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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_KERNEL_H
3#define _LINUX_KERNEL_H
4
5#include <stdarg.h>
6#include <linux/align.h>
7#include <linux/limits.h>
8#include <linux/linkage.h>
9#include <linux/stddef.h>
10#include <linux/types.h>
11#include <linux/compiler.h>
12#include <linux/bitops.h>
13#include <linux/kstrtox.h>
14#include <linux/log2.h>
15#include <linux/math.h>
16#include <linux/minmax.h>
17#include <linux/typecheck.h>
18#include <linux/panic.h>
19#include <linux/printk.h>
20#include <linux/build_bug.h>
21#include <linux/static_call_types.h>
22#include <asm/byteorder.h>
23
24#include <uapi/linux/kernel.h>
25
26#define STACK_MAGIC 0xdeadbeef
27
28/**
29 * REPEAT_BYTE - repeat the value @x multiple times as an unsigned long value
30 * @x: value to repeat
31 *
32 * NOTE: @x is not checked for > 0xff; larger values produce odd results.
33 */
34#define REPEAT_BYTE(x) ((~0ul / 0xff) * (x))
35
36/* generic data direction definitions */
37#define READ 0
38#define WRITE 1
39
40/**
41 * ARRAY_SIZE - get the number of elements in array @arr
42 * @arr: array to be sized
43 */
44#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
45
46#define PTR_IF(cond, ptr) ((cond) ? (ptr) : NULL)
47
48#define u64_to_user_ptr(x) ( \
49{ \
50 typecheck(u64, (x)); \
51 (void __user *)(uintptr_t)(x); \
52} \
53)
54
55#define typeof_member(T, m) typeof(((T*)0)->m)
56
57#define _RET_IP_ (unsigned long)__builtin_return_address(0)
58#define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; })
59
60/**
61 * upper_32_bits - return bits 32-63 of a number
62 * @n: the number we're accessing
63 *
64 * A basic shift-right of a 64- or 32-bit quantity. Use this to suppress
65 * the "right shift count >= width of type" warning when that quantity is
66 * 32-bits.
67 */
68#define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
69
70/**
71 * lower_32_bits - return bits 0-31 of a number
72 * @n: the number we're accessing
73 */
74#define lower_32_bits(n) ((u32)((n) & 0xffffffff))
75
76/**
77 * upper_16_bits - return bits 16-31 of a number
78 * @n: the number we're accessing
79 */
80#define upper_16_bits(n) ((u16)((n) >> 16))
81
82/**
83 * lower_16_bits - return bits 0-15 of a number
84 * @n: the number we're accessing
85 */
86#define lower_16_bits(n) ((u16)((n) & 0xffff))
87
88struct completion;
89struct user;
90
91#ifdef CONFIG_PREEMPT_VOLUNTARY
92
93extern int __cond_resched(void);
94# define might_resched() __cond_resched()
95
96#elif defined(CONFIG_PREEMPT_DYNAMIC)
97
98extern int __cond_resched(void);
99
100DECLARE_STATIC_CALL(might_resched, __cond_resched);
101
102static __always_inline void might_resched(void)
103{
104 static_call_mod(might_resched)();
105}
106
107#else
108
109# define might_resched() do { } while (0)
110
111#endif /* CONFIG_PREEMPT_* */
112
113#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
114extern void ___might_sleep(const char *file, int line, int preempt_offset);
115extern void __might_sleep(const char *file, int line, int preempt_offset);
116extern void __cant_sleep(const char *file, int line, int preempt_offset);
117extern void __cant_migrate(const char *file, int line);
118
119/**
120 * might_sleep - annotation for functions that can sleep
121 *
122 * this macro will print a stack trace if it is executed in an atomic
123 * context (spinlock, irq-handler, ...). Additional sections where blocking is
124 * not allowed can be annotated with non_block_start() and non_block_end()
125 * pairs.
126 *
127 * This is a useful debugging help to be able to catch problems early and not
128 * be bitten later when the calling function happens to sleep when it is not
129 * supposed to.
130 */
131# define might_sleep() \
132 do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
133/**
134 * cant_sleep - annotation for functions that cannot sleep
135 *
136 * this macro will print a stack trace if it is executed with preemption enabled
137 */
138# define cant_sleep() \
139 do { __cant_sleep(__FILE__, __LINE__, 0); } while (0)
140# define sched_annotate_sleep() (current->task_state_change = 0)
141
142/**
143 * cant_migrate - annotation for functions that cannot migrate
144 *
145 * Will print a stack trace if executed in code which is migratable
146 */
147# define cant_migrate() \
148 do { \
149 if (IS_ENABLED(CONFIG_SMP)) \
150 __cant_migrate(__FILE__, __LINE__); \
151 } while (0)
152
153/**
154 * non_block_start - annotate the start of section where sleeping is prohibited
155 *
156 * This is on behalf of the oom reaper, specifically when it is calling the mmu
157 * notifiers. The problem is that if the notifier were to block on, for example,
158 * mutex_lock() and if the process which holds that mutex were to perform a
159 * sleeping memory allocation, the oom reaper is now blocked on completion of
160 * that memory allocation. Other blocking calls like wait_event() pose similar
161 * issues.
162 */
163# define non_block_start() (current->non_block_count++)
164/**
165 * non_block_end - annotate the end of section where sleeping is prohibited
166 *
167 * Closes a section opened by non_block_start().
168 */
169# define non_block_end() WARN_ON(current->non_block_count-- == 0)
170#else
171 static inline void ___might_sleep(const char *file, int line,
172 int preempt_offset) { }
173 static inline void __might_sleep(const char *file, int line,
174 int preempt_offset) { }
175# define might_sleep() do { might_resched(); } while (0)
176# define cant_sleep() do { } while (0)
177# define cant_migrate() do { } while (0)
178# define sched_annotate_sleep() do { } while (0)
179# define non_block_start() do { } while (0)
180# define non_block_end() do { } while (0)
181#endif
182
183#define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
184
185#if defined(CONFIG_MMU) && \
186 (defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP))
187#define might_fault() __might_fault(__FILE__, __LINE__)
188void __might_fault(const char *file, int line);
189#else
190static inline void might_fault(void) { }
191#endif
192
193void do_exit(long error_code) __noreturn;
194void complete_and_exit(struct completion *, long) __noreturn;
195
196extern int num_to_str(char *buf, int size,
197 unsigned long long num, unsigned int width);
198
199/* lib/printf utilities */
200
201extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...);
202extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list);
203extern __printf(3, 4)
204int snprintf(char *buf, size_t size, const char *fmt, ...);
205extern __printf(3, 0)
206int vsnprintf(char *buf, size_t size, const char *fmt, va_list args);
207extern __printf(3, 4)
208int scnprintf(char *buf, size_t size, const char *fmt, ...);
209extern __printf(3, 0)
210int vscnprintf(char *buf, size_t size, const char *fmt, va_list args);
211extern __printf(2, 3) __malloc
212char *kasprintf(gfp_t gfp, const char *fmt, ...);
213extern __printf(2, 0) __malloc
214char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
215extern __printf(2, 0)
216const char *kvasprintf_const(gfp_t gfp, const char *fmt, va_list args);
217
218extern __scanf(2, 3)
219int sscanf(const char *, const char *, ...);
220extern __scanf(2, 0)
221int vsscanf(const char *, const char *, va_list);
222
223extern int no_hash_pointers_enable(char *str);
224
225extern int get_option(char **str, int *pint);
226extern char *get_options(const char *str, int nints, int *ints);
227extern unsigned long long memparse(const char *ptr, char **retptr);
228extern bool parse_option_str(const char *str, const char *option);
229extern char *next_arg(char *args, char **param, char **val);
230
231extern int core_kernel_text(unsigned long addr);
232extern int init_kernel_text(unsigned long addr);
233extern int core_kernel_data(unsigned long addr);
234extern int __kernel_text_address(unsigned long addr);
235extern int kernel_text_address(unsigned long addr);
236extern int func_ptr_is_kernel_text(void *ptr);
237
238extern void bust_spinlocks(int yes);
239
240extern int root_mountflags;
241
242extern bool early_boot_irqs_disabled;
243
244/*
245 * Values used for system_state. Ordering of the states must not be changed
246 * as code checks for <, <=, >, >= STATE.
247 */
248extern enum system_states {
249 SYSTEM_BOOTING,
250 SYSTEM_SCHEDULING,
251 SYSTEM_RUNNING,
252 SYSTEM_HALT,
253 SYSTEM_POWER_OFF,
254 SYSTEM_RESTART,
255 SYSTEM_SUSPEND,
256} system_state;
257
258extern const char hex_asc[];
259#define hex_asc_lo(x) hex_asc[((x) & 0x0f)]
260#define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4]
261
262static inline char *hex_byte_pack(char *buf, u8 byte)
263{
264 *buf++ = hex_asc_hi(byte);
265 *buf++ = hex_asc_lo(byte);
266 return buf;
267}
268
269extern const char hex_asc_upper[];
270#define hex_asc_upper_lo(x) hex_asc_upper[((x) & 0x0f)]
271#define hex_asc_upper_hi(x) hex_asc_upper[((x) & 0xf0) >> 4]
272
273static inline char *hex_byte_pack_upper(char *buf, u8 byte)
274{
275 *buf++ = hex_asc_upper_hi(byte);
276 *buf++ = hex_asc_upper_lo(byte);
277 return buf;
278}
279
280extern int hex_to_bin(char ch);
281extern int __must_check hex2bin(u8 *dst, const char *src, size_t count);
282extern char *bin2hex(char *dst, const void *src, size_t count);
283
284bool mac_pton(const char *s, u8 *mac);
285
286/*
287 * General tracing related utility functions - trace_printk(),
288 * tracing_on/tracing_off and tracing_start()/tracing_stop
289 *
290 * Use tracing_on/tracing_off when you want to quickly turn on or off
291 * tracing. It simply enables or disables the recording of the trace events.
292 * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on
293 * file, which gives a means for the kernel and userspace to interact.
294 * Place a tracing_off() in the kernel where you want tracing to end.
295 * From user space, examine the trace, and then echo 1 > tracing_on
296 * to continue tracing.
297 *
298 * tracing_stop/tracing_start has slightly more overhead. It is used
299 * by things like suspend to ram where disabling the recording of the
300 * trace is not enough, but tracing must actually stop because things
301 * like calling smp_processor_id() may crash the system.
302 *
303 * Most likely, you want to use tracing_on/tracing_off.
304 */
305
306enum ftrace_dump_mode {
307 DUMP_NONE,
308 DUMP_ALL,
309 DUMP_ORIG,
310};
311
312#ifdef CONFIG_TRACING
313void tracing_on(void);
314void tracing_off(void);
315int tracing_is_on(void);
316void tracing_snapshot(void);
317void tracing_snapshot_alloc(void);
318
319extern void tracing_start(void);
320extern void tracing_stop(void);
321
322static inline __printf(1, 2)
323void ____trace_printk_check_format(const char *fmt, ...)
324{
325}
326#define __trace_printk_check_format(fmt, args...) \
327do { \
328 if (0) \
329 ____trace_printk_check_format(fmt, ##args); \
330} while (0)
331
332/**
333 * trace_printk - printf formatting in the ftrace buffer
334 * @fmt: the printf format for printing
335 *
336 * Note: __trace_printk is an internal function for trace_printk() and
337 * the @ip is passed in via the trace_printk() macro.
338 *
339 * This function allows a kernel developer to debug fast path sections
340 * that printk is not appropriate for. By scattering in various
341 * printk like tracing in the code, a developer can quickly see
342 * where problems are occurring.
343 *
344 * This is intended as a debugging tool for the developer only.
345 * Please refrain from leaving trace_printks scattered around in
346 * your code. (Extra memory is used for special buffers that are
347 * allocated when trace_printk() is used.)
348 *
349 * A little optimization trick is done here. If there's only one
350 * argument, there's no need to scan the string for printf formats.
351 * The trace_puts() will suffice. But how can we take advantage of
352 * using trace_puts() when trace_printk() has only one argument?
353 * By stringifying the args and checking the size we can tell
354 * whether or not there are args. __stringify((__VA_ARGS__)) will
355 * turn into "()\0" with a size of 3 when there are no args, anything
356 * else will be bigger. All we need to do is define a string to this,
357 * and then take its size and compare to 3. If it's bigger, use
358 * do_trace_printk() otherwise, optimize it to trace_puts(). Then just
359 * let gcc optimize the rest.
360 */
361
362#define trace_printk(fmt, ...) \
363do { \
364 char _______STR[] = __stringify((__VA_ARGS__)); \
365 if (sizeof(_______STR) > 3) \
366 do_trace_printk(fmt, ##__VA_ARGS__); \
367 else \
368 trace_puts(fmt); \
369} while (0)
370
371#define do_trace_printk(fmt, args...) \
372do { \
373 static const char *trace_printk_fmt __used \
374 __section("__trace_printk_fmt") = \
375 __builtin_constant_p(fmt) ? fmt : NULL; \
376 \
377 __trace_printk_check_format(fmt, ##args); \
378 \
379 if (__builtin_constant_p(fmt)) \
380 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \
381 else \
382 __trace_printk(_THIS_IP_, fmt, ##args); \
383} while (0)
384
385extern __printf(2, 3)
386int __trace_bprintk(unsigned long ip, const char *fmt, ...);
387
388extern __printf(2, 3)
389int __trace_printk(unsigned long ip, const char *fmt, ...);
390
391/**
392 * trace_puts - write a string into the ftrace buffer
393 * @str: the string to record
394 *
395 * Note: __trace_bputs is an internal function for trace_puts and
396 * the @ip is passed in via the trace_puts macro.
397 *
398 * This is similar to trace_printk() but is made for those really fast
399 * paths that a developer wants the least amount of "Heisenbug" effects,
400 * where the processing of the print format is still too much.
401 *
402 * This function allows a kernel developer to debug fast path sections
403 * that printk is not appropriate for. By scattering in various
404 * printk like tracing in the code, a developer can quickly see
405 * where problems are occurring.
406 *
407 * This is intended as a debugging tool for the developer only.
408 * Please refrain from leaving trace_puts scattered around in
409 * your code. (Extra memory is used for special buffers that are
410 * allocated when trace_puts() is used.)
411 *
412 * Returns: 0 if nothing was written, positive # if string was.
413 * (1 when __trace_bputs is used, strlen(str) when __trace_puts is used)
414 */
415
416#define trace_puts(str) ({ \
417 static const char *trace_printk_fmt __used \
418 __section("__trace_printk_fmt") = \
419 __builtin_constant_p(str) ? str : NULL; \
420 \
421 if (__builtin_constant_p(str)) \
422 __trace_bputs(_THIS_IP_, trace_printk_fmt); \
423 else \
424 __trace_puts(_THIS_IP_, str, strlen(str)); \
425})
426extern int __trace_bputs(unsigned long ip, const char *str);
427extern int __trace_puts(unsigned long ip, const char *str, int size);
428
429extern void trace_dump_stack(int skip);
430
431/*
432 * The double __builtin_constant_p is because gcc will give us an error
433 * if we try to allocate the static variable to fmt if it is not a
434 * constant. Even with the outer if statement.
435 */
436#define ftrace_vprintk(fmt, vargs) \
437do { \
438 if (__builtin_constant_p(fmt)) { \
439 static const char *trace_printk_fmt __used \
440 __section("__trace_printk_fmt") = \
441 __builtin_constant_p(fmt) ? fmt : NULL; \
442 \
443 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \
444 } else \
445 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \
446} while (0)
447
448extern __printf(2, 0) int
449__ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
450
451extern __printf(2, 0) int
452__ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
453
454extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode);
455#else
456static inline void tracing_start(void) { }
457static inline void tracing_stop(void) { }
458static inline void trace_dump_stack(int skip) { }
459
460static inline void tracing_on(void) { }
461static inline void tracing_off(void) { }
462static inline int tracing_is_on(void) { return 0; }
463static inline void tracing_snapshot(void) { }
464static inline void tracing_snapshot_alloc(void) { }
465
466static inline __printf(1, 2)
467int trace_printk(const char *fmt, ...)
468{
469 return 0;
470}
471static __printf(1, 0) inline int
472ftrace_vprintk(const char *fmt, va_list ap)
473{
474 return 0;
475}
476static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
477#endif /* CONFIG_TRACING */
478
479/* This counts to 12. Any more, it will return 13th argument. */
480#define __COUNT_ARGS(_0, _1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11, _12, _n, X...) _n
481#define COUNT_ARGS(X...) __COUNT_ARGS(, ##X, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0)
482
483#define __CONCAT(a, b) a ## b
484#define CONCATENATE(a, b) __CONCAT(a, b)
485
486/**
487 * container_of - cast a member of a structure out to the containing structure
488 * @ptr: the pointer to the member.
489 * @type: the type of the container struct this is embedded in.
490 * @member: the name of the member within the struct.
491 *
492 */
493#define container_of(ptr, type, member) ({ \
494 void *__mptr = (void *)(ptr); \
495 BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \
496 !__same_type(*(ptr), void), \
497 "pointer type mismatch in container_of()"); \
498 ((type *)(__mptr - offsetof(type, member))); })
499
500/**
501 * container_of_safe - cast a member of a structure out to the containing structure
502 * @ptr: the pointer to the member.
503 * @type: the type of the container struct this is embedded in.
504 * @member: the name of the member within the struct.
505 *
506 * If IS_ERR_OR_NULL(ptr), ptr is returned unchanged.
507 */
508#define container_of_safe(ptr, type, member) ({ \
509 void *__mptr = (void *)(ptr); \
510 BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \
511 !__same_type(*(ptr), void), \
512 "pointer type mismatch in container_of()"); \
513 IS_ERR_OR_NULL(__mptr) ? ERR_CAST(__mptr) : \
514 ((type *)(__mptr - offsetof(type, member))); })
515
516/* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
517#ifdef CONFIG_FTRACE_MCOUNT_RECORD
518# define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
519#endif
520
521/* Permissions on a sysfs file: you didn't miss the 0 prefix did you? */
522#define VERIFY_OCTAL_PERMISSIONS(perms) \
523 (BUILD_BUG_ON_ZERO((perms) < 0) + \
524 BUILD_BUG_ON_ZERO((perms) > 0777) + \
525 /* USER_READABLE >= GROUP_READABLE >= OTHER_READABLE */ \
526 BUILD_BUG_ON_ZERO((((perms) >> 6) & 4) < (((perms) >> 3) & 4)) + \
527 BUILD_BUG_ON_ZERO((((perms) >> 3) & 4) < ((perms) & 4)) + \
528 /* USER_WRITABLE >= GROUP_WRITABLE */ \
529 BUILD_BUG_ON_ZERO((((perms) >> 6) & 2) < (((perms) >> 3) & 2)) + \
530 /* OTHER_WRITABLE? Generally considered a bad idea. */ \
531 BUILD_BUG_ON_ZERO((perms) & 2) + \
532 (perms))
533#endif
1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * NOTE:
4 *
5 * This header has combined a lot of unrelated to each other stuff.
6 * The process of splitting its content is in progress while keeping
7 * backward compatibility. That's why it's highly recommended NOT to
8 * include this header inside another header file, especially under
9 * generic or architectural include/ directory.
10 */
11#ifndef _LINUX_KERNEL_H
12#define _LINUX_KERNEL_H
13
14#include <linux/stdarg.h>
15#include <linux/align.h>
16#include <linux/array_size.h>
17#include <linux/limits.h>
18#include <linux/linkage.h>
19#include <linux/stddef.h>
20#include <linux/types.h>
21#include <linux/compiler.h>
22#include <linux/container_of.h>
23#include <linux/bitops.h>
24#include <linux/hex.h>
25#include <linux/kstrtox.h>
26#include <linux/log2.h>
27#include <linux/math.h>
28#include <linux/minmax.h>
29#include <linux/typecheck.h>
30#include <linux/panic.h>
31#include <linux/printk.h>
32#include <linux/build_bug.h>
33#include <linux/sprintf.h>
34#include <linux/static_call_types.h>
35#include <linux/instruction_pointer.h>
36#include <linux/wordpart.h>
37
38#include <asm/byteorder.h>
39
40#include <uapi/linux/kernel.h>
41
42#define STACK_MAGIC 0xdeadbeef
43
44/* generic data direction definitions */
45#define READ 0
46#define WRITE 1
47
48#define PTR_IF(cond, ptr) ((cond) ? (ptr) : NULL)
49
50#define u64_to_user_ptr(x) ( \
51{ \
52 typecheck(u64, (x)); \
53 (void __user *)(uintptr_t)(x); \
54} \
55)
56
57struct completion;
58struct user;
59
60#ifdef CONFIG_PREEMPT_VOLUNTARY_BUILD
61
62extern int __cond_resched(void);
63# define might_resched() __cond_resched()
64
65#elif defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL)
66
67extern int __cond_resched(void);
68
69DECLARE_STATIC_CALL(might_resched, __cond_resched);
70
71static __always_inline void might_resched(void)
72{
73 static_call_mod(might_resched)();
74}
75
76#elif defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY)
77
78extern int dynamic_might_resched(void);
79# define might_resched() dynamic_might_resched()
80
81#else
82
83# define might_resched() do { } while (0)
84
85#endif /* CONFIG_PREEMPT_* */
86
87#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
88extern void __might_resched(const char *file, int line, unsigned int offsets);
89extern void __might_sleep(const char *file, int line);
90extern void __cant_sleep(const char *file, int line, int preempt_offset);
91extern void __cant_migrate(const char *file, int line);
92
93/**
94 * might_sleep - annotation for functions that can sleep
95 *
96 * this macro will print a stack trace if it is executed in an atomic
97 * context (spinlock, irq-handler, ...). Additional sections where blocking is
98 * not allowed can be annotated with non_block_start() and non_block_end()
99 * pairs.
100 *
101 * This is a useful debugging help to be able to catch problems early and not
102 * be bitten later when the calling function happens to sleep when it is not
103 * supposed to.
104 */
105# define might_sleep() \
106 do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0)
107/**
108 * cant_sleep - annotation for functions that cannot sleep
109 *
110 * this macro will print a stack trace if it is executed with preemption enabled
111 */
112# define cant_sleep() \
113 do { __cant_sleep(__FILE__, __LINE__, 0); } while (0)
114# define sched_annotate_sleep() (current->task_state_change = 0)
115
116/**
117 * cant_migrate - annotation for functions that cannot migrate
118 *
119 * Will print a stack trace if executed in code which is migratable
120 */
121# define cant_migrate() \
122 do { \
123 if (IS_ENABLED(CONFIG_SMP)) \
124 __cant_migrate(__FILE__, __LINE__); \
125 } while (0)
126
127/**
128 * non_block_start - annotate the start of section where sleeping is prohibited
129 *
130 * This is on behalf of the oom reaper, specifically when it is calling the mmu
131 * notifiers. The problem is that if the notifier were to block on, for example,
132 * mutex_lock() and if the process which holds that mutex were to perform a
133 * sleeping memory allocation, the oom reaper is now blocked on completion of
134 * that memory allocation. Other blocking calls like wait_event() pose similar
135 * issues.
136 */
137# define non_block_start() (current->non_block_count++)
138/**
139 * non_block_end - annotate the end of section where sleeping is prohibited
140 *
141 * Closes a section opened by non_block_start().
142 */
143# define non_block_end() WARN_ON(current->non_block_count-- == 0)
144#else
145 static inline void __might_resched(const char *file, int line,
146 unsigned int offsets) { }
147static inline void __might_sleep(const char *file, int line) { }
148# define might_sleep() do { might_resched(); } while (0)
149# define cant_sleep() do { } while (0)
150# define cant_migrate() do { } while (0)
151# define sched_annotate_sleep() do { } while (0)
152# define non_block_start() do { } while (0)
153# define non_block_end() do { } while (0)
154#endif
155
156#define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
157
158#if defined(CONFIG_MMU) && \
159 (defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP))
160#define might_fault() __might_fault(__FILE__, __LINE__)
161void __might_fault(const char *file, int line);
162#else
163static inline void might_fault(void) { }
164#endif
165
166void do_exit(long error_code) __noreturn;
167
168extern int core_kernel_text(unsigned long addr);
169extern int __kernel_text_address(unsigned long addr);
170extern int kernel_text_address(unsigned long addr);
171extern int func_ptr_is_kernel_text(void *ptr);
172
173extern void bust_spinlocks(int yes);
174
175extern int root_mountflags;
176
177extern bool early_boot_irqs_disabled;
178
179/*
180 * Values used for system_state. Ordering of the states must not be changed
181 * as code checks for <, <=, >, >= STATE.
182 */
183extern enum system_states {
184 SYSTEM_BOOTING,
185 SYSTEM_SCHEDULING,
186 SYSTEM_FREEING_INITMEM,
187 SYSTEM_RUNNING,
188 SYSTEM_HALT,
189 SYSTEM_POWER_OFF,
190 SYSTEM_RESTART,
191 SYSTEM_SUSPEND,
192} system_state;
193
194/*
195 * General tracing related utility functions - trace_printk(),
196 * tracing_on/tracing_off and tracing_start()/tracing_stop
197 *
198 * Use tracing_on/tracing_off when you want to quickly turn on or off
199 * tracing. It simply enables or disables the recording of the trace events.
200 * This also corresponds to the user space /sys/kernel/tracing/tracing_on
201 * file, which gives a means for the kernel and userspace to interact.
202 * Place a tracing_off() in the kernel where you want tracing to end.
203 * From user space, examine the trace, and then echo 1 > tracing_on
204 * to continue tracing.
205 *
206 * tracing_stop/tracing_start has slightly more overhead. It is used
207 * by things like suspend to ram where disabling the recording of the
208 * trace is not enough, but tracing must actually stop because things
209 * like calling smp_processor_id() may crash the system.
210 *
211 * Most likely, you want to use tracing_on/tracing_off.
212 */
213
214enum ftrace_dump_mode {
215 DUMP_NONE,
216 DUMP_ALL,
217 DUMP_ORIG,
218 DUMP_PARAM,
219};
220
221#ifdef CONFIG_TRACING
222void tracing_on(void);
223void tracing_off(void);
224int tracing_is_on(void);
225void tracing_snapshot(void);
226void tracing_snapshot_alloc(void);
227
228extern void tracing_start(void);
229extern void tracing_stop(void);
230
231static inline __printf(1, 2)
232void ____trace_printk_check_format(const char *fmt, ...)
233{
234}
235#define __trace_printk_check_format(fmt, args...) \
236do { \
237 if (0) \
238 ____trace_printk_check_format(fmt, ##args); \
239} while (0)
240
241/**
242 * trace_printk - printf formatting in the ftrace buffer
243 * @fmt: the printf format for printing
244 *
245 * Note: __trace_printk is an internal function for trace_printk() and
246 * the @ip is passed in via the trace_printk() macro.
247 *
248 * This function allows a kernel developer to debug fast path sections
249 * that printk is not appropriate for. By scattering in various
250 * printk like tracing in the code, a developer can quickly see
251 * where problems are occurring.
252 *
253 * This is intended as a debugging tool for the developer only.
254 * Please refrain from leaving trace_printks scattered around in
255 * your code. (Extra memory is used for special buffers that are
256 * allocated when trace_printk() is used.)
257 *
258 * A little optimization trick is done here. If there's only one
259 * argument, there's no need to scan the string for printf formats.
260 * The trace_puts() will suffice. But how can we take advantage of
261 * using trace_puts() when trace_printk() has only one argument?
262 * By stringifying the args and checking the size we can tell
263 * whether or not there are args. __stringify((__VA_ARGS__)) will
264 * turn into "()\0" with a size of 3 when there are no args, anything
265 * else will be bigger. All we need to do is define a string to this,
266 * and then take its size and compare to 3. If it's bigger, use
267 * do_trace_printk() otherwise, optimize it to trace_puts(). Then just
268 * let gcc optimize the rest.
269 */
270
271#define trace_printk(fmt, ...) \
272do { \
273 char _______STR[] = __stringify((__VA_ARGS__)); \
274 if (sizeof(_______STR) > 3) \
275 do_trace_printk(fmt, ##__VA_ARGS__); \
276 else \
277 trace_puts(fmt); \
278} while (0)
279
280#define do_trace_printk(fmt, args...) \
281do { \
282 static const char *trace_printk_fmt __used \
283 __section("__trace_printk_fmt") = \
284 __builtin_constant_p(fmt) ? fmt : NULL; \
285 \
286 __trace_printk_check_format(fmt, ##args); \
287 \
288 if (__builtin_constant_p(fmt)) \
289 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \
290 else \
291 __trace_printk(_THIS_IP_, fmt, ##args); \
292} while (0)
293
294extern __printf(2, 3)
295int __trace_bprintk(unsigned long ip, const char *fmt, ...);
296
297extern __printf(2, 3)
298int __trace_printk(unsigned long ip, const char *fmt, ...);
299
300/**
301 * trace_puts - write a string into the ftrace buffer
302 * @str: the string to record
303 *
304 * Note: __trace_bputs is an internal function for trace_puts and
305 * the @ip is passed in via the trace_puts macro.
306 *
307 * This is similar to trace_printk() but is made for those really fast
308 * paths that a developer wants the least amount of "Heisenbug" effects,
309 * where the processing of the print format is still too much.
310 *
311 * This function allows a kernel developer to debug fast path sections
312 * that printk is not appropriate for. By scattering in various
313 * printk like tracing in the code, a developer can quickly see
314 * where problems are occurring.
315 *
316 * This is intended as a debugging tool for the developer only.
317 * Please refrain from leaving trace_puts scattered around in
318 * your code. (Extra memory is used for special buffers that are
319 * allocated when trace_puts() is used.)
320 *
321 * Returns: 0 if nothing was written, positive # if string was.
322 * (1 when __trace_bputs is used, strlen(str) when __trace_puts is used)
323 */
324
325#define trace_puts(str) ({ \
326 static const char *trace_printk_fmt __used \
327 __section("__trace_printk_fmt") = \
328 __builtin_constant_p(str) ? str : NULL; \
329 \
330 if (__builtin_constant_p(str)) \
331 __trace_bputs(_THIS_IP_, trace_printk_fmt); \
332 else \
333 __trace_puts(_THIS_IP_, str, strlen(str)); \
334})
335extern int __trace_bputs(unsigned long ip, const char *str);
336extern int __trace_puts(unsigned long ip, const char *str, int size);
337
338extern void trace_dump_stack(int skip);
339
340/*
341 * The double __builtin_constant_p is because gcc will give us an error
342 * if we try to allocate the static variable to fmt if it is not a
343 * constant. Even with the outer if statement.
344 */
345#define ftrace_vprintk(fmt, vargs) \
346do { \
347 if (__builtin_constant_p(fmt)) { \
348 static const char *trace_printk_fmt __used \
349 __section("__trace_printk_fmt") = \
350 __builtin_constant_p(fmt) ? fmt : NULL; \
351 \
352 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \
353 } else \
354 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \
355} while (0)
356
357extern __printf(2, 0) int
358__ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
359
360extern __printf(2, 0) int
361__ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
362
363extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode);
364#else
365static inline void tracing_start(void) { }
366static inline void tracing_stop(void) { }
367static inline void trace_dump_stack(int skip) { }
368
369static inline void tracing_on(void) { }
370static inline void tracing_off(void) { }
371static inline int tracing_is_on(void) { return 0; }
372static inline void tracing_snapshot(void) { }
373static inline void tracing_snapshot_alloc(void) { }
374
375static inline __printf(1, 2)
376int trace_printk(const char *fmt, ...)
377{
378 return 0;
379}
380static __printf(1, 0) inline int
381ftrace_vprintk(const char *fmt, va_list ap)
382{
383 return 0;
384}
385static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
386#endif /* CONFIG_TRACING */
387
388/* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
389#ifdef CONFIG_FTRACE_MCOUNT_RECORD
390# define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
391#endif
392
393/* Permissions on a sysfs file: you didn't miss the 0 prefix did you? */
394#define VERIFY_OCTAL_PERMISSIONS(perms) \
395 (BUILD_BUG_ON_ZERO((perms) < 0) + \
396 BUILD_BUG_ON_ZERO((perms) > 0777) + \
397 /* USER_READABLE >= GROUP_READABLE >= OTHER_READABLE */ \
398 BUILD_BUG_ON_ZERO((((perms) >> 6) & 4) < (((perms) >> 3) & 4)) + \
399 BUILD_BUG_ON_ZERO((((perms) >> 3) & 4) < ((perms) & 4)) + \
400 /* USER_WRITABLE >= GROUP_WRITABLE */ \
401 BUILD_BUG_ON_ZERO((((perms) >> 6) & 2) < (((perms) >> 3) & 2)) + \
402 /* OTHER_WRITABLE? Generally considered a bad idea. */ \
403 BUILD_BUG_ON_ZERO((perms) & 2) + \
404 (perms))
405#endif