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 #include <linux/errno.h>
15
16 #ifdef CONFIG_THREAD_INFO_IN_TASK
17 /*
18 * For CONFIG_THREAD_INFO_IN_TASK kernels we need <asm/current.h> for the
19 * definition of current, but for !CONFIG_THREAD_INFO_IN_TASK kernels,
20 * including <asm/current.h> can cause a circular dependency on some platforms.
21 */
22 #include <asm/current.h>
23 #define current_thread_info() ((struct thread_info *)current)
24 #endif
25
26 #include <linux/bitops.h>
27
28 /*
29 * For per-arch arch_within_stack_frames() implementations, defined in
30 * asm/thread_info.h.
31 */
32 enum {
33 BAD_STACK = -1,
34 NOT_STACK = 0,
35 GOOD_FRAME,
36 GOOD_STACK,
37 };
38
39 #include <asm/thread_info.h>
40
41 #ifdef __KERNEL__
42
43 #ifndef arch_set_restart_data
44 #define arch_set_restart_data(restart) do { } while (0)
45 #endif
46
set_restart_fn(struct restart_block * restart,long (* fn)(struct restart_block *))47 static inline long set_restart_fn(struct restart_block *restart,
48 long (*fn)(struct restart_block *))
49 {
50 restart->fn = fn;
51 arch_set_restart_data(restart);
52 return -ERESTART_RESTARTBLOCK;
53 }
54
55 #ifndef THREAD_ALIGN
56 #define THREAD_ALIGN THREAD_SIZE
57 #endif
58
59 #define THREADINFO_GFP (GFP_KERNEL_ACCOUNT | __GFP_ZERO)
60
61 /*
62 * flag set/clear/test wrappers
63 * - pass TIF_xxxx constants to these functions
64 */
65
set_ti_thread_flag(struct thread_info * ti,int flag)66 static inline void set_ti_thread_flag(struct thread_info *ti, int flag)
67 {
68 set_bit(flag, (unsigned long *)&ti->flags);
69 }
70
clear_ti_thread_flag(struct thread_info * ti,int flag)71 static inline void clear_ti_thread_flag(struct thread_info *ti, int flag)
72 {
73 clear_bit(flag, (unsigned long *)&ti->flags);
74 }
75
update_ti_thread_flag(struct thread_info * ti,int flag,bool value)76 static inline void update_ti_thread_flag(struct thread_info *ti, int flag,
77 bool value)
78 {
79 if (value)
80 set_ti_thread_flag(ti, flag);
81 else
82 clear_ti_thread_flag(ti, flag);
83 }
84
test_and_set_ti_thread_flag(struct thread_info * ti,int flag)85 static inline int test_and_set_ti_thread_flag(struct thread_info *ti, int flag)
86 {
87 return test_and_set_bit(flag, (unsigned long *)&ti->flags);
88 }
89
test_and_clear_ti_thread_flag(struct thread_info * ti,int flag)90 static inline int test_and_clear_ti_thread_flag(struct thread_info *ti, int flag)
91 {
92 return test_and_clear_bit(flag, (unsigned long *)&ti->flags);
93 }
94
test_ti_thread_flag(struct thread_info * ti,int flag)95 static inline int test_ti_thread_flag(struct thread_info *ti, int flag)
96 {
97 return test_bit(flag, (unsigned long *)&ti->flags);
98 }
99
100 #define set_thread_flag(flag) \
101 set_ti_thread_flag(current_thread_info(), flag)
102 #define clear_thread_flag(flag) \
103 clear_ti_thread_flag(current_thread_info(), flag)
104 #define update_thread_flag(flag, value) \
105 update_ti_thread_flag(current_thread_info(), flag, value)
106 #define test_and_set_thread_flag(flag) \
107 test_and_set_ti_thread_flag(current_thread_info(), flag)
108 #define test_and_clear_thread_flag(flag) \
109 test_and_clear_ti_thread_flag(current_thread_info(), flag)
110 #define test_thread_flag(flag) \
111 test_ti_thread_flag(current_thread_info(), flag)
112
113 #define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED)
114
115 #ifndef CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES
arch_within_stack_frames(const void * const stack,const void * const stackend,const void * obj,unsigned long len)116 static inline int arch_within_stack_frames(const void * const stack,
117 const void * const stackend,
118 const void *obj, unsigned long len)
119 {
120 return 0;
121 }
122 #endif
123
124 #ifdef CONFIG_HARDENED_USERCOPY
125 extern void __check_object_size(const void *ptr, unsigned long n,
126 bool to_user);
127
check_object_size(const void * ptr,unsigned long n,bool to_user)128 static __always_inline void check_object_size(const void *ptr, unsigned long n,
129 bool to_user)
130 {
131 if (!__builtin_constant_p(n))
132 __check_object_size(ptr, n, to_user);
133 }
134 #else
check_object_size(const void * ptr,unsigned long n,bool to_user)135 static inline void check_object_size(const void *ptr, unsigned long n,
136 bool to_user)
137 { }
138 #endif /* CONFIG_HARDENED_USERCOPY */
139
140 extern void __compiletime_error("copy source size is too small")
141 __bad_copy_from(void);
142 extern void __compiletime_error("copy destination size is too small")
143 __bad_copy_to(void);
144
copy_overflow(int size,unsigned long count)145 static inline void copy_overflow(int size, unsigned long count)
146 {
147 WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
148 }
149
150 static __always_inline __must_check bool
check_copy_size(const void * addr,size_t bytes,bool is_source)151 check_copy_size(const void *addr, size_t bytes, bool is_source)
152 {
153 int sz = __compiletime_object_size(addr);
154 if (unlikely(sz >= 0 && sz < bytes)) {
155 if (!__builtin_constant_p(bytes))
156 copy_overflow(sz, bytes);
157 else if (is_source)
158 __bad_copy_from();
159 else
160 __bad_copy_to();
161 return false;
162 }
163 if (WARN_ON_ONCE(bytes > INT_MAX))
164 return false;
165 check_object_size(addr, bytes, is_source);
166 return true;
167 }
168
169 #ifndef arch_setup_new_exec
arch_setup_new_exec(void)170 static inline void arch_setup_new_exec(void) { }
171 #endif
172
173 #endif /* __KERNEL__ */
174
175 #endif /* _LINUX_THREAD_INFO_H */
176