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uvm_mremap.c revision 1.7
      1  1.7  drochner /*	$NetBSD: uvm_mremap.c,v 1.7 2007/08/08 11:08:18 drochner Exp $	*/
      2  1.1      yamt 
      3  1.1      yamt /*-
      4  1.1      yamt  * Copyright (c)2006 YAMAMOTO Takashi,
      5  1.1      yamt  * All rights reserved.
      6  1.1      yamt  *
      7  1.1      yamt  * Redistribution and use in source and binary forms, with or without
      8  1.1      yamt  * modification, are permitted provided that the following conditions
      9  1.1      yamt  * are met:
     10  1.1      yamt  * 1. Redistributions of source code must retain the above copyright
     11  1.1      yamt  *    notice, this list of conditions and the following disclaimer.
     12  1.1      yamt  * 2. Redistributions in binary form must reproduce the above copyright
     13  1.1      yamt  *    notice, this list of conditions and the following disclaimer in the
     14  1.1      yamt  *    documentation and/or other materials provided with the distribution.
     15  1.1      yamt  *
     16  1.1      yamt  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     17  1.1      yamt  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     18  1.1      yamt  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     19  1.1      yamt  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     20  1.1      yamt  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     21  1.1      yamt  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     22  1.1      yamt  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     23  1.1      yamt  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     24  1.1      yamt  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     25  1.1      yamt  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     26  1.1      yamt  * SUCH DAMAGE.
     27  1.1      yamt  */
     28  1.1      yamt 
     29  1.1      yamt #include <sys/cdefs.h>
     30  1.7  drochner __KERNEL_RCSID(0, "$NetBSD: uvm_mremap.c,v 1.7 2007/08/08 11:08:18 drochner Exp $");
     31  1.1      yamt 
     32  1.1      yamt #include <sys/param.h>
     33  1.5     joerg #include <sys/mman.h>
     34  1.5     joerg #include <sys/syscallargs.h>
     35  1.6        ad #include <sys/proc.h>
     36  1.1      yamt 
     37  1.1      yamt #include <uvm/uvm.h>
     38  1.1      yamt 
     39  1.1      yamt static int
     40  1.1      yamt uvm_mapent_extend(struct vm_map *map, vaddr_t endva, vsize_t size)
     41  1.1      yamt {
     42  1.1      yamt 	struct vm_map_entry *entry;
     43  1.1      yamt 	struct vm_map_entry *reserved_entry;
     44  1.1      yamt 	struct uvm_object *uobj;
     45  1.1      yamt 	int error = 0;
     46  1.1      yamt 
     47  1.1      yamt 	vm_map_lock(map);
     48  1.1      yamt 	if (!uvm_map_lookup_entry(map, endva, &reserved_entry)) {
     49  1.1      yamt 		error = ENOENT;
     50  1.1      yamt 		goto done;
     51  1.1      yamt 	}
     52  1.1      yamt 	if (reserved_entry->start != endva ||
     53  1.1      yamt 	    reserved_entry->end != endva + size ||
     54  1.1      yamt 	    reserved_entry->object.uvm_obj != NULL ||
     55  1.1      yamt 	    reserved_entry->aref.ar_amap != NULL) {
     56  1.1      yamt 		error = EINVAL;
     57  1.1      yamt 		goto done;
     58  1.1      yamt 	}
     59  1.1      yamt 	entry = reserved_entry->prev;
     60  1.1      yamt 	KASSERT(&map->header != entry);
     61  1.1      yamt 	if (entry->end != endva) {
     62  1.1      yamt 		error = EINVAL;
     63  1.1      yamt 		goto done;
     64  1.1      yamt 	}
     65  1.1      yamt 
     66  1.1      yamt 	/*
     67  1.1      yamt 	 * now, make reserved_entry compatible with entry, and then
     68  1.1      yamt 	 * try to merge.
     69  1.1      yamt 	 */
     70  1.1      yamt 
     71  1.1      yamt 	uobj = entry->object.uvm_obj;
     72  1.1      yamt 	if (uobj) {
     73  1.1      yamt 		voff_t offset = entry->offset;
     74  1.1      yamt 		voff_t newoffset;
     75  1.1      yamt 
     76  1.1      yamt 		newoffset = offset + entry->end - entry->start;
     77  1.1      yamt 		if (newoffset <= offset) {
     78  1.1      yamt 			error = E2BIG; /* XXX */
     79  1.1      yamt 			goto done;
     80  1.1      yamt 		}
     81  1.1      yamt 		simple_lock(&uobj->vmobjlock);
     82  1.1      yamt 		KASSERT(uobj->uo_refs > 0);
     83  1.1      yamt 		uobj->uo_refs++;
     84  1.1      yamt 		simple_unlock(&uobj->vmobjlock);
     85  1.1      yamt 		reserved_entry->object.uvm_obj = uobj;
     86  1.1      yamt 		reserved_entry->offset = newoffset;
     87  1.1      yamt 	}
     88  1.1      yamt 	reserved_entry->etype = entry->etype;
     89  1.1      yamt 	if (UVM_ET_ISCOPYONWRITE(entry)) {
     90  1.1      yamt 		reserved_entry->etype |= UVM_ET_NEEDSCOPY;
     91  1.1      yamt 	}
     92  1.1      yamt 	reserved_entry->flags &= ~UVM_MAP_NOMERGE;
     93  1.1      yamt 	reserved_entry->protection = entry->protection;
     94  1.1      yamt 	reserved_entry->max_protection = entry->max_protection;
     95  1.1      yamt 	reserved_entry->inheritance = entry->inheritance;
     96  1.1      yamt 	reserved_entry->advice = entry->advice;
     97  1.1      yamt 	reserved_entry->wired_count = 0; /* XXX should inherit? */
     98  1.1      yamt 	uvm_mapent_trymerge(map, reserved_entry, 0);
     99  1.1      yamt done:
    100  1.1      yamt 	vm_map_unlock(map);
    101  1.1      yamt 
    102  1.1      yamt 	return error;
    103  1.1      yamt }
    104  1.1      yamt 
    105  1.1      yamt /*
    106  1.1      yamt  * uvm_mremap: move and/or resize existing mappings.
    107  1.1      yamt  */
    108  1.1      yamt 
    109  1.1      yamt int
    110  1.3      yamt uvm_mremap(struct vm_map *oldmap, vaddr_t oldva, vsize_t oldsize,
    111  1.3      yamt     struct vm_map *newmap, vaddr_t *newvap, vsize_t newsize,
    112  1.3      yamt     struct proc *newproc, int flags)
    113  1.1      yamt {
    114  1.1      yamt 	vaddr_t dstva;
    115  1.1      yamt 	vsize_t movesize;
    116  1.1      yamt 	vaddr_t newva;
    117  1.5     joerg 	vaddr_t align = 0;
    118  1.1      yamt 	int error = 0;
    119  1.5     joerg 	const bool fixed = (flags & MAP_FIXED) != 0;
    120  1.1      yamt 
    121  1.1      yamt 	if (fixed) {
    122  1.1      yamt 		newva = *newvap;
    123  1.1      yamt 	} else {
    124  1.1      yamt 		newva = 0;
    125  1.1      yamt 	}
    126  1.1      yamt 	if ((oldva & PAGE_MASK) != 0 ||
    127  1.1      yamt 	    (newva & PAGE_MASK) != 0 ||
    128  1.1      yamt 	    (oldsize & PAGE_MASK) != 0 ||
    129  1.1      yamt 	    (newsize & PAGE_MASK) != 0) {
    130  1.1      yamt 		return EINVAL;
    131  1.1      yamt 	}
    132  1.1      yamt 	/* XXX zero-size should be allowed? */
    133  1.1      yamt 	if (oldva + oldsize <= oldva || newva + newsize <= newva) {
    134  1.1      yamt 		return EINVAL;
    135  1.1      yamt 	}
    136  1.1      yamt 
    137  1.1      yamt 	/*
    138  1.5     joerg 	 * Try to see if any requested alignment can even be attemped.
    139  1.5     joerg 	 * Make sure we can express the alignment (asking for a >= 4GB
    140  1.5     joerg 	 * alignment on an ILP32 architecure make no sense) and the
    141  1.5     joerg 	 * alignment is at least for a page sized quanitiy.  If the
    142  1.5     joerg 	 * request was for a fixed mapping, make sure supplied address
    143  1.5     joerg 	 * adheres to the request alignment.
    144  1.5     joerg 	 */
    145  1.5     joerg 	align = (flags & MAP_ALIGNMENT_MASK) >> MAP_ALIGNMENT_SHIFT;
    146  1.5     joerg 	if (align) {
    147  1.5     joerg 		if (align >= sizeof(vaddr_t) * NBBY)
    148  1.5     joerg 			return(EINVAL);
    149  1.5     joerg 		align = 1L << align;
    150  1.5     joerg 		if (align < PAGE_SIZE)
    151  1.5     joerg 			return(EINVAL);
    152  1.5     joerg 		if (align >= vm_map_max(oldmap))
    153  1.5     joerg 			return(ENOMEM);
    154  1.5     joerg 		if (flags & MAP_FIXED) {
    155  1.5     joerg 			if ((*newvap & (align-1)) != 0)
    156  1.5     joerg 				return(EINVAL);
    157  1.5     joerg 			align = 0;
    158  1.5     joerg 		}
    159  1.5     joerg 	}
    160  1.5     joerg 
    161  1.5     joerg 	/*
    162  1.1      yamt 	 * check the easy cases first.
    163  1.1      yamt 	 */
    164  1.1      yamt 
    165  1.5     joerg 	if ((!fixed || newva == oldva) && newmap == oldmap &&
    166  1.5     joerg 	    (align == 0 || (oldva & ~(align - 1)) == 0)) {
    167  1.1      yamt 		vaddr_t va;
    168  1.1      yamt 
    169  1.1      yamt 		if (newsize == oldsize) {
    170  1.2      yamt 			newva = oldva;
    171  1.2      yamt 			goto done;
    172  1.1      yamt 		}
    173  1.1      yamt 		if (newsize < oldsize) {
    174  1.1      yamt 			uvm_unmap(oldmap, oldva + newsize, oldva + oldsize);
    175  1.2      yamt 			newva = oldva;
    176  1.2      yamt 			goto done;
    177  1.1      yamt 		}
    178  1.1      yamt 		va = oldva + oldsize;
    179  1.1      yamt 		if (uvm_map_reserve(oldmap, newsize - oldsize, 0, 0, &va,
    180  1.1      yamt 		    UVM_FLAG_FIXED)) {
    181  1.1      yamt 			newva = oldva;
    182  1.1      yamt 			goto extend;
    183  1.1      yamt 		}
    184  1.1      yamt 		if (fixed) {
    185  1.1      yamt 			return ENOMEM;
    186  1.1      yamt 		}
    187  1.1      yamt 	}
    188  1.1      yamt 
    189  1.1      yamt 	/*
    190  1.1      yamt 	 * we need to move mappings.
    191  1.1      yamt 	 */
    192  1.1      yamt 
    193  1.1      yamt 	if (!fixed) {
    194  1.1      yamt 		KASSERT(&newproc->p_vmspace->vm_map == newmap);
    195  1.1      yamt 		newva = newproc->p_emul->e_vm_default_addr(newproc,
    196  1.3      yamt 		    (vaddr_t)newproc->p_vmspace->vm_daddr, newsize);
    197  1.1      yamt 	}
    198  1.1      yamt 	dstva = newva;
    199  1.5     joerg 	if (!uvm_map_reserve(newmap, newsize, oldva, align, &dstva,
    200  1.1      yamt 	    fixed ? UVM_FLAG_FIXED : 0)) {
    201  1.1      yamt 		return ENOMEM;
    202  1.1      yamt 	}
    203  1.1      yamt 	KASSERT(!fixed || dstva == newva);
    204  1.1      yamt 	newva = dstva;
    205  1.1      yamt 	movesize = MIN(oldsize, newsize);
    206  1.1      yamt 	error = uvm_map_extract(oldmap, oldva, movesize, newmap, &dstva,
    207  1.1      yamt 	    UVM_EXTRACT_RESERVED);
    208  1.1      yamt 	KASSERT(dstva == newva);
    209  1.1      yamt 	if (error != 0) {
    210  1.1      yamt 		/* undo uvm_map_reserve */
    211  1.1      yamt 		uvm_unmap(newmap, newva, newva + newsize);
    212  1.1      yamt 		return error;
    213  1.1      yamt 	}
    214  1.1      yamt 	if (newsize > oldsize) {
    215  1.1      yamt extend:
    216  1.1      yamt 		error = uvm_mapent_extend(newmap, newva + oldsize,
    217  1.1      yamt 		    newsize - oldsize);
    218  1.1      yamt 		if (error != 0) {
    219  1.1      yamt 			/* undo uvm_map_reserve and uvm_map_extract */
    220  1.1      yamt 			uvm_unmap(newmap, newva, newva + newsize);
    221  1.1      yamt 			return error;
    222  1.1      yamt 		}
    223  1.1      yamt 	}
    224  1.1      yamt 
    225  1.1      yamt 	/*
    226  1.1      yamt 	 * now we won't fail.  remove original entries.
    227  1.1      yamt 	 */
    228  1.1      yamt 
    229  1.1      yamt 	if (oldva != newva || oldmap != newmap) {
    230  1.1      yamt 		uvm_unmap(oldmap, oldva, oldva + oldsize);
    231  1.1      yamt 	}
    232  1.2      yamt done:
    233  1.1      yamt 	*newvap = newva;
    234  1.1      yamt 	return 0;
    235  1.1      yamt }
    236  1.5     joerg 
    237  1.5     joerg /*
    238  1.5     joerg  * sys_mremap: mremap system call.
    239  1.5     joerg  */
    240  1.5     joerg 
    241  1.5     joerg int
    242  1.5     joerg sys_mremap(struct lwp *l, void *v, register_t *retval)
    243  1.5     joerg {
    244  1.5     joerg 	struct sys_mremap_args /* {
    245  1.5     joerg 		syscallarg(void *) old_address;
    246  1.5     joerg 		syscallarg(size_t) old_size;
    247  1.5     joerg 		syscallarg(void *) new_address;
    248  1.5     joerg 		syscallarg(size_t) new_size;
    249  1.5     joerg 		syscallarg(int) flags;
    250  1.5     joerg 	} */ *uap = v;
    251  1.5     joerg 
    252  1.5     joerg 	struct proc *p;
    253  1.5     joerg 	struct vm_map *map;
    254  1.5     joerg 	vaddr_t oldva;
    255  1.5     joerg 	vaddr_t newva;
    256  1.5     joerg 	size_t oldsize;
    257  1.5     joerg 	size_t newsize;
    258  1.5     joerg 	int flags;
    259  1.5     joerg 	int error;
    260  1.5     joerg 
    261  1.5     joerg 	flags = SCARG(uap, flags);
    262  1.5     joerg 	oldva = (vaddr_t)SCARG(uap, old_address);
    263  1.5     joerg 	oldsize = (vsize_t)(SCARG(uap, old_size));
    264  1.5     joerg 	newva = (vaddr_t)SCARG(uap, new_address);
    265  1.5     joerg 	newsize = (vsize_t)(SCARG(uap, new_size));
    266  1.5     joerg 
    267  1.5     joerg 	if ((flags & ~(MAP_FIXED | MAP_ALIGNMENT_MASK)) != 0) {
    268  1.5     joerg 		error = EINVAL;
    269  1.5     joerg 		goto done;
    270  1.5     joerg 	}
    271  1.5     joerg 
    272  1.7  drochner 	oldsize = round_page(oldsize);
    273  1.7  drochner 	newsize = round_page(newsize);
    274  1.7  drochner 
    275  1.5     joerg 	p = l->l_proc;
    276  1.5     joerg 	map = &p->p_vmspace->vm_map;
    277  1.5     joerg 	error = uvm_mremap(map, oldva, oldsize, map, &newva, newsize, p,
    278  1.5     joerg 	    flags);
    279  1.5     joerg 
    280  1.5     joerg done:
    281  1.5     joerg 	*retval = (error != 0) ? 0 : (register_t)newva;
    282  1.5     joerg 	return error;
    283  1.5     joerg 
    284  1.5     joerg }
    285