x86: Check stack overflow in detail
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / include / linux / kernel.h
CommitLineData
1da177e4
LT
1#ifndef _LINUX_KERNEL_H
2#define _LINUX_KERNEL_H
3
4/*
5 * 'kernel.h' contains some often-used function prototypes etc
6 */
a79ff731
AD
7#define __ALIGN_KERNEL(x, a) __ALIGN_KERNEL_MASK(x, (typeof(x))(a) - 1)
8#define __ALIGN_KERNEL_MASK(x, mask) (((x) + (mask)) & ~(mask))
1da177e4
LT
9
10#ifdef __KERNEL__
11
12#include <stdarg.h>
13#include <linux/linkage.h>
14#include <linux/stddef.h>
15#include <linux/types.h>
16#include <linux/compiler.h>
17#include <linux/bitops.h>
f0d1b0b3 18#include <linux/log2.h>
e0deaff4 19#include <linux/typecheck.h>
968ab183 20#include <linux/printk.h>
e9d376f0 21#include <linux/dynamic_debug.h>
1da177e4
LT
22#include <asm/byteorder.h>
23#include <asm/bug.h>
24
4be929be
AD
25#define USHRT_MAX ((u16)(~0U))
26#define SHRT_MAX ((s16)(USHRT_MAX>>1))
27#define SHRT_MIN ((s16)(-SHRT_MAX - 1))
1da177e4
LT
28#define INT_MAX ((int)(~0U>>1))
29#define INT_MIN (-INT_MAX - 1)
30#define UINT_MAX (~0U)
31#define LONG_MAX ((long)(~0UL>>1))
32#define LONG_MIN (-LONG_MAX - 1)
33#define ULONG_MAX (~0UL)
111ebb6e
OH
34#define LLONG_MAX ((long long)(~0ULL>>1))
35#define LLONG_MIN (-LLONG_MAX - 1)
36#define ULLONG_MAX (~0ULL)
1da177e4
LT
37
38#define STACK_MAGIC 0xdeadbeef
39
a79ff731 40#define ALIGN(x, a) __ALIGN_KERNEL((x), (a))
9f93ff5b 41#define __ALIGN_MASK(x, mask) __ALIGN_KERNEL_MASK((x), (mask))
a83308e6 42#define PTR_ALIGN(p, a) ((typeof(p))ALIGN((unsigned long)(p), (a)))
f10db627 43#define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0)
2ea58144 44
c5e631cf
RR
45#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
46
9b3be9f9
YL
47/*
48 * This looks more complex than it should be. But we need to
49 * get the type for the ~ right in round_down (it needs to be
50 * as wide as the result!), and we want to evaluate the macro
51 * arguments just once each.
52 */
53#define __round_mask(x, y) ((__typeof__(x))((y)-1))
54#define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
55#define round_down(x, y) ((x) & ~__round_mask(x, y))
56
4552d5dc 57#define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
930631ed 58#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
36a26c69
NB
59#define DIV_ROUND_UP_ULL(ll,d) \
60 ({ unsigned long long _tmp = (ll)+(d)-1; do_div(_tmp, d); _tmp; })
61
62#if BITS_PER_LONG == 32
63# define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP_ULL(ll, d)
64#else
65# define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP(ll,d)
66#endif
074e61ec
JM
67
68/* The `const' in roundup() prevents gcc-3.3 from calling __divdi3 */
b28efd54
EP
69#define roundup(x, y) ( \
70{ \
6070bf35 71 const typeof(y) __y = y; \
b28efd54
EP
72 (((x) + (__y - 1)) / __y) * __y; \
73} \
74)
686a0f3d
EP
75#define rounddown(x, y) ( \
76{ \
77 typeof(x) __x = (x); \
78 __x - (__x % (y)); \
79} \
80)
9fe06081
DW
81#define DIV_ROUND_CLOSEST(x, divisor)( \
82{ \
83 typeof(divisor) __divisor = divisor; \
84 (((x) + ((__divisor) / 2)) / (__divisor)); \
85} \
86)
1da177e4 87
ca31e146
EGM
88#define _RET_IP_ (unsigned long)__builtin_return_address(0)
89#define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; })
90
90c699a9 91#ifdef CONFIG_LBDAF
2da96acd
JA
92# include <asm/div64.h>
93# define sector_div(a, b) do_div(a, b)
94#else
95# define sector_div(n, b)( \
96{ \
97 int _res; \
98 _res = (n) % (b); \
99 (n) /= (b); \
100 _res; \
101} \
102)
103#endif
104
218e180e
AM
105/**
106 * upper_32_bits - return bits 32-63 of a number
107 * @n: the number we're accessing
108 *
109 * A basic shift-right of a 64- or 32-bit quantity. Use this to suppress
110 * the "right shift count >= width of type" warning when that quantity is
111 * 32-bits.
112 */
113#define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
114
204b885e
JR
115/**
116 * lower_32_bits - return bits 0-31 of a number
117 * @n: the number we're accessing
118 */
119#define lower_32_bits(n) ((u32)(n))
120
1da177e4 121struct completion;
df2e71fb
AM
122struct pt_regs;
123struct user;
1da177e4 124
070cb065
UKK
125#ifdef CONFIG_PREEMPT_VOLUNTARY
126extern int _cond_resched(void);
127# define might_resched() _cond_resched()
128#else
129# define might_resched() do { } while (0)
130#endif
131
d902db1e 132#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
d894837f 133 void __might_sleep(const char *file, int line, int preempt_offset);
1da177e4
LT
134/**
135 * might_sleep - annotation for functions that can sleep
136 *
137 * this macro will print a stack trace if it is executed in an atomic
138 * context (spinlock, irq-handler, ...).
139 *
140 * This is a useful debugging help to be able to catch problems early and not
e20ec991 141 * be bitten later when the calling function happens to sleep when it is not
1da177e4
LT
142 * supposed to.
143 */
f8cbd99b 144# define might_sleep() \
e4aafea2 145 do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
1da177e4 146#else
d894837f
SK
147 static inline void __might_sleep(const char *file, int line,
148 int preempt_offset) { }
f8cbd99b 149# define might_sleep() do { might_resched(); } while (0)
1da177e4
LT
150#endif
151
368a5fa1 152#define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
f8cbd99b 153
71a90484
AM
154/*
155 * abs() handles unsigned and signed longs, ints, shorts and chars. For all
156 * input types abs() returns a signed long.
157 * abs() should not be used for 64-bit types (s64, u64, long long) - use abs64()
158 * for those.
159 */
160#define abs(x) ({ \
161 long ret; \
162 if (sizeof(x) == sizeof(long)) { \
163 long __x = (x); \
164 ret = (__x < 0) ? -__x : __x; \
165 } else { \
166 int __x = (x); \
167 ret = (__x < 0) ? -__x : __x; \
168 } \
169 ret; \
1da177e4
LT
170 })
171
658716d1
BB
172#define abs64(x) ({ \
173 s64 __x = (x); \
174 (__x < 0) ? -__x : __x; \
175 })
176
3ee1afa3
NP
177#ifdef CONFIG_PROVE_LOCKING
178void might_fault(void);
179#else
180static inline void might_fault(void)
181{
182 might_sleep();
183}
184#endif
185
e041c683 186extern struct atomic_notifier_head panic_notifier_list;
c7ff0d9c 187extern long (*panic_blink)(int state);
1da177e4 188NORET_TYPE void panic(const char * fmt, ...)
a586df06 189 __attribute__ ((NORET_AND format (printf, 1, 2))) __cold;
dd287796
AM
190extern void oops_enter(void);
191extern void oops_exit(void);
863a6049 192void print_oops_end_marker(void);
dd287796 193extern int oops_may_print(void);
ec701584 194NORET_TYPE void do_exit(long error_code)
1da177e4
LT
195 ATTRIB_NORET;
196NORET_TYPE void complete_and_exit(struct completion *, long)
197 ATTRIB_NORET;
33ee3b2e
AD
198
199/* Internal, do not use. */
200int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res);
201int __must_check _kstrtol(const char *s, unsigned int base, long *res);
202
203int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res);
204int __must_check kstrtoll(const char *s, unsigned int base, long long *res);
205static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res)
206{
207 /*
208 * We want to shortcut function call, but
209 * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0.
210 */
211 if (sizeof(unsigned long) == sizeof(unsigned long long) &&
212 __alignof__(unsigned long) == __alignof__(unsigned long long))
213 return kstrtoull(s, base, (unsigned long long *)res);
214 else
215 return _kstrtoul(s, base, res);
216}
217
218static inline int __must_check kstrtol(const char *s, unsigned int base, long *res)
219{
220 /*
221 * We want to shortcut function call, but
222 * __builtin_types_compatible_p(long, long long) = 0.
223 */
224 if (sizeof(long) == sizeof(long long) &&
225 __alignof__(long) == __alignof__(long long))
226 return kstrtoll(s, base, (long long *)res);
227 else
228 return _kstrtol(s, base, res);
229}
230
231int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res);
232int __must_check kstrtoint(const char *s, unsigned int base, int *res);
233
234static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res)
235{
236 return kstrtoull(s, base, res);
237}
238
239static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res)
240{
241 return kstrtoll(s, base, res);
242}
243
244static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res)
245{
246 return kstrtouint(s, base, res);
247}
248
249static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res)
250{
251 return kstrtoint(s, base, res);
252}
253
254int __must_check kstrtou16(const char *s, unsigned int base, u16 *res);
255int __must_check kstrtos16(const char *s, unsigned int base, s16 *res);
256int __must_check kstrtou8(const char *s, unsigned int base, u8 *res);
257int __must_check kstrtos8(const char *s, unsigned int base, s8 *res);
258
c196e32a
AD
259int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res);
260int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res);
261int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res);
262int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res);
263int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res);
264int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res);
265int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res);
266int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res);
267int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res);
268int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res);
269
270static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res)
271{
272 return kstrtoull_from_user(s, count, base, res);
273}
274
275static inline int __must_check kstrtos64_from_user(const char __user *s, size_t count, unsigned int base, s64 *res)
276{
277 return kstrtoll_from_user(s, count, base, res);
278}
279
280static inline int __must_check kstrtou32_from_user(const char __user *s, size_t count, unsigned int base, u32 *res)
281{
282 return kstrtouint_from_user(s, count, base, res);
283}
284
285static inline int __must_check kstrtos32_from_user(const char __user *s, size_t count, unsigned int base, s32 *res)
286{
287 return kstrtoint_from_user(s, count, base, res);
288}
289
67d0a075
JP
290/* Obsolete, do not use. Use kstrto<foo> instead */
291
1da177e4
LT
292extern unsigned long simple_strtoul(const char *,char **,unsigned int);
293extern long simple_strtol(const char *,char **,unsigned int);
294extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
295extern long long simple_strtoll(const char *,char **,unsigned int);
33ee3b2e
AD
296#define strict_strtoul kstrtoul
297#define strict_strtol kstrtol
298#define strict_strtoull kstrtoull
299#define strict_strtoll kstrtoll
300
67d0a075
JP
301/* lib/printf utilities */
302
b9075fa9
JP
303extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...);
304extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list);
305extern __printf(3, 4)
306int snprintf(char *buf, size_t size, const char *fmt, ...);
307extern __printf(3, 0)
308int vsnprintf(char *buf, size_t size, const char *fmt, va_list args);
309extern __printf(3, 4)
310int scnprintf(char *buf, size_t size, const char *fmt, ...);
311extern __printf(3, 0)
312int vscnprintf(char *buf, size_t size, const char *fmt, va_list args);
313extern __printf(2, 3)
314char *kasprintf(gfp_t gfp, const char *fmt, ...);
11443ec7 315extern char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
1da177e4
LT
316
317extern int sscanf(const char *, const char *, ...)
318 __attribute__ ((format (scanf, 2, 3)));
319extern int vsscanf(const char *, const char *, va_list)
320 __attribute__ ((format (scanf, 2, 0)));
321
322extern int get_option(char **str, int *pint);
323extern char *get_options(const char *str, int nints, int *ints);
d974ae37 324extern unsigned long long memparse(const char *ptr, char **retptr);
1da177e4 325
5e376613 326extern int core_kernel_text(unsigned long addr);
cdbe61bf 327extern int core_kernel_data(unsigned long addr);
1da177e4
LT
328extern int __kernel_text_address(unsigned long addr);
329extern int kernel_text_address(unsigned long addr);
ab7476cf 330extern int func_ptr_is_kernel_text(void *ptr);
ab7476cf 331
04a2e6a5
EB
332struct pid;
333extern struct pid *session_of_pgrp(struct pid *pgrp);
1da177e4 334
1da177e4
LT
335unsigned long int_sqrt(unsigned long);
336
1da177e4 337extern void bust_spinlocks(int yes);
e3e8a75d 338extern void wake_up_klogd(void);
1da177e4 339extern int oops_in_progress; /* If set, an oops, panic(), BUG() or die() is in progress */
aa727107 340extern int panic_timeout;
1da177e4 341extern int panic_on_oops;
8da5adda 342extern int panic_on_unrecovered_nmi;
5211a242 343extern int panic_on_io_nmi;
1da177e4 344extern const char *print_tainted(void);
25ddbb18
AK
345extern void add_taint(unsigned flag);
346extern int test_taint(unsigned flag);
347extern unsigned long get_taint(void);
b920de1b 348extern int root_mountflags;
1da177e4 349
2ce802f6
TH
350extern bool early_boot_irqs_disabled;
351
1da177e4
LT
352/* Values used for system_state */
353extern enum system_states {
354 SYSTEM_BOOTING,
355 SYSTEM_RUNNING,
356 SYSTEM_HALT,
357 SYSTEM_POWER_OFF,
358 SYSTEM_RESTART,
729b4d4c 359 SYSTEM_SUSPEND_DISK,
1da177e4
LT
360} system_state;
361
25ddbb18
AK
362#define TAINT_PROPRIETARY_MODULE 0
363#define TAINT_FORCED_MODULE 1
364#define TAINT_UNSAFE_SMP 2
365#define TAINT_FORCED_RMMOD 3
366#define TAINT_MACHINE_CHECK 4
367#define TAINT_BAD_PAGE 5
368#define TAINT_USER 6
369#define TAINT_DIE 7
370#define TAINT_OVERRIDDEN_ACPI_TABLE 8
371#define TAINT_WARN 9
26e9a397 372#define TAINT_CRAP 10
92946bc7 373#define TAINT_FIRMWARE_WORKAROUND 11
2449b8ba 374#define TAINT_OOT_MODULE 12
1da177e4 375
3fc95772
HH
376extern const char hex_asc[];
377#define hex_asc_lo(x) hex_asc[((x) & 0x0f)]
378#define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4]
379
55036ba7 380static inline char *hex_byte_pack(char *buf, u8 byte)
3fc95772
HH
381{
382 *buf++ = hex_asc_hi(byte);
383 *buf++ = hex_asc_lo(byte);
384 return buf;
385}
99eaf3c4 386
55036ba7
AS
387static inline char * __deprecated pack_hex_byte(char *buf, u8 byte)
388{
389 return hex_byte_pack(buf, byte);
390}
391
90378889 392extern int hex_to_bin(char ch);
b7804983 393extern int __must_check hex2bin(u8 *dst, const char *src, size_t count);
90378889 394
526211bc
IM
395/*
396 * General tracing related utility functions - trace_printk(),
2002c258
SR
397 * tracing_on/tracing_off and tracing_start()/tracing_stop
398 *
399 * Use tracing_on/tracing_off when you want to quickly turn on or off
400 * tracing. It simply enables or disables the recording of the trace events.
156f5a78 401 * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on
2002c258
SR
402 * file, which gives a means for the kernel and userspace to interact.
403 * Place a tracing_off() in the kernel where you want tracing to end.
404 * From user space, examine the trace, and then echo 1 > tracing_on
405 * to continue tracing.
406 *
407 * tracing_stop/tracing_start has slightly more overhead. It is used
408 * by things like suspend to ram where disabling the recording of the
409 * trace is not enough, but tracing must actually stop because things
410 * like calling smp_processor_id() may crash the system.
411 *
412 * Most likely, you want to use tracing_on/tracing_off.
526211bc 413 */
2002c258
SR
414#ifdef CONFIG_RING_BUFFER
415void tracing_on(void);
416void tracing_off(void);
417/* trace_off_permanent stops recording with no way to bring it back */
418void tracing_off_permanent(void);
419int tracing_is_on(void);
420#else
421static inline void tracing_on(void) { }
422static inline void tracing_off(void) { }
423static inline void tracing_off_permanent(void) { }
424static inline int tracing_is_on(void) { return 0; }
425#endif
cecbca96
FW
426
427enum ftrace_dump_mode {
428 DUMP_NONE,
429 DUMP_ALL,
430 DUMP_ORIG,
431};
432
526211bc
IM
433#ifdef CONFIG_TRACING
434extern void tracing_start(void);
435extern void tracing_stop(void);
436extern void ftrace_off_permanent(void);
437
b9075fa9
JP
438static inline __printf(1, 2)
439void ____trace_printk_check_format(const char *fmt, ...)
769b0441
FW
440{
441}
442#define __trace_printk_check_format(fmt, args...) \
443do { \
444 if (0) \
445 ____trace_printk_check_format(fmt, ##args); \
446} while (0)
447
526211bc
IM
448/**
449 * trace_printk - printf formatting in the ftrace buffer
450 * @fmt: the printf format for printing
451 *
452 * Note: __trace_printk is an internal function for trace_printk and
453 * the @ip is passed in via the trace_printk macro.
454 *
455 * This function allows a kernel developer to debug fast path sections
456 * that printk is not appropriate for. By scattering in various
457 * printk like tracing in the code, a developer can quickly see
458 * where problems are occurring.
459 *
460 * This is intended as a debugging tool for the developer only.
461 * Please refrain from leaving trace_printks scattered around in
462 * your code.
463 */
769b0441
FW
464
465#define trace_printk(fmt, args...) \
466do { \
769b0441 467 __trace_printk_check_format(fmt, ##args); \
48ead020
FW
468 if (__builtin_constant_p(fmt)) { \
469 static const char *trace_printk_fmt \
470 __attribute__((section("__trace_printk_fmt"))) = \
471 __builtin_constant_p(fmt) ? fmt : NULL; \
472 \
473 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \
474 } else \
475 __trace_printk(_THIS_IP_, fmt, ##args); \
769b0441
FW
476} while (0)
477
b9075fa9
JP
478extern __printf(2, 3)
479int __trace_bprintk(unsigned long ip, const char *fmt, ...);
48ead020 480
b9075fa9
JP
481extern __printf(2, 3)
482int __trace_printk(unsigned long ip, const char *fmt, ...);
769b0441 483
03889384
SR
484extern void trace_dump_stack(void);
485
48ead020
FW
486/*
487 * The double __builtin_constant_p is because gcc will give us an error
488 * if we try to allocate the static variable to fmt if it is not a
489 * constant. Even with the outer if statement.
490 */
769b0441
FW
491#define ftrace_vprintk(fmt, vargs) \
492do { \
48ead020
FW
493 if (__builtin_constant_p(fmt)) { \
494 static const char *trace_printk_fmt \
495 __attribute__((section("__trace_printk_fmt"))) = \
496 __builtin_constant_p(fmt) ? fmt : NULL; \
7bffc23e 497 \
48ead020
FW
498 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \
499 } else \
500 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \
769b0441
FW
501} while (0)
502
48ead020
FW
503extern int
504__ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
505
526211bc
IM
506extern int
507__ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
769b0441 508
cecbca96 509extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode);
526211bc 510#else
b9075fa9
JP
511static inline __printf(1, 2)
512int trace_printk(const char *fmt, ...);
526211bc
IM
513
514static inline void tracing_start(void) { }
515static inline void tracing_stop(void) { }
516static inline void ftrace_off_permanent(void) { }
e36c5458 517static inline void trace_dump_stack(void) { }
526211bc
IM
518static inline int
519trace_printk(const char *fmt, ...)
520{
521 return 0;
522}
523static inline int
524ftrace_vprintk(const char *fmt, va_list ap)
525{
526 return 0;
527}
cecbca96 528static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
769b0441 529#endif /* CONFIG_TRACING */
526211bc 530
1da177e4 531/*
bdf4bbaa 532 * min()/max()/clamp() macros that also do
1da177e4
LT
533 * strict type-checking.. See the
534 * "unnecessary" pointer comparison.
535 */
bdf4bbaa
HH
536#define min(x, y) ({ \
537 typeof(x) _min1 = (x); \
538 typeof(y) _min2 = (y); \
539 (void) (&_min1 == &_min2); \
540 _min1 < _min2 ? _min1 : _min2; })
541
542#define max(x, y) ({ \
543 typeof(x) _max1 = (x); \
544 typeof(y) _max2 = (y); \
545 (void) (&_max1 == &_max2); \
546 _max1 > _max2 ? _max1 : _max2; })
547
f27c85c5
HPP
548#define min3(x, y, z) ({ \
549 typeof(x) _min1 = (x); \
550 typeof(y) _min2 = (y); \
551 typeof(z) _min3 = (z); \
552 (void) (&_min1 == &_min2); \
553 (void) (&_min1 == &_min3); \
554 _min1 < _min2 ? (_min1 < _min3 ? _min1 : _min3) : \
555 (_min2 < _min3 ? _min2 : _min3); })
556
557#define max3(x, y, z) ({ \
558 typeof(x) _max1 = (x); \
559 typeof(y) _max2 = (y); \
560 typeof(z) _max3 = (z); \
561 (void) (&_max1 == &_max2); \
562 (void) (&_max1 == &_max3); \
563 _max1 > _max2 ? (_max1 > _max3 ? _max1 : _max3) : \
564 (_max2 > _max3 ? _max2 : _max3); })
565
c8bf1336
MP
566/**
567 * min_not_zero - return the minimum that is _not_ zero, unless both are zero
568 * @x: value1
569 * @y: value2
570 */
571#define min_not_zero(x, y) ({ \
572 typeof(x) __x = (x); \
573 typeof(y) __y = (y); \
574 __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); })
575
bdf4bbaa
HH
576/**
577 * clamp - return a value clamped to a given range with strict typechecking
578 * @val: current value
579 * @min: minimum allowable value
580 * @max: maximum allowable value
581 *
582 * This macro does strict typechecking of min/max to make sure they are of the
583 * same type as val. See the unnecessary pointer comparisons.
584 */
585#define clamp(val, min, max) ({ \
586 typeof(val) __val = (val); \
587 typeof(min) __min = (min); \
588 typeof(max) __max = (max); \
589 (void) (&__val == &__min); \
590 (void) (&__val == &__max); \
591 __val = __val < __min ? __min: __val; \
592 __val > __max ? __max: __val; })
1da177e4
LT
593
594/*
595 * ..and if you can't take the strict
596 * types, you can specify one yourself.
597 *
bdf4bbaa
HH
598 * Or not use min/max/clamp at all, of course.
599 */
600#define min_t(type, x, y) ({ \
601 type __min1 = (x); \
602 type __min2 = (y); \
603 __min1 < __min2 ? __min1: __min2; })
604
605#define max_t(type, x, y) ({ \
606 type __max1 = (x); \
607 type __max2 = (y); \
608 __max1 > __max2 ? __max1: __max2; })
609
610/**
611 * clamp_t - return a value clamped to a given range using a given type
612 * @type: the type of variable to use
613 * @val: current value
614 * @min: minimum allowable value
615 * @max: maximum allowable value
616 *
617 * This macro does no typechecking and uses temporary variables of type
618 * 'type' to make all the comparisons.
1da177e4 619 */
bdf4bbaa
HH
620#define clamp_t(type, val, min, max) ({ \
621 type __val = (val); \
622 type __min = (min); \
623 type __max = (max); \
624 __val = __val < __min ? __min: __val; \
625 __val > __max ? __max: __val; })
1da177e4 626
bdf4bbaa
HH
627/**
628 * clamp_val - return a value clamped to a given range using val's type
629 * @val: current value
630 * @min: minimum allowable value
631 * @max: maximum allowable value
632 *
633 * This macro does no typechecking and uses temporary variables of whatever
634 * type the input argument 'val' is. This is useful when val is an unsigned
635 * type and min and max are literals that will otherwise be assigned a signed
636 * integer type.
637 */
638#define clamp_val(val, min, max) ({ \
639 typeof(val) __val = (val); \
640 typeof(val) __min = (min); \
641 typeof(val) __max = (max); \
642 __val = __val < __min ? __min: __val; \
643 __val > __max ? __max: __val; })
1da177e4 644
91f68b73
WF
645
646/*
647 * swap - swap value of @a and @b
648 */
ac7b9004
PZ
649#define swap(a, b) \
650 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
91f68b73 651
1da177e4
LT
652/**
653 * container_of - cast a member of a structure out to the containing structure
1da177e4
LT
654 * @ptr: the pointer to the member.
655 * @type: the type of the container struct this is embedded in.
656 * @member: the name of the member within the struct.
657 *
658 */
659#define container_of(ptr, type, member) ({ \
78db2ad6
DW
660 const typeof( ((type *)0)->member ) *__mptr = (ptr); \
661 (type *)( (char *)__mptr - offsetof(type,member) );})
1da177e4 662
903c0c7c
KM
663#ifdef __CHECKER__
664#define BUILD_BUG_ON_NOT_POWER_OF_2(n)
ca39599c
DDAG
665#define BUILD_BUG_ON_ZERO(e) (0)
666#define BUILD_BUG_ON_NULL(e) ((void*)0)
903c0c7c
KM
667#define BUILD_BUG_ON(condition)
668#else /* __CHECKER__ */
669
cc8ef6eb
RD
670/* Force a compilation error if a constant expression is not a power of 2 */
671#define BUILD_BUG_ON_NOT_POWER_OF_2(n) \
672 BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0))
673
4552d5dc
JB
674/* Force a compilation error if condition is true, but also produce a
675 result (of value 0 and type size_t), so the expression can be used
676 e.g. in a structure initializer (or where-ever else comma expressions
677 aren't permitted). */
8c87df45
JB
678#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))
679#define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); }))
4552d5dc 680
7ef88ad5
RR
681/**
682 * BUILD_BUG_ON - break compile if a condition is true.
ffbbf2da 683 * @condition: the condition which the compiler should know is false.
7ef88ad5
RR
684 *
685 * If you have some code which relies on certain constants being equal, or
686 * other compile-time-evaluated condition, you should use BUILD_BUG_ON to
687 * detect if someone changes it.
688 *
689 * The implementation uses gcc's reluctance to create a negative array, but
690 * gcc (as of 4.4) only emits that error for obvious cases (eg. not arguments
691 * to inline functions). So as a fallback we use the optimizer; if it can't
692 * prove the condition is false, it will cause a link error on the undefined
693 * "__build_bug_on_failed". This error message can be harder to track down
694 * though, hence the two different methods.
695 */
696#ifndef __OPTIMIZE__
697#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
698#else
699extern int __build_bug_on_failed;
700#define BUILD_BUG_ON(condition) \
701 do { \
702 ((void)sizeof(char[1 - 2*!!(condition)])); \
703 if (condition) __build_bug_on_failed = 1; \
704 } while(0)
705#endif
903c0c7c 706#endif /* __CHECKER__ */
7ef88ad5 707
b9d4f426
AL
708/* Trap pasters of __FUNCTION__ at compile-time */
709#define __FUNCTION__ (__func__)
710
711/* This helps us to avoid #ifdef CONFIG_NUMA */
712#ifdef CONFIG_NUMA
713#define NUMA_BUILD 1
714#else
715#define NUMA_BUILD 0
716#endif
717
718/* This helps us avoid #ifdef CONFIG_COMPACTION */
719#ifdef CONFIG_COMPACTION
720#define COMPACTION_BUILD 1
721#else
722#define COMPACTION_BUILD 0
723#endif
724
725/* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
726#ifdef CONFIG_FTRACE_MCOUNT_RECORD
727# define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
728#endif
9d00f92f
WC
729
730struct sysinfo;
731extern int do_sysinfo(struct sysinfo *info);
732
733#endif /* __KERNEL__ */
734
735#define SI_LOAD_SHIFT 16
736struct sysinfo {
737 long uptime; /* Seconds since boot */
738 unsigned long loads[3]; /* 1, 5, and 15 minute load averages */
739 unsigned long totalram; /* Total usable main memory size */
740 unsigned long freeram; /* Available memory size */
741 unsigned long sharedram; /* Amount of shared memory */
742 unsigned long bufferram; /* Memory used by buffers */
743 unsigned long totalswap; /* Total swap space size */
744 unsigned long freeswap; /* swap space still available */
745 unsigned short procs; /* Number of current processes */
746 unsigned short pad; /* explicit padding for m68k */
747 unsigned long totalhigh; /* Total high memory size */
748 unsigned long freehigh; /* Available high memory size */
749 unsigned int mem_unit; /* Memory unit size in bytes */
750 char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding: libc5 uses this.. */
751};
752
1da177e4 753#endif