LXR linux/arch/arm/include/asm/syscall.h

   1/*
   2 * Access to user system call parameters and results
   3 *
   4 * See asm-generic/syscall.h for descriptions of what we must do here.
   5 */
   6
   7#ifndef _ASM_ARM_SYSCALL_H
   8#define _ASM_ARM_SYSCALL_H
   9
  10#include <linux/err.h>
  11#include <linux/sched.h>
  12
  13#include <asm/unistd.h>
  14
  15#define NR_syscalls (__NR_syscalls)
  16
  17extern const unsigned long sys_call_table[];
  18
  19static inline int syscall_get_nr(struct task_struct *task,
  20                                 struct pt_regs *regs)
  21{
  22        return task_thread_info(task)->syscall;
  23}
  24
  25static inline void syscall_rollback(struct task_struct *task,
  26                                    struct pt_regs *regs)
  27{
  28        regs->ARM_r0 = regs->ARM_ORIG_r0;
  29}
  30
  31static inline long syscall_get_error(struct task_struct *task,
  32                                     struct pt_regs *regs)
  33{
  34        unsigned long error = regs->ARM_r0;
  35        return IS_ERR_VALUE(error) ? error : 0;
  36}
  37
  38static inline long syscall_get_return_value(struct task_struct *task,
  39                                            struct pt_regs *regs)
  40{
  41        return regs->ARM_r0;
  42}
  43
  44static inline void syscall_set_return_value(struct task_struct *task,
  45                                            struct pt_regs *regs,
  46                                            int error, long val)
  47{
  48        regs->ARM_r0 = (long) error ? error : val;
  49}
  50
  51#define SYSCALL_MAX_ARGS 7
  52
  53static inline void syscall_get_arguments(struct task_struct *task,
  54                                         struct pt_regs *regs,
  55                                         unsigned int i, unsigned int n,
  56                                         unsigned long *args)
  57{
  58        if (i + n > SYSCALL_MAX_ARGS) {
  59                unsigned long *args_bad = args + SYSCALL_MAX_ARGS - i;
  60                unsigned int n_bad = n + i - SYSCALL_MAX_ARGS;
  61                pr_warning("%s called with max args %d, handling only %d\n",
  62                           __func__, i + n, SYSCALL_MAX_ARGS);
  63                memset(args_bad, 0, n_bad * sizeof(args[0]));
  64                n = SYSCALL_MAX_ARGS - i;
  65        }
  66
  67        if (i == 0) {
  68                args[0] = regs->ARM_ORIG_r0;
  69                args++;
  70                i++;
  71                n--;
  72        }
  73
  74        memcpy(args, &regs->ARM_r0 + i, n * sizeof(args[0]));
  75}
  76
  77static inline void syscall_set_arguments(struct task_struct *task,
  78                                         struct pt_regs *regs,
  79                                         unsigned int i, unsigned int n,
  80                                         const unsigned long *args)
  81{
  82        if (i + n > SYSCALL_MAX_ARGS) {
  83                pr_warning("%s called with max args %d, handling only %d\n",
  84                           __func__, i + n, SYSCALL_MAX_ARGS);
  85                n = SYSCALL_MAX_ARGS - i;
  86        }
  87
  88        if (i == 0) {
  89                regs->ARM_ORIG_r0 = args[0];
  90                args++;
  91                i++;
  92                n--;
  93        }
  94
  95        memcpy(&regs->ARM_r0 + i, args, n * sizeof(args[0]));
  96}
  97
  98#endif /* _ASM_ARM_SYSCALL_H */
  99