Linux kernel mirror (for testing)
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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#if IS_ENABLED(CONFIG_DEBUG_STACK_USAGE) || IS_ENABLED(CONFIG_DEBUG_KMEMLEAK)
47# define THREADINFO_GFP (GFP_KERNEL_ACCOUNT | __GFP_NOTRACK | \
48 __GFP_ZERO)
49#else
50# define THREADINFO_GFP (GFP_KERNEL_ACCOUNT | __GFP_NOTRACK)
51#endif
52
53/*
54 * flag set/clear/test wrappers
55 * - pass TIF_xxxx constants to these functions
56 */
57
58static inline void set_ti_thread_flag(struct thread_info *ti, int flag)
59{
60 set_bit(flag, (unsigned long *)&ti->flags);
61}
62
63static inline void clear_ti_thread_flag(struct thread_info *ti, int flag)
64{
65 clear_bit(flag, (unsigned long *)&ti->flags);
66}
67
68static inline int test_and_set_ti_thread_flag(struct thread_info *ti, int flag)
69{
70 return test_and_set_bit(flag, (unsigned long *)&ti->flags);
71}
72
73static inline int test_and_clear_ti_thread_flag(struct thread_info *ti, int flag)
74{
75 return test_and_clear_bit(flag, (unsigned long *)&ti->flags);
76}
77
78static inline int test_ti_thread_flag(struct thread_info *ti, int flag)
79{
80 return test_bit(flag, (unsigned long *)&ti->flags);
81}
82
83#define set_thread_flag(flag) \
84 set_ti_thread_flag(current_thread_info(), flag)
85#define clear_thread_flag(flag) \
86 clear_ti_thread_flag(current_thread_info(), flag)
87#define test_and_set_thread_flag(flag) \
88 test_and_set_ti_thread_flag(current_thread_info(), flag)
89#define test_and_clear_thread_flag(flag) \
90 test_and_clear_ti_thread_flag(current_thread_info(), flag)
91#define test_thread_flag(flag) \
92 test_ti_thread_flag(current_thread_info(), flag)
93
94#define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED)
95
96#ifndef CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES
97static inline int arch_within_stack_frames(const void * const stack,
98 const void * const stackend,
99 const void *obj, unsigned long len)
100{
101 return 0;
102}
103#endif
104
105#ifdef CONFIG_HARDENED_USERCOPY
106extern void __check_object_size(const void *ptr, unsigned long n,
107 bool to_user);
108
109static __always_inline void check_object_size(const void *ptr, unsigned long n,
110 bool to_user)
111{
112 if (!__builtin_constant_p(n))
113 __check_object_size(ptr, n, to_user);
114}
115#else
116static inline void check_object_size(const void *ptr, unsigned long n,
117 bool to_user)
118{ }
119#endif /* CONFIG_HARDENED_USERCOPY */
120
121extern void __compiletime_error("copy source size is too small")
122__bad_copy_from(void);
123extern void __compiletime_error("copy destination size is too small")
124__bad_copy_to(void);
125
126static inline void copy_overflow(int size, unsigned long count)
127{
128 WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
129}
130
131static __always_inline bool
132check_copy_size(const void *addr, size_t bytes, bool is_source)
133{
134 int sz = __compiletime_object_size(addr);
135 if (unlikely(sz >= 0 && sz < bytes)) {
136 if (!__builtin_constant_p(bytes))
137 copy_overflow(sz, bytes);
138 else if (is_source)
139 __bad_copy_from();
140 else
141 __bad_copy_to();
142 return false;
143 }
144 check_object_size(addr, bytes, is_source);
145 return true;
146}
147
148#ifndef arch_setup_new_exec
149static inline void arch_setup_new_exec(void) { }
150#endif
151
152#endif /* __KERNEL__ */
153
154#endif /* _LINUX_THREAD_INFO_H */