[mirror_ubuntu-bionic-kernel.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/bug.h>
#include <linux/restart_block.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,
};

#include <asm/thread_info.h>

#ifdef __KERNEL__

#ifndef THREAD_ALIGN
#define THREAD_ALIGN	THREAD_SIZE
#endif

#if IS_ENABLED(CONFIG_DEBUG_STACK_USAGE) || IS_ENABLED(CONFIG_DEBUG_KMEMLEAK)
# define THREADINFO_GFP		(GFP_KERNEL_ACCOUNT | __GFP_ZERO)
#else
# define THREADINFO_GFP		(GFP_KERNEL_ACCOUNT)
#endif

/*
 * 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 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);
}

#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 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 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);

static inline void copy_overflow(int size, unsigned long count)
{
	WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
}

static __always_inline bool
check_copy_size(const void *addr, size_t bytes, bool is_source)
{
	int sz = __compiletime_object_size(addr);
	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;
	}
	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
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
1da177e4 LT	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
ce6bd420	11	#include <linux/types.h>
edd63a27	12	#include <linux/bug.h>
53d74d05	13	#include <linux/restart_block.h>
a332d86d	14
c65eacbe	15	#ifdef CONFIG_THREAD_INFO_IN_TASK
dc3d2a67 MR	16	/*
	17	* For CONFIG_THREAD_INFO_IN_TASK kernels we need <asm/current.h> for the
	18	* definition of current, but for !CONFIG_THREAD_INFO_IN_TASK kernels,
	19	* including <asm/current.h> can cause a circular dependency on some platforms.
	20	*/
	21	#include <asm/current.h>
c65eacbe AL	22	#define current_thread_info() ((struct thread_info *)current)
	23	#endif
	24
1da177e4	25	#include <linux/bitops.h>
96dc4f9f S	26
	27	/*
	28	* For per-arch arch_within_stack_frames() implementations, defined in
	29	* asm/thread_info.h.
	30	*/
	31	enum {
	32	BAD_STACK = -1,
	33	NOT_STACK = 0,
	34	GOOD_FRAME,
	35	GOOD_STACK,
	36	};
	37
1da177e4 LT	38	#include <asm/thread_info.h>
	39
	40	#ifdef __KERNEL__
	41
48ac3c18 MR	42	#ifndef THREAD_ALIGN
	43	#define THREAD_ALIGN THREAD_SIZE
	44	#endif
	45
ca182551	46	#if IS_ENABLED(CONFIG_DEBUG_STACK_USAGE) \|\| IS_ENABLED(CONFIG_DEBUG_KMEMLEAK)
75f296d9	47	# define THREADINFO_GFP (GFP_KERNEL_ACCOUNT \| __GFP_ZERO)
2889f608	48	#else
75f296d9	49	# define THREADINFO_GFP (GFP_KERNEL_ACCOUNT)
2889f608 TG	50	#endif
2889f608 TG	51
1da177e4 LT	52	/*
	53	* flag set/clear/test wrappers
	54	* - pass TIF_xxxx constants to these functions
	55	*/
	56
1da177e4 LT	57	static inline void set_ti_thread_flag(struct thread_info *ti, int flag)
1da177e4 LT	58	{
5548fecd	59	set_bit(flag, (unsigned long *)&ti->flags);
1da177e4 LT	60	}
	61
	62	static inline void clear_ti_thread_flag(struct thread_info *ti, int flag)
	63	{
5548fecd	64	clear_bit(flag, (unsigned long *)&ti->flags);
1da177e4 LT	65	}
	66
	67	static inline int test_and_set_ti_thread_flag(struct thread_info *ti, int flag)
	68	{
5548fecd	69	return test_and_set_bit(flag, (unsigned long *)&ti->flags);
1da177e4 LT	70	}
	71
	72	static inline int test_and_clear_ti_thread_flag(struct thread_info *ti, int flag)
	73	{
5548fecd	74	return test_and_clear_bit(flag, (unsigned long *)&ti->flags);
1da177e4 LT	75	}
	76
	77	static inline int test_ti_thread_flag(struct thread_info *ti, int flag)
	78	{
5548fecd	79	return test_bit(flag, (unsigned long *)&ti->flags);
1da177e4 LT	80	}
1da177e4 LT	81
3b66a1ed RZ	82	#define set_thread_flag(flag) \
	83	set_ti_thread_flag(current_thread_info(), flag)
	84	#define clear_thread_flag(flag) \
	85	clear_ti_thread_flag(current_thread_info(), flag)
	86	#define test_and_set_thread_flag(flag) \
	87	test_and_set_ti_thread_flag(current_thread_info(), flag)
	88	#define test_and_clear_thread_flag(flag) \
	89	test_and_clear_ti_thread_flag(current_thread_info(), flag)
	90	#define test_thread_flag(flag) \
	91	test_ti_thread_flag(current_thread_info(), flag)
	92
ea811747 PZ	93	#define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED)
ea811747 PZ	94
0f60a8ef KC	95	#ifndef CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES
	96	static inline int arch_within_stack_frames(const void * const stack,
	97	const void * const stackend,
	98	const void *obj, unsigned long len)
	99	{
	100	return 0;
	101	}
	102	#endif
	103
f5509cc1 KC	104	#ifdef CONFIG_HARDENED_USERCOPY
	105	extern void __check_object_size(const void *ptr, unsigned long n,
	106	bool to_user);
	107
a85d6b82 KC	108	static __always_inline void check_object_size(const void *ptr, unsigned long n,
a85d6b82 KC	109	bool to_user)
f5509cc1	110	{
81409e9e KC	111	if (!__builtin_constant_p(n))
81409e9e KC	112	__check_object_size(ptr, n, to_user);
f5509cc1 KC	113	}
	114	#else
	115	static inline void check_object_size(const void *ptr, unsigned long n,
	116	bool to_user)
	117	{ }
	118	#endif /* CONFIG_HARDENED_USERCOPY */
	119
b0377fed AV	120	extern void __compiletime_error("copy source size is too small")
	121	__bad_copy_from(void);
	122	extern void __compiletime_error("copy destination size is too small")
	123	__bad_copy_to(void);
	124
	125	static inline void copy_overflow(int size, unsigned long count)
	126	{
	127	WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
	128	}
	129
	130	static __always_inline bool
	131	check_copy_size(const void *addr, size_t bytes, bool is_source)
	132	{
	133	int sz = __compiletime_object_size(addr);
	134	if (unlikely(sz >= 0 && sz < bytes)) {
	135	if (!__builtin_constant_p(bytes))
	136	copy_overflow(sz, bytes);
	137	else if (is_source)
	138	__bad_copy_from();
	139	else
	140	__bad_copy_to();
	141	return false;
	142	}
	143	check_object_size(addr, bytes, is_source);
	144	return true;
	145	}
	146
e9ea1e7f KH	147	#ifndef arch_setup_new_exec
	148	static inline void arch_setup_new_exec(void) { }
	149	#endif
	150
4e4c22c7	151	#endif /* __KERNEL__ */
1da177e4 LT	152
1da177e4 LT	153	#endif /* _LINUX_THREAD_INFO_H */