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/*
* Copyright (C) 2012 ARM Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#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_error(struct task_struct *task,
struct pt_regs *regs)
{
unsigned long error = regs->regs[0];
if (is_compat_thread(task_thread_info(task)))
error = sign_extend64(error, 31);
return IS_ERR_VALUE(error) ? error : 0;
}
static inline long syscall_get_return_value(struct task_struct *task,
struct pt_regs *regs)
{
return regs->regs[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;
}
#define SYSCALL_MAX_ARGS 6
static inline void syscall_get_arguments(struct task_struct *task,
struct pt_regs *regs,
unsigned int i, unsigned int n,
unsigned long *args)
{
if (n == 0)
return;
if (i + n > SYSCALL_MAX_ARGS) {
unsigned long *args_bad = args + SYSCALL_MAX_ARGS - i;
unsigned int n_bad = n + i - SYSCALL_MAX_ARGS;
pr_warning("%s called with max args %d, handling only %d\n",
__func__, i + n, SYSCALL_MAX_ARGS);
memset(args_bad, 0, n_bad * sizeof(args[0]));
}
if (i == 0) {
args[0] = regs->orig_x0;
args++;
i++;
n--;
}
memcpy(args, ®s->regs[i], n * sizeof(args[0]));
}
static inline void syscall_set_arguments(struct task_struct *task,
struct pt_regs *regs,
unsigned int i, unsigned int n,
const unsigned long *args)
{
if (n == 0)
return;
if (i + n > SYSCALL_MAX_ARGS) {
pr_warning("%s called with max args %d, handling only %d\n",
__func__, i + n, SYSCALL_MAX_ARGS);
n = SYSCALL_MAX_ARGS - i;
}
if (i == 0) {
regs->orig_x0 = args[0];
args++;
i++;
n--;
}
memcpy(®s->regs[i], args, n * sizeof(args[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(void)
{
if (is_compat_task())
return AUDIT_ARCH_ARM;
return AUDIT_ARCH_AARCH64;
}
#endif /* __ASM_SYSCALL_H */
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