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