/* SPDX-License-Identifier: GPL-2.0 */
/* thread_info.h: common low-level thread information accessors
 *
 * Copyright (C) 2002  David Howells (dhowells@redhat.com)
 * - Incorporating suggestions made by Linus Torvalds
 */

#ifndef _LINUX_THREAD_INFO_H
#define _LINUX_THREAD_INFO_H

#include <linux/types.h>
#include <linux/limits.h>
#include <linux/bug.h>
#include <linux/restart_block.h>
#include <linux/errno.h>

#ifdef CONFIG_THREAD_INFO_IN_TASK
/*
 * For CONFIG_THREAD_INFO_IN_TASK kernels we need <asm/current.h> for the
 * definition of current, but for !CONFIG_THREAD_INFO_IN_TASK kernels,
 * including <asm/current.h> can cause a circular dependency on some platforms.
 */
#include <asm/current.h>
#define current_thread_info() ((struct thread_info *)current)
#endif

#include <linux/bitops.h>

/*
 * For per-arch arch_within_stack_frames() implementations, defined in
 * asm/thread_info.h.
 */
enum {
        BAD_STACK = -1,
        NOT_STACK = 0,
        GOOD_FRAME,
        GOOD_STACK,
};

#ifdef CONFIG_GENERIC_ENTRY
enum syscall_work_bit {
        SYSCALL_WORK_BIT_SECCOMP,
        SYSCALL_WORK_BIT_SYSCALL_TRACEPOINT,
        SYSCALL_WORK_BIT_SYSCALL_TRACE,
        SYSCALL_WORK_BIT_SYSCALL_EMU,
        SYSCALL_WORK_BIT_SYSCALL_AUDIT,
        SYSCALL_WORK_BIT_SYSCALL_USER_DISPATCH,
        SYSCALL_WORK_BIT_SYSCALL_EXIT_TRAP,
        SYSCALL_WORK_BIT_SYSCALL_RSEQ_SLICE,
};

#define SYSCALL_WORK_SECCOMP                    BIT(SYSCALL_WORK_BIT_SECCOMP)
#define SYSCALL_WORK_SYSCALL_TRACEPOINT         BIT(SYSCALL_WORK_BIT_SYSCALL_TRACEPOINT)
#define SYSCALL_WORK_SYSCALL_TRACE              BIT(SYSCALL_WORK_BIT_SYSCALL_TRACE)
#define SYSCALL_WORK_SYSCALL_EMU                BIT(SYSCALL_WORK_BIT_SYSCALL_EMU)
#define SYSCALL_WORK_SYSCALL_AUDIT              BIT(SYSCALL_WORK_BIT_SYSCALL_AUDIT)
#define SYSCALL_WORK_SYSCALL_USER_DISPATCH      BIT(SYSCALL_WORK_BIT_SYSCALL_USER_DISPATCH)
#define SYSCALL_WORK_SYSCALL_EXIT_TRAP          BIT(SYSCALL_WORK_BIT_SYSCALL_EXIT_TRAP)
#define SYSCALL_WORK_SYSCALL_RSEQ_SLICE         BIT(SYSCALL_WORK_BIT_SYSCALL_RSEQ_SLICE)
#endif

#include <asm/thread_info.h>

#ifndef TIF_NEED_RESCHED_LAZY
#ifdef CONFIG_ARCH_HAS_PREEMPT_LAZY
#error Inconsistent PREEMPT_LAZY
#endif
#define TIF_NEED_RESCHED_LAZY TIF_NEED_RESCHED
#define _TIF_NEED_RESCHED_LAZY _TIF_NEED_RESCHED
#endif

#ifndef TIF_RSEQ
# define TIF_RSEQ       TIF_NOTIFY_RESUME
# define _TIF_RSEQ      _TIF_NOTIFY_RESUME
#endif

#ifdef __KERNEL__

#ifndef arch_set_restart_data
#define arch_set_restart_data(restart) do { } while (0)
#endif

static inline long set_restart_fn(struct restart_block *restart,
                                        long (*fn)(struct restart_block *))
{
        restart->fn = fn;
        arch_set_restart_data(restart);
        return -ERESTART_RESTARTBLOCK;
}

#ifndef THREAD_ALIGN
#define THREAD_ALIGN    THREAD_SIZE
#endif

#define THREADINFO_GFP          (GFP_KERNEL_ACCOUNT | __GFP_ZERO)

/*
 * flag set/clear/test wrappers
 * - pass TIF_xxxx constants to these functions
 */

static inline void set_ti_thread_flag(struct thread_info *ti, int flag)
{
        set_bit(flag, (unsigned long *)&ti->flags);
}

static inline void clear_ti_thread_flag(struct thread_info *ti, int flag)
{
        clear_bit(flag, (unsigned long *)&ti->flags);
}

static inline void update_ti_thread_flag(struct thread_info *ti, int flag,
                                         bool value)
{
        if (value)
                set_ti_thread_flag(ti, flag);
        else
                clear_ti_thread_flag(ti, flag);
}

static inline int test_and_set_ti_thread_flag(struct thread_info *ti, int flag)
{
        return test_and_set_bit(flag, (unsigned long *)&ti->flags);
}

static inline int test_and_clear_ti_thread_flag(struct thread_info *ti, int flag)
{
        return test_and_clear_bit(flag, (unsigned long *)&ti->flags);
}

static inline int test_ti_thread_flag(struct thread_info *ti, int flag)
{
        return test_bit(flag, (unsigned long *)&ti->flags);
}

/*
 * This may be used in noinstr code, and needs to be __always_inline to prevent
 * inadvertent instrumentation.
 */
static __always_inline unsigned long read_ti_thread_flags(struct thread_info *ti)
{
        return READ_ONCE(ti->flags);
}

#define set_thread_flag(flag) \
        set_ti_thread_flag(current_thread_info(), flag)
#define clear_thread_flag(flag) \
        clear_ti_thread_flag(current_thread_info(), flag)
#define update_thread_flag(flag, value) \
        update_ti_thread_flag(current_thread_info(), flag, value)
#define test_and_set_thread_flag(flag) \
        test_and_set_ti_thread_flag(current_thread_info(), flag)
#define test_and_clear_thread_flag(flag) \
        test_and_clear_ti_thread_flag(current_thread_info(), flag)
#define test_thread_flag(flag) \
        test_ti_thread_flag(current_thread_info(), flag)
#define read_thread_flags() \
        read_ti_thread_flags(current_thread_info())

#define read_task_thread_flags(t) \
        read_ti_thread_flags(task_thread_info(t))

#ifdef CONFIG_GENERIC_ENTRY
#define set_syscall_work(fl) \
        set_bit(SYSCALL_WORK_BIT_##fl, &current_thread_info()->syscall_work)
#define test_syscall_work(fl) \
        test_bit(SYSCALL_WORK_BIT_##fl, &current_thread_info()->syscall_work)
#define clear_syscall_work(fl) \
        clear_bit(SYSCALL_WORK_BIT_##fl, &current_thread_info()->syscall_work)

#define set_task_syscall_work(t, fl) \
        set_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work)
#define test_task_syscall_work(t, fl) \
        test_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work)
#define clear_task_syscall_work(t, fl) \
        clear_bit(SYSCALL_WORK_BIT_##fl, &task_thread_info(t)->syscall_work)

#else /* CONFIG_GENERIC_ENTRY */

#define set_syscall_work(fl)                                            \
        set_ti_thread_flag(current_thread_info(), TIF_##fl)
#define test_syscall_work(fl) \
        test_ti_thread_flag(current_thread_info(), TIF_##fl)
#define clear_syscall_work(fl) \
        clear_ti_thread_flag(current_thread_info(), TIF_##fl)

#define set_task_syscall_work(t, fl) \
        set_ti_thread_flag(task_thread_info(t), TIF_##fl)
#define test_task_syscall_work(t, fl) \
        test_ti_thread_flag(task_thread_info(t), TIF_##fl)
#define clear_task_syscall_work(t, fl) \
        clear_ti_thread_flag(task_thread_info(t), TIF_##fl)
#endif /* !CONFIG_GENERIC_ENTRY */

#ifdef _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H

static __always_inline bool tif_test_bit(int bit)
{
        return arch_test_bit(bit,
                             (unsigned long *)(&current_thread_info()->flags));
}

#else

static __always_inline bool tif_test_bit(int bit)
{
        return test_bit(bit,
                        (unsigned long *)(&current_thread_info()->flags));
}

#endif /* _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H */

static __always_inline bool tif_need_resched(void)
{
        return tif_test_bit(TIF_NEED_RESCHED);
}

#ifndef CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES
static inline int arch_within_stack_frames(const void * const stack,
                                           const void * const stackend,
                                           const void *obj, unsigned long len)
{
        return 0;
}
#endif

#ifndef arch_setup_new_exec
static inline void arch_setup_new_exec(void) { }
#endif

void arch_task_cache_init(void); /* for CONFIG_SH */
void arch_release_task_struct(struct task_struct *tsk);
int arch_dup_task_struct(struct task_struct *dst,
                                struct task_struct *src);

#endif  /* __KERNEL__ */

#endif /* _LINUX_THREAD_INFO_H */