arch/s390/kernel/sys_s390.c

   1 /*
   2  *  arch/s390/kernel/sys_s390.c
   3  *
   4  *  S390 version
   5  *    Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
   6  *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
   7  *               Thomas Spatzier (tspat@de.ibm.com)
   8  *
   9  *  Derived from "arch/i386/kernel/sys_i386.c"
  10  *
  11  *  This file contains various random system calls that
  12  *  have a non-standard calling sequence on the Linux/s390
  13  *  platform.
  14  */
  15
  16 #include <linux/errno.h>
  17 #include <linux/sched.h>
  18 #include <linux/mm.h>
  19 #include <linux/fs.h>
  20 #include <linux/smp.h>
  21 #include <linux/sem.h>
  22 #include <linux/msg.h>
  23 #include <linux/shm.h>
  24 #include <linux/stat.h>
  25 #include <linux/syscalls.h>
  26 #include <linux/mman.h>
  27 #include <linux/file.h>
  28 #include <linux/utsname.h>
  29 #include <linux/personality.h>
  30 #include <linux/unistd.h>
  31 #include <linux/ipc.h>
  32 #include <asm/uaccess.h>
  33 #include "entry.h"
  34
  35 /*
  36  * Perform the mmap() system call. Linux for S/390 isn't able to handle more
  37  * than 5 system call parameters, so this system call uses a memory block
  38  * for parameter passing.
  39  */
  40
  41 struct s390_mmap_arg_struct {
  42         unsigned long addr;
  43         unsigned long len;
  44         unsigned long prot;
  45         unsigned long flags;
  46         unsigned long fd;
  47         unsigned long offset;
  48 };
  49
  50 SYSCALL_DEFINE1(mmap2, struct s390_mmap_arg_struct __user *, arg)
  51 {
  52         struct s390_mmap_arg_struct a;
  53         int error = -EFAULT;
  54
  55         if (copy_from_user(&a, arg, sizeof(a)))
  56                 goto out;
  57         error = sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, a.offset);
  58 out:
  59         return error;
  60 }
  61
  62 /*
  63  * sys_ipc() is the de-multiplexer for the SysV IPC calls.
  64  */
  65 SYSCALL_DEFINE5(s390_ipc, uint, call, int, first, unsigned long, second,
  66                 unsigned long, third, void __user *, ptr)
  67 {
  68         if (call >> 16)
  69                 return -EINVAL;
  70         /* The s390 sys_ipc variant has only five parameters instead of six
  71          * like the generic variant. The only difference is the handling of
  72          * the SEMTIMEDOP subcall where on s390 the third parameter is used
  73          * as a pointer to a struct timespec where the generic variant uses
  74          * the fifth parameter.
  75          * Therefore we can call the generic variant by simply passing the
  76          * third parameter also as fifth parameter.
  77          */
  78         return sys_ipc(call, first, second, third, ptr, third);
  79 }
  80
  81 #ifdef CONFIG_64BIT
  82 SYSCALL_DEFINE1(s390_personality, unsigned int, personality)
  83 {
  84         unsigned int ret;
  85
  86         if (current->personality == PER_LINUX32 && personality == PER_LINUX)
  87                 personality = PER_LINUX32;
  88         ret = sys_personality(personality);
  89         if (ret == PER_LINUX32)
  90                 ret = PER_LINUX;
  91
  92         return ret;
  93 }
  94 #endif /* CONFIG_64BIT */
  95
  96 /*
  97  * Wrapper function for sys_fadvise64/fadvise64_64
  98  */
  99 #ifndef CONFIG_64BIT
 100
 101 SYSCALL_DEFINE5(s390_fadvise64, int, fd, u32, offset_high, u32, offset_low,
 102                 size_t, len, int, advice)
 103 {
 104         return sys_fadvise64(fd, (u64) offset_high << 32 | offset_low,
 105                         len, advice);
 106 }
 107
 108 struct fadvise64_64_args {
 109         int fd;
 110         long long offset;
 111         long long len;
 112         int advice;
 113 };
 114
 115 SYSCALL_DEFINE1(s390_fadvise64_64, struct fadvise64_64_args __user *, args)
 116 {
 117         struct fadvise64_64_args a;
 118
 119         if ( copy_from_user(&a, args, sizeof(a)) )
 120                 return -EFAULT;
 121         return sys_fadvise64_64(a.fd, a.offset, a.len, a.advice);
 122 }
 123
 124 /*
 125  * This is a wrapper to call sys_fallocate(). For 31 bit s390 the last
 126  * 64 bit argument "len" is split into the upper and lower 32 bits. The
 127  * system call wrapper in the user space loads the value to %r6/%r7.
 128  * The code in entry.S keeps the values in %r2 - %r6 where they are and
 129  * stores %r7 to 96(%r15). But the standard C linkage requires that
 130  * the whole 64 bit value for len is stored on the stack and doesn't
 131  * use %r6 at all. So s390_fallocate has to convert the arguments from
 132  *   %r2: fd, %r3: mode, %r4/%r5: offset, %r6/96(%r15)-99(%r15): len
 133  * to
 134  *   %r2: fd, %r3: mode, %r4/%r5: offset, 96(%r15)-103(%r15): len
 135  */
 136 SYSCALL_DEFINE(s390_fallocate)(int fd, int mode, loff_t offset,
 137                                u32 len_high, u32 len_low)
 138 {
 139         return sys_fallocate(fd, mode, offset, ((u64)len_high << 32) | len_low);
 140 }
 141 #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
 142 asmlinkage long SyS_s390_fallocate(long fd, long mode, loff_t offset,
 143                                    long len_high, long len_low)
 144 {
 145         return SYSC_s390_fallocate((int) fd, (int) mode, offset,
 146                                    (u32) len_high, (u32) len_low);
 147 }
 148 SYSCALL_ALIAS(sys_s390_fallocate, SyS_s390_fallocate);
 149 #endif
 150
 151 #endif