LXR linux/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 <uapi/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 */
  25extern const unsigned int sys_call_table[];
  26extern const unsigned int sys_call_table_emu[];
  27
  28static inline long syscall_get_nr(struct task_struct *task,
  29                                  struct pt_regs *regs)
  30{
  31        return test_pt_regs_flag(regs, PIF_SYSCALL) ?
  32                (regs->int_code & 0xffff) : -1;
  33}
  34
  35static inline void syscall_rollback(struct task_struct *task,
  36                                    struct pt_regs *regs)
  37{
  38        regs->gprs[2] = regs->orig_gpr2;
  39}
  40
  41static 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
  47static inline long syscall_get_return_value(struct task_struct *task,
  48                                            struct pt_regs *regs)
  49{
  50        return regs->gprs[2];
  51}
  52
  53static 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
  60static 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
  79static 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
  92static 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 AUDIT_ARCH_S390X;
  99}
 100#endif  /* _ASM_SYSCALL_H */
 101