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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/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 */
33enum {
34 BAD_STACK = -1,
35 NOT_STACK = 0,
36 GOOD_FRAME,
37 GOOD_STACK,
38};
39
40#ifdef CONFIG_GENERIC_ENTRY
41enum 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#ifndef TIF_NEED_RESCHED_LAZY
63#ifdef CONFIG_ARCH_HAS_PREEMPT_LAZY
64#error Inconsistent PREEMPT_LAZY
65#endif
66#define TIF_NEED_RESCHED_LAZY TIF_NEED_RESCHED
67#define _TIF_NEED_RESCHED_LAZY _TIF_NEED_RESCHED
68#endif
69
70#ifndef TIF_RSEQ
71# define TIF_RSEQ TIF_NOTIFY_RESUME
72# define _TIF_RSEQ _TIF_NOTIFY_RESUME
73#endif
74
75#ifdef __KERNEL__
76
77#ifndef arch_set_restart_data
78#define arch_set_restart_data(restart) do { } while (0)
79#endif
80
81static inline long set_restart_fn(struct restart_block *restart,
82 long (*fn)(struct restart_block *))
83{
84 restart->fn = fn;
85 arch_set_restart_data(restart);
86 return -ERESTART_RESTARTBLOCK;
87}
88
89#ifndef THREAD_ALIGN
90#define THREAD_ALIGN THREAD_SIZE
91#endif
92
93#define THREADINFO_GFP (GFP_KERNEL_ACCOUNT | __GFP_ZERO)
94
95/*
96 * flag set/clear/test wrappers
97 * - pass TIF_xxxx constants to these functions
98 */
99
100static inline void set_ti_thread_flag(struct thread_info *ti, int flag)
101{
102 set_bit(flag, (unsigned long *)&ti->flags);
103}
104
105static inline void clear_ti_thread_flag(struct thread_info *ti, int flag)
106{
107 clear_bit(flag, (unsigned long *)&ti->flags);
108}
109
110static inline void update_ti_thread_flag(struct thread_info *ti, int flag,
111 bool value)
112{
113 if (value)
114 set_ti_thread_flag(ti, flag);
115 else
116 clear_ti_thread_flag(ti, flag);
117}
118
119static inline int test_and_set_ti_thread_flag(struct thread_info *ti, int flag)
120{
121 return test_and_set_bit(flag, (unsigned long *)&ti->flags);
122}
123
124static inline int test_and_clear_ti_thread_flag(struct thread_info *ti, int flag)
125{
126 return test_and_clear_bit(flag, (unsigned long *)&ti->flags);
127}
128
129static inline int test_ti_thread_flag(struct thread_info *ti, int flag)
130{
131 return test_bit(flag, (unsigned long *)&ti->flags);
132}
133
134/*
135 * This may be used in noinstr code, and needs to be __always_inline to prevent
136 * inadvertent instrumentation.
137 */
138static __always_inline unsigned long read_ti_thread_flags(struct thread_info *ti)
139{
140 return READ_ONCE(ti->flags);
141}
142
143#define set_thread_flag(flag) \
144 set_ti_thread_flag(current_thread_info(), flag)
145#define clear_thread_flag(flag) \
146 clear_ti_thread_flag(current_thread_info(), flag)
147#define update_thread_flag(flag, value) \
148 update_ti_thread_flag(current_thread_info(), flag, value)
149#define test_and_set_thread_flag(flag) \
150 test_and_set_ti_thread_flag(current_thread_info(), flag)
151#define test_and_clear_thread_flag(flag) \
152 test_and_clear_ti_thread_flag(current_thread_info(), flag)
153#define test_thread_flag(flag) \
154 test_ti_thread_flag(current_thread_info(), flag)
155#define read_thread_flags() \
156 read_ti_thread_flags(current_thread_info())
157
158#define read_task_thread_flags(t) \
159 read_ti_thread_flags(task_thread_info(t))
160
161#ifdef CONFIG_GENERIC_ENTRY
162#define set_syscall_work(fl) \
163 set_bit(SYSCALL_WORK_BIT_##fl, ¤t_thread_info()->syscall_work)
164#define test_syscall_work(fl) \
165 test_bit(SYSCALL_WORK_BIT_##fl, ¤t_thread_info()->syscall_work)
166#define clear_syscall_work(fl) \
167 clear_bit(SYSCALL_WORK_BIT_##fl, ¤t_thread_info()->syscall_work)
168
169#define set_task_syscall_work(t, fl) \
170 set_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work)
171#define test_task_syscall_work(t, fl) \
172 test_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work)
173#define clear_task_syscall_work(t, fl) \
174 clear_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work)
175
176#else /* CONFIG_GENERIC_ENTRY */
177
178#define set_syscall_work(fl) \
179 set_ti_thread_flag(current_thread_info(), TIF_##fl)
180#define test_syscall_work(fl) \
181 test_ti_thread_flag(current_thread_info(), TIF_##fl)
182#define clear_syscall_work(fl) \
183 clear_ti_thread_flag(current_thread_info(), TIF_##fl)
184
185#define set_task_syscall_work(t, fl) \
186 set_ti_thread_flag(task_thread_info(t), TIF_##fl)
187#define test_task_syscall_work(t, fl) \
188 test_ti_thread_flag(task_thread_info(t), TIF_##fl)
189#define clear_task_syscall_work(t, fl) \
190 clear_ti_thread_flag(task_thread_info(t), TIF_##fl)
191#endif /* !CONFIG_GENERIC_ENTRY */
192
193#ifdef _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H
194
195static __always_inline bool tif_test_bit(int bit)
196{
197 return arch_test_bit(bit,
198 (unsigned long *)(¤t_thread_info()->flags));
199}
200
201#else
202
203static __always_inline bool tif_test_bit(int bit)
204{
205 return test_bit(bit,
206 (unsigned long *)(¤t_thread_info()->flags));
207}
208
209#endif /* _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H */
210
211static __always_inline bool tif_need_resched(void)
212{
213 return tif_test_bit(TIF_NEED_RESCHED);
214}
215
216#ifndef CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES
217static inline int arch_within_stack_frames(const void * const stack,
218 const void * const stackend,
219 const void *obj, unsigned long len)
220{
221 return 0;
222}
223#endif
224
225#ifndef arch_setup_new_exec
226static inline void arch_setup_new_exec(void) { }
227#endif
228
229void arch_task_cache_init(void); /* for CONFIG_SH */
230void arch_release_task_struct(struct task_struct *tsk);
231int arch_dup_task_struct(struct task_struct *dst,
232 struct task_struct *src);
233
234#endif /* __KERNEL__ */
235
236#endif /* _LINUX_THREAD_INFO_H */