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 #include "internal.h"
  16
  17 long sys_fork(void)
  18 {
  19         long ret;
  20
  21         current->thread.forking = 1;
  22         ret = do_fork(SIGCHLD, UPT_SP(&current->thread.regs.regs),
  23                       &current->thread.regs, 0, NULL, NULL);
  24         current->thread.forking = 0;
  25         return ret;
  26 }
  27
  28 long sys_vfork(void)
  29 {
  30         long ret;
  31
  32         current->thread.forking = 1;
  33         ret = do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD,
  34                       UPT_SP(&current->thread.regs.regs),
  35                       &current->thread.regs, 0, NULL, NULL);
  36         current->thread.forking = 0;
  37         return ret;
  38 }
  39
  40 /* common code for old and new mmaps */
  41 long sys_mmap2(unsigned long addr, unsigned long len,
  42                unsigned long prot, unsigned long flags,
  43                unsigned long fd, unsigned long pgoff)
  44 {
  45         long error = -EBADF;
  46         struct file * file = NULL;
  47
  48         flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
  49         if (!(flags & MAP_ANONYMOUS)) {
  50                 file = fget(fd);
  51                 if (!file)
  52                         goto out;
  53         }
  54
  55         down_write(&current->mm->mmap_sem);
  56         error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
  57         up_write(&current->mm->mmap_sem);
  58
  59         if (file)
  60                 fput(file);
  61  out:
  62         return error;
  63 }
  64
  65 long old_mmap(unsigned long addr, unsigned long len,
  66               unsigned long prot, unsigned long flags,
  67               unsigned long fd, unsigned long offset)
  68 {
  69         long err = -EINVAL;
  70         if (offset & ~PAGE_MASK)
  71                 goto out;
  72
  73         err = sys_mmap2(addr, len, prot, flags, fd, offset >> PAGE_SHIFT);
  74  out:
  75         return err;
  76 }
  77
  78 long sys_uname(struct old_utsname __user * name)
  79 {
  80         long err;
  81         if (!name)
  82                 return -EFAULT;
  83         down_read(&uts_sem);
  84         err = copy_to_user(name, utsname(), sizeof (*name));
  85         up_read(&uts_sem);
  86         return err?-EFAULT:0;
  87 }
  88
  89 long sys_olduname(struct oldold_utsname __user * name)
  90 {
  91         long error;
  92
  93         if (!name)
  94                 return -EFAULT;
  95         if (!access_ok(VERIFY_WRITE,name,sizeof(struct oldold_utsname)))
  96                 return -EFAULT;
  97
  98         down_read(&uts_sem);
  99
 100         error = __copy_to_user(&name->sysname, &utsname()->sysname,
 101                                __OLD_UTS_LEN);
 102         error |= __put_user(0, name->sysname + __OLD_UTS_LEN);
 103         error |= __copy_to_user(&name->nodename, &utsname()->nodename,
 104                                 __OLD_UTS_LEN);
 105         error |= __put_user(0, name->nodename + __OLD_UTS_LEN);
 106         error |= __copy_to_user(&name->release, &utsname()->release,
 107                                 __OLD_UTS_LEN);
 108         error |= __put_user(0, name->release + __OLD_UTS_LEN);
 109         error |= __copy_to_user(&name->version, &utsname()->version,
 110                                 __OLD_UTS_LEN);
 111         error |= __put_user(0, name->version + __OLD_UTS_LEN);
 112         error |= __copy_to_user(&name->machine, &utsname()->machine,
 113                                 __OLD_UTS_LEN);
 114         error |= __put_user(0, name->machine + __OLD_UTS_LEN);
 115
 116         up_read(&uts_sem);
 117
 118         error = error ? -EFAULT : 0;
 119
 120         return error;
 121 }
 122
 123 int kernel_execve(const char *filename, char *const argv[], char *const envp[])
 124 {
 125         mm_segment_t fs;
 126         int ret;
 127
 128         fs = get_fs();
 129         set_fs(KERNEL_DS);
 130         ret = um_execve(filename, argv, envp);
 131         set_fs(fs);
 132
 133         return ret;
 134 }