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_ZERO)
48#else
49# define THREADINFO_GFP (GFP_KERNEL_ACCOUNT)
50#endif
51
52/*
53 * flag set/clear/test wrappers
54 * - pass TIF_xxxx constants to these functions
55 */
56
57static inline void set_ti_thread_flag(struct thread_info *ti, int flag)
58{
59 set_bit(flag, (unsigned long *)&ti->flags);
60}
61
62static inline void clear_ti_thread_flag(struct thread_info *ti, int flag)
63{
64 clear_bit(flag, (unsigned long *)&ti->flags);
65}
66
67static inline int test_and_set_ti_thread_flag(struct thread_info *ti, int flag)
68{
69 return test_and_set_bit(flag, (unsigned long *)&ti->flags);
70}
71
72static inline int test_and_clear_ti_thread_flag(struct thread_info *ti, int flag)
73{
74 return test_and_clear_bit(flag, (unsigned long *)&ti->flags);
75}
76
77static inline int test_ti_thread_flag(struct thread_info *ti, int flag)
78{
79 return test_bit(flag, (unsigned long *)&ti->flags);
80}
81
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
93#define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED)
94
95#ifndef CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES
96static 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
104#ifdef CONFIG_HARDENED_USERCOPY
105extern void __check_object_size(const void *ptr, unsigned long n,
106 bool to_user);
107
108static __always_inline void check_object_size(const void *ptr, unsigned long n,
109 bool to_user)
110{
111 if (!__builtin_constant_p(n))
112 __check_object_size(ptr, n, to_user);
113}
114#else
115static inline void check_object_size(const void *ptr, unsigned long n,
116 bool to_user)
117{ }
118#endif /* CONFIG_HARDENED_USERCOPY */
119
120extern void __compiletime_error("copy source size is too small")
121__bad_copy_from(void);
122extern void __compiletime_error("copy destination size is too small")
123__bad_copy_to(void);
124
125static inline void copy_overflow(int size, unsigned long count)
126{
127 WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
128}
129
130static __always_inline bool
131check_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
147#ifndef arch_setup_new_exec
148static inline void arch_setup_new_exec(void) { }
149#endif
150
151#endif /* __KERNEL__ */
152
153#endif /* _LINUX_THREAD_INFO_H */