arch/s390/kernel/sys_s390.c

   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
  39 struct 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
  48 SYSCALL_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);
  56 out:
  57         return error;
  58 }
  59
  60 /*
  61  * sys_ipc() is the de-multiplexer for the SysV IPC calls.
  62  */
  63 SYSCALL_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
  80 SYSCALL_DEFINE1(s390_personality, unsigned int, personality)
  81 {
  82         unsigned int ret;
  83
  84         if (current->personality == PER_LINUX32 && personality == PER_LINUX)
  85                 personality = PER_LINUX32;
  86         ret = sys_personality(personality);
  87         if (ret == PER_LINUX32)
  88                 ret = PER_LINUX;
  89
  90         return ret;
  91 }
  92 #endif /* CONFIG_64BIT */
  93
  94 /*
  95  * Wrapper function for sys_fadvise64/fadvise64_64
  96  */
  97 #ifndef CONFIG_64BIT
  98
  99 SYSCALL_DEFINE5(s390_fadvise64, int, fd, u32, offset_high, u32, offset_low,
 100                 size_t, len, int, advice)
 101 {
 102         return sys_fadvise64(fd, (u64) offset_high << 32 | offset_low,
 103                         len, advice);
 104 }
 105
 106 struct fadvise64_64_args {
 107         int fd;
 108         long long offset;
 109         long long len;
 110         int advice;
 111 };
 112
 113 SYSCALL_DEFINE1(s390_fadvise64_64, struct fadvise64_64_args __user *, args)
 114 {
 115         struct fadvise64_64_args a;
 116
 117         if ( copy_from_user(&a, args, sizeof(a)) )
 118                 return -EFAULT;
 119         return sys_fadvise64_64(a.fd, a.offset, a.len, a.advice);
 120 }
 121
 122 /*
 123  * This is a wrapper to call sys_fallocate(). For 31 bit s390 the last
 124  * 64 bit argument "len" is split into the upper and lower 32 bits. The
 125  * system call wrapper in the user space loads the value to %r6/%r7.
 126  * The code in entry.S keeps the values in %r2 - %r6 where they are and
 127  * stores %r7 to 96(%r15). But the standard C linkage requires that
 128  * the whole 64 bit value for len is stored on the stack and doesn't
 129  * use %r6 at all. So s390_fallocate has to convert the arguments from
 130  *   %r2: fd, %r3: mode, %r4/%r5: offset, %r6/96(%r15)-99(%r15): len
 131  * to
 132  *   %r2: fd, %r3: mode, %r4/%r5: offset, 96(%r15)-103(%r15): len
 133  */
 134 SYSCALL_DEFINE(s390_fallocate)(int fd, int mode, loff_t offset,
 135                                u32 len_high, u32 len_low)
 136 {
 137         return sys_fallocate(fd, mode, offset, ((u64)len_high << 32) | len_low);
 138 }
 139 #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
 140 asmlinkage long SyS_s390_fallocate(long fd, long mode, loff_t offset,
 141                                    long len_high, long len_low)
 142 {
 143         return SYSC_s390_fallocate((int) fd, (int) mode, offset,
 144                                    (u32) len_high, (u32) len_low);
 145 }
 146 SYSCALL_ALIAS(sys_s390_fallocate, SyS_s390_fallocate);
 147 #endif
 148
 149 #endif