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/bug.h>
13#include <linux/restart_block.h>
14
15#ifdef CONFIG_THREAD_INFO_IN_TASK
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>
22#define current_thread_info() ((struct thread_info *)current)
23#endif
24
25#include <linux/bitops.h>
26
27/*
28 * For per-arch arch_within_stack_frames() implementations, defined in
29 * asm/thread_info.h.
30 */
31enum {
32 BAD_STACK = -1,
33 NOT_STACK = 0,
34 GOOD_FRAME,
35 GOOD_STACK,
36};
37
38#include <asm/thread_info.h>
39
40#ifdef __KERNEL__
41
42#ifndef THREAD_ALIGN
43#define THREAD_ALIGN THREAD_SIZE
44#endif
45
46#define THREADINFO_GFP (GFP_KERNEL_ACCOUNT | __GFP_ZERO)
47
48/*
49 * flag set/clear/test wrappers
50 * - pass TIF_xxxx constants to these functions
51 */
52
53static inline void set_ti_thread_flag(struct thread_info *ti, int flag)
54{
55 set_bit(flag, (unsigned long *)&ti->flags);
56}
57
58static inline void clear_ti_thread_flag(struct thread_info *ti, int flag)
59{
60 clear_bit(flag, (unsigned long *)&ti->flags);
61}
62
63static inline void update_ti_thread_flag(struct thread_info *ti, int flag,
64 bool value)
65{
66 if (value)
67 set_ti_thread_flag(ti, flag);
68 else
69 clear_ti_thread_flag(ti, flag);
70}
71
72static inline int test_and_set_ti_thread_flag(struct thread_info *ti, int flag)
73{
74 return test_and_set_bit(flag, (unsigned long *)&ti->flags);
75}
76
77static inline int test_and_clear_ti_thread_flag(struct thread_info *ti, int flag)
78{
79 return test_and_clear_bit(flag, (unsigned long *)&ti->flags);
80}
81
82static inline int test_ti_thread_flag(struct thread_info *ti, int flag)
83{
84 return test_bit(flag, (unsigned long *)&ti->flags);
85}
86
87#define set_thread_flag(flag) \
88 set_ti_thread_flag(current_thread_info(), flag)
89#define clear_thread_flag(flag) \
90 clear_ti_thread_flag(current_thread_info(), flag)
91#define update_thread_flag(flag, value) \
92 update_ti_thread_flag(current_thread_info(), flag, value)
93#define test_and_set_thread_flag(flag) \
94 test_and_set_ti_thread_flag(current_thread_info(), flag)
95#define test_and_clear_thread_flag(flag) \
96 test_and_clear_ti_thread_flag(current_thread_info(), flag)
97#define test_thread_flag(flag) \
98 test_ti_thread_flag(current_thread_info(), flag)
99
100#define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED)
101
102#ifndef CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES
103static inline int arch_within_stack_frames(const void * const stack,
104 const void * const stackend,
105 const void *obj, unsigned long len)
106{
107 return 0;
108}
109#endif
110
111#ifdef CONFIG_HARDENED_USERCOPY
112extern void __check_object_size(const void *ptr, unsigned long n,
113 bool to_user);
114
115static __always_inline void check_object_size(const void *ptr, unsigned long n,
116 bool to_user)
117{
118 if (!__builtin_constant_p(n))
119 __check_object_size(ptr, n, to_user);
120}
121#else
122static inline void check_object_size(const void *ptr, unsigned long n,
123 bool to_user)
124{ }
125#endif /* CONFIG_HARDENED_USERCOPY */
126
127extern void __compiletime_error("copy source size is too small")
128__bad_copy_from(void);
129extern void __compiletime_error("copy destination size is too small")
130__bad_copy_to(void);
131
132static inline void copy_overflow(int size, unsigned long count)
133{
134 WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
135}
136
137static __always_inline bool
138check_copy_size(const void *addr, size_t bytes, bool is_source)
139{
140 int sz = __compiletime_object_size(addr);
141 if (unlikely(sz >= 0 && sz < bytes)) {
142 if (!__builtin_constant_p(bytes))
143 copy_overflow(sz, bytes);
144 else if (is_source)
145 __bad_copy_from();
146 else
147 __bad_copy_to();
148 return false;
149 }
150 check_object_size(addr, bytes, is_source);
151 return true;
152}
153
154#ifndef arch_setup_new_exec
155static inline void arch_setup_new_exec(void) { }
156#endif
157
158#endif /* __KERNEL__ */
159
160#endif /* _LINUX_THREAD_INFO_H */
161