arch/arm64/include/asm/syscall.h

   1 /*
   2  * Copyright (C) 2012 ARM Ltd.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15  */
  16 #ifndef __ASM_SYSCALL_H
  17 #define __ASM_SYSCALL_H
  18
  19 #include <uapi/linux/audit.h>
  20 #include <linux/compat.h>
  21 #include <linux/err.h>
  22
  23 typedef long (*syscall_fn_t)(struct pt_regs *regs);
  24
  25 extern const syscall_fn_t sys_call_table[];
  26
  27 #ifdef CONFIG_COMPAT
  28 extern const syscall_fn_t compat_sys_call_table[];
  29 #endif
  30
  31 static inline int syscall_get_nr(struct task_struct *task,
  32                                  struct pt_regs *regs)
  33 {
  34         return regs->syscallno;
  35 }
  36
  37 static inline void syscall_rollback(struct task_struct *task,
  38                                     struct pt_regs *regs)
  39 {
  40         regs->regs[0] = regs->orig_x0;
  41 }
  42
  43
  44 static inline long syscall_get_error(struct task_struct *task,
  45                                      struct pt_regs *regs)
  46 {
  47         unsigned long error = regs->regs[0];
  48         return IS_ERR_VALUE(error) ? error : 0;
  49 }
  50
  51 static inline long syscall_get_return_value(struct task_struct *task,
  52                                             struct pt_regs *regs)
  53 {
  54         return regs->regs[0];
  55 }
  56
  57 static inline void syscall_set_return_value(struct task_struct *task,
  58                                             struct pt_regs *regs,
  59                                             int error, long val)
  60 {
  61         regs->regs[0] = (long) error ? error : val;
  62 }
  63
  64 #define SYSCALL_MAX_ARGS 6
  65
  66 static inline void syscall_get_arguments(struct task_struct *task,
  67                                          struct pt_regs *regs,
  68                                          unsigned long *args)
  69 {
  70         args[0] = regs->orig_x0;
  71         args++;
  72
  73         memcpy(args, &regs->regs[1], 5 * sizeof(args[0]));
  74 }
  75
  76 static inline void syscall_set_arguments(struct task_struct *task,
  77                                          struct pt_regs *regs,
  78                                          const unsigned long *args)
  79 {
  80         regs->orig_x0 = args[0];
  81         args++;
  82
  83         memcpy(&regs->regs[1], args, 5 * sizeof(args[0]));
  84 }
  85
  86 /*
  87  * We don't care about endianness (__AUDIT_ARCH_LE bit) here because
  88  * AArch64 has the same system calls both on little- and big- endian.
  89  */
  90 static inline int syscall_get_arch(void)
  91 {
  92         if (is_compat_task())
  93                 return AUDIT_ARCH_ARM;
  94
  95         return AUDIT_ARCH_AARCH64;
  96 }
  97
  98 #endif  /* __ASM_SYSCALL_H */