arch/s390/include/asm/syscall.h

   1 /*
   2  * Access to user system call parameters and results
   3  *
   4  *  Copyright IBM Corp. 2008
   5  *  Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License (version 2 only)
   9  * as published by the Free Software Foundation.
  10  */
  11
  12 #ifndef _ASM_SYSCALL_H
  13 #define _ASM_SYSCALL_H  1
  14
  15 #include <linux/sched.h>
  16 #include <asm/ptrace.h>
  17
  18 static inline long syscall_get_nr(struct task_struct *task,
  19                                   struct pt_regs *regs)
  20 {
  21         return regs->svcnr ? regs->svcnr : -1;
  22 }
  23
  24 static inline void syscall_rollback(struct task_struct *task,
  25                                     struct pt_regs *regs)
  26 {
  27         regs->gprs[2] = regs->orig_gpr2;
  28 }
  29
  30 static inline long syscall_get_error(struct task_struct *task,
  31                                      struct pt_regs *regs)
  32 {
  33         return (regs->gprs[2] >= -4096UL) ? -regs->gprs[2] : 0;
  34 }
  35
  36 static inline long syscall_get_return_value(struct task_struct *task,
  37                                             struct pt_regs *regs)
  38 {
  39         return regs->gprs[2];
  40 }
  41
  42 static inline void syscall_set_return_value(struct task_struct *task,
  43                                             struct pt_regs *regs,
  44                                             int error, long val)
  45 {
  46         regs->gprs[2] = error ? -error : val;
  47 }
  48
  49 static inline void syscall_get_arguments(struct task_struct *task,
  50                                          struct pt_regs *regs,
  51                                          unsigned int i, unsigned int n,
  52                                          unsigned long *args)
  53 {
  54         unsigned long mask = -1UL;
  55
  56         BUG_ON(i + n > 6);
  57 #ifdef CONFIG_COMPAT
  58         if (test_tsk_thread_flag(task, TIF_31BIT))
  59                 mask = 0xffffffff;
  60 #endif
  61         if (i + n == 6)
  62                 args[--n] = regs->args[0] & mask;
  63         while (n-- > 0)
  64                 if (i + n > 0)
  65                         args[n] = regs->gprs[2 + i + n] & mask;
  66         if (i == 0)
  67                 args[0] = regs->orig_gpr2 & mask;
  68 }
  69
  70 static inline void syscall_set_arguments(struct task_struct *task,
  71                                          struct pt_regs *regs,
  72                                          unsigned int i, unsigned int n,
  73                                          const unsigned long *args)
  74 {
  75         BUG_ON(i + n > 6);
  76         if (i + n == 6)
  77                 regs->args[0] = args[--n];
  78         while (n-- > 0)
  79                 if (i + n > 0)
  80                         regs->gprs[2 + i + n] = args[n];
  81         if (i == 0)
  82                 regs->orig_gpr2 = args[0];
  83 }
  84
  85 #endif  /* _ASM_SYSCALL_H */