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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 */
31enum {
32 BAD_STACK = -1,
33 NOT_STACK = 0,
34 GOOD_FRAME,
35 GOOD_STACK,
36};
37
38#ifdef CONFIG_GENERIC_ENTRY
39enum 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
73static inline void set_ti_thread_flag(struct thread_info *ti, int flag)
74{
75 set_bit(flag, (unsigned long *)&ti->flags);
76}
77
78static inline void clear_ti_thread_flag(struct thread_info *ti, int flag)
79{
80 clear_bit(flag, (unsigned long *)&ti->flags);
81}
82
83static 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
92static inline int test_and_set_ti_thread_flag(struct thread_info *ti, int flag)
93{
94 return test_and_set_bit(flag, (unsigned long *)&ti->flags);
95}
96
97static inline int test_and_clear_ti_thread_flag(struct thread_info *ti, int flag)
98{
99 return test_and_clear_bit(flag, (unsigned long *)&ti->flags);
100}
101
102static inline int test_ti_thread_flag(struct thread_info *ti, int flag)
103{
104 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
155static 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
164extern void __check_object_size(const void *ptr, unsigned long n,
165 bool to_user);
166
167static __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
174static inline void check_object_size(const void *ptr, unsigned long n,
175 bool to_user)
176{ }
177#endif /* CONFIG_HARDENED_USERCOPY */
178
179extern void __compiletime_error("copy source size is too small")
180__bad_copy_from(void);
181extern void __compiletime_error("copy destination size is too small")
182__bad_copy_to(void);
183
184static inline void copy_overflow(int size, unsigned long count)
185{
186 WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
187}
188
189static __always_inline __must_check bool
190check_copy_size(const void *addr, size_t bytes, bool is_source)
191{
192 int sz = __compiletime_object_size(addr);
193 if (unlikely(sz >= 0 && sz < bytes)) {
194 if (!__builtin_constant_p(bytes))
195 copy_overflow(sz, bytes);
196 else if (is_source)
197 __bad_copy_from();
198 else
199 __bad_copy_to();
200 return false;
201 }
202 if (WARN_ON_ONCE(bytes > INT_MAX))
203 return false;
204 check_object_size(addr, bytes, is_source);
205 return true;
206}
207
208#ifndef arch_setup_new_exec
209static inline void arch_setup_new_exec(void) { }
210#endif
211
212#endif /* __KERNEL__ */
213
214#endif /* _LINUX_THREAD_INFO_H */