LXR linux/arch/s390/kernel/sys

   1/*
   2 *  S390 version
   3 *    Copyright IBM Corp. 1999, 2000
   4 *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
   5 *               Thomas Spatzier (tspat@de.ibm.com)
   6 *
   7 *  Derived from "arch/i386/kernel/sys_i386.c"
   8 *
   9 *  This file contains various random system calls that
  10 *  have a non-standard calling sequence on the Linux/s390
  11 *  platform.
  12 */
  13
  14#include <linux/errno.h>
  15#include <linux/sched.h>
  16#include <linux/mm.h>
  17#include <linux/fs.h>
  18#include <linux/smp.h>
  19#include <linux/sem.h>
  20#include <linux/msg.h>
  21#include <linux/shm.h>
  22#include <linux/stat.h>
  23#include <linux/syscalls.h>
  24#include <linux/mman.h>
  25#include <linux/file.h>
  26#include <linux/utsname.h>
  27#include <linux/personality.h>
  28#include <linux/unistd.h>
  29#include <linux/ipc.h>
  30#include <asm/uaccess.h>
  31#include "entry.h"
  32
  33/*
  34 * Perform the mmap() system call. Linux for S/390 isn't able to handle more
  35 * than 5 system call parameters, so this system call uses a memory block
  36 * for parameter passing.
  37 */
  38
  39struct s390_mmap_arg_struct {
  40        unsigned long addr;
  41        unsigned long len;
  42        unsigned long prot;
  43        unsigned long flags;
  44        unsigned long fd;
  45        unsigned long offset;
  46};
  47
  48SYSCALL_DEFINE1(mmap2, struct s390_mmap_arg_struct __user *, arg)
  49{
  50        struct s390_mmap_arg_struct a;
  51        int error = -EFAULT;
  52
  53        if (copy_from_user(&a, arg, sizeof(a)))
  54                goto out;
  55        error = sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, a.offset);
  56out:
  57        return error;
  58}
  59
  60/*
  61 * sys_ipc() is the de-multiplexer for the SysV IPC calls.
  62 */
  63SYSCALL_DEFINE5(s390_ipc, uint, call, int, first, unsigned long, second,
  64                unsigned long, third, void __user *, ptr)
  65{
  66        if (call >> 16)
  67                return -EINVAL;
  68        /* The s390 sys_ipc variant has only five parameters instead of six
  69         * like the generic variant. The only difference is the handling of
  70         * the SEMTIMEDOP subcall where on s390 the third parameter is used
  71         * as a pointer to a struct timespec where the generic variant uses
  72         * the fifth parameter.
  73         * Therefore we can call the generic variant by simply passing the
  74         * third parameter also as fifth parameter.
  75         */
  76        return sys_ipc(call, first, second, third, ptr, third);
  77}
  78
  79#ifdef CONFIG_64BIT
  80SYSCALL_DEFINE1(s390_personality, unsigned int, personality)
  81{
  82        unsigned int ret;
  83
  84        if (personality(current->personality) == PER_LINUX32 &&
  85            personality(personality) == PER_LINUX)
  86                personality |= PER_LINUX32;
  87        ret = sys_personality(personality);
  88        if (personality(ret) == PER_LINUX32)
  89                ret &= ~PER_LINUX32;
  90
  91        return ret;
  92}
  93#endif /* CONFIG_64BIT */
  94
  95/*
  96 * Wrapper function for sys_fadvise64/fadvise64_64
  97 */
  98#ifndef CONFIG_64BIT
  99
 100SYSCALL_DEFINE5(s390_fadvise64, int, fd, u32, offset_high, u32, offset_low,
 101                size_t, len, int, advice)
 102{
 103        return sys_fadvise64(fd, (u64) offset_high << 32 | offset_low,
 104                        len, advice);
 105}
 106
 107struct fadvise64_64_args {
 108        int fd;
 109        long long offset;
 110        long long len;
 111        int advice;
 112};
 113
 114SYSCALL_DEFINE1(s390_fadvise64_64, struct fadvise64_64_args __user *, args)
 115{
 116        struct fadvise64_64_args a;
 117
 118        if ( copy_from_user(&a, args, sizeof(a)) )
 119                return -EFAULT;
 120        return sys_fadvise64_64(a.fd, a.offset, a.len, a.advice);
 121}
 122
 123/*
 124 * This is a wrapper to call sys_fallocate(). For 31 bit s390 the last
 125 * 64 bit argument "len" is split into the upper and lower 32 bits. The
 126 * system call wrapper in the user space loads the value to %r6/%r7.
 127 * The code in entry.S keeps the values in %r2 - %r6 where they are and
 128 * stores %r7 to 96(%r15). But the standard C linkage requires that
 129 * the whole 64 bit value for len is stored on the stack and doesn't
 130 * use %r6 at all. So s390_fallocate has to convert the arguments from
 131 *   %r2: fd, %r3: mode, %r4/%r5: offset, %r6/96(%r15)-99(%r15): len
 132 * to
 133 *   %r2: fd, %r3: mode, %r4/%r5: offset, 96(%r15)-103(%r15): len
 134 */
 135SYSCALL_DEFINE5(s390_fallocate, int, fd, int, mode, loff_t, offset,
 136                               u32, len_high, u32, len_low)
 137{
 138        return sys_fallocate(fd, mode, offset, ((u64)len_high << 32) | len_low);
 139}
 140#endif
 141