OSCL-LXR linux-6.0.1/​include/​linux/​kernel.h	Source navigation Diff markup Identifier search General search
	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 /* SPDX-License-Identifier: GPL-2.0 */
 /*
  * NOTE:
  *
  * This header has combined a lot of unrelated to each other stuff.
  * The process of splitting its content is in progress while keeping
  * backward compatibility. That's why it's highly recommended NOT to
  * include this header inside another header file, especially under
  * generic or architectural include/ directory.
  */
 #ifndef _LINUX_KERNEL_H
 #define _LINUX_KERNEL_H
 
 #include <linux/stdarg.h>
 #include <linux/align.h>
 #include <linux/limits.h>
 #include <linux/linkage.h>
 #include <linux/stddef.h>
 #include <linux/types.h>
 #include <linux/compiler.h>
 #include <linux/container_of.h>
 #include <linux/bitops.h>
 #include <linux/kstrtox.h>
 #include <linux/log2.h>
 #include <linux/math.h>
 #include <linux/minmax.h>
 #include <linux/typecheck.h>
 #include <linux/panic.h>
 #include <linux/printk.h>
 #include <linux/build_bug.h>
 #include <linux/static_call_types.h>
 #include <linux/instruction_pointer.h>
 #include <asm/byteorder.h>
 
 #include <uapi/linux/kernel.h>
 
 #define STACK_MAGIC 0xdeadbeef
 
 /**
  * REPEAT_BYTE - repeat the value @x multiple times as an unsigned long value
  * @x: value to repeat
  *
  * NOTE: @x is not checked for > 0xff; larger values produce odd results.
  */
 #define REPEAT_BYTE(x)  ((~0ul / 0xff) * (x))
 
 /* generic data direction definitions */
 #define READ            0
 #define WRITE           1
 
 /**
  * ARRAY_SIZE - get the number of elements in array @arr
  * @arr: array to be sized
  */
 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
 
 #define PTR_IF(cond, ptr)   ((cond) ? (ptr) : NULL)
 
 #define u64_to_user_ptr(x) (        \
 {                   \
     typecheck(u64, (x));        \
     (void __user *)(uintptr_t)(x);  \
 }                   \
 )
 
 /**
  * upper_32_bits - return bits 32-63 of a number
  * @n: the number we're accessing
  *
  * A basic shift-right of a 64- or 32-bit quantity.  Use this to suppress
  * the "right shift count >= width of type" warning when that quantity is
  * 32-bits.
  */
 #define upper_32_bits(n) ((u32)(((n) >> 16) >> 16))
 
 /**
  * lower_32_bits - return bits 0-31 of a number
  * @n: the number we're accessing
  */
 #define lower_32_bits(n) ((u32)((n) & 0xffffffff))
 
 /**
  * upper_16_bits - return bits 16-31 of a number
  * @n: the number we're accessing
  */
 #define upper_16_bits(n) ((u16)((n) >> 16))
 
 /**
  * lower_16_bits - return bits 0-15 of a number
  * @n: the number we're accessing
  */
 #define lower_16_bits(n) ((u16)((n) & 0xffff))
 
 struct completion;
 struct user;
 
 #ifdef CONFIG_PREEMPT_VOLUNTARY_BUILD
 
 extern int __cond_resched(void);
 # define might_resched() __cond_resched()
 
 #elif defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL)
 
 extern int __cond_resched(void);
 
 DECLARE_STATIC_CALL(might_resched, __cond_resched);
 
 static __always_inline void might_resched(void)
 {
     static_call_mod(might_resched)();
 }
 
 #elif defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY)
 
 extern int dynamic_might_resched(void);
 # define might_resched() dynamic_might_resched()
 
 #else
 
 # define might_resched() do { } while (0)
 
 #endif /* CONFIG_PREEMPT_* */
 
 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
 extern void __might_resched(const char *file, int line, unsigned int offsets);
 extern void __might_sleep(const char *file, int line);
 extern void __cant_sleep(const char *file, int line, int preempt_offset);
 extern void __cant_migrate(const char *file, int line);
 
 /**
  * might_sleep - annotation for functions that can sleep
  *
  * this macro will print a stack trace if it is executed in an atomic
  * context (spinlock, irq-handler, ...). Additional sections where blocking is
  * not allowed can be annotated with non_block_start() and non_block_end()
  * pairs.
  *
  * This is a useful debugging help to be able to catch problems early and not
  * be bitten later when the calling function happens to sleep when it is not
  * supposed to.
  */
 # define might_sleep() \
     do { __might_sleep(__FILE__, __LINE__); might_resched(); } while (0)
 /**
  * cant_sleep - annotation for functions that cannot sleep
  *
  * this macro will print a stack trace if it is executed with preemption enabled
  */
 # define cant_sleep() \
     do { __cant_sleep(__FILE__, __LINE__, 0); } while (0)
 # define sched_annotate_sleep() (current->task_state_change = 0)
 
 /**
  * cant_migrate - annotation for functions that cannot migrate
  *
  * Will print a stack trace if executed in code which is migratable
  */
 # define cant_migrate()                         \
     do {                                \
         if (IS_ENABLED(CONFIG_SMP))             \
             __cant_migrate(__FILE__, __LINE__);     \
     } while (0)
 
 /**
  * non_block_start - annotate the start of section where sleeping is prohibited
  *
  * This is on behalf of the oom reaper, specifically when it is calling the mmu
  * notifiers. The problem is that if the notifier were to block on, for example,
  * mutex_lock() and if the process which holds that mutex were to perform a
  * sleeping memory allocation, the oom reaper is now blocked on completion of
  * that memory allocation. Other blocking calls like wait_event() pose similar
  * issues.
  */
 # define non_block_start() (current->non_block_count++)
 /**
  * non_block_end - annotate the end of section where sleeping is prohibited
  *
  * Closes a section opened by non_block_start().
  */
 # define non_block_end() WARN_ON(current->non_block_count-- == 0)
 #else
   static inline void __might_resched(const char *file, int line,
                      unsigned int offsets) { }
 static inline void __might_sleep(const char *file, int line) { }
 # define might_sleep() do { might_resched(); } while (0)
 # define cant_sleep() do { } while (0)
 # define cant_migrate()     do { } while (0)
 # define sched_annotate_sleep() do { } while (0)
 # define non_block_start() do { } while (0)
 # define non_block_end() do { } while (0)
 #endif
 
 #define might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
 
 #if defined(CONFIG_MMU) && \
     (defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP))
 #define might_fault() __might_fault(__FILE__, __LINE__)
 void __might_fault(const char *file, int line);
 #else
 static inline void might_fault(void) { }
 #endif
 
 void do_exit(long error_code) __noreturn;
 
 extern int num_to_str(char *buf, int size,
               unsigned long long num, unsigned int width);
 
 /* lib/printf utilities */
 
 extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...);
 extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list);
 extern __printf(3, 4)
 int snprintf(char *buf, size_t size, const char *fmt, ...);
 extern __printf(3, 0)
 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args);
 extern __printf(3, 4)
 int scnprintf(char *buf, size_t size, const char *fmt, ...);
 extern __printf(3, 0)
 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args);
 extern __printf(2, 3) __malloc
 char *kasprintf(gfp_t gfp, const char *fmt, ...);
 extern __printf(2, 0) __malloc
 char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
 extern __printf(2, 0)
 const char *kvasprintf_const(gfp_t gfp, const char *fmt, va_list args);
 
 extern __scanf(2, 3)
 int sscanf(const char *, const char *, ...);
 extern __scanf(2, 0)
 int vsscanf(const char *, const char *, va_list);
 
 extern int no_hash_pointers_enable(char *str);
 
 extern int get_option(char **str, int *pint);
 extern char *get_options(const char *str, int nints, int *ints);
 extern unsigned long long memparse(const char *ptr, char **retptr);
 extern bool parse_option_str(const char *str, const char *option);
 extern char *next_arg(char *args, char **param, char **val);
 
 extern int core_kernel_text(unsigned long addr);
 extern int __kernel_text_address(unsigned long addr);
 extern int kernel_text_address(unsigned long addr);
 extern int func_ptr_is_kernel_text(void *ptr);
 
 extern void bust_spinlocks(int yes);
 
 extern int root_mountflags;
 
 extern bool early_boot_irqs_disabled;
 
 /*
  * Values used for system_state. Ordering of the states must not be changed
  * as code checks for <, <=, >, >= STATE.
  */
 extern enum system_states {
     SYSTEM_BOOTING,
     SYSTEM_SCHEDULING,
     SYSTEM_FREEING_INITMEM,
     SYSTEM_RUNNING,
     SYSTEM_HALT,
     SYSTEM_POWER_OFF,
     SYSTEM_RESTART,
     SYSTEM_SUSPEND,
 } system_state;
 
 extern const char hex_asc[];
 #define hex_asc_lo(x)   hex_asc[((x) & 0x0f)]
 #define hex_asc_hi(x)   hex_asc[((x) & 0xf0) >> 4]
 
 static inline char *hex_byte_pack(char *buf, u8 byte)
 {
     *buf++ = hex_asc_hi(byte);
     *buf++ = hex_asc_lo(byte);
     return buf;
 }
 
 extern const char hex_asc_upper[];
 #define hex_asc_upper_lo(x) hex_asc_upper[((x) & 0x0f)]
 #define hex_asc_upper_hi(x) hex_asc_upper[((x) & 0xf0) >> 4]
 
 static inline char *hex_byte_pack_upper(char *buf, u8 byte)
 {
     *buf++ = hex_asc_upper_hi(byte);
     *buf++ = hex_asc_upper_lo(byte);
     return buf;
 }
 
 extern int hex_to_bin(unsigned char ch);
 extern int __must_check hex2bin(u8 *dst, const char *src, size_t count);
 extern char *bin2hex(char *dst, const void *src, size_t count);
 
 bool mac_pton(const char *s, u8 *mac);
 
 /*
  * General tracing related utility functions - trace_printk(),
  * tracing_on/tracing_off and tracing_start()/tracing_stop
  *
  * Use tracing_on/tracing_off when you want to quickly turn on or off
  * tracing. It simply enables or disables the recording of the trace events.
  * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on
  * file, which gives a means for the kernel and userspace to interact.
  * Place a tracing_off() in the kernel where you want tracing to end.
  * From user space, examine the trace, and then echo 1 > tracing_on
  * to continue tracing.
  *
  * tracing_stop/tracing_start has slightly more overhead. It is used
  * by things like suspend to ram where disabling the recording of the
  * trace is not enough, but tracing must actually stop because things
  * like calling smp_processor_id() may crash the system.
  *
  * Most likely, you want to use tracing_on/tracing_off.
  */
 
 enum ftrace_dump_mode {
     DUMP_NONE,
     DUMP_ALL,
     DUMP_ORIG,
 };
 
 #ifdef CONFIG_TRACING
 void tracing_on(void);
 void tracing_off(void);
 int tracing_is_on(void);
 void tracing_snapshot(void);
 void tracing_snapshot_alloc(void);
 
 extern void tracing_start(void);
 extern void tracing_stop(void);
 
 static inline __printf(1, 2)
 void ____trace_printk_check_format(const char *fmt, ...)
 {
 }
 #define __trace_printk_check_format(fmt, args...)           \
 do {                                    \
     if (0)                              \
         ____trace_printk_check_format(fmt, ##args);     \
 } while (0)
 
 /**
  * trace_printk - printf formatting in the ftrace buffer
  * @fmt: the printf format for printing
  *
  * Note: __trace_printk is an internal function for trace_printk() and
  *       the @ip is passed in via the trace_printk() macro.
  *
  * This function allows a kernel developer to debug fast path sections
  * that printk is not appropriate for. By scattering in various
  * printk like tracing in the code, a developer can quickly see
  * where problems are occurring.
  *
  * This is intended as a debugging tool for the developer only.
  * Please refrain from leaving trace_printks scattered around in
  * your code. (Extra memory is used for special buffers that are
  * allocated when trace_printk() is used.)
  *
  * A little optimization trick is done here. If there's only one
  * argument, there's no need to scan the string for printf formats.
  * The trace_puts() will suffice. But how can we take advantage of
  * using trace_puts() when trace_printk() has only one argument?
  * By stringifying the args and checking the size we can tell
  * whether or not there are args. __stringify((__VA_ARGS__)) will
  * turn into "()\0" with a size of 3 when there are no args, anything
  * else will be bigger. All we need to do is define a string to this,
  * and then take its size and compare to 3. If it's bigger, use
  * do_trace_printk() otherwise, optimize it to trace_puts(). Then just
  * let gcc optimize the rest.
  */
 
 #define trace_printk(fmt, ...)              \
 do {                            \
     char _______STR[] = __stringify((__VA_ARGS__)); \
     if (sizeof(_______STR) > 3)         \
         do_trace_printk(fmt, ##__VA_ARGS__);    \
     else                        \
         trace_puts(fmt);            \
 } while (0)
 
 #define do_trace_printk(fmt, args...)                   \
 do {                                    \
     static const char *trace_printk_fmt __used          \
         __section("__trace_printk_fmt") =           \
         __builtin_constant_p(fmt) ? fmt : NULL;         \
                                     \
     __trace_printk_check_format(fmt, ##args);           \
                                     \
     if (__builtin_constant_p(fmt))                  \
         __trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args);   \
     else                                \
         __trace_printk(_THIS_IP_, fmt, ##args);         \
 } while (0)
 
 extern __printf(2, 3)
 int __trace_bprintk(unsigned long ip, const char *fmt, ...);
 
 extern __printf(2, 3)
 int __trace_printk(unsigned long ip, const char *fmt, ...);
 
 /**
  * trace_puts - write a string into the ftrace buffer
  * @str: the string to record
  *
  * Note: __trace_bputs is an internal function for trace_puts and
  *       the @ip is passed in via the trace_puts macro.
  *
  * This is similar to trace_printk() but is made for those really fast
  * paths that a developer wants the least amount of "Heisenbug" effects,
  * where the processing of the print format is still too much.
  *
  * This function allows a kernel developer to debug fast path sections
  * that printk is not appropriate for. By scattering in various
  * printk like tracing in the code, a developer can quickly see
  * where problems are occurring.
  *
  * This is intended as a debugging tool for the developer only.
  * Please refrain from leaving trace_puts scattered around in
  * your code. (Extra memory is used for special buffers that are
  * allocated when trace_puts() is used.)
  *
  * Returns: 0 if nothing was written, positive # if string was.
  *  (1 when __trace_bputs is used, strlen(str) when __trace_puts is used)
  */
 
 #define trace_puts(str) ({                      \
     static const char *trace_printk_fmt __used          \
         __section("__trace_printk_fmt") =           \
         __builtin_constant_p(str) ? str : NULL;         \
                                     \
     if (__builtin_constant_p(str))                  \
         __trace_bputs(_THIS_IP_, trace_printk_fmt);     \
     else                                \
         __trace_puts(_THIS_IP_, str, strlen(str));      \
 })
 extern int __trace_bputs(unsigned long ip, const char *str);
 extern int __trace_puts(unsigned long ip, const char *str, int size);
 
 extern void trace_dump_stack(int skip);
 
 /*
  * The double __builtin_constant_p is because gcc will give us an error
  * if we try to allocate the static variable to fmt if it is not a
  * constant. Even with the outer if statement.
  */
 #define ftrace_vprintk(fmt, vargs)                  \
 do {                                    \
     if (__builtin_constant_p(fmt)) {                \
         static const char *trace_printk_fmt __used      \
           __section("__trace_printk_fmt") =         \
             __builtin_constant_p(fmt) ? fmt : NULL;     \
                                     \
         __ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs);  \
     } else                              \
         __ftrace_vprintk(_THIS_IP_, fmt, vargs);        \
 } while (0)
 
 extern __printf(2, 0) int
 __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
 
 extern __printf(2, 0) int
 __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
 
 extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode);
 #else
 static inline void tracing_start(void) { }
 static inline void tracing_stop(void) { }
 static inline void trace_dump_stack(int skip) { }
 
 static inline void tracing_on(void) { }
 static inline void tracing_off(void) { }
 static inline int tracing_is_on(void) { return 0; }
 static inline void tracing_snapshot(void) { }
 static inline void tracing_snapshot_alloc(void) { }
 
 static inline __printf(1, 2)
 int trace_printk(const char *fmt, ...)
 {
     return 0;
 }
 static __printf(1, 0) inline int
 ftrace_vprintk(const char *fmt, va_list ap)
 {
     return 0;
 }
 static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
 #endif /* CONFIG_TRACING */
 
 /* This counts to 12. Any more, it will return 13th argument. */
 #define __COUNT_ARGS(_0, _1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11, _12, _n, X...) _n
 #define COUNT_ARGS(X...) __COUNT_ARGS(, ##X, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0)
 
 #define __CONCAT(a, b) a ## b
 #define CONCATENATE(a, b) __CONCAT(a, b)
 
 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
 #endif
 
 /* Permissions on a sysfs file: you didn't miss the 0 prefix did you? */
 #define VERIFY_OCTAL_PERMISSIONS(perms)                     \
     (BUILD_BUG_ON_ZERO((perms) < 0) +                   \
      BUILD_BUG_ON_ZERO((perms) > 0777) +                    \
      /* USER_READABLE >= GROUP_READABLE >= OTHER_READABLE */        \
      BUILD_BUG_ON_ZERO((((perms) >> 6) & 4) < (((perms) >> 3) & 4)) +   \
      BUILD_BUG_ON_ZERO((((perms) >> 3) & 4) < ((perms) & 4)) +      \
      /* USER_WRITABLE >= GROUP_WRITABLE */                  \
      BUILD_BUG_ON_ZERO((((perms) >> 6) & 2) < (((perms) >> 3) & 2)) +   \
      /* OTHER_WRITABLE?  Generally considered a bad idea. */        \
      BUILD_BUG_ON_ZERO((perms) & 2) +                   \
      (perms))
 #endif

This page was automatically generated by the 2.1.0 LXR engine. The LXR team