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 #ifdef CONFIG_GENERIC_ENTRY
40 enum syscall_work_bit {
41 SYSCALL_WORK_BIT_SECCOMP,
42 SYSCALL_WORK_BIT_SYSCALL_TRACEPOINT,
43 SYSCALL_WORK_BIT_SYSCALL_TRACE,
44 SYSCALL_WORK_BIT_SYSCALL_EMU,
45 SYSCALL_WORK_BIT_SYSCALL_AUDIT,
46 SYSCALL_WORK_BIT_SYSCALL_USER_DISPATCH,
47 SYSCALL_WORK_BIT_SYSCALL_EXIT_TRAP,
48 };
49
50 #define SYSCALL_WORK_SECCOMP BIT(SYSCALL_WORK_BIT_SECCOMP)
51 #define SYSCALL_WORK_SYSCALL_TRACEPOINT BIT(SYSCALL_WORK_BIT_SYSCALL_TRACEPOINT)
52 #define SYSCALL_WORK_SYSCALL_TRACE BIT(SYSCALL_WORK_BIT_SYSCALL_TRACE)
53 #define SYSCALL_WORK_SYSCALL_EMU BIT(SYSCALL_WORK_BIT_SYSCALL_EMU)
54 #define SYSCALL_WORK_SYSCALL_AUDIT BIT(SYSCALL_WORK_BIT_SYSCALL_AUDIT)
55 #define SYSCALL_WORK_SYSCALL_USER_DISPATCH BIT(SYSCALL_WORK_BIT_SYSCALL_USER_DISPATCH)
56 #define SYSCALL_WORK_SYSCALL_EXIT_TRAP BIT(SYSCALL_WORK_BIT_SYSCALL_EXIT_TRAP)
57 #endif
58
59 #include <asm/thread_info.h>
60
61 #ifdef __KERNEL__
62
63 #ifndef arch_set_restart_data
64 #define arch_set_restart_data(restart) do { } while (0)
65 #endif
66
set_restart_fn(struct restart_block * restart,long (* fn)(struct restart_block *))67 static inline long set_restart_fn(struct restart_block *restart,
68 long (*fn)(struct restart_block *))
69 {
70 restart->fn = fn;
71 arch_set_restart_data(restart);
72 return -ERESTART_RESTARTBLOCK;
73 }
74
75 #ifndef THREAD_ALIGN
76 #define THREAD_ALIGN THREAD_SIZE
77 #endif
78
79 #define THREADINFO_GFP (GFP_KERNEL_ACCOUNT | __GFP_ZERO)
80
81 /*
82 * flag set/clear/test wrappers
83 * - pass TIF_xxxx constants to these functions
84 */
85
set_ti_thread_flag(struct thread_info * ti,int flag)86 static inline void set_ti_thread_flag(struct thread_info *ti, int flag)
87 {
88 set_bit(flag, (unsigned long *)&ti->flags);
89 }
90
clear_ti_thread_flag(struct thread_info * ti,int flag)91 static inline void clear_ti_thread_flag(struct thread_info *ti, int flag)
92 {
93 clear_bit(flag, (unsigned long *)&ti->flags);
94 }
95
update_ti_thread_flag(struct thread_info * ti,int flag,bool value)96 static inline void update_ti_thread_flag(struct thread_info *ti, int flag,
97 bool value)
98 {
99 if (value)
100 set_ti_thread_flag(ti, flag);
101 else
102 clear_ti_thread_flag(ti, flag);
103 }
104
test_and_set_ti_thread_flag(struct thread_info * ti,int flag)105 static inline int test_and_set_ti_thread_flag(struct thread_info *ti, int flag)
106 {
107 return test_and_set_bit(flag, (unsigned long *)&ti->flags);
108 }
109
test_and_clear_ti_thread_flag(struct thread_info * ti,int flag)110 static inline int test_and_clear_ti_thread_flag(struct thread_info *ti, int flag)
111 {
112 return test_and_clear_bit(flag, (unsigned long *)&ti->flags);
113 }
114
test_ti_thread_flag(struct thread_info * ti,int flag)115 static inline int test_ti_thread_flag(struct thread_info *ti, int flag)
116 {
117 return test_bit(flag, (unsigned long *)&ti->flags);
118 }
119
120 #define set_thread_flag(flag) \
121 set_ti_thread_flag(current_thread_info(), flag)
122 #define clear_thread_flag(flag) \
123 clear_ti_thread_flag(current_thread_info(), flag)
124 #define update_thread_flag(flag, value) \
125 update_ti_thread_flag(current_thread_info(), flag, value)
126 #define test_and_set_thread_flag(flag) \
127 test_and_set_ti_thread_flag(current_thread_info(), flag)
128 #define test_and_clear_thread_flag(flag) \
129 test_and_clear_ti_thread_flag(current_thread_info(), flag)
130 #define test_thread_flag(flag) \
131 test_ti_thread_flag(current_thread_info(), flag)
132
133 #ifdef CONFIG_GENERIC_ENTRY
134 #define set_syscall_work(fl) \
135 set_bit(SYSCALL_WORK_BIT_##fl, ¤t_thread_info()->syscall_work)
136 #define test_syscall_work(fl) \
137 test_bit(SYSCALL_WORK_BIT_##fl, ¤t_thread_info()->syscall_work)
138 #define clear_syscall_work(fl) \
139 clear_bit(SYSCALL_WORK_BIT_##fl, ¤t_thread_info()->syscall_work)
140
141 #define set_task_syscall_work(t, fl) \
142 set_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work)
143 #define test_task_syscall_work(t, fl) \
144 test_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work)
145 #define clear_task_syscall_work(t, fl) \
146 clear_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work)
147
148 #else /* CONFIG_GENERIC_ENTRY */
149
150 #define set_syscall_work(fl) \
151 set_ti_thread_flag(current_thread_info(), TIF_##fl)
152 #define test_syscall_work(fl) \
153 test_ti_thread_flag(current_thread_info(), TIF_##fl)
154 #define clear_syscall_work(fl) \
155 clear_ti_thread_flag(current_thread_info(), TIF_##fl)
156
157 #define set_task_syscall_work(t, fl) \
158 set_ti_thread_flag(task_thread_info(t), TIF_##fl)
159 #define test_task_syscall_work(t, fl) \
160 test_ti_thread_flag(task_thread_info(t), TIF_##fl)
161 #define clear_task_syscall_work(t, fl) \
162 clear_ti_thread_flag(task_thread_info(t), TIF_##fl)
163 #endif /* !CONFIG_GENERIC_ENTRY */
164
165 #define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED)
166
167 #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)168 static inline int arch_within_stack_frames(const void * const stack,
169 const void * const stackend,
170 const void *obj, unsigned long len)
171 {
172 return 0;
173 }
174 #endif
175
176 #ifdef CONFIG_HARDENED_USERCOPY
177 extern void __check_object_size(const void *ptr, unsigned long n,
178 bool to_user);
179
check_object_size(const void * ptr,unsigned long n,bool to_user)180 static __always_inline void check_object_size(const void *ptr, unsigned long n,
181 bool to_user)
182 {
183 if (!__builtin_constant_p(n))
184 __check_object_size(ptr, n, to_user);
185 }
186 #else
check_object_size(const void * ptr,unsigned long n,bool to_user)187 static inline void check_object_size(const void *ptr, unsigned long n,
188 bool to_user)
189 { }
190 #endif /* CONFIG_HARDENED_USERCOPY */
191
192 extern void __compiletime_error("copy source size is too small")
193 __bad_copy_from(void);
194 extern void __compiletime_error("copy destination size is too small")
195 __bad_copy_to(void);
196
copy_overflow(int size,unsigned long count)197 static inline void copy_overflow(int size, unsigned long count)
198 {
199 WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
200 }
201
202 static __always_inline __must_check bool
check_copy_size(const void * addr,size_t bytes,bool is_source)203 check_copy_size(const void *addr, size_t bytes, bool is_source)
204 {
205 int sz = __compiletime_object_size(addr);
206 if (unlikely(sz >= 0 && sz < bytes)) {
207 if (!__builtin_constant_p(bytes))
208 copy_overflow(sz, bytes);
209 else if (is_source)
210 __bad_copy_from();
211 else
212 __bad_copy_to();
213 return false;
214 }
215 if (WARN_ON_ONCE(bytes > INT_MAX))
216 return false;
217 check_object_size(addr, bytes, is_source);
218 return true;
219 }
220
221 #ifndef arch_setup_new_exec
arch_setup_new_exec(void)222 static inline void arch_setup_new_exec(void) { }
223 #endif
224
225 #endif /* __KERNEL__ */
226
227 #endif /* _LINUX_THREAD_INFO_H */
228