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