tty: Move session_of_pgrp() and make static
[deliverable/linux.git] / include / linux / kernel.h
CommitLineData
1da177e4
LT
1#ifndef _LINUX_KERNEL_H
2#define _LINUX_KERNEL_H
3
1da177e4
LT
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>
f0d1b0b3 11#include <linux/log2.h>
e0deaff4 12#include <linux/typecheck.h>
968ab183 13#include <linux/printk.h>
e9d376f0 14#include <linux/dynamic_debug.h>
1da177e4 15#include <asm/byteorder.h>
607ca46e 16#include <uapi/linux/kernel.h>
1da177e4 17
4be929be
AD
18#define USHRT_MAX ((u16)(~0U))
19#define SHRT_MAX ((s16)(USHRT_MAX>>1))
20#define SHRT_MIN ((s16)(-SHRT_MAX - 1))
1da177e4
LT
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)
111ebb6e
OH
27#define LLONG_MAX ((long long)(~0ULL>>1))
28#define LLONG_MIN (-LLONG_MAX - 1)
29#define ULLONG_MAX (~0ULL)
a3860c1c 30#define SIZE_MAX (~(size_t)0)
1da177e4 31
89a07141
AE
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
1da177e4
LT
45#define STACK_MAGIC 0xdeadbeef
46
44696908
DM
47#define REPEAT_BYTE(x) ((~0ul / 0xff) * (x))
48
a79ff731 49#define ALIGN(x, a) __ALIGN_KERNEL((x), (a))
9f93ff5b 50#define __ALIGN_MASK(x, mask) __ALIGN_KERNEL_MASK((x), (mask))
a83308e6 51#define PTR_ALIGN(p, a) ((typeof(p))ALIGN((unsigned long)(p), (a)))
f10db627 52#define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0)
2ea58144 53
c5e631cf
RR
54#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
55
9b3be9f9
YL
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
4552d5dc 66#define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
930631ed 67#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
36a26c69
NB
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
074e61ec
JM
76
77/* The `const' in roundup() prevents gcc-3.3 from calling __divdi3 */
b28efd54
EP
78#define roundup(x, y) ( \
79{ \
6070bf35 80 const typeof(y) __y = y; \
b28efd54
EP
81 (((x) + (__y - 1)) / __y) * __y; \
82} \
83)
686a0f3d
EP
84#define rounddown(x, y) ( \
85{ \
86 typeof(x) __x = (x); \
87 __x - (__x % (y)); \
88} \
89)
b6d86d3d
GR
90
91/*
92 * Divide positive or negative dividend by positive divisor and round
c4e18497
GR
93 * to closest integer. Result is undefined for negative divisors and
94 * for negative dividends if the divisor variable type is unsigned.
b6d86d3d 95 */
9fe06081
DW
96#define DIV_ROUND_CLOSEST(x, divisor)( \
97{ \
b6d86d3d
GR
98 typeof(x) __x = x; \
99 typeof(divisor) __d = divisor; \
c4e18497
GR
100 (((typeof(x))-1) > 0 || \
101 ((typeof(divisor))-1) > 0 || (__x) > 0) ? \
b6d86d3d
GR
102 (((__x) + ((__d) / 2)) / (__d)) : \
103 (((__x) - ((__d) / 2)) / (__d)); \
9fe06081
DW
104} \
105)
1da177e4 106
9993bc63
SQ
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
ca31e146
EGM
120#define _RET_IP_ (unsigned long)__builtin_return_address(0)
121#define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; })
122
90c699a9 123#ifdef CONFIG_LBDAF
2da96acd
JA
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
218e180e
AM
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
204b885e
JR
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
1da177e4 153struct completion;
df2e71fb 154struct pt_regs;
155struct user;
1da177e4 156
070cb065
UKK
157#ifdef CONFIG_PREEMPT_VOLUNTARY
158extern int _cond_resched(void);
159# define might_resched() _cond_resched()
160#else
161# define might_resched() do { } while (0)
162#endif
163
d902db1e 164#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
d894837f 165 void __might_sleep(const char *file, int line, int preempt_offset);
1da177e4
LT
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
e20ec991 173 * be bitten later when the calling function happens to sleep when it is not
1da177e4
LT
174 * supposed to.
175 */
f8cbd99b 176# define might_sleep() \
e4aafea2 177 do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
1da177e4 178#else
d894837f
SK
179 static inline void __might_sleep(const char *file, int line,
180 int preempt_offset) { }
f8cbd99b 181# define might_sleep() do { might_resched(); } while (0)
1da177e4
LT
182#endif
183
368a5fa1 184#define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
f8cbd99b 185
71a90484
AM
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; \
1da177e4
LT
202 })
203
658716d1
BB
204#define abs64(x) ({ \
205 s64 __x = (x); \
206 (__x < 0) ? -__x : __x; \
207 })
208
89770b0a
DB
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 */
223static inline u32 reciprocal_scale(u32 val, u32 ep_ro)
224{
225 return (u32)(((u64) val * ep_ro) >> 32);
226}
227
386e7906
AL
228#if defined(CONFIG_MMU) && \
229 (defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP))
3ee1afa3
NP
230void might_fault(void);
231#else
662bbcb2 232static inline void might_fault(void) { }
3ee1afa3
NP
233#endif
234
e041c683 235extern struct atomic_notifier_head panic_notifier_list;
c7ff0d9c 236extern long (*panic_blink)(int state);
9402c95f 237__printf(1, 2)
4da47859 238void panic(const char *fmt, ...)
ff2d8b19 239 __noreturn __cold;
dd287796
AM
240extern void oops_enter(void);
241extern void oops_exit(void);
863a6049 242void print_oops_end_marker(void);
dd287796 243extern int oops_may_print(void);
9402c95f 244void do_exit(long error_code)
ff2d8b19 245 __noreturn;
9402c95f 246void complete_and_exit(struct completion *, long)
ff2d8b19 247 __noreturn;
33ee3b2e
AD
248
249/* Internal, do not use. */
250int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res);
251int __must_check _kstrtol(const char *s, unsigned int base, long *res);
252
253int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res);
254int __must_check kstrtoll(const char *s, unsigned int base, long long *res);
4c925d60
EZ
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*/
33ee3b2e
AD
272static 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
4c925d60
EZ
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 */
33ee3b2e
AD
301static 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
314int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res);
315int __must_check kstrtoint(const char *s, unsigned int base, int *res);
316
317static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res)
318{
319 return kstrtoull(s, base, res);
320}
321
322static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res)
323{
324 return kstrtoll(s, base, res);
325}
326
327static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res)
328{
329 return kstrtouint(s, base, res);
330}
331
332static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res)
333{
334 return kstrtoint(s, base, res);
335}
336
337int __must_check kstrtou16(const char *s, unsigned int base, u16 *res);
338int __must_check kstrtos16(const char *s, unsigned int base, s16 *res);
339int __must_check kstrtou8(const char *s, unsigned int base, u8 *res);
340int __must_check kstrtos8(const char *s, unsigned int base, s8 *res);
341
c196e32a
AD
342int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res);
343int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res);
344int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res);
345int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res);
346int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res);
347int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res);
348int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res);
349int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res);
350int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res);
351int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res);
352
353static 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
358static 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
363static 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
368static 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
67d0a075
JP
373/* Obsolete, do not use. Use kstrto<foo> instead */
374
1da177e4
LT
375extern unsigned long simple_strtoul(const char *,char **,unsigned int);
376extern long simple_strtol(const char *,char **,unsigned int);
377extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
378extern long long simple_strtoll(const char *,char **,unsigned int);
33ee3b2e 379
1ac101a5
KH
380extern int num_to_str(char *buf, int size, unsigned long long num);
381
67d0a075
JP
382/* lib/printf utilities */
383
b9075fa9
JP
384extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...);
385extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list);
386extern __printf(3, 4)
387int snprintf(char *buf, size_t size, const char *fmt, ...);
388extern __printf(3, 0)
389int vsnprintf(char *buf, size_t size, const char *fmt, va_list args);
390extern __printf(3, 4)
391int scnprintf(char *buf, size_t size, const char *fmt, ...);
392extern __printf(3, 0)
393int vscnprintf(char *buf, size_t size, const char *fmt, va_list args);
394extern __printf(2, 3)
395char *kasprintf(gfp_t gfp, const char *fmt, ...);
11443ec7 396extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
1da177e4 397
6061d949
JP
398extern __scanf(2, 3)
399int sscanf(const char *, const char *, ...);
400extern __scanf(2, 0)
401int vsscanf(const char *, const char *, va_list);
1da177e4
LT
402
403extern int get_option(char **str, int *pint);
404extern char *get_options(const char *str, int nints, int *ints);
d974ae37 405extern unsigned long long memparse(const char *ptr, char **retptr);
6ccc72b8 406extern bool parse_option_str(const char *str, const char *option);
1da177e4 407
5e376613 408extern int core_kernel_text(unsigned long addr);
cdbe61bf 409extern int core_kernel_data(unsigned long addr);
1da177e4
LT
410extern int __kernel_text_address(unsigned long addr);
411extern int kernel_text_address(unsigned long addr);
ab7476cf 412extern int func_ptr_is_kernel_text(void *ptr);
ab7476cf 413
1da177e4
LT
414unsigned long int_sqrt(unsigned long);
415
1da177e4
LT
416extern void bust_spinlocks(int yes);
417extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */
aa727107 418extern int panic_timeout;
1da177e4 419extern int panic_on_oops;
8da5adda 420extern int panic_on_unrecovered_nmi;
5211a242 421extern int panic_on_io_nmi;
55af7796 422extern int sysctl_panic_on_stackoverflow;
5800dc3c
JB
423/*
424 * Only to be used by arch init code. If the user over-wrote the default
425 * CONFIG_PANIC_TIMEOUT, honor it.
426 */
427static inline void set_arch_panic_timeout(int timeout, int arch_default_timeout)
428{
429 if (panic_timeout == arch_default_timeout)
430 panic_timeout = timeout;
431}
1da177e4 432extern const char *print_tainted(void);
373d4d09
RR
433enum lockdep_ok {
434 LOCKDEP_STILL_OK,
435 LOCKDEP_NOW_UNRELIABLE
436};
437extern void add_taint(unsigned flag, enum lockdep_ok);
25ddbb18
AK
438extern int test_taint(unsigned flag);
439extern unsigned long get_taint(void);
b920de1b 440extern int root_mountflags;
1da177e4 441
2ce802f6
TH
442extern bool early_boot_irqs_disabled;
443
1da177e4
LT
444/* Values used for system_state */
445extern enum system_states {
446 SYSTEM_BOOTING,
447 SYSTEM_RUNNING,
448 SYSTEM_HALT,
449 SYSTEM_POWER_OFF,
450 SYSTEM_RESTART,
451} system_state;
452
25ddbb18
AK
453#define TAINT_PROPRIETARY_MODULE 0
454#define TAINT_FORCED_MODULE 1
8c90487c 455#define TAINT_CPU_OUT_OF_SPEC 2
25ddbb18
AK
456#define TAINT_FORCED_RMMOD 3
457#define TAINT_MACHINE_CHECK 4
458#define TAINT_BAD_PAGE 5
459#define TAINT_USER 6
460#define TAINT_DIE 7
461#define TAINT_OVERRIDDEN_ACPI_TABLE 8
462#define TAINT_WARN 9
26e9a397 463#define TAINT_CRAP 10
92946bc7 464#define TAINT_FIRMWARE_WORKAROUND 11
2449b8ba 465#define TAINT_OOT_MODULE 12
66cc69e3 466#define TAINT_UNSIGNED_MODULE 13
69361eef 467#define TAINT_SOFTLOCKUP 14
1da177e4 468
3fc95772
HH
469extern const char hex_asc[];
470#define hex_asc_lo(x) hex_asc[((x) & 0x0f)]
471#define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4]
472
55036ba7 473static inline char *hex_byte_pack(char *buf, u8 byte)
3fc95772
HH
474{
475 *buf++ = hex_asc_hi(byte);
476 *buf++ = hex_asc_lo(byte);
477 return buf;
478}
99eaf3c4 479
c26d436c
AN
480extern const char hex_asc_upper[];
481#define hex_asc_upper_lo(x) hex_asc_upper[((x) & 0x0f)]
482#define hex_asc_upper_hi(x) hex_asc_upper[((x) & 0xf0) >> 4]
483
484static inline char *hex_byte_pack_upper(char *buf, u8 byte)
485{
486 *buf++ = hex_asc_upper_hi(byte);
487 *buf++ = hex_asc_upper_lo(byte);
488 return buf;
489}
490
90378889 491extern int hex_to_bin(char ch);
b7804983 492extern int __must_check hex2bin(u8 *dst, const char *src, size_t count);
53d91c5c 493extern char *bin2hex(char *dst, const void *src, size_t count);
90378889 494
a69f5edb 495bool mac_pton(const char *s, u8 *mac);
4cd5773a 496
526211bc
IM
497/*
498 * General tracing related utility functions - trace_printk(),
2002c258
SR
499 * tracing_on/tracing_off and tracing_start()/tracing_stop
500 *
501 * Use tracing_on/tracing_off when you want to quickly turn on or off
502 * tracing. It simply enables or disables the recording of the trace events.
156f5a78 503 * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on
2002c258
SR
504 * file, which gives a means for the kernel and userspace to interact.
505 * Place a tracing_off() in the kernel where you want tracing to end.
506 * From user space, examine the trace, and then echo 1 > tracing_on
507 * to continue tracing.
508 *
509 * tracing_stop/tracing_start has slightly more overhead. It is used
510 * by things like suspend to ram where disabling the recording of the
511 * trace is not enough, but tracing must actually stop because things
512 * like calling smp_processor_id() may crash the system.
513 *
514 * Most likely, you want to use tracing_on/tracing_off.
526211bc 515 */
2002c258 516#ifdef CONFIG_RING_BUFFER
2002c258
SR
517/* trace_off_permanent stops recording with no way to bring it back */
518void tracing_off_permanent(void);
2002c258 519#else
2002c258 520static inline void tracing_off_permanent(void) { }
2002c258 521#endif
cecbca96
FW
522
523enum ftrace_dump_mode {
524 DUMP_NONE,
525 DUMP_ALL,
526 DUMP_ORIG,
527};
528
526211bc 529#ifdef CONFIG_TRACING
93d68e52
SR
530void tracing_on(void);
531void tracing_off(void);
532int tracing_is_on(void);
ad909e21
SRRH
533void tracing_snapshot(void);
534void tracing_snapshot_alloc(void);
93d68e52 535
526211bc
IM
536extern void tracing_start(void);
537extern void tracing_stop(void);
526211bc 538
b9075fa9
JP
539static inline __printf(1, 2)
540void ____trace_printk_check_format(const char *fmt, ...)
769b0441
FW
541{
542}
543#define __trace_printk_check_format(fmt, args...) \
544do { \
545 if (0) \
546 ____trace_printk_check_format(fmt, ##args); \
547} while (0)
548
526211bc
IM
549/**
550 * trace_printk - printf formatting in the ftrace buffer
551 * @fmt: the printf format for printing
552 *
553 * Note: __trace_printk is an internal function for trace_printk and
554 * the @ip is passed in via the trace_printk macro.
555 *
556 * This function allows a kernel developer to debug fast path sections
557 * that printk is not appropriate for. By scattering in various
558 * printk like tracing in the code, a developer can quickly see
559 * where problems are occurring.
560 *
561 * This is intended as a debugging tool for the developer only.
562 * Please refrain from leaving trace_printks scattered around in
09ae7234
SRRH
563 * your code. (Extra memory is used for special buffers that are
564 * allocated when trace_printk() is used)
9d3c752c
SRRH
565 *
566 * A little optization trick is done here. If there's only one
567 * argument, there's no need to scan the string for printf formats.
568 * The trace_puts() will suffice. But how can we take advantage of
569 * using trace_puts() when trace_printk() has only one argument?
570 * By stringifying the args and checking the size we can tell
571 * whether or not there are args. __stringify((__VA_ARGS__)) will
572 * turn into "()\0" with a size of 3 when there are no args, anything
573 * else will be bigger. All we need to do is define a string to this,
574 * and then take its size and compare to 3. If it's bigger, use
575 * do_trace_printk() otherwise, optimize it to trace_puts(). Then just
576 * let gcc optimize the rest.
526211bc 577 */
769b0441 578
9d3c752c
SRRH
579#define trace_printk(fmt, ...) \
580do { \
581 char _______STR[] = __stringify((__VA_ARGS__)); \
582 if (sizeof(_______STR) > 3) \
583 do_trace_printk(fmt, ##__VA_ARGS__); \
584 else \
585 trace_puts(fmt); \
586} while (0)
587
588#define do_trace_printk(fmt, args...) \
769b0441 589do { \
07d777fe
SR
590 static const char *trace_printk_fmt \
591 __attribute__((section("__trace_printk_fmt"))) = \
592 __builtin_constant_p(fmt) ? fmt : NULL; \
593 \
769b0441 594 __trace_printk_check_format(fmt, ##args); \
48ead020 595 \
07d777fe 596 if (__builtin_constant_p(fmt)) \
48ead020 597 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \
07d777fe
SR
598 else \
599 __trace_printk(_THIS_IP_, fmt, ##args); \
769b0441
FW
600} while (0)
601
b9075fa9
JP
602extern __printf(2, 3)
603int __trace_bprintk(unsigned long ip, const char *fmt, ...);
48ead020 604
b9075fa9
JP
605extern __printf(2, 3)
606int __trace_printk(unsigned long ip, const char *fmt, ...);
769b0441 607
09ae7234
SRRH
608/**
609 * trace_puts - write a string into the ftrace buffer
610 * @str: the string to record
611 *
612 * Note: __trace_bputs is an internal function for trace_puts and
613 * the @ip is passed in via the trace_puts macro.
614 *
615 * This is similar to trace_printk() but is made for those really fast
616 * paths that a developer wants the least amount of "Heisenbug" affects,
617 * where the processing of the print format is still too much.
618 *
619 * This function allows a kernel developer to debug fast path sections
620 * that printk is not appropriate for. By scattering in various
621 * printk like tracing in the code, a developer can quickly see
622 * where problems are occurring.
623 *
624 * This is intended as a debugging tool for the developer only.
625 * Please refrain from leaving trace_puts scattered around in
626 * your code. (Extra memory is used for special buffers that are
627 * allocated when trace_puts() is used)
628 *
629 * Returns: 0 if nothing was written, positive # if string was.
630 * (1 when __trace_bputs is used, strlen(str) when __trace_puts is used)
631 */
632
09ae7234
SRRH
633#define trace_puts(str) ({ \
634 static const char *trace_printk_fmt \
635 __attribute__((section("__trace_printk_fmt"))) = \
636 __builtin_constant_p(str) ? str : NULL; \
637 \
638 if (__builtin_constant_p(str)) \
639 __trace_bputs(_THIS_IP_, trace_printk_fmt); \
640 else \
641 __trace_puts(_THIS_IP_, str, strlen(str)); \
642})
bcf312cf
SR
643extern int __trace_bputs(unsigned long ip, const char *str);
644extern int __trace_puts(unsigned long ip, const char *str, int size);
09ae7234 645
c142be8e 646extern void trace_dump_stack(int skip);
03889384 647
48ead020
FW
648/*
649 * The double __builtin_constant_p is because gcc will give us an error
650 * if we try to allocate the static variable to fmt if it is not a
651 * constant. Even with the outer if statement.
652 */
769b0441
FW
653#define ftrace_vprintk(fmt, vargs) \
654do { \
48ead020
FW
655 if (__builtin_constant_p(fmt)) { \
656 static const char *trace_printk_fmt \
657 __attribute__((section("__trace_printk_fmt"))) = \
658 __builtin_constant_p(fmt) ? fmt : NULL; \
7bffc23e 659 \
48ead020
FW
660 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \
661 } else \
662 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \
769b0441
FW
663} while (0)
664
48ead020
FW
665extern int
666__ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
667
526211bc
IM
668extern int
669__ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
769b0441 670
cecbca96 671extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode);
526211bc 672#else
526211bc
IM
673static inline void tracing_start(void) { }
674static inline void tracing_stop(void) { }
e67bc51e 675static inline void trace_dump_stack(int skip) { }
93d68e52
SR
676
677static inline void tracing_on(void) { }
678static inline void tracing_off(void) { }
679static inline int tracing_is_on(void) { return 0; }
ad909e21
SRRH
680static inline void tracing_snapshot(void) { }
681static inline void tracing_snapshot_alloc(void) { }
93d68e52 682
60efc15a
MH
683static inline __printf(1, 2)
684int trace_printk(const char *fmt, ...)
526211bc
IM
685{
686 return 0;
687}
688static inline int
689ftrace_vprintk(const char *fmt, va_list ap)
690{
691 return 0;
692}
cecbca96 693static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
769b0441 694#endif /* CONFIG_TRACING */
526211bc 695
1da177e4 696/*
bdf4bbaa 697 * min()/max()/clamp() macros that also do
1da177e4
LT
698 * strict type-checking.. See the
699 * "unnecessary" pointer comparison.
700 */
bdf4bbaa
HH
701#define min(x, y) ({ \
702 typeof(x) _min1 = (x); \
703 typeof(y) _min2 = (y); \
704 (void) (&_min1 == &_min2); \
705 _min1 < _min2 ? _min1 : _min2; })
706
707#define max(x, y) ({ \
708 typeof(x) _max1 = (x); \
709 typeof(y) _max2 = (y); \
710 (void) (&_max1 == &_max2); \
711 _max1 > _max2 ? _max1 : _max2; })
712
2e1d06e1
MN
713#define min3(x, y, z) min((typeof(x))min(x, y), z)
714#define max3(x, y, z) max((typeof(x))max(x, y), z)
f27c85c5 715
c8bf1336
MP
716/**
717 * min_not_zero - return the minimum that is _not_ zero, unless both are zero
718 * @x: value1
719 * @y: value2
720 */
721#define min_not_zero(x, y) ({ \
722 typeof(x) __x = (x); \
723 typeof(y) __y = (y); \
724 __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); })
725
bdf4bbaa
HH
726/**
727 * clamp - return a value clamped to a given range with strict typechecking
728 * @val: current value
2e1d06e1
MN
729 * @lo: lowest allowable value
730 * @hi: highest allowable value
bdf4bbaa 731 *
c185b07f 732 * This macro does strict typechecking of lo/hi to make sure they are of the
bdf4bbaa
HH
733 * same type as val. See the unnecessary pointer comparisons.
734 */
2e1d06e1 735#define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi)
1da177e4
LT
736
737/*
738 * ..and if you can't take the strict
739 * types, you can specify one yourself.
740 *
bdf4bbaa
HH
741 * Or not use min/max/clamp at all, of course.
742 */
743#define min_t(type, x, y) ({ \
744 type __min1 = (x); \
745 type __min2 = (y); \
746 __min1 < __min2 ? __min1: __min2; })
747
748#define max_t(type, x, y) ({ \
749 type __max1 = (x); \
750 type __max2 = (y); \
751 __max1 > __max2 ? __max1: __max2; })
752
753/**
754 * clamp_t - return a value clamped to a given range using a given type
755 * @type: the type of variable to use
756 * @val: current value
c185b07f
MN
757 * @lo: minimum allowable value
758 * @hi: maximum allowable value
bdf4bbaa
HH
759 *
760 * This macro does no typechecking and uses temporary variables of type
761 * 'type' to make all the comparisons.
1da177e4 762 */
c185b07f 763#define clamp_t(type, val, lo, hi) min_t(type, max_t(type, val, lo), hi)
1da177e4 764
bdf4bbaa
HH
765/**
766 * clamp_val - return a value clamped to a given range using val's type
767 * @val: current value
c185b07f
MN
768 * @lo: minimum allowable value
769 * @hi: maximum allowable value
bdf4bbaa
HH
770 *
771 * This macro does no typechecking and uses temporary variables of whatever
772 * type the input argument 'val' is. This is useful when val is an unsigned
773 * type and min and max are literals that will otherwise be assigned a signed
774 * integer type.
775 */
c185b07f 776#define clamp_val(val, lo, hi) clamp_t(typeof(val), val, lo, hi)
1da177e4 777
91f68b73
WF
778
779/*
780 * swap - swap value of @a and @b
781 */
ac7b9004
PZ
782#define swap(a, b) \
783 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
91f68b73 784
1da177e4
LT
785/**
786 * container_of - cast a member of a structure out to the containing structure
1da177e4
LT
787 * @ptr: the pointer to the member.
788 * @type: the type of the container struct this is embedded in.
789 * @member: the name of the member within the struct.
790 *
791 */
792#define container_of(ptr, type, member) ({ \
78db2ad6
DW
793 const typeof( ((type *)0)->member ) *__mptr = (ptr); \
794 (type *)( (char *)__mptr - offsetof(type,member) );})
1da177e4 795
b9d4f426
AL
796/* Trap pasters of __FUNCTION__ at compile-time */
797#define __FUNCTION__ (__func__)
798
b9d4f426
AL
799/* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
800#ifdef CONFIG_FTRACE_MCOUNT_RECORD
801# define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
802#endif
9d00f92f 803
58f86cc8
RR
804/* Permissions on a sysfs file: you didn't miss the 0 prefix did you? */
805#define VERIFY_OCTAL_PERMISSIONS(perms) \
806 (BUILD_BUG_ON_ZERO((perms) < 0) + \
807 BUILD_BUG_ON_ZERO((perms) > 0777) + \
808 /* User perms >= group perms >= other perms */ \
809 BUILD_BUG_ON_ZERO(((perms) >> 6) < (((perms) >> 3) & 7)) + \
810 BUILD_BUG_ON_ZERO((((perms) >> 3) & 7) < ((perms) & 7)) + \
37549e94
RR
811 /* Other writable? Generally considered a bad idea. */ \
812 BUILD_BUG_ON_ZERO((perms) & 2) + \
58f86cc8 813 (perms))
1da177e4 814#endif
This page took 1.152256 seconds and 5 git commands to generate.