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/audit.h>
  16 #include <linux/sched.h>
  17 #include <linux/err.h>
  18 #include <asm/ptrace.h>
  19
  20 /*
  21  * The syscall table always contains 32 bit pointers since we know that the
  22  * address of the function to be called is (way) below 4GB.  So the "int"
  23  * type here is what we want [need] for both 32 bit and 64 bit systems.
  24  */
  25 extern const unsigned int sys_call_table[];
  26 extern const unsigned int sys_call_table_emu[];
  27
  28 static inline long syscall_get_nr(struct task_struct *task,
  29                                   struct pt_regs *regs)
  30 {
  31         return test_tsk_thread_flag(task, TIF_SYSCALL) ?
  32                 (regs->int_code & 0xffff) : -1;
  33 }
  34
  35 static inline void syscall_rollback(struct task_struct *task,
  36                                     struct pt_regs *regs)
  37 {
  38         regs->gprs[2] = regs->orig_gpr2;
  39 }
  40
  41 static inline long syscall_get_error(struct task_struct *task,
  42                                      struct pt_regs *regs)
  43 {
  44         return IS_ERR_VALUE(regs->gprs[2]) ? regs->gprs[2] : 0;
  45 }
  46
  47 static inline long syscall_get_return_value(struct task_struct *task,
  48                                             struct pt_regs *regs)
  49 {
  50         return regs->gprs[2];
  51 }
  52
  53 static inline void syscall_set_return_value(struct task_struct *task,
  54                                             struct pt_regs *regs,
  55                                             int error, long val)
  56 {
  57         regs->gprs[2] = error ? error : val;
  58 }
  59
  60 static inline void syscall_get_arguments(struct task_struct *task,
  61                                          struct pt_regs *regs,
  62                                          unsigned int i, unsigned int n,
  63                                          unsigned long *args)
  64 {
  65         unsigned long mask = -1UL;
  66
  67         BUG_ON(i + n > 6);
  68 #ifdef CONFIG_COMPAT
  69         if (test_tsk_thread_flag(task, TIF_31BIT))
  70                 mask = 0xffffffff;
  71 #endif
  72         while (n-- > 0)
  73                 if (i + n > 0)
  74                         args[n] = regs->gprs[2 + i + n] & mask;
  75         if (i == 0)
  76                 args[0] = regs->orig_gpr2 & mask;
  77 }
  78
  79 static inline void syscall_set_arguments(struct task_struct *task,
  80                                          struct pt_regs *regs,
  81                                          unsigned int i, unsigned int n,
  82                                          const unsigned long *args)
  83 {
  84         BUG_ON(i + n > 6);
  85         while (n-- > 0)
  86                 if (i + n > 0)
  87                         regs->gprs[2 + i + n] = args[n];
  88         if (i == 0)
  89                 regs->orig_gpr2 = args[0];
  90 }
  91
  92 static inline int syscall_get_arch(void)
  93 {
  94 #ifdef CONFIG_COMPAT
  95         if (test_tsk_thread_flag(current, TIF_31BIT))
  96                 return AUDIT_ARCH_S390;
  97 #endif
  98         return sizeof(long) == 8 ? AUDIT_ARCH_S390X : AUDIT_ARCH_S390;
  99 }
 100 #endif  /* _ASM_SYSCALL_H */