[linux-block.git] / include / linux / thread_info.h

/* SPDX-License-Identifier: GPL-2.0 */
/* thread_info.h: common low-level thread information accessors
 *
 * Copyright (C) 2002  David Howells (dhowells@redhat.com)
 * - Incorporating suggestions made by Linus Torvalds
 */

#ifndef _LINUX_THREAD_INFO_H
#define _LINUX_THREAD_INFO_H

#include <linux/types.h>
#include <linux/limits.h>
#include <linux/bug.h>
#include <linux/restart_block.h>
#include <linux/errno.h>

#ifdef CONFIG_THREAD_INFO_IN_TASK
/*
 * For CONFIG_THREAD_INFO_IN_TASK kernels we need <asm/current.h> for the
 * definition of current, but for !CONFIG_THREAD_INFO_IN_TASK kernels,
 * including <asm/current.h> can cause a circular dependency on some platforms.
 */
#include <asm/current.h>
#define current_thread_info() ((struct thread_info *)current)
#endif

#include <linux/bitops.h>

/*
 * For per-arch arch_within_stack_frames() implementations, defined in
 * asm/thread_info.h.
 */
enum {
	BAD_STACK = -1,
	NOT_STACK = 0,
	GOOD_FRAME,
	GOOD_STACK,
};

#ifdef CONFIG_GENERIC_ENTRY
enum syscall_work_bit {
	SYSCALL_WORK_BIT_SECCOMP,
	SYSCALL_WORK_BIT_SYSCALL_TRACEPOINT,
	SYSCALL_WORK_BIT_SYSCALL_TRACE,
	SYSCALL_WORK_BIT_SYSCALL_EMU,
	SYSCALL_WORK_BIT_SYSCALL_AUDIT,
	SYSCALL_WORK_BIT_SYSCALL_USER_DISPATCH,
	SYSCALL_WORK_BIT_SYSCALL_EXIT_TRAP,
};

#define SYSCALL_WORK_SECCOMP		BIT(SYSCALL_WORK_BIT_SECCOMP)
#define SYSCALL_WORK_SYSCALL_TRACEPOINT	BIT(SYSCALL_WORK_BIT_SYSCALL_TRACEPOINT)
#define SYSCALL_WORK_SYSCALL_TRACE	BIT(SYSCALL_WORK_BIT_SYSCALL_TRACE)
#define SYSCALL_WORK_SYSCALL_EMU	BIT(SYSCALL_WORK_BIT_SYSCALL_EMU)
#define SYSCALL_WORK_SYSCALL_AUDIT	BIT(SYSCALL_WORK_BIT_SYSCALL_AUDIT)
#define SYSCALL_WORK_SYSCALL_USER_DISPATCH BIT(SYSCALL_WORK_BIT_SYSCALL_USER_DISPATCH)
#define SYSCALL_WORK_SYSCALL_EXIT_TRAP	BIT(SYSCALL_WORK_BIT_SYSCALL_EXIT_TRAP)
#endif

#include <asm/thread_info.h>

#ifdef __KERNEL__

#ifndef arch_set_restart_data
#define arch_set_restart_data(restart) do { } while (0)
#endif

static inline long set_restart_fn(struct restart_block *restart,
					long (*fn)(struct restart_block *))
{
	restart->fn = fn;
	arch_set_restart_data(restart);
	return -ERESTART_RESTARTBLOCK;
}

#ifndef THREAD_ALIGN
#define THREAD_ALIGN	THREAD_SIZE
#endif

#define THREADINFO_GFP		(GFP_KERNEL_ACCOUNT | __GFP_ZERO)

/*
 * flag set/clear/test wrappers
 * - pass TIF_xxxx constants to these functions
 */

static inline void set_ti_thread_flag(struct thread_info *ti, int flag)
{
	set_bit(flag, (unsigned long *)&ti->flags);
}

static inline void clear_ti_thread_flag(struct thread_info *ti, int flag)
{
	clear_bit(flag, (unsigned long *)&ti->flags);
}

static inline void update_ti_thread_flag(struct thread_info *ti, int flag,
					 bool value)
{
	if (value)
		set_ti_thread_flag(ti, flag);
	else
		clear_ti_thread_flag(ti, flag);
}

static inline int test_and_set_ti_thread_flag(struct thread_info *ti, int flag)
{
	return test_and_set_bit(flag, (unsigned long *)&ti->flags);
}

static inline int test_and_clear_ti_thread_flag(struct thread_info *ti, int flag)
{
	return test_and_clear_bit(flag, (unsigned long *)&ti->flags);
}

static inline int test_ti_thread_flag(struct thread_info *ti, int flag)
{
	return test_bit(flag, (unsigned long *)&ti->flags);
}

/*
 * This may be used in noinstr code, and needs to be __always_inline to prevent
 * inadvertent instrumentation.
 */
static __always_inline unsigned long read_ti_thread_flags(struct thread_info *ti)
{
	return READ_ONCE(ti->flags);
}

#define set_thread_flag(flag) \
	set_ti_thread_flag(current_thread_info(), flag)
#define clear_thread_flag(flag) \
	clear_ti_thread_flag(current_thread_info(), flag)
#define update_thread_flag(flag, value) \
	update_ti_thread_flag(current_thread_info(), flag, value)
#define test_and_set_thread_flag(flag) \
	test_and_set_ti_thread_flag(current_thread_info(), flag)
#define test_and_clear_thread_flag(flag) \
	test_and_clear_ti_thread_flag(current_thread_info(), flag)
#define test_thread_flag(flag) \
	test_ti_thread_flag(current_thread_info(), flag)
#define read_thread_flags() \
	read_ti_thread_flags(current_thread_info())

#define read_task_thread_flags(t) \
	read_ti_thread_flags(task_thread_info(t))

#ifdef CONFIG_GENERIC_ENTRY
#define set_syscall_work(fl) \
	set_bit(SYSCALL_WORK_BIT_##fl, &current_thread_info()->syscall_work)
#define test_syscall_work(fl) \
	test_bit(SYSCALL_WORK_BIT_##fl, &current_thread_info()->syscall_work)
#define clear_syscall_work(fl) \
	clear_bit(SYSCALL_WORK_BIT_##fl, &current_thread_info()->syscall_work)

#define set_task_syscall_work(t, fl) \
	set_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work)
#define test_task_syscall_work(t, fl) \
	test_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work)
#define clear_task_syscall_work(t, fl) \
	clear_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work)

#else /* CONFIG_GENERIC_ENTRY */

#define set_syscall_work(fl)						\
	set_ti_thread_flag(current_thread_info(), TIF_##fl)
#define test_syscall_work(fl) \
	test_ti_thread_flag(current_thread_info(), TIF_##fl)
#define clear_syscall_work(fl) \
	clear_ti_thread_flag(current_thread_info(), TIF_##fl)

#define set_task_syscall_work(t, fl) \
	set_ti_thread_flag(task_thread_info(t), TIF_##fl)
#define test_task_syscall_work(t, fl) \
	test_ti_thread_flag(task_thread_info(t), TIF_##fl)
#define clear_task_syscall_work(t, fl) \
	clear_ti_thread_flag(task_thread_info(t), TIF_##fl)
#endif /* !CONFIG_GENERIC_ENTRY */

#define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED)

#ifndef CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES
static inline int arch_within_stack_frames(const void * const stack,
					   const void * const stackend,
					   const void *obj, unsigned long len)
{
	return 0;
}
#endif

#ifdef CONFIG_HARDENED_USERCOPY
extern void __check_object_size(const void *ptr, unsigned long n,
					bool to_user);

static __always_inline void check_object_size(const void *ptr, unsigned long n,
					      bool to_user)
{
	if (!__builtin_constant_p(n))
		__check_object_size(ptr, n, to_user);
}
#else
static inline void check_object_size(const void *ptr, unsigned long n,
				     bool to_user)
{ }
#endif /* CONFIG_HARDENED_USERCOPY */

extern void __compiletime_error("copy source size is too small")
__bad_copy_from(void);
extern void __compiletime_error("copy destination size is too small")
__bad_copy_to(void);

void __copy_overflow(int size, unsigned long count);

static inline void copy_overflow(int size, unsigned long count)
{
	if (IS_ENABLED(CONFIG_BUG))
		__copy_overflow(size, count);
}

static __always_inline __must_check bool
check_copy_size(const void *addr, size_t bytes, bool is_source)
{
	int sz = __builtin_object_size(addr, 0);
	if (unlikely(sz >= 0 && sz < bytes)) {
		if (!__builtin_constant_p(bytes))
			copy_overflow(sz, bytes);
		else if (is_source)
			__bad_copy_from();
		else
			__bad_copy_to();
		return false;
	}
	if (WARN_ON_ONCE(bytes > INT_MAX))
		return false;
	check_object_size(addr, bytes, is_source);
	return true;
}

#ifndef arch_setup_new_exec
static inline void arch_setup_new_exec(void) { }
#endif

#endif	/* __KERNEL__ */

#endif /* _LINUX_THREAD_INFO_H */
Commit	Line	Data
	1	/* SPDX-License-Identifier: GPL-2.0 */
	2	/* thread_info.h: common low-level thread information accessors
	3	*
	4	* Copyright (C) 2002 David Howells (dhowells@redhat.com)
	5	* - Incorporating suggestions made by Linus Torvalds
	6	*/
	7
	8	#ifndef _LINUX_THREAD_INFO_H
	9	#define _LINUX_THREAD_INFO_H
	10
	11	#include <linux/types.h>
	12	#include <linux/limits.h>
	13	#include <linux/bug.h>
	14	#include <linux/restart_block.h>
	15	#include <linux/errno.h>
	16
	17	#ifdef CONFIG_THREAD_INFO_IN_TASK
	18	/*
	19	* For CONFIG_THREAD_INFO_IN_TASK kernels we need <asm/current.h> for the
	20	* definition of current, but for !CONFIG_THREAD_INFO_IN_TASK kernels,
	21	* including <asm/current.h> can cause a circular dependency on some platforms.
	22	*/
	23	#include <asm/current.h>
	24	#define current_thread_info() ((struct thread_info *)current)
	25	#endif
	26
	27	#include <linux/bitops.h>
	28
	29	/*
	30	* For per-arch arch_within_stack_frames() implementations, defined in
	31	* asm/thread_info.h.
	32	*/
	33	enum {
	34	BAD_STACK = -1,
	35	NOT_STACK = 0,
	36	GOOD_FRAME,
	37	GOOD_STACK,
	38	};
	39
	40	#ifdef CONFIG_GENERIC_ENTRY
	41	enum syscall_work_bit {
	42	SYSCALL_WORK_BIT_SECCOMP,
	43	SYSCALL_WORK_BIT_SYSCALL_TRACEPOINT,
	44	SYSCALL_WORK_BIT_SYSCALL_TRACE,
	45	SYSCALL_WORK_BIT_SYSCALL_EMU,
	46	SYSCALL_WORK_BIT_SYSCALL_AUDIT,
	47	SYSCALL_WORK_BIT_SYSCALL_USER_DISPATCH,
	48	SYSCALL_WORK_BIT_SYSCALL_EXIT_TRAP,
	49	};
	50
	51	#define SYSCALL_WORK_SECCOMP BIT(SYSCALL_WORK_BIT_SECCOMP)
	52	#define SYSCALL_WORK_SYSCALL_TRACEPOINT BIT(SYSCALL_WORK_BIT_SYSCALL_TRACEPOINT)
	53	#define SYSCALL_WORK_SYSCALL_TRACE BIT(SYSCALL_WORK_BIT_SYSCALL_TRACE)
	54	#define SYSCALL_WORK_SYSCALL_EMU BIT(SYSCALL_WORK_BIT_SYSCALL_EMU)
	55	#define SYSCALL_WORK_SYSCALL_AUDIT BIT(SYSCALL_WORK_BIT_SYSCALL_AUDIT)
	56	#define SYSCALL_WORK_SYSCALL_USER_DISPATCH BIT(SYSCALL_WORK_BIT_SYSCALL_USER_DISPATCH)
	57	#define SYSCALL_WORK_SYSCALL_EXIT_TRAP BIT(SYSCALL_WORK_BIT_SYSCALL_EXIT_TRAP)
	58	#endif
	59
	60	#include <asm/thread_info.h>
	61
	62	#ifdef __KERNEL__
	63
	64	#ifndef arch_set_restart_data
	65	#define arch_set_restart_data(restart) do { } while (0)
	66	#endif
	67
	68	static inline long set_restart_fn(struct restart_block *restart,
	69	long (fn)(struct restart_block ))
	70	{
	71	restart->fn = fn;
	72	arch_set_restart_data(restart);
	73	return -ERESTART_RESTARTBLOCK;
	74	}
	75
	76	#ifndef THREAD_ALIGN
	77	#define THREAD_ALIGN THREAD_SIZE
	78	#endif
	79
	80	#define THREADINFO_GFP (GFP_KERNEL_ACCOUNT \| __GFP_ZERO)
	81
	82	/*
	83	* flag set/clear/test wrappers
	84	* - pass TIF_xxxx constants to these functions
	85	*/
	86
	87	static inline void set_ti_thread_flag(struct thread_info *ti, int flag)
	88	{
	89	set_bit(flag, (unsigned long *)&ti->flags);
	90	}
	91
	92	static inline void clear_ti_thread_flag(struct thread_info *ti, int flag)
	93	{
	94	clear_bit(flag, (unsigned long *)&ti->flags);
	95	}
	96
	97	static inline void update_ti_thread_flag(struct thread_info *ti, int flag,
	98	bool value)
	99	{
	100	if (value)
	101	set_ti_thread_flag(ti, flag);
	102	else
	103	clear_ti_thread_flag(ti, flag);
	104	}
	105
	106	static inline int test_and_set_ti_thread_flag(struct thread_info *ti, int flag)
	107	{
	108	return test_and_set_bit(flag, (unsigned long *)&ti->flags);
	109	}
	110
	111	static inline int test_and_clear_ti_thread_flag(struct thread_info *ti, int flag)
	112	{
	113	return test_and_clear_bit(flag, (unsigned long *)&ti->flags);
	114	}
	115
	116	static inline int test_ti_thread_flag(struct thread_info *ti, int flag)
	117	{
	118	return test_bit(flag, (unsigned long *)&ti->flags);
	119	}
	120
	121	/*
	122	* This may be used in noinstr code, and needs to be __always_inline to prevent
	123	* inadvertent instrumentation.
	124	*/
	125	static __always_inline unsigned long read_ti_thread_flags(struct thread_info *ti)
	126	{
	127	return READ_ONCE(ti->flags);
	128	}
	129
	130	#define set_thread_flag(flag) \
	131	set_ti_thread_flag(current_thread_info(), flag)
	132	#define clear_thread_flag(flag) \
	133	clear_ti_thread_flag(current_thread_info(), flag)
	134	#define update_thread_flag(flag, value) \
	135	update_ti_thread_flag(current_thread_info(), flag, value)
	136	#define test_and_set_thread_flag(flag) \
	137	test_and_set_ti_thread_flag(current_thread_info(), flag)
	138	#define test_and_clear_thread_flag(flag) \
	139	test_and_clear_ti_thread_flag(current_thread_info(), flag)
	140	#define test_thread_flag(flag) \
	141	test_ti_thread_flag(current_thread_info(), flag)
	142	#define read_thread_flags() \
	143	read_ti_thread_flags(current_thread_info())
	144
	145	#define read_task_thread_flags(t) \
	146	read_ti_thread_flags(task_thread_info(t))
	147
	148	#ifdef CONFIG_GENERIC_ENTRY
	149	#define set_syscall_work(fl) \
	150	set_bit(SYSCALL_WORK_BIT_##fl, &current_thread_info()->syscall_work)
	151	#define test_syscall_work(fl) \
	152	test_bit(SYSCALL_WORK_BIT_##fl, &current_thread_info()->syscall_work)
	153	#define clear_syscall_work(fl) \
	154	clear_bit(SYSCALL_WORK_BIT_##fl, &current_thread_info()->syscall_work)
	155
	156	#define set_task_syscall_work(t, fl) \
	157	set_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work)
	158	#define test_task_syscall_work(t, fl) \
	159	test_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work)
	160	#define clear_task_syscall_work(t, fl) \
	161	clear_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work)
	162
	163	#else /* CONFIG_GENERIC_ENTRY */
	164
	165	#define set_syscall_work(fl) \
	166	set_ti_thread_flag(current_thread_info(), TIF_##fl)
	167	#define test_syscall_work(fl) \
	168	test_ti_thread_flag(current_thread_info(), TIF_##fl)
	169	#define clear_syscall_work(fl) \
	170	clear_ti_thread_flag(current_thread_info(), TIF_##fl)
	171
	172	#define set_task_syscall_work(t, fl) \
	173	set_ti_thread_flag(task_thread_info(t), TIF_##fl)
	174	#define test_task_syscall_work(t, fl) \
	175	test_ti_thread_flag(task_thread_info(t), TIF_##fl)
	176	#define clear_task_syscall_work(t, fl) \
	177	clear_ti_thread_flag(task_thread_info(t), TIF_##fl)
	178	#endif /* !CONFIG_GENERIC_ENTRY */
	179
	180	#define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED)
	181
	182	#ifndef CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES
	183	static inline int arch_within_stack_frames(const void * const stack,
	184	const void * const stackend,
	185	const void *obj, unsigned long len)
	186	{
	187	return 0;
	188	}
	189	#endif
	190
	191	#ifdef CONFIG_HARDENED_USERCOPY
	192	extern void __check_object_size(const void *ptr, unsigned long n,
	193	bool to_user);
	194
	195	static __always_inline void check_object_size(const void *ptr, unsigned long n,
	196	bool to_user)
	197	{
	198	if (!__builtin_constant_p(n))
	199	__check_object_size(ptr, n, to_user);
	200	}
	201	#else
	202	static inline void check_object_size(const void *ptr, unsigned long n,
	203	bool to_user)
	204	{ }
	205	#endif /* CONFIG_HARDENED_USERCOPY */
	206
	207	extern void __compiletime_error("copy source size is too small")
	208	__bad_copy_from(void);
	209	extern void __compiletime_error("copy destination size is too small")
	210	__bad_copy_to(void);
	211
	212	void __copy_overflow(int size, unsigned long count);
	213
	214	static inline void copy_overflow(int size, unsigned long count)
	215	{
	216	if (IS_ENABLED(CONFIG_BUG))
	217	__copy_overflow(size, count);
	218	}
	219
	220	static __always_inline __must_check bool
	221	check_copy_size(const void *addr, size_t bytes, bool is_source)
	222	{
	223	int sz = __builtin_object_size(addr, 0);
	224	if (unlikely(sz >= 0 && sz < bytes)) {
	225	if (!__builtin_constant_p(bytes))
	226	copy_overflow(sz, bytes);
	227	else if (is_source)
	228	__bad_copy_from();
	229	else
	230	__bad_copy_to();
	231	return false;
	232	}
	233	if (WARN_ON_ONCE(bytes > INT_MAX))
	234	return false;
	235	check_object_size(addr, bytes, is_source);
	236	return true;
	237	}
	238
	239	#ifndef arch_setup_new_exec
	240	static inline void arch_setup_new_exec(void) { }
	241	#endif
	242
	243	#endif /* __KERNEL__ */
	244
	245	#endif /* _LINUX_THREAD_INFO_H */