thread_info.h

  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, &current_thread_info()->syscall_work)
164#define test_syscall_work(fl) \
165	test_bit(SYSCALL_WORK_BIT_##fl, &current_thread_info()->syscall_work)
166#define clear_syscall_work(fl) \
167	clear_bit(SYSCALL_WORK_BIT_##fl, &current_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 *)(&current_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 *)(&current_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 */