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/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2012 ARM Ltd.
*/
#ifndef __ASM_SYSCALL_H
#define __ASM_SYSCALL_H
#include <uapi/linux/audit.h>
#include <linux/compat.h>
#include <linux/err.h>
typedef long (*syscall_fn_t)(const struct pt_regs *regs);
extern const syscall_fn_t sys_call_table[];
#ifdef CONFIG_COMPAT
extern const syscall_fn_t compat_sys_call_table[];
#endif
static inline int syscall_get_nr(struct task_struct *task,
struct pt_regs *regs)
{
return regs->syscallno;
}
static inline void syscall_rollback(struct task_struct *task,
struct pt_regs *regs)
{
regs->regs[0] = regs->orig_x0;
}
static inline long syscall_get_return_value(struct task_struct *task,
struct pt_regs *regs)
{
unsigned long val = regs->regs[0];
if (is_compat_thread(task_thread_info(task)))
val = sign_extend64(val, 31);
return val;
}
static inline long syscall_get_error(struct task_struct *task,
struct pt_regs *regs)
{
unsigned long error = syscall_get_return_value(task, regs);
return IS_ERR_VALUE(error) ? error : 0;
}
static inline void syscall_set_return_value(struct task_struct *task,
struct pt_regs *regs,
int error, long val)
{
if (error)
val = error;
if (is_compat_thread(task_thread_info(task)))
val = lower_32_bits(val);
regs->regs[0] = val;
}
static inline void syscall_set_nr(struct task_struct *task,
struct pt_regs *regs,
int nr)
{
regs->syscallno = nr;
if (nr == -1) {
/*
* When the syscall number is set to -1, the syscall will be
* skipped. In this case the syscall return value has to be
* set explicitly, otherwise the first syscall argument is
* returned as the syscall return value.
*/
syscall_set_return_value(task, regs, -ENOSYS, 0);
}
}
#define SYSCALL_MAX_ARGS 6
static inline void syscall_get_arguments(struct task_struct *task,
struct pt_regs *regs,
unsigned long *args)
{
args[0] = regs->orig_x0;
args++;
memcpy(args, ®s->regs[1], 5 * sizeof(args[0]));
}
static inline void syscall_set_arguments(struct task_struct *task,
struct pt_regs *regs,
const unsigned long *args)
{
memcpy(®s->regs[0], args, 6 * sizeof(args[0]));
/*
* Also copy the first argument into orig_x0
* so that syscall_get_arguments() would return it
* instead of the previous value.
*/
regs->orig_x0 = regs->regs[0];
}
/*
* We don't care about endianness (__AUDIT_ARCH_LE bit) here because
* AArch64 has the same system calls both on little- and big- endian.
*/
static inline int syscall_get_arch(struct task_struct *task)
{
if (is_compat_thread(task_thread_info(task)))
return AUDIT_ARCH_ARM;
return AUDIT_ARCH_AARCH64;
}
int syscall_trace_enter(struct pt_regs *regs);
void syscall_trace_exit(struct pt_regs *regs);
#endif /* __ASM_SYSCALL_H */
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