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1/* thread_info.h: common low-level thread information accessors
2 *
3 * Copyright (C) 2002 David Howells (dhowells@redhat.com)
4 * - Incorporating suggestions made by Linus Torvalds
5 */
6
7#ifndef _LINUX_THREAD_INFO_H
8#define _LINUX_THREAD_INFO_H
9
10#include <linux/types.h>
11#include <linux/bug.h>
12#include <linux/restart_block.h>
13
14#ifdef CONFIG_THREAD_INFO_IN_TASK
15/*
16 * For CONFIG_THREAD_INFO_IN_TASK kernels we need <asm/current.h> for the
17 * definition of current, but for !CONFIG_THREAD_INFO_IN_TASK kernels,
18 * including <asm/current.h> can cause a circular dependency on some platforms.
19 */
20#include <asm/current.h>
21#define current_thread_info() ((struct thread_info *)current)
22#endif
23
24#include <linux/bitops.h>
25
26/*
27 * For per-arch arch_within_stack_frames() implementations, defined in
28 * asm/thread_info.h.
29 */
30enum {
31 BAD_STACK = -1,
32 NOT_STACK = 0,
33 GOOD_FRAME,
34 GOOD_STACK,
35};
36
37#include <asm/thread_info.h>
38
39#ifdef __KERNEL__
40
41#ifdef CONFIG_DEBUG_STACK_USAGE
42# define THREADINFO_GFP (GFP_KERNEL_ACCOUNT | __GFP_NOTRACK | \
43 __GFP_ZERO)
44#else
45# define THREADINFO_GFP (GFP_KERNEL_ACCOUNT | __GFP_NOTRACK)
46#endif
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 int test_and_set_ti_thread_flag(struct thread_info *ti, int flag)
64{
65 return test_and_set_bit(flag, (unsigned long *)&ti->flags);
66}
67
68static inline int test_and_clear_ti_thread_flag(struct thread_info *ti, int flag)
69{
70 return test_and_clear_bit(flag, (unsigned long *)&ti->flags);
71}
72
73static inline int test_ti_thread_flag(struct thread_info *ti, int flag)
74{
75 return test_bit(flag, (unsigned long *)&ti->flags);
76}
77
78#define set_thread_flag(flag) \
79 set_ti_thread_flag(current_thread_info(), flag)
80#define clear_thread_flag(flag) \
81 clear_ti_thread_flag(current_thread_info(), flag)
82#define test_and_set_thread_flag(flag) \
83 test_and_set_ti_thread_flag(current_thread_info(), flag)
84#define test_and_clear_thread_flag(flag) \
85 test_and_clear_ti_thread_flag(current_thread_info(), flag)
86#define test_thread_flag(flag) \
87 test_ti_thread_flag(current_thread_info(), flag)
88
89#define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED)
90
91#ifndef CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES
92static inline int arch_within_stack_frames(const void * const stack,
93 const void * const stackend,
94 const void *obj, unsigned long len)
95{
96 return 0;
97}
98#endif
99
100#ifdef CONFIG_HARDENED_USERCOPY
101extern void __check_object_size(const void *ptr, unsigned long n,
102 bool to_user);
103
104static __always_inline void check_object_size(const void *ptr, unsigned long n,
105 bool to_user)
106{
107 if (!__builtin_constant_p(n))
108 __check_object_size(ptr, n, to_user);
109}
110#else
111static inline void check_object_size(const void *ptr, unsigned long n,
112 bool to_user)
113{ }
114#endif /* CONFIG_HARDENED_USERCOPY */
115
116extern void __compiletime_error("copy source size is too small")
117__bad_copy_from(void);
118extern void __compiletime_error("copy destination size is too small")
119__bad_copy_to(void);
120
121static inline void copy_overflow(int size, unsigned long count)
122{
123 WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
124}
125
126static __always_inline bool
127check_copy_size(const void *addr, size_t bytes, bool is_source)
128{
129 int sz = __compiletime_object_size(addr);
130 if (unlikely(sz >= 0 && sz < bytes)) {
131 if (!__builtin_constant_p(bytes))
132 copy_overflow(sz, bytes);
133 else if (is_source)
134 __bad_copy_from();
135 else
136 __bad_copy_to();
137 return false;
138 }
139 check_object_size(addr, bytes, is_source);
140 return true;
141}
142
143#ifndef arch_setup_new_exec
144static inline void arch_setup_new_exec(void) { }
145#endif
146
147#endif /* __KERNEL__ */
148
149#endif /* _LINUX_THREAD_INFO_H */