Line data Source code
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/limits.h>
13 : #include <linux/bug.h>
14 : #include <linux/restart_block.h>
15 : #include <linux/errno.h>
16 :
17 : #ifdef CONFIG_THREAD_INFO_IN_TASK
18 : /*
19 : * For CONFIG_THREAD_INFO_IN_TASK kernels we need <asm/current.h> for the
20 : * definition of current, but for !CONFIG_THREAD_INFO_IN_TASK kernels,
21 : * including <asm/current.h> can cause a circular dependency on some platforms.
22 : */
23 : #include <asm/current.h>
24 : #define current_thread_info() ((struct thread_info *)current)
25 : #endif
26 :
27 : #include <linux/bitops.h>
28 :
29 : /*
30 : * For per-arch arch_within_stack_frames() implementations, defined in
31 : * asm/thread_info.h.
32 : */
33 : enum {
34 : BAD_STACK = -1,
35 : NOT_STACK = 0,
36 : GOOD_FRAME,
37 : GOOD_STACK,
38 : };
39 :
40 : #ifdef CONFIG_GENERIC_ENTRY
41 : enum syscall_work_bit {
42 : SYSCALL_WORK_BIT_SECCOMP,
43 : SYSCALL_WORK_BIT_SYSCALL_TRACEPOINT,
44 : SYSCALL_WORK_BIT_SYSCALL_TRACE,
45 : SYSCALL_WORK_BIT_SYSCALL_EMU,
46 : SYSCALL_WORK_BIT_SYSCALL_AUDIT,
47 : SYSCALL_WORK_BIT_SYSCALL_USER_DISPATCH,
48 : SYSCALL_WORK_BIT_SYSCALL_EXIT_TRAP,
49 : };
50 :
51 : #define SYSCALL_WORK_SECCOMP BIT(SYSCALL_WORK_BIT_SECCOMP)
52 : #define SYSCALL_WORK_SYSCALL_TRACEPOINT BIT(SYSCALL_WORK_BIT_SYSCALL_TRACEPOINT)
53 : #define SYSCALL_WORK_SYSCALL_TRACE BIT(SYSCALL_WORK_BIT_SYSCALL_TRACE)
54 : #define SYSCALL_WORK_SYSCALL_EMU BIT(SYSCALL_WORK_BIT_SYSCALL_EMU)
55 : #define SYSCALL_WORK_SYSCALL_AUDIT BIT(SYSCALL_WORK_BIT_SYSCALL_AUDIT)
56 : #define SYSCALL_WORK_SYSCALL_USER_DISPATCH BIT(SYSCALL_WORK_BIT_SYSCALL_USER_DISPATCH)
57 : #define SYSCALL_WORK_SYSCALL_EXIT_TRAP BIT(SYSCALL_WORK_BIT_SYSCALL_EXIT_TRAP)
58 : #endif
59 :
60 : #include <asm/thread_info.h>
61 :
62 : #ifdef __KERNEL__
63 :
64 : #ifndef arch_set_restart_data
65 : #define arch_set_restart_data(restart) do { } while (0)
66 : #endif
67 :
68 : static inline long set_restart_fn(struct restart_block *restart,
69 : long (*fn)(struct restart_block *))
70 : {
71 0 : restart->fn = fn;
72 : arch_set_restart_data(restart);
73 : return -ERESTART_RESTARTBLOCK;
74 : }
75 :
76 : #ifndef THREAD_ALIGN
77 : #define THREAD_ALIGN THREAD_SIZE
78 : #endif
79 :
80 : #define THREADINFO_GFP (GFP_KERNEL_ACCOUNT | __GFP_ZERO)
81 :
82 : /*
83 : * flag set/clear/test wrappers
84 : * - pass TIF_xxxx constants to these functions
85 : */
86 :
87 : static inline void set_ti_thread_flag(struct thread_info *ti, int flag)
88 : {
89 624 : set_bit(flag, (unsigned long *)&ti->flags);
90 : }
91 :
92 : static inline void clear_ti_thread_flag(struct thread_info *ti, int flag)
93 : {
94 2066 : clear_bit(flag, (unsigned long *)&ti->flags);
95 : }
96 :
97 : static inline void update_ti_thread_flag(struct thread_info *ti, int flag,
98 : bool value)
99 : {
100 : if (value)
101 : set_ti_thread_flag(ti, flag);
102 : else
103 : clear_ti_thread_flag(ti, flag);
104 : }
105 :
106 : static inline int test_and_set_ti_thread_flag(struct thread_info *ti, int flag)
107 : {
108 0 : return test_and_set_bit(flag, (unsigned long *)&ti->flags);
109 : }
110 :
111 : static inline int test_and_clear_ti_thread_flag(struct thread_info *ti, int flag)
112 : {
113 0 : return test_and_clear_bit(flag, (unsigned long *)&ti->flags);
114 : }
115 :
116 : static inline int test_ti_thread_flag(struct thread_info *ti, int flag)
117 : {
118 7122 : return test_bit(flag, (unsigned long *)&ti->flags);
119 : }
120 :
121 : /*
122 : * This may be used in noinstr code, and needs to be __always_inline to prevent
123 : * inadvertent instrumentation.
124 : */
125 : static __always_inline unsigned long read_ti_thread_flags(struct thread_info *ti)
126 : {
127 0 : return READ_ONCE(ti->flags);
128 : }
129 :
130 : #define set_thread_flag(flag) \
131 : set_ti_thread_flag(current_thread_info(), flag)
132 : #define clear_thread_flag(flag) \
133 : clear_ti_thread_flag(current_thread_info(), flag)
134 : #define update_thread_flag(flag, value) \
135 : update_ti_thread_flag(current_thread_info(), flag, value)
136 : #define test_and_set_thread_flag(flag) \
137 : test_and_set_ti_thread_flag(current_thread_info(), flag)
138 : #define test_and_clear_thread_flag(flag) \
139 : test_and_clear_ti_thread_flag(current_thread_info(), flag)
140 : #define test_thread_flag(flag) \
141 : test_ti_thread_flag(current_thread_info(), flag)
142 : #define read_thread_flags() \
143 : read_ti_thread_flags(current_thread_info())
144 :
145 : #define read_task_thread_flags(t) \
146 : read_ti_thread_flags(task_thread_info(t))
147 :
148 : #ifdef CONFIG_GENERIC_ENTRY
149 : #define set_syscall_work(fl) \
150 : set_bit(SYSCALL_WORK_BIT_##fl, ¤t_thread_info()->syscall_work)
151 : #define test_syscall_work(fl) \
152 : test_bit(SYSCALL_WORK_BIT_##fl, ¤t_thread_info()->syscall_work)
153 : #define clear_syscall_work(fl) \
154 : clear_bit(SYSCALL_WORK_BIT_##fl, ¤t_thread_info()->syscall_work)
155 :
156 : #define set_task_syscall_work(t, fl) \
157 : set_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work)
158 : #define test_task_syscall_work(t, fl) \
159 : test_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work)
160 : #define clear_task_syscall_work(t, fl) \
161 : clear_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work)
162 :
163 : #else /* CONFIG_GENERIC_ENTRY */
164 :
165 : #define set_syscall_work(fl) \
166 : set_ti_thread_flag(current_thread_info(), TIF_##fl)
167 : #define test_syscall_work(fl) \
168 : test_ti_thread_flag(current_thread_info(), TIF_##fl)
169 : #define clear_syscall_work(fl) \
170 : clear_ti_thread_flag(current_thread_info(), TIF_##fl)
171 :
172 : #define set_task_syscall_work(t, fl) \
173 : set_ti_thread_flag(task_thread_info(t), TIF_##fl)
174 : #define test_task_syscall_work(t, fl) \
175 : test_ti_thread_flag(task_thread_info(t), TIF_##fl)
176 : #define clear_task_syscall_work(t, fl) \
177 : clear_ti_thread_flag(task_thread_info(t), TIF_##fl)
178 : #endif /* !CONFIG_GENERIC_ENTRY */
179 :
180 : #define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED)
181 :
182 : #ifndef CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES
183 : static inline int arch_within_stack_frames(const void * const stack,
184 : const void * const stackend,
185 : const void *obj, unsigned long len)
186 : {
187 : return 0;
188 : }
189 : #endif
190 :
191 : #ifdef CONFIG_HARDENED_USERCOPY
192 : extern void __check_object_size(const void *ptr, unsigned long n,
193 : bool to_user);
194 :
195 : static __always_inline void check_object_size(const void *ptr, unsigned long n,
196 : bool to_user)
197 : {
198 : if (!__builtin_constant_p(n))
199 : __check_object_size(ptr, n, to_user);
200 : }
201 : #else
202 : static inline void check_object_size(const void *ptr, unsigned long n,
203 : bool to_user)
204 : { }
205 : #endif /* CONFIG_HARDENED_USERCOPY */
206 :
207 : extern void __compiletime_error("copy source size is too small")
208 : __bad_copy_from(void);
209 : extern void __compiletime_error("copy destination size is too small")
210 : __bad_copy_to(void);
211 :
212 : void __copy_overflow(int size, unsigned long count);
213 :
214 0 : static inline void copy_overflow(int size, unsigned long count)
215 : {
216 : if (IS_ENABLED(CONFIG_BUG))
217 0 : __copy_overflow(size, count);
218 0 : }
219 :
220 : static __always_inline __must_check bool
221 : check_copy_size(const void *addr, size_t bytes, bool is_source)
222 : {
223 0 : int sz = __builtin_object_size(addr, 0);
224 0 : if (unlikely(sz >= 0 && sz < bytes)) {
225 0 : if (!__builtin_constant_p(bytes))
226 0 : copy_overflow(sz, bytes);
227 : else if (is_source)
228 0 : __bad_copy_from();
229 : else
230 0 : __bad_copy_to();
231 : return false;
232 : }
233 0 : if (WARN_ON_ONCE(bytes > INT_MAX))
234 : return false;
235 : check_object_size(addr, bytes, is_source);
236 : return true;
237 : }
238 :
239 : #ifndef arch_setup_new_exec
240 : static inline void arch_setup_new_exec(void) { }
241 : #endif
242 :
243 : #endif /* __KERNEL__ */
244 :
245 : #endif /* _LINUX_THREAD_INFO_H */
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