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mm.h revision 1.2.4.2 
      1 /*	$NetBSD: mm.h,v 1.2.4.2 2014/05/18 17:46:01 rmind Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2013 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Taylor R. Campbell.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #ifndef _LINUX_MM_H_
     33 #define _LINUX_MM_H_
     34 
     35 #include <sys/kauth.h>
     36 #include <sys/file.h>
     37 #include <sys/mman.h>
     38 #include <sys/proc.h>
     39 #include <sys/vnode.h>
     40 
     41 #include <uvm/uvm_extern.h>
     42 
     43 /* XXX Ugh bletch!  Whattakludge!  Linux's sense is reversed...  */
     44 #undef	PAGE_MASK
     45 #define	PAGE_MASK	(~(PAGE_SIZE-1))
     46 
     47 #define	PAGE_ALIGN(x)		(((x) + (PAGE_SIZE-1)) & ~(PAGE_SIZE-1))
     48 #define	offset_in_page(x)	((x) & (PAGE_SIZE-1))
     49 
     50 /*
     51  * ###################################################################
     52  * ############### XXX THIS NEEDS SERIOUS SCRUTINY XXX ###############
     53  * ###################################################################
     54  */
     55 
     56 /*
     57  * XXX unsigned long is a loser but will probably work accidentally.
     58  * XXX struct file might not map quite right between Linux and NetBSD.
     59  * XXX This is large enough it should take its own file.
     60  */
     61 
     62 static inline unsigned long
     63 vm_mmap(struct file *file, unsigned long base, unsigned long size,
     64     unsigned long prot, unsigned long flags, unsigned long token)
     65 {
     66 	struct vnode *vnode;
     67 	vaddr_t addr;
     68 	int error;
     69 
     70 	/*
     71 	 * Cargo-culted from sys_mmap.  Various conditions kasserted
     72 	 * rather than checked for expedience and safey.
     73 	 */
     74 
     75 	KASSERT(base == 0);
     76 	KASSERT(prot == (PROT_READ | PROT_WRITE));
     77 	KASSERT(flags == MAP_SHARED);
     78 
     79 	KASSERT(file->f_type == DTYPE_VNODE);
     80 	vnode = file->f_data;
     81 
     82 	KASSERT(vnode->v_type == VCHR);
     83 	KASSERT((file->f_flag & (FREAD | FWRITE)) == (FREAD | FWRITE));
     84 
     85 	{
     86 		struct vattr va;
     87 
     88 		vn_lock(vnode, (LK_SHARED | LK_RETRY));
     89 		error = VOP_GETATTR(vnode, &va, kauth_cred_get());
     90 		VOP_UNLOCK(vnode);
     91 		if (error)
     92 			goto out;
     93 		/* XXX kassert?  */
     94 		if ((va.va_flags & (SF_SNAPSHOT | IMMUTABLE | APPEND)) != 0) {
     95 			error = EACCES;
     96 			goto out;
     97 		}
     98 	}
     99 
    100 	/* XXX pax_mprotect?  pax_aslr?  */
    101 
    102 	addr = (*curproc->p_emul->e_vm_default_addr)(curproc,
    103 	    (vaddr_t)curproc->p_vmspace->vm_daddr, size);
    104 	error = uvm_mmap(&curproc->p_vmspace->vm_map, &addr, size,
    105 	    (VM_PROT_READ | VM_PROT_WRITE), (VM_PROT_READ | VM_PROT_WRITE),
    106 	    MAP_SHARED, vnode, base,
    107 	    curproc->p_rlimit[RLIMIT_MEMLOCK].rlim_cur);
    108 	if (error)
    109 		goto out;
    110 
    111 	KASSERT(addr <= -1024UL); /* XXX Kludgerosity!  */
    112 
    113 out:	/* XXX errno NetBSD->Linux (kludgerific) */
    114 	return (error? (-error) : (unsigned long)addr);
    115 }
    116 
    117 #endif  /* _LINUX_MM_H_ */
    118