**
160 * lower_32_bits - return bits 0-31 of a number
161 * @n: the number we're accessing
162 */
163 #define lower_32_bits(n) ((u32)(n))
164
165 struct completion;
166 struct pt_regs;
167 struct user;
168
169 #ifdef CONFIG_PREEMPT_VOLUNTARY
170 extern int _cond_resched(void);
171 # define might_resched() _cond_resched()
172 #else
173 # define might_resched() do { } while (0)
174 #endif
175
176 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
177 void ___might_sleep(const char *file, int line, int preempt_offset);
178 void __might_sleep(const char *file, int line, int preempt_offset);
179 /**
180 * might_sleep - annotation for functions that can sleep
181 *
182 * this macro will print a stack trace if it is executed in an atomic
183 * context (spinlock, irq-handler, ...).
184 *
185 * This is a useful debugging help to be able to catch problems early and not
186 * be bitten later when the calling function happens to sleep when it is not
187 * supposed to.
188 */
189 # define might_sleep() \
190 do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
191 # define sched_annotate_sleep() (current->task_state_change = 0)
192 #else
193 static inline void ___might_sleep(const char *file, int line,
194 int preempt_offset) { }
195 static inline void __might_sleep(const char *file, int line,
196 int preempt_offset) { }
197 # define might_sleep() do { might_resched(); } while (0)
198 # define sched_annotate_sleep() do { } while (0)
199 #endif
200
201 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
202
203 /**
204 * abs - return absolute value of an argument
205 * @x: the value. If it is unsigned type, it is converted to signed type first.
206 * char is treated as if it was signed (regardless of whether it really is)
207 * but the macro's return type is preserved as char.
208 *
209 * Return: an absolute value of x.
210 */
211 #define abs(x) __abs_choose_expr(x, long long, \
212 __abs_choose_expr(x, long, \
213 __abs_choose_expr(x, int, \
214 __abs_choose_expr(x, short, \
215 __abs_choose_expr(x, char, \
216 __builtin_choose_expr( \
217 __builtin_types_compatible_p(typeof(x), char), \
218 (char)({ signed char __x = (x); __x<0?-__x:__x; }), \
219 ((void)0)))))))
220
221 #define __abs_choose_expr(x, type, other) __builtin_choose_expr( \
222 __builtin_types_compatible_p(typeof(x), signed type) || \
223 __builtin_types_compatible_p(typeof(x), unsigned type), \
224 ({ signed type __x = (x); __x < 0 ? -__x : __x; }), other)
225
226 /**
227 * reciprocal_scale - "scale" a value into range [0, ep_ro)
228 * @val: value
229 * @ep_ro: right open interval endpoint
230 *
231 * Perform a "reciprocal multiplication" in order to "scale" a value into
232 * range [0, ep_ro), where the upper interval endpoint is right-open.
233 * This is useful, e.g. for accessing a index of an array containing
234 * ep_ro elements, for example. Think of it as sort of modulus, only that
235 * the result isn't that of modulo. ;) Note that if initial input is a
236 * small value, then result will return 0.
237 *
238 * Return: a result based on val in interval [0, ep_ro).
239 */
240 static inline u32 reciprocal_scale(u32 val, u32 ep_ro)
241 {
242 return (u32)(((u64) val * ep_ro) >> 32);
243 }
244
245 #if defined(CONFIG_MMU) && \
246 (defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP))
247 #define might_fault() __might_fault(__FILE__, __LINE__)
248 void __might_fault(const char *file, int line);
249 #else
250 static inline void might_fault(void) { }
251 #endif
252
253 extern struct atomic_notifier_head panic_notifier_list;
254 extern long (*panic_blink)(int state);
255 __printf(1, 2)
256 void panic(const char *fmt, ...)
257 __noreturn __cold;
258 extern void oops_enter(void);
259 extern void oops_exit(void);
260 void print_oops_end_marker(void);
261 extern int oops_may_print(void);
262 void do_exit(long error_code)
263 __noreturn;
264 void complete_and_exit(struct completion *, long)
265 __noreturn;
266
267 /* Internal, do not use. */
268 int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res);
269 int __must_check _kstrtol(const char *s, unsigned int base, long *res);
270
271 int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res);
272 int __must_check kstrtoll(const char *s, unsigned int base, long long *res);
273
274 /**
275 * kstrtoul - convert a string to an unsigned long
276 * @s: The start of the string. The string must be null-terminated, and may also
277 * include a single newline before its terminating null. The first character
278 * may also be a plus sign, but not a minus sign.
279 * @base: The number base to use. The maximum supported base is 16. If base is
280 * given as 0, then the base of the string is automatically detected with the
281 * conventional semantics - If it begins with 0x the number will be parsed as a
282 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be
283 * parsed as an octal number. Otherwise it will be parsed as a decimal.
284 * @res: Where to write the result of the conversion on success.
285 *
286 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
287 * Used as a replacement for the obsolete simple_strtoull. Return code must
288 * be checked.
289 */
290 static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res)
291 {
292 /*
293 * We want to shortcut function call, but
294 * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0.
295 */
296 if (sizeof(unsigned long) == sizeof(unsigned long long) &&
297 __alignof__(unsigned long) == __alignof__(unsigned long long))
298 return kstrtoull(s, base, (unsigned long long *)res);
299 else
300 return _kstrtoul(s, base, res);
301 }
302
303 /**
304 * kstrtol - convert a string to a long
305 * @s: The start of the string. The string must be null-terminated, and may also
306 * include a single newline before its terminating null. The first character
307 * may also be a plus sign or a minus sign.
308 * @base: The number base to use. The maximum supported base is 16. If base is
309 * given as 0, then the base of the string is automatically detected with the
310 * conventional semantics - If it begins with 0x the number will be parsed as a
311 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be
312 * parsed as an octal number. Otherwise it will be parsed as a decimal.
313 * @res: Where to write the result of the conversion on success.
314 *
315 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
316 * Used as a replacement for the obsolete simple_strtoull. Return code must
317 * be checked.
318 */
319 static inline int __must_check kstrtol(const char *s, unsigned int base, long *res)
320 {
321 /*
322 * We want to shortcut function call, but
323 * __builtin_types_compatible_p(long, long long) = 0.
324 */
325 if (sizeof(long) == sizeof(long long) &&
326 __alignof__(long) == __alignof__(long long))
327 return kstrtoll(s, base, (long long *)res);
328 else
329 return _kstrtol(s, base, res);
330 }
331
332 int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res);
333 int __must_check kstrtoint(const char *s, unsigned int base, int *res);
334
335 static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res)
336 {
337 return kstrtoull(s, base, res);
338 }
339
340 static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res)
341 {
342 return kstrtoll(s, base, res);
343 }
344
345 static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res)
346 {
347 return kstrtouint(s, base, res);
348 }
349
350 static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res)
351 {
352 return kstrtoint(s, base, res);
353 }
354
355 int __must_check kstrtou16(const char *s, unsigned int base, u16 *res);
356 int __must_check kstrtos16(const char *s, unsigned int base, s16 *res);
357 int __must_check kstrtou8(const char *s, unsigned int base, u8 *res);
358 int __must_check kstrtos8(const char *s, unsigned int base, s8 *res);
359 int __must_check kstrtobool(const char *s, bool *res);
360
361 int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res);
362 int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res);
363 int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res);
364 int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res);
365 int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res);
366 int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res);
367 int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res);
368 int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res);
369 int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res);
370 int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res);
371 int __must_check kstrtobool_from_user(const char __user *s, size_t count, bool *res);
372
373 static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res)
374 {
375 return kstrtoull_from_user(s, count, base, res);
376 }
377
378 static inline int __must_check kstrtos64_from_user(const char __user *s, size_t count, unsigned int base, s64 *res)
379 {
380 return kstrtoll_from_user(s, count, base, res);
381 }
382
383 static inline int __must_check kstrtou32_from_user(const char __user *s, size_t count, unsigned int base, u32 *res)
384 {
385 return kstrtouint_from_user(s, count, base, res);
386 }
387
388 static inline int __must_check kstrtos32_from_user(const char __user *s, size_t count, unsigned int base, s32 *res)
389 {
390 return kstrtoint_from_user(s, count, base, res);
391 }
392
393 /* Obsolete, do not use. Use kstrto<foo> instead */
394
395 extern unsigned long simple_strtoul(const char *,char **,unsigned int);
396 extern long simple_strtol(const char *,char **,unsigned int);
397 extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
398 extern long long simple_strtoll(const char *,char **,unsigned int);
399
400 extern int num_to_str(char *buf, int size, unsigned long long num);
401
402 /* lib/printf utilities */
403
404 extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...);
405 extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list);
406 extern __printf(3, 4)
407 int snprintf(char *buf, size_t size, const char *fmt, ...);
408 extern __printf(3, 0)
409 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args);
410 extern __printf(3, 4)
411 int scnprintf(char *buf, size_t size, const char *fmt, ...);
412 extern __printf(3, 0)
413 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args);
414 extern __printf(2, 3)
415 char *kasprintf(gfp_t gfp, const char *fmt, ...);
416 extern __printf(2, 0)
417 char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
418 extern __printf(2, 0)
419 const char *kvasprintf_const(gfp_t gfp, const char *fmt, va_list args);
420
421 extern __scanf(2, 3)
422 int sscanf(const char *, const char *, ...);
423 extern __scanf(2, 0)
424 int vsscanf(const char *, const char *, va_list);
425
426 extern int get_option(char **str, int *pint);
427 extern char *get_options(const char *str, int nints, int *ints);
428 extern unsigned long long memparse(const char *ptr, char **retptr);
429 extern bool parse_option_str(const char *str, const char *option);
430
431 extern int core_kernel_text(unsigned long addr);
432 extern int core_kernel_data(unsigned long addr);
433 extern int __kernel_text_address(unsigned long addr);
434 extern int kernel_text_address(unsigned long addr);
435 extern int func_ptr_is_kernel_text(void *ptr);
436
437 unsigned long int_sqrt(unsigned long);
438
439 extern void bust_spinlocks(int yes);
440 extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */
441 extern int panic_timeout;
442 extern int panic_on_oops;
443 extern int panic_on_unrecovered_nmi;
444 extern int panic_on_io_nmi;
445 extern int panic_on_warn;
446 extern int sysctl_panic_on_stackoverflow;
447
448 extern bool crash_kexec_post_notifiers;
449
450 /*
451 * Only to be used by arch init code. If the user over-wrote the default
452 * CONFIG_PANIC_TIMEOUT, honor it.
453 */
454 static inline void set_arch_panic_timeout(int timeout, int arch_default_timeout)
455 {
456 if (panic_timeout == arch_default_timeout)
457 panic_timeout = timeout;
458 }
459 extern const char *print_tainted(void);
460 enum lockdep_ok {
461 LOCKDEP_STILL_OK,
462 LOCKDEP_NOW_UNRELIABLE
463 };
464 extern void add_taint(unsigned flag, enum lockdep_ok);
465 extern int test_taint(unsigned flag);
466 extern unsigned long get_taint(void);
467 extern int root_mountflags;
468
469 extern bool early_boot_irqs_disabled;
470
471 /* Values used for system_state */
472 extern enum system_states {
473 SYSTEM_BOOTING,
474 SYSTEM_RUNNING,
475 SYSTEM_HALT,
476 SYSTEM_POWER_OFF,
477 SYSTEM_RESTART,
478 } system_state;
479
480 #define TAINT_PROPRIETARY_MODULE 0
481 #define TAINT_FORCED_MODULE 1
482 #define TAINT_CPU_OUT_OF_SPEC 2
483 #define TAINT_FORCED_RMMOD 3
484 #define TAINT_MACHINE_CHECK 4
485 #define TAINT_BAD_PAGE 5
486 #define TAINT_USER 6
487 #define TAINT_DIE 7
488 #define TAINT_OVERRIDDEN_ACPI_TABLE 8
489 #define TAINT_WARN 9
490 #define TAINT_CRAP 10
491 #define TAINT_FIRMWARE_WORKAROUND 11
492 #define TAINT_OOT_MODULE 12
493 #define TAINT_UNSIGNED_MODULE 13
494 #define TAINT_SOFTLOCKUP 14
495 #define TAINT_LIVEPATCH 15
496
497 extern const char hex_asc[];
498 #define hex_asc_lo(x) hex_asc[((x) & 0x0f)]
499 #define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4]
500
501 static inline char *hex_byte_pack(char *buf, u8 byte)
502 {
503 *buf++ = hex_asc_hi(byte);
504 *buf++ = hex_asc_lo(byte);
505 return buf;
506 }
507
508 extern const char hex_asc_upper[];
509 #define hex_asc_upper_lo(x) hex_asc_upper[((x) & 0x0f)]
510 #define hex_asc_upper_hi(x) hex_asc_upper[((x) & 0xf0) >> 4]
511
512 static inline char *hex_byte_pack_upper(char *buf, u8 byte)
513 {
514 *buf++ = hex_asc_upper_hi(byte);
515 *buf++ = hex_asc_upper_lo(byte);
516 return buf;
517 }
518
519 extern int hex_to_bin(char ch);
520 extern int __must_check hex2bin(u8 *dst, const char *src, size_t count);
521 extern char *bin2hex(char *dst, const void *src, size_t count);
522
523 bool mac_pton(const char *s, u8 *mac);
524
525 /*
526 * General tracing related utility functions - trace_printk(),
527 * tracing_on/tracing_off and tracing_start()/tracing_stop
528 *
529 * Use tracing_on/tracing_off when you want to quickly turn on or off
530 * tracing. It simply enables or disables the recording of the trace events.
531 * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on
532 * file, which gives a means for the kernel and userspace to interact.
533 * Place a tracing_off() in the kernel where you want tracing to end.
534 * From user space, examine the trace, and then echo 1 > tracing_on
535 * to continue tracing.
536 *
537 * tracing_stop/tracing_start has slightly more overhead. It is used
538 * by things like suspend to ram where disabling the recording of the
539 * trace is not enough, but tracing must actually stop because things
540 * like calling smp_processor_id() may crash the system.
541 *
542 * Most likely, you want to use tracing_on/tracing_off.
543 */
544
545 enum ftrace_dump_mode {
546 DUMP_NONE,
547 DUMP_ALL,
548 DUMP_ORIG,
549 };
550
551 #ifdef CONFIG_TRACING
552 void tracing_on(void);
553 void tracing_off(void);
554 int tracing_is_on(void);
555 void tracing_snapshot(void);
556 void tracing_snapshot_alloc(void);
557
558 extern void tracing_start(void);
559 extern void tracing_stop(void);
560
561 static inline __printf(1, 2)
562 void ____trace_printk_check_format(const char *fmt, ...)
563 {
564 }
565 #define __trace_printk_check_format(fmt, args...) \
566 do { \
567 if (0) \
568 ____trace_printk_check_format(fmt, ##args); \
569 } while (0)
570
571 /**
572 * trace_printk - printf formatting in the ftrace buffer
573 * @fmt: the printf format for printing
574 *
575 * Note: __trace_printk is an internal function for trace_printk and
576 * the @ip is passed in via the trace_printk macro.
577 *
578 * This function allows a kernel developer to debug fast path sections
579 * that printk is not appropriate for. By scattering in various
580 * printk like tracing in the code, a developer can quickly see
581 * where problems are occurring.
582 *
583 * This is intended as a debugging tool for the developer only.
584 * Please refrain from leaving trace_printks scattered around in
585 * your code. (Extra memory is used for special buffers that are
586 * allocated when trace_printk() is used)
587 *
588 * A little optization trick is done here. If there's only one
589 * argument, there's no need to scan the string for printf formats.
590 * The trace_puts() will suffice. But how can we take advantage of
591 * using trace_puts() when trace_printk() has only one argument?
592 * By stringifying the args and checking the size we can tell
593 * whether or not there are args. __stringify((__VA_ARGS__)) will
594 * turn into "()\0" with a size of 3 when there are no args, anything
595 * else will be bigger. All we need to do is define a string to this,
596 * and then take its size and compare to 3. If it's bigger, use
597 * do_trace_printk() otherwise, optimize it to trace_puts(). Then just
598 * let gcc optimize the rest.
599 */
600
601 #define trace_printk(fmt, ...) \
602 do { \
603 char _______STR[] = __stringify((__VA_ARGS__)); \
604 if (sizeof(_______STR) > 3) \
605 do_trace_printk(fmt, ##__VA_ARGS__); \
606 else \
607 trace_puts(fmt); \
608 } while (0)
609
610 #define do_trace_printk(fmt, args...) \
611 do { \
612 static const char *trace_printk_fmt __used \
613 __attribute__((section("__trace_printk_fmt"))) = \
614 __builtin_constant_p(fmt) ? fmt : NULL; \
615 \
616 __trace_printk_check_format(fmt, ##args); \
617 \
618 if (__builtin_constant_p(fmt)) \
619 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \
620 else \
621 __trace_printk(_THIS_IP_, fmt, ##args); \
622 } while (0)
623
624 extern __printf(2, 3)
625 int __trace_bprintk(unsigned long ip, const char *fmt, ...);
626
627 extern __printf(2, 3)
628 int __trace_printk(unsigned long ip, const char *fmt, ...);
629
630 /**
631 * trace_puts - write a string into the ftrace buffer
632 * @str: the string to record
633 *
634 * Note: __trace_bputs is an internal function for trace_puts and
635 * the @ip is passed in via the trace_puts macro.
636 *
637 * This is similar to trace_printk() but is made for those really fast
638 * paths that a developer wants the least amount of "Heisenbug" affects,
639 * where the processing of the print format is still too much.
640 *
641 * This function allows a kernel developer to debug fast path sections
642 * that printk is not appropriate for. By scattering in various
643 * printk like tracing in the code, a developer can quickly see
644 * where problems are occurring.
645 *
646 * This is intended as a debugging tool for the developer only.
647 * Please refrain from leaving trace_puts scattered around in
648 * your code. (Extra memory is used for special buffers that are
649 * allocated when trace_puts() is used)
650 *
651 * Returns: 0 if nothing was written, positive # if string was.
652 * (1 when __trace_bputs is used, strlen(str) when __trace_puts is used)
653 */
654
655 #define trace_puts(str) ({ \
656 static const char *trace_printk_fmt __used \
657 __attribute__((section("__trace_printk_fmt"))) = \
658 __builtin_constant_p(str) ? str : NULL; \
659 \
660 if (__builtin_constant_p(str)) \
661 __trace_bputs(_THIS_IP_, trace_printk_fmt); \
662 else \
663 __trace_puts(_THIS_IP_, str, strlen(str)); \
664 })
665 extern int __trace_bputs(unsigned long ip, const char *str);
666 extern int __trace_puts(unsigned long ip, const char *str, int size);
667
668 extern void trace_dump_stack(int skip);
669
670 /*
671 * The double __builtin_constant_p is because gcc will give us an error
672 * if we try to allocate the static variable to fmt if it is not a
673 * constant. Even with the outer if statement.
674 */
675 #define ftrace_vprintk(fmt, vargs) \
676 do { \
677 if (__builtin_constant_p(fmt)) { \
678 static const char *trace_printk_fmt __used \
679 __attribute__((section("__trace_printk_fmt"))) = \
680 __builtin_constant_p(fmt) ? fmt : NULL; \
681 \
682 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \
683 } else \
684 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \
685 } while (0)
686
687 extern __printf(2, 0) int
688 __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
689
690 extern __printf(2, 0) int
691 __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
692
693 extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode);
694 #else
695 static inline void tracing_start(void) { }
696 static inline void tracing_stop(void) { }
697 static inline void trace_dump_stack(int skip) { }
698
699 static inline void tracing_on(void) { }
700 static inline void tracing_off(void) { }
701 static inline int tracing_is_on(void) { return 0; }
702 static inline void tracing_snapshot(void) { }
703 static inline void tracing_snapshot_alloc(void) { }
704
705 static inline __printf(1, 2)
706 int trace_printk(const char *fmt, ...)
707 {
708 return 0;
709 }
710 static __printf(1, 0) inline int
711 ftrace_vprintk(const char *fmt, va_list ap)
712 {
713 return 0;
714 }
715 static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
716 #endif /* CONFIG_TRACING */
717
718 /*
719 * min()/max()/clamp() macros that also do
720 * strict type-checking.. See the
721 * "unnecessary" pointer comparison.
722 */
723 #define min(x, y) ({ \
724 typeof(x) _min1 = (x); \
725 typeof(y) _min2 = (y); \
726 (void) (&_min1 == &_min2); \
727 _min1 < _min2 ? _min1 : _min2; })
728
729 #define max(x, y) ({ \
730 typeof(x) _max1 = (x); \
731 typeof(y) _max2 = (y); \
732 (void) (&_max1 == &_max2); \
733 _max1 > _max2 ? _max1 : _max2; })
734
735 #define min3(x, y, z) min((typeof(x))min(x, y), z)
736 #define max3(x, y, z) max((typeof(x))max(x, y), z)
737
738 /**
739 * min_not_zero - return the minimum that is _not_ zero, unless both are zero
740 * @x: value1
741 * @y: value2
742 */
743 #define min_not_zero(x, y) ({ \
744 typeof(x) __x = (x); \
745 typeof(y) __y = (y); \
746 __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); })
747
748 /**
749 * clamp - return a value clamped to a given range with strict typechecking
750 * @val: current value
751 * @lo: lowest allowable value
752 * @hi: highest allowable value
753 *
754 * This macro does strict typechecking of lo/hi to make sure they are of the
755 * same type as val. See the unnecessary pointer comparisons.
756 */
757 #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi)
758
759 /*
760 * ..and if you can't take the strict
761 * types, you can specify one yourself.
762 *
763 * Or not use min/max/clamp at all, of course.
764 */
765 #define min_t(type, x, y) ({ \
766 type __min1 = (x); \
767 type __min2 = (y); \
768 __min1 < __min2 ? __min1: __min2; })
769
770 #define max_t(type, x, y) ({ \
771 type __max1 = (x); \
772 type __max2 = (y); \
773 __max1 > __max2 ? __max1: __max2; })
774
775 /**
776 * clamp_t - return a value clamped to a given range using a given type
777 * @type: the type of variable to use
778 * @val: current value
779 * @lo: minimum allowable value
780 * @hi: maximum allowable value
781 *
782 * This macro does no typechecking and uses temporary variables of type
783 * 'type' to make all the comparisons.
784 */
785 #define clamp_t(type, val, lo, hi) min_t(type, max_t(type, val, lo), hi)
786
787 /**
788 * clamp_val - return a value clamped to a given range using val's type
789 * @val: current value
790 * @lo: minimum allowable value
791 * @hi: maximum allowable value
792 *
793 * This macro does no typechecking and uses temporary variables of whatever
794 * type the input argument 'val' is. This is useful when val is an unsigned
795 * type and min and max are literals that will otherwise be assigned a signed
796 * integer type.
797 */
798 #define clamp_val(val, lo, hi) clamp_t(typeof(val), val, lo, hi)
799
800
801 /*
802 * swap - swap value of @a and @b
803 */
804 #define swap(a, b) \
805 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
806
807 /**
808 * container_of - cast a member of a structure out to the containing structure
809 * @ptr: the pointer to the member.
810 * @type: the type of the container struct this is embedded in.
811 * @member: the name of the member within the struct.
812 *
813 */
814 #define container_of(ptr, type, member) ({ \
815 const typeof( ((type *)0)->member ) *__mptr = (ptr); \
816 (type *)( (char *)__mptr - offsetof(type,member) );})
817
818 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
819 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
820 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
821 #endif
822
823 /* Permissions on a sysfs file: you didn't miss the 0 prefix did you? */
824 #define VERIFY_OCTAL_PERMISSIONS(perms) \
825 (BUILD_BUG_ON_ZERO((perms) < 0) + \
826 BUILD_BUG_ON_ZERO((perms) > 0777) + \
827 /* USER_READABLE >= GROUP_READABLE >= OTHER_READABLE */ \
828 BUILD_BUG_ON_ZERO((((perms) >> 6) & 4) < (((perms) >> 3) & 4)) + \
829 BUILD_BUG_ON_ZERO((((perms) >> 3) & 4) < ((perms) & 4)) + \
830 /* USER_WRITABLE >= GROUP_WRITABLE */ \
831 BUILD_BUG_ON_ZERO((((perms) >> 6) & 2) < (((perms) >> 3) & 2)) + \
832 /* OTHER_WRITABLE? Generally considered a bad idea. */ \
833 BUILD_BUG_ON_ZERO((perms) & 2) + \
834 (perms))
835 #endif
836
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