linux/include/linux/kernel.h
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   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _LINUX_KERNEL_H
   3#define _LINUX_KERNEL_H
   4
   5
   6#include <stdarg.h>
   7#include <linux/linkage.h>
   8#include <linux/stddef.h>
   9#include <linux/types.h>
  10#include <linux/compiler.h>
  11#include <linux/bitops.h>
  12#include <linux/log2.h>
  13#include <linux/typecheck.h>
  14#include <linux/printk.h>
  15#include <linux/build_bug.h>
  16#include <asm/byteorder.h>
  17#include <uapi/linux/kernel.h>
  18
  19#define USHRT_MAX       ((u16)(~0U))
  20#define SHRT_MAX        ((s16)(USHRT_MAX>>1))
  21#define SHRT_MIN        ((s16)(-SHRT_MAX - 1))
  22#define INT_MAX         ((int)(~0U>>1))
  23#define INT_MIN         (-INT_MAX - 1)
  24#define UINT_MAX        (~0U)
  25#define LONG_MAX        ((long)(~0UL>>1))
  26#define LONG_MIN        (-LONG_MAX - 1)
  27#define ULONG_MAX       (~0UL)
  28#define LLONG_MAX       ((long long)(~0ULL>>1))
  29#define LLONG_MIN       (-LLONG_MAX - 1)
  30#define ULLONG_MAX      (~0ULL)
  31#define SIZE_MAX        (~(size_t)0)
  32
  33#define U8_MAX          ((u8)~0U)
  34#define S8_MAX          ((s8)(U8_MAX>>1))
  35#define S8_MIN          ((s8)(-S8_MAX - 1))
  36#define U16_MAX         ((u16)~0U)
  37#define S16_MAX         ((s16)(U16_MAX>>1))
  38#define S16_MIN         ((s16)(-S16_MAX - 1))
  39#define U32_MAX         ((u32)~0U)
  40#define S32_MAX         ((s32)(U32_MAX>>1))
  41#define S32_MIN         ((s32)(-S32_MAX - 1))
  42#define U64_MAX         ((u64)~0ULL)
  43#define S64_MAX         ((s64)(U64_MAX>>1))
  44#define S64_MIN         ((s64)(-S64_MAX - 1))
  45
  46#define STACK_MAGIC     0xdeadbeef
  47
  48/**
  49 * REPEAT_BYTE - repeat the value @x multiple times as an unsigned long value
  50 * @x: value to repeat
  51 *
  52 * NOTE: @x is not checked for > 0xff; larger values produce odd results.
  53 */
  54#define REPEAT_BYTE(x)  ((~0ul / 0xff) * (x))
  55
  56/* @a is a power of 2 value */
  57#define ALIGN(x, a)             __ALIGN_KERNEL((x), (a))
  58#define ALIGN_DOWN(x, a)        __ALIGN_KERNEL((x) - ((a) - 1), (a))
  59#define __ALIGN_MASK(x, mask)   __ALIGN_KERNEL_MASK((x), (mask))
  60#define PTR_ALIGN(p, a)         ((typeof(p))ALIGN((unsigned long)(p), (a)))
  61#define IS_ALIGNED(x, a)                (((x) & ((typeof(x))(a) - 1)) == 0)
  62
  63/* generic data direction definitions */
  64#define READ                    0
  65#define WRITE                   1
  66
  67/**
  68 * ARRAY_SIZE - get the number of elements in array @arr
  69 * @arr: array to be sized
  70 */
  71#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
  72
  73#define u64_to_user_ptr(x) (            \
  74{                                       \
  75        typecheck(u64, x);              \
  76        (void __user *)(uintptr_t)x;    \
  77}                                       \
  78)
  79
  80/*
  81 * This looks more complex than it should be. But we need to
  82 * get the type for the ~ right in round_down (it needs to be
  83 * as wide as the result!), and we want to evaluate the macro
  84 * arguments just once each.
  85 */
  86#define __round_mask(x, y) ((__typeof__(x))((y)-1))
  87#define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
  88#define round_down(x, y) ((x) & ~__round_mask(x, y))
  89
  90/**
  91 * FIELD_SIZEOF - get the size of a struct's field
  92 * @t: the target struct
  93 * @f: the target struct's field
  94 * Return: the size of @f in the struct definition without having a
  95 * declared instance of @t.
  96 */
  97#define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
  98
  99#define DIV_ROUND_UP __KERNEL_DIV_ROUND_UP
 100
 101#define DIV_ROUND_DOWN_ULL(ll, d) \
 102        ({ unsigned long long _tmp = (ll); do_div(_tmp, d); _tmp; })
 103
 104#define DIV_ROUND_UP_ULL(ll, d)         DIV_ROUND_DOWN_ULL((ll) + (d) - 1, (d))
 105
 106#if BITS_PER_LONG == 32
 107# define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP_ULL(ll, d)
 108#else
 109# define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP(ll,d)
 110#endif
 111
 112/* The `const' in roundup() prevents gcc-3.3 from calling __divdi3 */
 113#define roundup(x, y) (                                 \
 114{                                                       \
 115        const typeof(y) __y = y;                        \
 116        (((x) + (__y - 1)) / __y) * __y;                \
 117}                                                       \
 118)
 119#define rounddown(x, y) (                               \
 120{                                                       \
 121        typeof(x) __x = (x);                            \
 122        __x - (__x % (y));                              \
 123}                                                       \
 124)
 125
 126/*
 127 * Divide positive or negative dividend by positive or negative divisor
 128 * and round to closest integer. Result is undefined for negative
 129 * divisors if the dividend variable type is unsigned and for negative
 130 * dividends if the divisor variable type is unsigned.
 131 */
 132#define DIV_ROUND_CLOSEST(x, divisor)(                  \
 133{                                                       \
 134        typeof(x) __x = x;                              \
 135        typeof(divisor) __d = divisor;                  \
 136        (((typeof(x))-1) > 0 ||                         \
 137         ((typeof(divisor))-1) > 0 ||                   \
 138         (((__x) > 0) == ((__d) > 0))) ?                \
 139                (((__x) + ((__d) / 2)) / (__d)) :       \
 140                (((__x) - ((__d) / 2)) / (__d));        \
 141}                                                       \
 142)
 143/*
 144 * Same as above but for u64 dividends. divisor must be a 32-bit
 145 * number.
 146 */
 147#define DIV_ROUND_CLOSEST_ULL(x, divisor)(              \
 148{                                                       \
 149        typeof(divisor) __d = divisor;                  \
 150        unsigned long long _tmp = (x) + (__d) / 2;      \
 151        do_div(_tmp, __d);                              \
 152        _tmp;                                           \
 153}                                                       \
 154)
 155
 156/*
 157 * Multiplies an integer by a fraction, while avoiding unnecessary
 158 * overflow or loss of precision.
 159 */
 160#define mult_frac(x, numer, denom)(                     \
 161{                                                       \
 162        typeof(x) quot = (x) / (denom);                 \
 163        typeof(x) rem  = (x) % (denom);                 \
 164        (quot * (numer)) + ((rem * (numer)) / (denom)); \
 165}                                                       \
 166)
 167
 168
 169#define _RET_IP_                (unsigned long)__builtin_return_address(0)
 170#define _THIS_IP_  ({ __label__ __here; __here: (unsigned long)&&__here; })
 171
 172#ifdef CONFIG_LBDAF
 173# include <asm/div64.h>
 174# define sector_div(a, b) do_div(a, b)
 175#else
 176# define sector_div(n, b)( \
 177{ \
 178        int _res; \
 179        _res = (n) % (b); \
 180        (n) /= (b); \
 181        _res; \
 182} \
 183)
 184#endif
 185
 186/**
 187 * upper_32_bits - return bits 32-63 of a number
 188 * @n: the number we're accessing
 189 *
 190 * A basic shift-right of a 64- or 32-bit quantity.  Use this to suppress
 191 * the "right shift count >= width of type" warning when that quantity is
 192 * 32-bits.
 193 */
 194#define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
 195
 196/**
 197 * lower_32_bits - return bits 0-31 of a number
 198 * @n: the number we're accessing
 199 */
 200#define lower_32_bits(n) ((u32)(n))
 201
 202struct completion;
 203struct pt_regs;
 204struct user;
 205
 206#ifdef CONFIG_PREEMPT_VOLUNTARY
 207extern int _cond_resched(void);
 208# define might_resched() _cond_resched()
 209#else
 210# define might_resched() do { } while (0)
 211#endif
 212
 213#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
 214  void ___might_sleep(const char *file, int line, int preempt_offset);
 215  void __might_sleep(const char *file, int line, int preempt_offset);
 216/**
 217 * might_sleep - annotation for functions that can sleep
 218 *
 219 * this macro will print a stack trace if it is executed in an atomic
 220 * context (spinlock, irq-handler, ...).
 221 *
 222 * This is a useful debugging help to be able to catch problems early and not
 223 * be bitten later when the calling function happens to sleep when it is not
 224 * supposed to.
 225 */
 226# define might_sleep() \
 227        do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
 228# define sched_annotate_sleep() (current->task_state_change = 0)
 229#else
 230  static inline void ___might_sleep(const char *file, int line,
 231                                   int preempt_offset) { }
 232  static inline void __might_sleep(const char *file, int line,
 233                                   int preempt_offset) { }
 234# define might_sleep() do { might_resched(); } while (0)
 235# define sched_annotate_sleep() do { } while (0)
 236#endif
 237
 238#define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
 239
 240/**
 241 * abs - return absolute value of an argument
 242 * @x: the value.  If it is unsigned type, it is converted to signed type first.
 243 *     char is treated as if it was signed (regardless of whether it really is)
 244 *     but the macro's return type is preserved as char.
 245 *
 246 * Return: an absolute value of x.
 247 */
 248#define abs(x)  __abs_choose_expr(x, long long,                         \
 249                __abs_choose_expr(x, long,                              \
 250                __abs_choose_expr(x, int,                               \
 251                __abs_choose_expr(x, short,                             \
 252                __abs_choose_expr(x, char,                              \
 253                __builtin_choose_expr(                                  \
 254                        __builtin_types_compatible_p(typeof(x), char),  \
 255                        (char)({ signed char __x = (x); __x<0?-__x:__x; }), \
 256                        ((void)0)))))))
 257
 258#define __abs_choose_expr(x, type, other) __builtin_choose_expr(        \
 259        __builtin_types_compatible_p(typeof(x),   signed type) ||       \
 260        __builtin_types_compatible_p(typeof(x), unsigned type),         \
 261        ({ signed type __x = (x); __x < 0 ? -__x : __x; }), other)
 262
 263/**
 264 * reciprocal_scale - "scale" a value into range [0, ep_ro)
 265 * @val: value
 266 * @ep_ro: right open interval endpoint
 267 *
 268 * Perform a "reciprocal multiplication" in order to "scale" a value into
 269 * range [0, @ep_ro), where the upper interval endpoint is right-open.
 270 * This is useful, e.g. for accessing a index of an array containing
 271 * @ep_ro elements, for example. Think of it as sort of modulus, only that
 272 * the result isn't that of modulo. ;) Note that if initial input is a
 273 * small value, then result will return 0.
 274 *
 275 * Return: a result based on @val in interval [0, @ep_ro).
 276 */
 277static inline u32 reciprocal_scale(u32 val, u32 ep_ro)
 278{
 279        return (u32)(((u64) val * ep_ro) >> 32);
 280}
 281
 282#if defined(CONFIG_MMU) && \
 283        (defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP))
 284#define might_fault() __might_fault(__FILE__, __LINE__)
 285void __might_fault(const char *file, int line);
 286#else
 287static inline void might_fault(void) { }
 288#endif
 289
 290extern struct atomic_notifier_head panic_notifier_list;
 291extern long (*panic_blink)(int state);
 292__printf(1, 2)
 293void panic(const char *fmt, ...) __noreturn __cold;
 294void nmi_panic(struct pt_regs *regs, const char *msg);
 295extern void oops_enter(void);
 296extern void oops_exit(void);
 297void print_oops_end_marker(void);
 298extern int oops_may_print(void);
 299void do_exit(long error_code) __noreturn;
 300void complete_and_exit(struct completion *, long) __noreturn;
 301
 302#ifdef CONFIG_ARCH_HAS_REFCOUNT
 303void refcount_error_report(struct pt_regs *regs, const char *err);
 304#else
 305static inline void refcount_error_report(struct pt_regs *regs, const char *err)
 306{ }
 307#endif
 308
 309/* Internal, do not use. */
 310int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res);
 311int __must_check _kstrtol(const char *s, unsigned int base, long *res);
 312
 313int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res);
 314int __must_check kstrtoll(const char *s, unsigned int base, long long *res);
 315
 316/**
 317 * kstrtoul - convert a string to an unsigned long
 318 * @s: The start of the string. The string must be null-terminated, and may also
 319 *  include a single newline before its terminating null. The first character
 320 *  may also be a plus sign, but not a minus sign.
 321 * @base: The number base to use. The maximum supported base is 16. If base is
 322 *  given as 0, then the base of the string is automatically detected with the
 323 *  conventional semantics - If it begins with 0x the number will be parsed as a
 324 *  hexadecimal (case insensitive), if it otherwise begins with 0, it will be
 325 *  parsed as an octal number. Otherwise it will be parsed as a decimal.
 326 * @res: Where to write the result of the conversion on success.
 327 *
 328 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
 329 * Used as a replacement for the obsolete simple_strtoull. Return code must
 330 * be checked.
 331*/
 332static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res)
 333{
 334        /*
 335         * We want to shortcut function call, but
 336         * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0.
 337         */
 338        if (sizeof(unsigned long) == sizeof(unsigned long long) &&
 339            __alignof__(unsigned long) == __alignof__(unsigned long long))
 340                return kstrtoull(s, base, (unsigned long long *)res);
 341        else
 342                return _kstrtoul(s, base, res);
 343}
 344
 345/**
 346 * kstrtol - convert a string to a long
 347 * @s: The start of the string. The string must be null-terminated, and may also
 348 *  include a single newline before its terminating null. The first character
 349 *  may also be a plus sign or a minus sign.
 350 * @base: The number base to use. The maximum supported base is 16. If base is
 351 *  given as 0, then the base of the string is automatically detected with the
 352 *  conventional semantics - If it begins with 0x the number will be parsed as a
 353 *  hexadecimal (case insensitive), if it otherwise begins with 0, it will be
 354 *  parsed as an octal number. Otherwise it will be parsed as a decimal.
 355 * @res: Where to write the result of the conversion on success.
 356 *
 357 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
 358 * Used as a replacement for the obsolete simple_strtoull. Return code must
 359 * be checked.
 360 */
 361static inline int __must_check kstrtol(const char *s, unsigned int base, long *res)
 362{
 363        /*
 364         * We want to shortcut function call, but
 365         * __builtin_types_compatible_p(long, long long) = 0.
 366         */
 367        if (sizeof(long) == sizeof(long long) &&
 368            __alignof__(long) == __alignof__(long long))
 369                return kstrtoll(s, base, (long long *)res);
 370        else
 371                return _kstrtol(s, base, res);
 372}
 373
 374int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res);
 375int __must_check kstrtoint(const char *s, unsigned int base, int *res);
 376
 377static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res)
 378{
 379        return kstrtoull(s, base, res);
 380}
 381
 382static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res)
 383{
 384        return kstrtoll(s, base, res);
 385}
 386
 387static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res)
 388{
 389        return kstrtouint(s, base, res);
 390}
 391
 392static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res)
 393{
 394        return kstrtoint(s, base, res);
 395}
 396
 397int __must_check kstrtou16(const char *s, unsigned int base, u16 *res);
 398int __must_check kstrtos16(const char *s, unsigned int base, s16 *res);
 399int __must_check kstrtou8(const char *s, unsigned int base, u8 *res);
 400int __must_check kstrtos8(const char *s, unsigned int base, s8 *res);
 401int __must_check kstrtobool(const char *s, bool *res);
 402
 403int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res);
 404int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res);
 405int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res);
 406int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res);
 407int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res);
 408int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res);
 409int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res);
 410int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res);
 411int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res);
 412int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res);
 413int __must_check kstrtobool_from_user(const char __user *s, size_t count, bool *res);
 414
 415static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res)
 416{
 417        return kstrtoull_from_user(s, count, base, res);
 418}
 419
 420static inline int __must_check kstrtos64_from_user(const char __user *s, size_t count, unsigned int base, s64 *res)
 421{
 422        return kstrtoll_from_user(s, count, base, res);
 423}
 424
 425static inline int __must_check kstrtou32_from_user(const char __user *s, size_t count, unsigned int base, u32 *res)
 426{
 427        return kstrtouint_from_user(s, count, base, res);
 428}
 429
 430static inline int __must_check kstrtos32_from_user(const char __user *s, size_t count, unsigned int base, s32 *res)
 431{
 432        return kstrtoint_from_user(s, count, base, res);
 433}
 434
 435/* Obsolete, do not use.  Use kstrto<foo> instead */
 436
 437extern unsigned long simple_strtoul(const char *,char **,unsigned int);
 438extern long simple_strtol(const char *,char **,unsigned int);
 439extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
 440extern long long simple_strtoll(const char *,char **,unsigned int);
 441
 442extern int num_to_str(char *buf, int size,
 443                      unsigned long long num, unsigned int width);
 444
 445/* lib/printf utilities */
 446
 447extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...);
 448extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list);
 449extern __printf(3, 4)
 450int snprintf(char *buf, size_t size, const char *fmt, ...);
 451extern __printf(3, 0)
 452int vsnprintf(char *buf, size_t size, const char *fmt, va_list args);
 453extern __printf(3, 4)
 454int scnprintf(char *buf, size_t size, const char *fmt, ...);
 455extern __printf(3, 0)
 456int vscnprintf(char *buf, size_t size, const char *fmt, va_list args);
 457extern __printf(2, 3) __malloc
 458char *kasprintf(gfp_t gfp, const char *fmt, ...);
 459extern __printf(2, 0) __malloc
 460char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
 461extern __printf(2, 0)
 462const char *kvasprintf_const(gfp_t gfp, const char *fmt, va_list args);
 463
 464extern __scanf(2, 3)
 465int sscanf(const char *, const char *, ...);
 466extern __scanf(2, 0)
 467int vsscanf(const char *, const char *, va_list);
 468
 469extern int get_option(char **str, int *pint);
 470extern char *get_options(const char *str, int nints, int *ints);
 471extern unsigned long long memparse(const char *ptr, char **retptr);
 472extern bool parse_option_str(const char *str, const char *option);
 473extern char *next_arg(char *args, char **param, char **val);
 474
 475extern int core_kernel_text(unsigned long addr);
 476extern int init_kernel_text(unsigned long addr);
 477extern int core_kernel_data(unsigned long addr);
 478extern int __kernel_text_address(unsigned long addr);
 479extern int kernel_text_address(unsigned long addr);
 480extern int func_ptr_is_kernel_text(void *ptr);
 481
 482unsigned long int_sqrt(unsigned long);
 483
 484#if BITS_PER_LONG < 64
 485u32 int_sqrt64(u64 x);
 486#else
 487static inline u32 int_sqrt64(u64 x)
 488{
 489        return (u32)int_sqrt(x);
 490}
 491#endif
 492
 493extern void bust_spinlocks(int yes);
 494extern int oops_in_progress;            /* If set, an oops, panic(), BUG() or die() is in progress */
 495extern int panic_timeout;
 496extern int panic_on_oops;
 497extern int panic_on_unrecovered_nmi;
 498extern int panic_on_io_nmi;
 499extern int panic_on_warn;
 500extern int sysctl_panic_on_rcu_stall;
 501extern int sysctl_panic_on_stackoverflow;
 502
 503extern bool crash_kexec_post_notifiers;
 504
 505/*
 506 * panic_cpu is used for synchronizing panic() and crash_kexec() execution. It
 507 * holds a CPU number which is executing panic() currently. A value of
 508 * PANIC_CPU_INVALID means no CPU has entered panic() or crash_kexec().
 509 */
 510extern atomic_t panic_cpu;
 511#define PANIC_CPU_INVALID       -1
 512
 513/*
 514 * Only to be used by arch init code. If the user over-wrote the default
 515 * CONFIG_PANIC_TIMEOUT, honor it.
 516 */
 517static inline void set_arch_panic_timeout(int timeout, int arch_default_timeout)
 518{
 519        if (panic_timeout == arch_default_timeout)
 520                panic_timeout = timeout;
 521}
 522extern const char *print_tainted(void);
 523enum lockdep_ok {
 524        LOCKDEP_STILL_OK,
 525        LOCKDEP_NOW_UNRELIABLE
 526};
 527extern void add_taint(unsigned flag, enum lockdep_ok);
 528extern int test_taint(unsigned flag);
 529extern unsigned long get_taint(void);
 530extern int root_mountflags;
 531
 532extern bool early_boot_irqs_disabled;
 533
 534/*
 535 * Values used for system_state. Ordering of the states must not be changed
 536 * as code checks for <, <=, >, >= STATE.
 537 */
 538extern enum system_states {
 539        SYSTEM_BOOTING,
 540        SYSTEM_SCHEDULING,
 541        SYSTEM_RUNNING,
 542        SYSTEM_HALT,
 543        SYSTEM_POWER_OFF,
 544        SYSTEM_RESTART,
 545} system_state;
 546
 547/* This cannot be an enum because some may be used in assembly source. */
 548#define TAINT_PROPRIETARY_MODULE        0
 549#define TAINT_FORCED_MODULE             1
 550#define TAINT_CPU_OUT_OF_SPEC           2
 551#define TAINT_FORCED_RMMOD              3
 552#define TAINT_MACHINE_CHECK             4
 553#define TAINT_BAD_PAGE                  5
 554#define TAINT_USER                      6
 555#define TAINT_DIE                       7
 556#define TAINT_OVERRIDDEN_ACPI_TABLE     8
 557#define TAINT_WARN                      9
 558#define TAINT_CRAP                      10
 559#define TAINT_FIRMWARE_WORKAROUND       11
 560#define TAINT_OOT_MODULE                12
 561#define TAINT_UNSIGNED_MODULE           13
 562#define TAINT_SOFTLOCKUP                14
 563#define TAINT_LIVEPATCH                 15
 564#define TAINT_AUX                       16
 565#define TAINT_RANDSTRUCT                17
 566#define TAINT_FLAGS_COUNT               18
 567
 568struct taint_flag {
 569        char c_true;    /* character printed when tainted */
 570        char c_false;   /* character printed when not tainted */
 571        bool module;    /* also show as a per-module taint flag */
 572};
 573
 574extern const struct taint_flag taint_flags[TAINT_FLAGS_COUNT];
 575
 576extern const char hex_asc[];
 577#define hex_asc_lo(x)   hex_asc[((x) & 0x0f)]
 578#define hex_asc_hi(x)   hex_asc[((x) & 0xf0) >> 4]
 579
 580static inline char *hex_byte_pack(char *buf, u8 byte)
 581{
 582        *buf++ = hex_asc_hi(byte);
 583        *buf++ = hex_asc_lo(byte);
 584        return buf;
 585}
 586
 587extern const char hex_asc_upper[];
 588#define hex_asc_upper_lo(x)     hex_asc_upper[((x) & 0x0f)]
 589#define hex_asc_upper_hi(x)     hex_asc_upper[((x) & 0xf0) >> 4]
 590
 591static inline char *hex_byte_pack_upper(char *buf, u8 byte)
 592{
 593        *buf++ = hex_asc_upper_hi(byte);
 594        *buf++ = hex_asc_upper_lo(byte);
 595        return buf;
 596}
 597
 598extern int hex_to_bin(char ch);
 599extern int __must_check hex2bin(u8 *dst, const char *src, size_t count);
 600extern char *bin2hex(char *dst, const void *src, size_t count);
 601
 602bool mac_pton(const char *s, u8 *mac);
 603
 604/*
 605 * General tracing related utility functions - trace_printk(),
 606 * tracing_on/tracing_off and tracing_start()/tracing_stop
 607 *
 608 * Use tracing_on/tracing_off when you want to quickly turn on or off
 609 * tracing. It simply enables or disables the recording of the trace events.
 610 * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on
 611 * file, which gives a means for the kernel and userspace to interact.
 612 * Place a tracing_off() in the kernel where you want tracing to end.
 613 * From user space, examine the trace, and then echo 1 > tracing_on
 614 * to continue tracing.
 615 *
 616 * tracing_stop/tracing_start has slightly more overhead. It is used
 617 * by things like suspend to ram where disabling the recording of the
 618 * trace is not enough, but tracing must actually stop because things
 619 * like calling smp_processor_id() may crash the system.
 620 *
 621 * Most likely, you want to use tracing_on/tracing_off.
 622 */
 623
 624enum ftrace_dump_mode {
 625        DUMP_NONE,
 626        DUMP_ALL,
 627        DUMP_ORIG,
 628};
 629
 630#ifdef CONFIG_TRACING
 631void tracing_on(void);
 632void tracing_off(void);
 633int tracing_is_on(void);
 634void tracing_snapshot(void);
 635void tracing_snapshot_alloc(void);
 636
 637extern void tracing_start(void);
 638extern void tracing_stop(void);
 639
 640static inline __printf(1, 2)
 641void ____trace_printk_check_format(const char *fmt, ...)
 642{
 643}
 644#define __trace_printk_check_format(fmt, args...)                       \
 645do {                                                                    \
 646        if (0)                                                          \
 647                ____trace_printk_check_format(fmt, ##args);             \
 648} while (0)
 649
 650/**
 651 * trace_printk - printf formatting in the ftrace buffer
 652 * @fmt: the printf format for printing
 653 *
 654 * Note: __trace_printk is an internal function for trace_printk() and
 655 *       the @ip is passed in via the trace_printk() macro.
 656 *
 657 * This function allows a kernel developer to debug fast path sections
 658 * that printk is not appropriate for. By scattering in various
 659 * printk like tracing in the code, a developer can quickly see
 660 * where problems are occurring.
 661 *
 662 * This is intended as a debugging tool for the developer only.
 663 * Please refrain from leaving trace_printks scattered around in
 664 * your code. (Extra memory is used for special buffers that are
 665 * allocated when trace_printk() is used.)
 666 *
 667 * A little optization trick is done here. If there's only one
 668 * argument, there's no need to scan the string for printf formats.
 669 * The trace_puts() will suffice. But how can we take advantage of
 670 * using trace_puts() when trace_printk() has only one argument?
 671 * By stringifying the args and checking the size we can tell
 672 * whether or not there are args. __stringify((__VA_ARGS__)) will
 673 * turn into "()\0" with a size of 3 when there are no args, anything
 674 * else will be bigger. All we need to do is define a string to this,
 675 * and then take its size and compare to 3. If it's bigger, use
 676 * do_trace_printk() otherwise, optimize it to trace_puts(). Then just
 677 * let gcc optimize the rest.
 678 */
 679
 680#define trace_printk(fmt, ...)                          \
 681do {                                                    \
 682        char _______STR[] = __stringify((__VA_ARGS__)); \
 683        if (sizeof(_______STR) > 3)                     \
 684                do_trace_printk(fmt, ##__VA_ARGS__);    \
 685        else                                            \
 686                trace_puts(fmt);                        \
 687} while (0)
 688
 689#define do_trace_printk(fmt, args...)                                   \
 690do {                                                                    \
 691        static const char *trace_printk_fmt __used                      \
 692                __attribute__((section("__trace_printk_fmt"))) =        \
 693                __builtin_constant_p(fmt) ? fmt : NULL;                 \
 694                                                                        \
 695        __trace_printk_check_format(fmt, ##args);                       \
 696                                                                        \
 697        if (__builtin_constant_p(fmt))                                  \
 698                __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args);   \
 699        else                                                            \
 700                __trace_printk(_THIS_IP_, fmt, ##args);                 \
 701} while (0)
 702
 703extern __printf(2, 3)
 704int __trace_bprintk(unsigned long ip, const char *fmt, ...);
 705
 706extern __printf(2, 3)
 707int __trace_printk(unsigned long ip, const char *fmt, ...);
 708
 709/**
 710 * trace_puts - write a string into the ftrace buffer
 711 * @str: the string to record
 712 *
 713 * Note: __trace_bputs is an internal function for trace_puts and
 714 *       the @ip is passed in via the trace_puts macro.
 715 *
 716 * This is similar to trace_printk() but is made for those really fast
 717 * paths that a developer wants the least amount of "Heisenbug" effects,
 718 * where the processing of the print format is still too much.
 719 *
 720 * This function allows a kernel developer to debug fast path sections
 721 * that printk is not appropriate for. By scattering in various
 722 * printk like tracing in the code, a developer can quickly see
 723 * where problems are occurring.
 724 *
 725 * This is intended as a debugging tool for the developer only.
 726 * Please refrain from leaving trace_puts scattered around in
 727 * your code. (Extra memory is used for special buffers that are
 728 * allocated when trace_puts() is used.)
 729 *
 730 * Returns: 0 if nothing was written, positive # if string was.
 731 *  (1 when __trace_bputs is used, strlen(str) when __trace_puts is used)
 732 */
 733
 734#define trace_puts(str) ({                                              \
 735        static const char *trace_printk_fmt __used                      \
 736                __attribute__((section("__trace_printk_fmt"))) =        \
 737                __builtin_constant_p(str) ? str : NULL;                 \
 738                                                                        \
 739        if (__builtin_constant_p(str))                                  \
 740                __trace_bputs(_THIS_IP_, trace_printk_fmt);             \
 741        else                                                            \
 742                __trace_puts(_THIS_IP_, str, strlen(str));              \
 743})
 744extern int __trace_bputs(unsigned long ip, const char *str);
 745extern int __trace_puts(unsigned long ip, const char *str, int size);
 746
 747extern void trace_dump_stack(int skip);
 748
 749/*
 750 * The double __builtin_constant_p is because gcc will give us an error
 751 * if we try to allocate the static variable to fmt if it is not a
 752 * constant. Even with the outer if statement.
 753 */
 754#define ftrace_vprintk(fmt, vargs)                                      \
 755do {                                                                    \
 756        if (__builtin_constant_p(fmt)) {                                \
 757                static const char *trace_printk_fmt __used              \
 758                  __attribute__((section("__trace_printk_fmt"))) =      \
 759                        __builtin_constant_p(fmt) ? fmt : NULL;         \
 760                                                                        \
 761                __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs);  \
 762        } else                                                          \
 763                __ftrace_vprintk(_THIS_IP_, fmt, vargs);                \
 764} while (0)
 765
 766extern __printf(2, 0) int
 767__ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
 768
 769extern __printf(2, 0) int
 770__ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
 771
 772extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode);
 773#else
 774static inline void tracing_start(void) { }
 775static inline void tracing_stop(void) { }
 776static inline void trace_dump_stack(int skip) { }
 777
 778static inline void tracing_on(void) { }
 779static inline void tracing_off(void) { }
 780static inline int tracing_is_on(void) { return 0; }
 781static inline void tracing_snapshot(void) { }
 782static inline void tracing_snapshot_alloc(void) { }
 783
 784static inline __printf(1, 2)
 785int trace_printk(const char *fmt, ...)
 786{
 787        return 0;
 788}
 789static __printf(1, 0) inline int
 790ftrace_vprintk(const char *fmt, va_list ap)
 791{
 792        return 0;
 793}
 794static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
 795#endif /* CONFIG_TRACING */
 796
 797/*
 798 * min()/max()/clamp() macros must accomplish three things:
 799 *
 800 * - avoid multiple evaluations of the arguments (so side-effects like
 801 *   "x++" happen only once) when non-constant.
 802 * - perform strict type-checking (to generate warnings instead of
 803 *   nasty runtime surprises). See the "unnecessary" pointer comparison
 804 *   in __typecheck().
 805 * - retain result as a constant expressions when called with only
 806 *   constant expressions (to avoid tripping VLA warnings in stack
 807 *   allocation usage).
 808 */
 809#define __typecheck(x, y) \
 810                (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
 811
 812/*
 813 * This returns a constant expression while determining if an argument is
 814 * a constant expression, most importantly without evaluating the argument.
 815 * Glory to Martin Uecker <Martin.Uecker@med.uni-goettingen.de>
 816 */
 817#define __is_constexpr(x) \
 818        (sizeof(int) == sizeof(*(8 ? ((void *)((long)(x) * 0l)) : (int *)8)))
 819
 820#define __no_side_effects(x, y) \
 821                (__is_constexpr(x) && __is_constexpr(y))
 822
 823#define __safe_cmp(x, y) \
 824                (__typecheck(x, y) && __no_side_effects(x, y))
 825
 826#define __cmp(x, y, op) ((x) op (y) ? (x) : (y))
 827
 828#define __cmp_once(x, y, unique_x, unique_y, op) ({     \
 829                typeof(x) unique_x = (x);               \
 830                typeof(y) unique_y = (y);               \
 831                __cmp(unique_x, unique_y, op); })
 832
 833#define __careful_cmp(x, y, op) \
 834        __builtin_choose_expr(__safe_cmp(x, y), \
 835                __cmp(x, y, op), \
 836                __cmp_once(x, y, __UNIQUE_ID(__x), __UNIQUE_ID(__y), op))
 837
 838/**
 839 * min - return minimum of two values of the same or compatible types
 840 * @x: first value
 841 * @y: second value
 842 */
 843#define min(x, y)       __careful_cmp(x, y, <)
 844
 845/**
 846 * max - return maximum of two values of the same or compatible types
 847 * @x: first value
 848 * @y: second value
 849 */
 850#define max(x, y)       __careful_cmp(x, y, >)
 851
 852/**
 853 * min3 - return minimum of three values
 854 * @x: first value
 855 * @y: second value
 856 * @z: third value
 857 */
 858#define min3(x, y, z) min((typeof(x))min(x, y), z)
 859
 860/**
 861 * max3 - return maximum of three values
 862 * @x: first value
 863 * @y: second value
 864 * @z: third value
 865 */
 866#define max3(x, y, z) max((typeof(x))max(x, y), z)
 867
 868/**
 869 * min_not_zero - return the minimum that is _not_ zero, unless both are zero
 870 * @x: value1
 871 * @y: value2
 872 */
 873#define min_not_zero(x, y) ({                   \
 874        typeof(x) __x = (x);                    \
 875        typeof(y) __y = (y);                    \
 876        __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); })
 877
 878/**
 879 * clamp - return a value clamped to a given range with strict typechecking
 880 * @val: current value
 881 * @lo: lowest allowable value
 882 * @hi: highest allowable value
 883 *
 884 * This macro does strict typechecking of @lo/@hi to make sure they are of the
 885 * same type as @val.  See the unnecessary pointer comparisons.
 886 */
 887#define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi)
 888
 889/*
 890 * ..and if you can't take the strict
 891 * types, you can specify one yourself.
 892 *
 893 * Or not use min/max/clamp at all, of course.
 894 */
 895
 896/**
 897 * min_t - return minimum of two values, using the specified type
 898 * @type: data type to use
 899 * @x: first value
 900 * @y: second value
 901 */
 902#define min_t(type, x, y)       __careful_cmp((type)(x), (type)(y), <)
 903
 904/**
 905 * max_t - return maximum of two values, using the specified type
 906 * @type: data type to use
 907 * @x: first value
 908 * @y: second value
 909 */
 910#define max_t(type, x, y)       __careful_cmp((type)(x), (type)(y), >)
 911
 912/**
 913 * clamp_t - return a value clamped to a given range using a given type
 914 * @type: the type of variable to use
 915 * @val: current value
 916 * @lo: minimum allowable value
 917 * @hi: maximum allowable value
 918 *
 919 * This macro does no typechecking and uses temporary variables of type
 920 * @type to make all the comparisons.
 921 */
 922#define clamp_t(type, val, lo, hi) min_t(type, max_t(type, val, lo), hi)
 923
 924/**
 925 * clamp_val - return a value clamped to a given range using val's type
 926 * @val: current value
 927 * @lo: minimum allowable value
 928 * @hi: maximum allowable value
 929 *
 930 * This macro does no typechecking and uses temporary variables of whatever
 931 * type the input argument @val is.  This is useful when @val is an unsigned
 932 * type and @lo and @hi are literals that will otherwise be assigned a signed
 933 * integer type.
 934 */
 935#define clamp_val(val, lo, hi) clamp_t(typeof(val), val, lo, hi)
 936
 937
 938/**
 939 * swap - swap values of @a and @b
 940 * @a: first value
 941 * @b: second value
 942 */
 943#define swap(a, b) \
 944        do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
 945
 946/* This counts to 12. Any more, it will return 13th argument. */
 947#define __COUNT_ARGS(_0, _1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11, _12, _n, X...) _n
 948#define COUNT_ARGS(X...) __COUNT_ARGS(, ##X, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0)
 949
 950#define __CONCAT(a, b) a ## b
 951#define CONCATENATE(a, b) __CONCAT(a, b)
 952
 953/**
 954 * container_of - cast a member of a structure out to the containing structure
 955 * @ptr:        the pointer to the member.
 956 * @type:       the type of the container struct this is embedded in.
 957 * @member:     the name of the member within the struct.
 958 *
 959 */
 960#define container_of(ptr, type, member) ({                              \
 961        void *__mptr = (void *)(ptr);                                   \
 962        BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) &&   \
 963                         !__same_type(*(ptr), void),                    \
 964                         "pointer type mismatch in container_of()");    \
 965        ((type *)(__mptr - offsetof(type, member))); })
 966
 967/* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
 968#ifdef CONFIG_FTRACE_MCOUNT_RECORD
 969# define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
 970#endif
 971
 972/* Permissions on a sysfs file: you didn't miss the 0 prefix did you? */
 973#define VERIFY_OCTAL_PERMISSIONS(perms)                                         \
 974        (BUILD_BUG_ON_ZERO((perms) < 0) +                                       \
 975         BUILD_BUG_ON_ZERO((perms) > 0777) +                                    \
 976         /* USER_READABLE >= GROUP_READABLE >= OTHER_READABLE */                \
 977         BUILD_BUG_ON_ZERO((((perms) >> 6) & 4) < (((perms) >> 3) & 4)) +       \
 978         BUILD_BUG_ON_ZERO((((perms) >> 3) & 4) < ((perms) & 4)) +              \
 979         /* USER_WRITABLE >= GROUP_WRITABLE */                                  \
 980         BUILD_BUG_ON_ZERO((((perms) >> 6) & 2) < (((perms) >> 3) & 2)) +       \
 981         /* OTHER_WRITABLE?  Generally considered a bad idea. */                \
 982         BUILD_BUG_ON_ZERO((perms) & 2) +                                       \
 983         (perms))
 984#endif
 985