arch/um/include/asm/syscall-generic.h

   1 /*
   2  * Access to user system call parameters and results
   3  *
   4  * See asm-generic/syscall.h for function descriptions.
   5  *
   6  * Copyright (C) 2015 Mickaël Salaün <mic@digikod.net>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #ifndef __UM_SYSCALL_GENERIC_H
  14 #define __UM_SYSCALL_GENERIC_H
  15
  16 #include <asm/ptrace.h>
  17 #include <linux/err.h>
  18 #include <linux/sched.h>
  19 #include <sysdep/ptrace.h>
  20
  21 static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
  22 {
  23
  24         return PT_REGS_SYSCALL_NR(regs);
  25 }
  26
  27 static inline void syscall_rollback(struct task_struct *task,
  28                                     struct pt_regs *regs)
  29 {
  30         /* do nothing */
  31 }
  32
  33 static inline long syscall_get_error(struct task_struct *task,
  34                                      struct pt_regs *regs)
  35 {
  36         const long error = regs_return_value(regs);
  37
  38         return IS_ERR_VALUE(error) ? error : 0;
  39 }
  40
  41 static inline long syscall_get_return_value(struct task_struct *task,
  42                                             struct pt_regs *regs)
  43 {
  44         return regs_return_value(regs);
  45 }
  46
  47 static inline void syscall_set_return_value(struct task_struct *task,
  48                                             struct pt_regs *regs,
  49                                             int error, long val)
  50 {
  51         PT_REGS_SET_SYSCALL_RETURN(regs, (long) error ?: val);
  52 }
  53
  54 static inline void syscall_get_arguments(struct task_struct *task,
  55                                          struct pt_regs *regs,
  56                                          unsigned int i, unsigned int n,
  57                                          unsigned long *args)
  58 {
  59         const struct uml_pt_regs *r = &regs->regs;
  60
  61         switch (i) {
  62         case 0:
  63                 if (!n--)
  64                         break;
  65                 *args++ = UPT_SYSCALL_ARG1(r);
  66         case 1:
  67                 if (!n--)
  68                         break;
  69                 *args++ = UPT_SYSCALL_ARG2(r);
  70         case 2:
  71                 if (!n--)
  72                         break;
  73                 *args++ = UPT_SYSCALL_ARG3(r);
  74         case 3:
  75                 if (!n--)
  76                         break;
  77                 *args++ = UPT_SYSCALL_ARG4(r);
  78         case 4:
  79                 if (!n--)
  80                         break;
  81                 *args++ = UPT_SYSCALL_ARG5(r);
  82         case 5:
  83                 if (!n--)
  84                         break;
  85                 *args++ = UPT_SYSCALL_ARG6(r);
  86         case 6:
  87                 if (!n--)
  88                         break;
  89         default:
  90                 BUG();
  91                 break;
  92         }
  93 }
  94
  95 static inline void syscall_set_arguments(struct task_struct *task,
  96                                          struct pt_regs *regs,
  97                                          unsigned int i, unsigned int n,
  98                                          const unsigned long *args)
  99 {
 100         struct uml_pt_regs *r = &regs->regs;
 101
 102         switch (i) {
 103         case 0:
 104                 if (!n--)
 105                         break;
 106                 UPT_SYSCALL_ARG1(r) = *args++;
 107         case 1:
 108                 if (!n--)
 109                         break;
 110                 UPT_SYSCALL_ARG2(r) = *args++;
 111         case 2:
 112                 if (!n--)
 113                         break;
 114                 UPT_SYSCALL_ARG3(r) = *args++;
 115         case 3:
 116                 if (!n--)
 117                         break;
 118                 UPT_SYSCALL_ARG4(r) = *args++;
 119         case 4:
 120                 if (!n--)
 121                         break;
 122                 UPT_SYSCALL_ARG5(r) = *args++;
 123         case 5:
 124                 if (!n--)
 125                         break;
 126                 UPT_SYSCALL_ARG6(r) = *args++;
 127         case 6:
 128                 if (!n--)
 129                         break;
 130         default:
 131                 BUG();
 132                 break;
 133         }
 134 }
 135
 136 /* See arch/x86/um/asm/syscall.h for syscall_get_arch() definition. */
 137
 138 #endif  /* __UM_SYSCALL_GENERIC_H */