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/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 : */
31 : enum {
32 : BAD_STACK = -1,
33 : NOT_STACK = 0,
34 : GOOD_FRAME,
35 : GOOD_STACK,
36 : };
37 :
38 : #ifdef CONFIG_GENERIC_ENTRY
39 : enum syscall_work_bit {
40 : SYSCALL_WORK_BIT_SECCOMP,
41 : SYSCALL_WORK_BIT_SYSCALL_TRACEPOINT,
42 : SYSCALL_WORK_BIT_SYSCALL_TRACE,
43 : SYSCALL_WORK_BIT_SYSCALL_EMU,
44 : SYSCALL_WORK_BIT_SYSCALL_AUDIT,
45 : SYSCALL_WORK_BIT_SYSCALL_USER_DISPATCH,
46 : SYSCALL_WORK_BIT_SYSCALL_EXIT_TRAP,
47 : };
48 :
49 : #define SYSCALL_WORK_SECCOMP BIT(SYSCALL_WORK_BIT_SECCOMP)
50 : #define SYSCALL_WORK_SYSCALL_TRACEPOINT BIT(SYSCALL_WORK_BIT_SYSCALL_TRACEPOINT)
51 : #define SYSCALL_WORK_SYSCALL_TRACE BIT(SYSCALL_WORK_BIT_SYSCALL_TRACE)
52 : #define SYSCALL_WORK_SYSCALL_EMU BIT(SYSCALL_WORK_BIT_SYSCALL_EMU)
53 : #define SYSCALL_WORK_SYSCALL_AUDIT BIT(SYSCALL_WORK_BIT_SYSCALL_AUDIT)
54 : #define SYSCALL_WORK_SYSCALL_USER_DISPATCH BIT(SYSCALL_WORK_BIT_SYSCALL_USER_DISPATCH)
55 : #define SYSCALL_WORK_SYSCALL_EXIT_TRAP BIT(SYSCALL_WORK_BIT_SYSCALL_EXIT_TRAP)
56 : #endif
57 :
58 : #include <asm/thread_info.h>
59 :
60 : #ifdef __KERNEL__
61 :
62 : #ifndef THREAD_ALIGN
63 : #define THREAD_ALIGN THREAD_SIZE
64 : #endif
65 :
66 : #define THREADINFO_GFP (GFP_KERNEL_ACCOUNT | __GFP_ZERO)
67 :
68 : /*
69 : * flag set/clear/test wrappers
70 : * - pass TIF_xxxx constants to these functions
71 : */
72 :
73 91950 : static inline void set_ti_thread_flag(struct thread_info *ti, int flag)
74 : {
75 91950 : set_bit(flag, (unsigned long *)&ti->flags);
76 0 : }
77 :
78 131391 : static inline void clear_ti_thread_flag(struct thread_info *ti, int flag)
79 : {
80 131391 : clear_bit(flag, (unsigned long *)&ti->flags);
81 18790 : }
82 :
83 : static inline void update_ti_thread_flag(struct thread_info *ti, int flag,
84 : bool value)
85 : {
86 : if (value)
87 : set_ti_thread_flag(ti, flag);
88 : else
89 : clear_ti_thread_flag(ti, flag);
90 : }
91 :
92 56851 : static inline int test_and_set_ti_thread_flag(struct thread_info *ti, int flag)
93 : {
94 56851 : return test_and_set_bit(flag, (unsigned long *)&ti->flags);
95 : }
96 :
97 2646 : static inline int test_and_clear_ti_thread_flag(struct thread_info *ti, int flag)
98 : {
99 2646 : return test_and_clear_bit(flag, (unsigned long *)&ti->flags);
100 : }
101 :
102 2160877 : static inline int test_ti_thread_flag(struct thread_info *ti, int flag)
103 : {
104 2160877 : return test_bit(flag, (unsigned long *)&ti->flags);
105 : }
106 :
107 : #define set_thread_flag(flag) \
108 : set_ti_thread_flag(current_thread_info(), flag)
109 : #define clear_thread_flag(flag) \
110 : clear_ti_thread_flag(current_thread_info(), flag)
111 : #define update_thread_flag(flag, value) \
112 : update_ti_thread_flag(current_thread_info(), flag, value)
113 : #define test_and_set_thread_flag(flag) \
114 : test_and_set_ti_thread_flag(current_thread_info(), flag)
115 : #define test_and_clear_thread_flag(flag) \
116 : test_and_clear_ti_thread_flag(current_thread_info(), flag)
117 : #define test_thread_flag(flag) \
118 : test_ti_thread_flag(current_thread_info(), flag)
119 :
120 : #ifdef CONFIG_GENERIC_ENTRY
121 : #define set_syscall_work(fl) \
122 : set_bit(SYSCALL_WORK_BIT_##fl, ¤t_thread_info()->syscall_work)
123 : #define test_syscall_work(fl) \
124 : test_bit(SYSCALL_WORK_BIT_##fl, ¤t_thread_info()->syscall_work)
125 : #define clear_syscall_work(fl) \
126 : clear_bit(SYSCALL_WORK_BIT_##fl, ¤t_thread_info()->syscall_work)
127 :
128 : #define set_task_syscall_work(t, fl) \
129 : set_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work)
130 : #define test_task_syscall_work(t, fl) \
131 : test_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work)
132 : #define clear_task_syscall_work(t, fl) \
133 : clear_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work)
134 :
135 : #else /* CONFIG_GENERIC_ENTRY */
136 :
137 : #define set_syscall_work(fl) \
138 : set_ti_thread_flag(current_thread_info(), TIF_##fl)
139 : #define test_syscall_work(fl) \
140 : test_ti_thread_flag(current_thread_info(), TIF_##fl)
141 : #define clear_syscall_work(fl) \
142 : clear_ti_thread_flag(current_thread_info(), TIF_##fl)
143 :
144 : #define set_task_syscall_work(t, fl) \
145 : set_ti_thread_flag(task_thread_info(t), TIF_##fl)
146 : #define test_task_syscall_work(t, fl) \
147 : test_ti_thread_flag(task_thread_info(t), TIF_##fl)
148 : #define clear_task_syscall_work(t, fl) \
149 : clear_ti_thread_flag(task_thread_info(t), TIF_##fl)
150 : #endif /* !CONFIG_GENERIC_ENTRY */
151 :
152 : #define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED)
153 :
154 : #ifndef CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES
155 : static inline int arch_within_stack_frames(const void * const stack,
156 : const void * const stackend,
157 : const void *obj, unsigned long len)
158 : {
159 : return 0;
160 : }
161 : #endif
162 :
163 : #ifdef CONFIG_HARDENED_USERCOPY
164 : extern void __check_object_size(const void *ptr, unsigned long n,
165 : bool to_user);
166 :
167 : static __always_inline void check_object_size(const void *ptr, unsigned long n,
168 : bool to_user)
169 : {
170 : if (!__builtin_constant_p(n))
171 : __check_object_size(ptr, n, to_user);
172 : }
173 : #else
174 105666 : static inline void check_object_size(const void *ptr, unsigned long n,
175 : bool to_user)
176 105666 : { }
177 : #endif /* CONFIG_HARDENED_USERCOPY */
178 :
179 : extern void __compiletime_error("copy source size is too small")
180 : __bad_copy_from(void);
181 : extern void __compiletime_error("copy destination size is too small")
182 : __bad_copy_to(void);
183 :
184 0 : static inline void copy_overflow(int size, unsigned long count)
185 : {
186 0 : WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
187 0 : }
188 :
189 : static __always_inline __must_check bool
190 181563 : check_copy_size(const void *addr, size_t bytes, bool is_source)
191 : {
192 181563 : int sz = __compiletime_object_size(addr);
193 147177 : if (unlikely(sz >= 0 && sz < bytes)) {
194 0 : if (!__builtin_constant_p(bytes))
195 0 : copy_overflow(sz, bytes);
196 0 : else if (is_source)
197 0 : __bad_copy_from();
198 : else
199 0 : __bad_copy_to();
200 : return false;
201 : }
202 181563 : if (WARN_ON_ONCE(bytes > INT_MAX))
203 0 : return false;
204 : check_object_size(addr, bytes, is_source);
205 : return true;
206 : }
207 :
208 : #ifndef arch_setup_new_exec
209 : static inline void arch_setup_new_exec(void) { }
210 : #endif
211 :
212 : #endif /* __KERNEL__ */
213 :
214 : #endif /* _LINUX_THREAD_INFO_H */
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