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/* 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/array_size.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/hex.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/sprintf.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
#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 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;
/*
* 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/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 */
/* 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