arch/um/kernel/syscall.c

   1 /*
   2  * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include "linux/file.h"
   7 #include "linux/fs.h"
   8 #include "linux/mm.h"
   9 #include "linux/sched.h"
  10 #include "linux/utsname.h"
  11 #include "asm/current.h"
  12 #include "asm/mman.h"
  13 #include "asm/uaccess.h"
  14 #include "asm/unistd.h"
  15
  16 /*  Unlocked, I don't care if this is a bit off */
  17 int nsyscalls = 0;
  18
  19 long sys_fork(void)
  20 {
  21         long ret;
  22
  23         current->thread.forking = 1;
  24         ret = do_fork(SIGCHLD, UPT_SP(&current->thread.regs.regs),
  25                       &current->thread.regs, 0, NULL, NULL);
  26         current->thread.forking = 0;
  27         return ret;
  28 }
  29
  30 long sys_vfork(void)
  31 {
  32         long ret;
  33
  34         current->thread.forking = 1;
  35         ret = do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD,
  36                       UPT_SP(&current->thread.regs.regs),
  37                       &current->thread.regs, 0, NULL, NULL);
  38         current->thread.forking = 0;
  39         return ret;
  40 }
  41
  42 /* common code for old and new mmaps */
  43 long sys_mmap2(unsigned long addr, unsigned long len,
  44                unsigned long prot, unsigned long flags,
  45                unsigned long fd, unsigned long pgoff)
  46 {
  47         long error = -EBADF;
  48         struct file * file = NULL;
  49
  50         flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
  51         if (!(flags & MAP_ANONYMOUS)) {
  52                 file = fget(fd);
  53                 if (!file)
  54                         goto out;
  55         }
  56
  57         down_write(&current->mm->mmap_sem);
  58         error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
  59         up_write(&current->mm->mmap_sem);
  60
  61         if (file)
  62                 fput(file);
  63  out:
  64         return error;
  65 }
  66
  67 long old_mmap(unsigned long addr, unsigned long len,
  68               unsigned long prot, unsigned long flags,
  69               unsigned long fd, unsigned long offset)
  70 {
  71         long err = -EINVAL;
  72         if (offset & ~PAGE_MASK)
  73                 goto out;
  74
  75         err = sys_mmap2(addr, len, prot, flags, fd, offset >> PAGE_SHIFT);
  76  out:
  77         return err;
  78 }
  79 /*
  80  * sys_pipe() is the normal C calling standard for creating
  81  * a pipe. It's not the way unix traditionally does this, though.
  82  */
  83 long sys_pipe(unsigned long __user * fildes)
  84 {
  85         int fd[2];
  86         long error;
  87
  88         error = do_pipe(fd);
  89         if (!error) {
  90                 if (copy_to_user(fildes, fd, sizeof(fd)))
  91                         error = -EFAULT;
  92         }
  93         return error;
  94 }
  95
  96
  97 long sys_uname(struct old_utsname __user * name)
  98 {
  99         long err;
 100         if (!name)
 101                 return -EFAULT;
 102         down_read(&uts_sem);
 103         err = copy_to_user(name, utsname(), sizeof (*name));
 104         up_read(&uts_sem);
 105         return err?-EFAULT:0;
 106 }
 107
 108 long sys_olduname(struct oldold_utsname __user * name)
 109 {
 110         long error;
 111
 112         if (!name)
 113                 return -EFAULT;
 114         if (!access_ok(VERIFY_WRITE,name,sizeof(struct oldold_utsname)))
 115                 return -EFAULT;
 116
 117         down_read(&uts_sem);
 118
 119         error = __copy_to_user(&name->sysname, &utsname()->sysname,
 120                                __OLD_UTS_LEN);
 121         error |= __put_user(0, name->sysname + __OLD_UTS_LEN);
 122         error |= __copy_to_user(&name->nodename, &utsname()->nodename,
 123                                 __OLD_UTS_LEN);
 124         error |= __put_user(0, name->nodename + __OLD_UTS_LEN);
 125         error |= __copy_to_user(&name->release, &utsname()->release,
 126                                 __OLD_UTS_LEN);
 127         error |= __put_user(0, name->release + __OLD_UTS_LEN);
 128         error |= __copy_to_user(&name->version, &utsname()->version,
 129                                 __OLD_UTS_LEN);
 130         error |= __put_user(0, name->version + __OLD_UTS_LEN);
 131         error |= __copy_to_user(&name->machine, &utsname()->machine,
 132                                 __OLD_UTS_LEN);
 133         error |= __put_user(0, name->machine + __OLD_UTS_LEN);
 134
 135         up_read(&uts_sem);
 136
 137         error = error ? -EFAULT : 0;
 138
 139         return error;
 140 }
 141
 142 int kernel_execve(const char *filename, char *const argv[], char *const envp[])
 143 {
 144         mm_segment_t fs;
 145         int ret;
 146
 147         fs = get_fs();
 148         set_fs(KERNEL_DS);
 149         ret = um_execve(filename, argv, envp);
 150         set_fs(fs);
 151
 152         return ret;
 153 }