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/log2.h> 14 #include <linux/math.h> 15 #include <linux/minmax.h> 16 #include <linux/typecheck.h> 17 #include <linux/printk.h> 18 #include <linux/build_bug.h> 19 #include <linux/static_call_types.h> 20 #include <asm/byteorder.h> 21 22 #include <uapi/linux/kernel.h> 23 24 #define STACK_MAGIC 0xdeadbeef 25 26 /** 27 * REPEAT_BYTE - repeat the value @x multiple times as an unsigned long value 28 * @x: value to repeat 29 * 30 * NOTE: @x is not checked for > 0xff; larger values produce odd results. 31 */ 32 #define REPEAT_BYTE(x) ((~0ul / 0xff) * (x)) 33 34 /* generic data direction definitions */ 35 #define READ 0 36 #define WRITE 1 37 38 /** 39 * ARRAY_SIZE - get the number of elements in array @arr 40 * @arr: array to be sized 41 */ 42 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr)) 43 44 #define PTR_IF(cond, ptr) ((cond) ? (ptr) : NULL) 45 46 #define u64_to_user_ptr(x) ( \ 47 { \ 48 typecheck(u64, (x)); \ 49 (void __user *)(uintptr_t)(x); \ 50 } \ 51 ) 52 53 #define typeof_member(T, m) typeof(((T*)0)->m) 54 55 #define _RET_IP_ (unsigned long)__builtin_return_address(0) 56 #define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; }) 57 58 /** 59 * upper_32_bits - return bits 32-63 of a number 60 * @n: the number we're accessing 61 * 62 * A basic shift-right of a 64- or 32-bit quantity. Use this to suppress 63 * the "right shift count >= width of type" warning when that quantity is 64 * 32-bits. 65 */ 66 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16)) 67 68 /** 69 * lower_32_bits - return bits 0-31 of a number 70 * @n: the number we're accessing 71 */ 72 #define lower_32_bits(n) ((u32)((n) & 0xffffffff)) 73 74 /** 75 * upper_16_bits - return bits 16-31 of a number 76 * @n: the number we're accessing 77 */ 78 #define upper_16_bits(n) ((u16)((n) >> 16)) 79 80 /** 81 * lower_16_bits - return bits 0-15 of a number 82 * @n: the number we're accessing 83 */ 84 #define lower_16_bits(n) ((u16)((n) & 0xffff)) 85 86 struct completion; 87 struct pt_regs; 88 struct user; 89 90 #ifdef CONFIG_PREEMPT_VOLUNTARY 91 92 extern int __cond_resched(void); 93 # define might_resched() __cond_resched() 94 95 #elif defined(CONFIG_PREEMPT_DYNAMIC) 96 97 extern int __cond_resched(void); 98 99 DECLARE_STATIC_CALL(might_resched, __cond_resched); 100 101 static __always_inline void might_resched(void) 102 { 103 static_call_mod(might_resched)(); 104 } 105 106 #else 107 108 # define might_resched() do { } while (0) 109 110 #endif /* CONFIG_PREEMPT_* */ 111 112 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP 113 extern void ___might_sleep(const char *file, int line, int preempt_offset); 114 extern void __might_sleep(const char *file, int line, int preempt_offset); 115 extern void __cant_sleep(const char *file, int line, int preempt_offset); 116 extern void __cant_migrate(const char *file, int line); 117 118 /** 119 * might_sleep - annotation for functions that can sleep 120 * 121 * this macro will print a stack trace if it is executed in an atomic 122 * context (spinlock, irq-handler, ...). Additional sections where blocking is 123 * not allowed can be annotated with non_block_start() and non_block_end() 124 * pairs. 125 * 126 * This is a useful debugging help to be able to catch problems early and not 127 * be bitten later when the calling function happens to sleep when it is not 128 * supposed to. 129 */ 130 # define might_sleep() \ 131 do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0) 132 /** 133 * cant_sleep - annotation for functions that cannot sleep 134 * 135 * this macro will print a stack trace if it is executed with preemption enabled 136 */ 137 # define cant_sleep() \ 138 do { __cant_sleep(__FILE__, __LINE__, 0); } while (0) 139 # define sched_annotate_sleep() (current->task_state_change = 0) 140 141 /** 142 * cant_migrate - annotation for functions that cannot migrate 143 * 144 * Will print a stack trace if executed in code which is migratable 145 */ 146 # define cant_migrate() \ 147 do { \ 148 if (IS_ENABLED(CONFIG_SMP)) \ 149 __cant_migrate(__FILE__, __LINE__); \ 150 } while (0) 151 152 /** 153 * non_block_start - annotate the start of section where sleeping is prohibited 154 * 155 * This is on behalf of the oom reaper, specifically when it is calling the mmu 156 * notifiers. The problem is that if the notifier were to block on, for example, 157 * mutex_lock() and if the process which holds that mutex were to perform a 158 * sleeping memory allocation, the oom reaper is now blocked on completion of 159 * that memory allocation. Other blocking calls like wait_event() pose similar 160 * issues. 161 */ 162 # define non_block_start() (current->non_block_count++) 163 /** 164 * non_block_end - annotate the end of section where sleeping is prohibited 165 * 166 * Closes a section opened by non_block_start(). 167 */ 168 # define non_block_end() WARN_ON(current->non_block_count-- == 0) 169 #else 170 static inline void ___might_sleep(const char *file, int line, 171 int preempt_offset) { } 172 static inline void __might_sleep(const char *file, int line, 173 int preempt_offset) { } 174 # define might_sleep() do { might_resched(); } while (0) 175 # define cant_sleep() do { } while (0) 176 # define cant_migrate() do { } while (0) 177 # define sched_annotate_sleep() do { } while (0) 178 # define non_block_start() do { } while (0) 179 # define non_block_end() do { } while (0) 180 #endif 181 182 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0) 183 184 #if defined(CONFIG_MMU) && \ 185 (defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP)) 186 #define might_fault() __might_fault(__FILE__, __LINE__) 187 void __might_fault(const char *file, int line); 188 #else 189 static inline void might_fault(void) { } 190 #endif 191 192 extern struct atomic_notifier_head panic_notifier_list; 193 extern long (*panic_blink)(int state); 194 __printf(1, 2) 195 void panic(const char *fmt, ...) __noreturn __cold; 196 void nmi_panic(struct pt_regs *regs, const char *msg); 197 extern void oops_enter(void); 198 extern void oops_exit(void); 199 extern bool oops_may_print(void); 200 void do_exit(long error_code) __noreturn; 201 void complete_and_exit(struct completion *, long) __noreturn; 202 203 /* Internal, do not use. */ 204 int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res); 205 int __must_check _kstrtol(const char *s, unsigned int base, long *res); 206 207 int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res); 208 int __must_check kstrtoll(const char *s, unsigned int base, long long *res); 209 210 /** 211 * kstrtoul - convert a string to an unsigned long 212 * @s: The start of the string. The string must be null-terminated, and may also 213 * include a single newline before its terminating null. The first character 214 * may also be a plus sign, but not a minus sign. 215 * @base: The number base to use. The maximum supported base is 16. If base is 216 * given as 0, then the base of the string is automatically detected with the 217 * conventional semantics - If it begins with 0x the number will be parsed as a 218 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be 219 * parsed as an octal number. Otherwise it will be parsed as a decimal. 220 * @res: Where to write the result of the conversion on success. 221 * 222 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. 223 * Preferred over simple_strtoul(). Return code must be checked. 224 */ 225 static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res) 226 { 227 /* 228 * We want to shortcut function call, but 229 * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0. 230 */ 231 if (sizeof(unsigned long) == sizeof(unsigned long long) && 232 __alignof__(unsigned long) == __alignof__(unsigned long long)) 233 return kstrtoull(s, base, (unsigned long long *)res); 234 else 235 return _kstrtoul(s, base, res); 236 } 237 238 /** 239 * kstrtol - convert a string to a long 240 * @s: The start of the string. The string must be null-terminated, and may also 241 * include a single newline before its terminating null. The first character 242 * may also be a plus sign or a minus sign. 243 * @base: The number base to use. The maximum supported base is 16. If base is 244 * given as 0, then the base of the string is automatically detected with the 245 * conventional semantics - If it begins with 0x the number will be parsed as a 246 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be 247 * parsed as an octal number. Otherwise it will be parsed as a decimal. 248 * @res: Where to write the result of the conversion on success. 249 * 250 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. 251 * Preferred over simple_strtol(). Return code must be checked. 252 */ 253 static inline int __must_check kstrtol(const char *s, unsigned int base, long *res) 254 { 255 /* 256 * We want to shortcut function call, but 257 * __builtin_types_compatible_p(long, long long) = 0. 258 */ 259 if (sizeof(long) == sizeof(long long) && 260 __alignof__(long) == __alignof__(long long)) 261 return kstrtoll(s, base, (long long *)res); 262 else 263 return _kstrtol(s, base, res); 264 } 265 266 int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res); 267 int __must_check kstrtoint(const char *s, unsigned int base, int *res); 268 269 static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res) 270 { 271 return kstrtoull(s, base, res); 272 } 273 274 static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res) 275 { 276 return kstrtoll(s, base, res); 277 } 278 279 static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res) 280 { 281 return kstrtouint(s, base, res); 282 } 283 284 static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res) 285 { 286 return kstrtoint(s, base, res); 287 } 288 289 int __must_check kstrtou16(const char *s, unsigned int base, u16 *res); 290 int __must_check kstrtos16(const char *s, unsigned int base, s16 *res); 291 int __must_check kstrtou8(const char *s, unsigned int base, u8 *res); 292 int __must_check kstrtos8(const char *s, unsigned int base, s8 *res); 293 int __must_check kstrtobool(const char *s, bool *res); 294 295 int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res); 296 int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res); 297 int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res); 298 int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res); 299 int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res); 300 int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res); 301 int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res); 302 int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res); 303 int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res); 304 int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res); 305 int __must_check kstrtobool_from_user(const char __user *s, size_t count, bool *res); 306 307 static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res) 308 { 309 return kstrtoull_from_user(s, count, base, res); 310 } 311 312 static inline int __must_check kstrtos64_from_user(const char __user *s, size_t count, unsigned int base, s64 *res) 313 { 314 return kstrtoll_from_user(s, count, base, res); 315 } 316 317 static inline int __must_check kstrtou32_from_user(const char __user *s, size_t count, unsigned int base, u32 *res) 318 { 319 return kstrtouint_from_user(s, count, base, res); 320 } 321 322 static inline int __must_check kstrtos32_from_user(const char __user *s, size_t count, unsigned int base, s32 *res) 323 { 324 return kstrtoint_from_user(s, count, base, res); 325 } 326 327 /* 328 * Use kstrto<foo> instead. 329 * 330 * NOTE: simple_strto<foo> does not check for the range overflow and, 331 * depending on the input, may give interesting results. 332 * 333 * Use these functions if and only if you cannot use kstrto<foo>, because 334 * the conversion ends on the first non-digit character, which may be far 335 * beyond the supported range. It might be useful to parse the strings like 336 * 10x50 or 12:21 without altering original string or temporary buffer in use. 337 * Keep in mind above caveat. 338 */ 339 340 extern unsigned long simple_strtoul(const char *,char **,unsigned int); 341 extern long simple_strtol(const char *,char **,unsigned int); 342 extern unsigned long long simple_strtoull(const char *,char **,unsigned int); 343 extern long long simple_strtoll(const char *,char **,unsigned int); 344 345 extern int num_to_str(char *buf, int size, 346 unsigned long long num, unsigned int width); 347 348 /* lib/printf utilities */ 349 350 extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...); 351 extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list); 352 extern __printf(3, 4) 353 int snprintf(char *buf, size_t size, const char *fmt, ...); 354 extern __printf(3, 0) 355 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args); 356 extern __printf(3, 4) 357 int scnprintf(char *buf, size_t size, const char *fmt, ...); 358 extern __printf(3, 0) 359 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args); 360 extern __printf(2, 3) __malloc 361 char *kasprintf(gfp_t gfp, const char *fmt, ...); 362 extern __printf(2, 0) __malloc 363 char *kvasprintf(gfp_t gfp, const char *fmt, va_list args); 364 extern __printf(2, 0) 365 const char *kvasprintf_const(gfp_t gfp, const char *fmt, va_list args); 366 367 extern __scanf(2, 3) 368 int sscanf(const char *, const char *, ...); 369 extern __scanf(2, 0) 370 int vsscanf(const char *, const char *, va_list); 371 372 extern int no_hash_pointers_enable(char *str); 373 374 extern int get_option(char **str, int *pint); 375 extern char *get_options(const char *str, int nints, int *ints); 376 extern unsigned long long memparse(const char *ptr, char **retptr); 377 extern bool parse_option_str(const char *str, const char *option); 378 extern char *next_arg(char *args, char **param, char **val); 379 380 extern int core_kernel_text(unsigned long addr); 381 extern int init_kernel_text(unsigned long addr); 382 extern int core_kernel_data(unsigned long addr); 383 extern int __kernel_text_address(unsigned long addr); 384 extern int kernel_text_address(unsigned long addr); 385 extern int func_ptr_is_kernel_text(void *ptr); 386 387 #ifdef CONFIG_SMP 388 extern unsigned int sysctl_oops_all_cpu_backtrace; 389 #else 390 #define sysctl_oops_all_cpu_backtrace 0 391 #endif /* CONFIG_SMP */ 392 393 extern void bust_spinlocks(int yes); 394 extern int panic_timeout; 395 extern unsigned long panic_print; 396 extern int panic_on_oops; 397 extern int panic_on_unrecovered_nmi; 398 extern int panic_on_io_nmi; 399 extern int panic_on_warn; 400 extern unsigned long panic_on_taint; 401 extern bool panic_on_taint_nousertaint; 402 extern int sysctl_panic_on_rcu_stall; 403 extern int sysctl_max_rcu_stall_to_panic; 404 extern int sysctl_panic_on_stackoverflow; 405 406 extern bool crash_kexec_post_notifiers; 407 408 /* 409 * panic_cpu is used for synchronizing panic() and crash_kexec() execution. It 410 * holds a CPU number which is executing panic() currently. A value of 411 * PANIC_CPU_INVALID means no CPU has entered panic() or crash_kexec(). 412 */ 413 extern atomic_t panic_cpu; 414 #define PANIC_CPU_INVALID -1 415 416 /* 417 * Only to be used by arch init code. If the user over-wrote the default 418 * CONFIG_PANIC_TIMEOUT, honor it. 419 */ 420 static inline void set_arch_panic_timeout(int timeout, int arch_default_timeout) 421 { 422 if (panic_timeout == arch_default_timeout) 423 panic_timeout = timeout; 424 } 425 extern const char *print_tainted(void); 426 enum lockdep_ok { 427 LOCKDEP_STILL_OK, 428 LOCKDEP_NOW_UNRELIABLE 429 }; 430 extern void add_taint(unsigned flag, enum lockdep_ok); 431 extern int test_taint(unsigned flag); 432 extern unsigned long get_taint(void); 433 extern int root_mountflags; 434 435 extern bool early_boot_irqs_disabled; 436 437 /* 438 * Values used for system_state. Ordering of the states must not be changed 439 * as code checks for <, <=, >, >= STATE. 440 */ 441 extern enum system_states { 442 SYSTEM_BOOTING, 443 SYSTEM_SCHEDULING, 444 SYSTEM_RUNNING, 445 SYSTEM_HALT, 446 SYSTEM_POWER_OFF, 447 SYSTEM_RESTART, 448 SYSTEM_SUSPEND, 449 } system_state; 450 451 /* This cannot be an enum because some may be used in assembly source. */ 452 #define TAINT_PROPRIETARY_MODULE 0 453 #define TAINT_FORCED_MODULE 1 454 #define TAINT_CPU_OUT_OF_SPEC 2 455 #define TAINT_FORCED_RMMOD 3 456 #define TAINT_MACHINE_CHECK 4 457 #define TAINT_BAD_PAGE 5 458 #define TAINT_USER 6 459 #define TAINT_DIE 7 460 #define TAINT_OVERRIDDEN_ACPI_TABLE 8 461 #define TAINT_WARN 9 462 #define TAINT_CRAP 10 463 #define TAINT_FIRMWARE_WORKAROUND 11 464 #define TAINT_OOT_MODULE 12 465 #define TAINT_UNSIGNED_MODULE 13 466 #define TAINT_SOFTLOCKUP 14 467 #define TAINT_LIVEPATCH 15 468 #define TAINT_AUX 16 469 #define TAINT_RANDSTRUCT 17 470 #define TAINT_FLAGS_COUNT 18 471 #define TAINT_FLAGS_MAX ((1UL << TAINT_FLAGS_COUNT) - 1) 472 473 struct taint_flag { 474 char c_true; /* character printed when tainted */ 475 char c_false; /* character printed when not tainted */ 476 bool module; /* also show as a per-module taint flag */ 477 }; 478 479 extern const struct taint_flag taint_flags[TAINT_FLAGS_COUNT]; 480 481 extern const char hex_asc[]; 482 #define hex_asc_lo(x) hex_asc[((x) & 0x0f)] 483 #define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4] 484 485 static inline char *hex_byte_pack(char *buf, u8 byte) 486 { 487 *buf++ = hex_asc_hi(byte); 488 *buf++ = hex_asc_lo(byte); 489 return buf; 490 } 491 492 extern const char hex_asc_upper[]; 493 #define hex_asc_upper_lo(x) hex_asc_upper[((x) & 0x0f)] 494 #define hex_asc_upper_hi(x) hex_asc_upper[((x) & 0xf0) >> 4] 495 496 static inline char *hex_byte_pack_upper(char *buf, u8 byte) 497 { 498 *buf++ = hex_asc_upper_hi(byte); 499 *buf++ = hex_asc_upper_lo(byte); 500 return buf; 501 } 502 503 extern int hex_to_bin(char ch); 504 extern int __must_check hex2bin(u8 *dst, const char *src, size_t count); 505 extern char *bin2hex(char *dst, const void *src, size_t count); 506 507 bool mac_pton(const char *s, u8 *mac); 508 509 /* 510 * General tracing related utility functions - trace_printk(), 511 * tracing_on/tracing_off and tracing_start()/tracing_stop 512 * 513 * Use tracing_on/tracing_off when you want to quickly turn on or off 514 * tracing. It simply enables or disables the recording of the trace events. 515 * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on 516 * file, which gives a means for the kernel and userspace to interact. 517 * Place a tracing_off() in the kernel where you want tracing to end. 518 * From user space, examine the trace, and then echo 1 > tracing_on 519 * to continue tracing. 520 * 521 * tracing_stop/tracing_start has slightly more overhead. It is used 522 * by things like suspend to ram where disabling the recording of the 523 * trace is not enough, but tracing must actually stop because things 524 * like calling smp_processor_id() may crash the system. 525 * 526 * Most likely, you want to use tracing_on/tracing_off. 527 */ 528 529 enum ftrace_dump_mode { 530 DUMP_NONE, 531 DUMP_ALL, 532 DUMP_ORIG, 533 }; 534 535 #ifdef CONFIG_TRACING 536 void tracing_on(void); 537 void tracing_off(void); 538 int tracing_is_on(void); 539 void tracing_snapshot(void); 540 void tracing_snapshot_alloc(void); 541 542 extern void tracing_start(void); 543 extern void tracing_stop(void); 544 545 static inline __printf(1, 2) 546 void ____trace_printk_check_format(const char *fmt, ...) 547 { 548 } 549 #define __trace_printk_check_format(fmt, args...) \ 550 do { \ 551 if (0) \ 552 ____trace_printk_check_format(fmt, ##args); \ 553 } while (0) 554 555 /** 556 * trace_printk - printf formatting in the ftrace buffer 557 * @fmt: the printf format for printing 558 * 559 * Note: __trace_printk is an internal function for trace_printk() and 560 * the @ip is passed in via the trace_printk() macro. 561 * 562 * This function allows a kernel developer to debug fast path sections 563 * that printk is not appropriate for. By scattering in various 564 * printk like tracing in the code, a developer can quickly see 565 * where problems are occurring. 566 * 567 * This is intended as a debugging tool for the developer only. 568 * Please refrain from leaving trace_printks scattered around in 569 * your code. (Extra memory is used for special buffers that are 570 * allocated when trace_printk() is used.) 571 * 572 * A little optimization trick is done here. If there's only one 573 * argument, there's no need to scan the string for printf formats. 574 * The trace_puts() will suffice. But how can we take advantage of 575 * using trace_puts() when trace_printk() has only one argument? 576 * By stringifying the args and checking the size we can tell 577 * whether or not there are args. __stringify((__VA_ARGS__)) will 578 * turn into "()\0" with a size of 3 when there are no args, anything 579 * else will be bigger. All we need to do is define a string to this, 580 * and then take its size and compare to 3. If it's bigger, use 581 * do_trace_printk() otherwise, optimize it to trace_puts(). Then just 582 * let gcc optimize the rest. 583 */ 584 585 #define trace_printk(fmt, ...) \ 586 do { \ 587 char _______STR[] = __stringify((__VA_ARGS__)); \ 588 if (sizeof(_______STR) > 3) \ 589 do_trace_printk(fmt, ##__VA_ARGS__); \ 590 else \ 591 trace_puts(fmt); \ 592 } while (0) 593 594 #define do_trace_printk(fmt, args...) \ 595 do { \ 596 static const char *trace_printk_fmt __used \ 597 __section("__trace_printk_fmt") = \ 598 __builtin_constant_p(fmt) ? fmt : NULL; \ 599 \ 600 __trace_printk_check_format(fmt, ##args); \ 601 \ 602 if (__builtin_constant_p(fmt)) \ 603 __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args); \ 604 else \ 605 __trace_printk(_THIS_IP_, fmt, ##args); \ 606 } while (0) 607 608 extern __printf(2, 3) 609 int __trace_bprintk(unsigned long ip, const char *fmt, ...); 610 611 extern __printf(2, 3) 612 int __trace_printk(unsigned long ip, const char *fmt, ...); 613 614 /** 615 * trace_puts - write a string into the ftrace buffer 616 * @str: the string to record 617 * 618 * Note: __trace_bputs is an internal function for trace_puts and 619 * the @ip is passed in via the trace_puts macro. 620 * 621 * This is similar to trace_printk() but is made for those really fast 622 * paths that a developer wants the least amount of "Heisenbug" effects, 623 * where the processing of the print format is still too much. 624 * 625 * This function allows a kernel developer to debug fast path sections 626 * that printk is not appropriate for. By scattering in various 627 * printk like tracing in the code, a developer can quickly see 628 * where problems are occurring. 629 * 630 * This is intended as a debugging tool for the developer only. 631 * Please refrain from leaving trace_puts scattered around in 632 * your code. (Extra memory is used for special buffers that are 633 * allocated when trace_puts() is used.) 634 * 635 * Returns: 0 if nothing was written, positive # if string was. 636 * (1 when __trace_bputs is used, strlen(str) when __trace_puts is used) 637 */ 638 639 #define trace_puts(str) ({ \ 640 static const char *trace_printk_fmt __used \ 641 __section("__trace_printk_fmt") = \ 642 __builtin_constant_p(str) ? str : NULL; \ 643 \ 644 if (__builtin_constant_p(str)) \ 645 __trace_bputs(_THIS_IP_, trace_printk_fmt); \ 646 else \ 647 __trace_puts(_THIS_IP_, str, strlen(str)); \ 648 }) 649 extern int __trace_bputs(unsigned long ip, const char *str); 650 extern int __trace_puts(unsigned long ip, const char *str, int size); 651 652 extern void trace_dump_stack(int skip); 653 654 /* 655 * The double __builtin_constant_p is because gcc will give us an error 656 * if we try to allocate the static variable to fmt if it is not a 657 * constant. Even with the outer if statement. 658 */ 659 #define ftrace_vprintk(fmt, vargs) \ 660 do { \ 661 if (__builtin_constant_p(fmt)) { \ 662 static const char *trace_printk_fmt __used \ 663 __section("__trace_printk_fmt") = \ 664 __builtin_constant_p(fmt) ? fmt : NULL; \ 665 \ 666 __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs); \ 667 } else \ 668 __ftrace_vprintk(_THIS_IP_, fmt, vargs); \ 669 } while (0) 670 671 extern __printf(2, 0) int 672 __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap); 673 674 extern __printf(2, 0) int 675 __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap); 676 677 extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode); 678 #else 679 static inline void tracing_start(void) { } 680 static inline void tracing_stop(void) { } 681 static inline void trace_dump_stack(int skip) { } 682 683 static inline void tracing_on(void) { } 684 static inline void tracing_off(void) { } 685 static inline int tracing_is_on(void) { return 0; } 686 static inline void tracing_snapshot(void) { } 687 static inline void tracing_snapshot_alloc(void) { } 688 689 static inline __printf(1, 2) 690 int trace_printk(const char *fmt, ...) 691 { 692 return 0; 693 } 694 static __printf(1, 0) inline int 695 ftrace_vprintk(const char *fmt, va_list ap) 696 { 697 return 0; 698 } 699 static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { } 700 #endif /* CONFIG_TRACING */ 701 702 /* This counts to 12. Any more, it will return 13th argument. */ 703 #define __COUNT_ARGS(_0, _1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11, _12, _n, X...) _n 704 #define COUNT_ARGS(X...) __COUNT_ARGS(, ##X, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0) 705 706 #define __CONCAT(a, b) a ## b 707 #define CONCATENATE(a, b) __CONCAT(a, b) 708 709 /** 710 * container_of - cast a member of a structure out to the containing structure 711 * @ptr: the pointer to the member. 712 * @type: the type of the container struct this is embedded in. 713 * @member: the name of the member within the struct. 714 * 715 */ 716 #define container_of(ptr, type, member) ({ \ 717 void *__mptr = (void *)(ptr); \ 718 BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \ 719 !__same_type(*(ptr), void), \ 720 "pointer type mismatch in container_of()"); \ 721 ((type *)(__mptr - offsetof(type, member))); }) 722 723 /** 724 * container_of_safe - cast a member of a structure out to the containing structure 725 * @ptr: the pointer to the member. 726 * @type: the type of the container struct this is embedded in. 727 * @member: the name of the member within the struct. 728 * 729 * If IS_ERR_OR_NULL(ptr), ptr is returned unchanged. 730 */ 731 #define container_of_safe(ptr, type, member) ({ \ 732 void *__mptr = (void *)(ptr); \ 733 BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \ 734 !__same_type(*(ptr), void), \ 735 "pointer type mismatch in container_of()"); \ 736 IS_ERR_OR_NULL(__mptr) ? ERR_CAST(__mptr) : \ 737 ((type *)(__mptr - offsetof(type, member))); }) 738 739 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */ 740 #ifdef CONFIG_FTRACE_MCOUNT_RECORD 741 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD 742 #endif 743 744 /* Permissions on a sysfs file: you didn't miss the 0 prefix did you? */ 745 #define VERIFY_OCTAL_PERMISSIONS(perms) \ 746 (BUILD_BUG_ON_ZERO((perms) < 0) + \ 747 BUILD_BUG_ON_ZERO((perms) > 0777) + \ 748 /* USER_READABLE >= GROUP_READABLE >= OTHER_READABLE */ \ 749 BUILD_BUG_ON_ZERO((((perms) >> 6) & 4) < (((perms) >> 3) & 4)) + \ 750 BUILD_BUG_ON_ZERO((((perms) >> 3) & 4) < ((perms) & 4)) + \ 751 /* USER_WRITABLE >= GROUP_WRITABLE */ \ 752 BUILD_BUG_ON_ZERO((((perms) >> 6) & 2) < (((perms) >> 3) & 2)) + \ 753 /* OTHER_WRITABLE? Generally considered a bad idea. */ \ 754 BUILD_BUG_ON_ZERO((perms) & 2) + \ 755 (perms)) 756 #endif 757