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