LXR linux/arch/s390/include/asm/syscall.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2/*
   3 * Access to user system call parameters and results
   4 *
   5 *  Copyright IBM Corp. 2008
   6 *  Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
   7 */
   8
   9#ifndef _ASM_SYSCALL_H
  10#define _ASM_SYSCALL_H  1
  11
  12#include <uapi/linux/audit.h>
  13#include <linux/sched.h>
  14#include <linux/err.h>
  15#include <asm/ptrace.h>
  16
  17/*
  18 * The syscall table always contains 32 bit pointers since we know that the
  19 * address of the function to be called is (way) below 4GB.  So the "int"
  20 * type here is what we want [need] for both 32 bit and 64 bit systems.
  21 */
  22extern const unsigned int sys_call_table[];
  23extern const unsigned int sys_call_table_emu[];
  24
  25static inline long syscall_get_nr(struct task_struct *task,
  26                                  struct pt_regs *regs)
  27{
  28        return test_pt_regs_flag(regs, PIF_SYSCALL) ?
  29                (regs->int_code & 0xffff) : -1;
  30}
  31
  32static inline void syscall_rollback(struct task_struct *task,
  33                                    struct pt_regs *regs)
  34{
  35        regs->gprs[2] = regs->orig_gpr2;
  36}
  37
  38static inline long syscall_get_error(struct task_struct *task,
  39                                     struct pt_regs *regs)
  40{
  41        return IS_ERR_VALUE(regs->gprs[2]) ? regs->gprs[2] : 0;
  42}
  43
  44static inline long syscall_get_return_value(struct task_struct *task,
  45                                            struct pt_regs *regs)
  46{
  47        return regs->gprs[2];
  48}
  49
  50static inline void syscall_set_return_value(struct task_struct *task,
  51                                            struct pt_regs *regs,
  52                                            int error, long val)
  53{
  54        regs->gprs[2] = error ? error : val;
  55}
  56
  57static inline void syscall_get_arguments(struct task_struct *task,
  58                                         struct pt_regs *regs,
  59                                         unsigned int i, unsigned int n,
  60                                         unsigned long *args)
  61{
  62        unsigned long mask = -1UL;
  63
  64        /*
  65         * No arguments for this syscall, there's nothing to do.
  66         */
  67        if (!n)
  68                return;
  69
  70        BUG_ON(i + n > 6);
  71#ifdef CONFIG_COMPAT
  72        if (test_tsk_thread_flag(task, TIF_31BIT))
  73                mask = 0xffffffff;
  74#endif
  75        while (n-- > 0)
  76                if (i + n > 0)
  77                        args[n] = regs->gprs[2 + i + n] & mask;
  78        if (i == 0)
  79                args[0] = regs->orig_gpr2 & mask;
  80}
  81
  82static inline void syscall_set_arguments(struct task_struct *task,
  83                                         struct pt_regs *regs,
  84                                         unsigned int i, unsigned int n,
  85                                         const unsigned long *args)
  86{
  87        BUG_ON(i + n > 6);
  88        while (n-- > 0)
  89                if (i + n > 0)
  90                        regs->gprs[2 + i + n] = args[n];
  91        if (i == 0)
  92                regs->orig_gpr2 = args[0];
  93}
  94
  95static inline int syscall_get_arch(void)
  96{
  97#ifdef CONFIG_COMPAT
  98        if (test_tsk_thread_flag(current, TIF_31BIT))
  99                return AUDIT_ARCH_S390;
 100#endif
 101        return AUDIT_ARCH_S390X;
 102}
 103#endif  /* _ASM_SYSCALL_H */
 104