WebSVN – HelenOS-historic – Diff – /kernel/trunk/generic/src/mm/backend_elf.c


/*
 * Copyright (C) 2006 Jakub Jermar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
/**
 * @file    backend_elf.c
 * @brief   Backend for address space areas backed by an ELF image.
 */
 
#include <elf.h>
#include <debug.h>
#include <arch/types.h>
#include <typedefs.h>
#include <mm/as.h>
#include <mm/frame.h>
#include <mm/slab.h>
#include <mm/page.h>
#include <genarch/mm/page_pt.h>
#include <genarch/mm/page_ht.h>
#include <align.h>
#include <memstr.h>
#include <macros.h>
#include <arch.h>
 
static int elf_page_fault(as_area_t *area, __address addr, pf_access_t access);
static void elf_frame_free(as_area_t *area, __address page, __address frame);
static void elf_share(as_area_t *area);
 
mem_backend_t elf_backend = {
    .page_fault = elf_page_fault,
    .frame_free = elf_frame_free,
    .share = elf_share
};
 
/** Service a page fault in the ELF backend address space area.
 *
 * The address space area and page tables must be already locked.
 *
 * @param area Pointer to the address space area.
 * @param addr Faulting virtual address.
 * @param access Access mode that caused the fault (i.e. read/write/exec).
 *
 * @return AS_PF_FAULT on failure (i.e. page fault) or AS_PF_OK on success (i.e. serviced).
 */
int elf_page_fault(as_area_t *area, __address addr, pf_access_t access)
{
    elf_header_t *elf = area->backend_data.elf;
    elf_segment_header_t *entry = area->backend_data.segment;
    btree_node_t *leaf;
    __address base, frame;
    index_t i;
 
    if (!as_area_check_access(area, access))
        return AS_PF_FAULT;
 
    ASSERT((addr >= entry->p_vaddr) && (addr < entry->p_vaddr + entry->p_memsz));
    i = (addr - entry->p_vaddr) >> PAGE_WIDTH;
    base = (__address) (((void *) elf) + entry->p_offset);
    ASSERT(ALIGN_UP(base, FRAME_SIZE) == base);
 
    if (area->sh_info) {
        bool found = false;
 
        /*
         * The address space area is shared.
         */
         
        mutex_lock(&area->sh_info->lock);
        frame = (__address) btree_search(&area->sh_info->pagemap,
            ALIGN_DOWN(addr, PAGE_SIZE) - area->base, &leaf);
        if (!frame) {
            int i;
 
            /*
             * Workaround for valid NULL address.
             */
 
            for (i = 0; i < leaf->keys; i++) {
                if (leaf->key[i] == ALIGN_DOWN(addr, PAGE_SIZE)) {
                    found = true;
                    break;
                }
            }
        }
        if (frame || found) {
            frame_reference_add(ADDR2PFN(frame));
            page_mapping_insert(AS, addr, frame, as_area_get_flags(area));
 
            if (!used_space_insert(area, ALIGN_DOWN(addr, PAGE_SIZE), 1))
                panic("Could not insert used space.\n");
            mutex_unlock(&area->sh_info->lock);
            return AS_PF_OK;
        }
    }
   
    /*
     * The area is either not shared or the pagemap does not contain the mapping.
     */
   
    if (ALIGN_DOWN(addr, PAGE_SIZE) + PAGE_SIZE < entry->p_vaddr + entry->p_filesz) {
        /*
         * Initialized portion of the segment. The memory is backed
         * directly by the content of the ELF image. Pages are
         * only copied if the segment is writable so that there
         * can be more instantions of the same memory ELF image
         * used at a time. Note that this could be later done
         * as COW.
         */
        if (entry->p_flags & PF_W) {
            frame = PFN2ADDR(frame_alloc(ONE_FRAME, 0));
            memcpy((void *) PA2KA(frame), (void *) (base + i*FRAME_SIZE), FRAME_SIZE);
           
            if (area->sh_info) {
                frame_reference_add(ADDR2PFN(frame));
                btree_insert(&area->sh_info->pagemap, ALIGN_DOWN(addr, PAGE_SIZE) - area->base,
                    (void *) frame, leaf);
            }
 
        } else {
            frame = KA2PA(base + i*FRAME_SIZE);
        }  
    } else if (ALIGN_DOWN(addr, PAGE_SIZE) >= ALIGN_UP(entry->p_vaddr + entry->p_filesz, PAGE_SIZE)) {
        /*
         * This is the uninitialized portion of the segment.
         * It is not physically present in the ELF image.
         * To resolve the situation, a frame must be allocated
         * and cleared.
         */
        frame = PFN2ADDR(frame_alloc(ONE_FRAME, 0));
        memsetb(PA2KA(frame), FRAME_SIZE, 0);
 
        if (area->sh_info) {
            frame_reference_add(ADDR2PFN(frame));
            btree_insert(&area->sh_info->pagemap, ALIGN_DOWN(addr, PAGE_SIZE) - area->base,
                (void *) frame, leaf);
        }
 
    } else {
        size_t size;
        /*
         * The mixed case.
         * The lower part is backed by the ELF image and
         * the upper part is anonymous memory.
         */
        size = entry->p_filesz - (i<<PAGE_WIDTH);
        frame = PFN2ADDR(frame_alloc(ONE_FRAME, 0));
        memsetb(PA2KA(frame) + size, FRAME_SIZE - size, 0);
        memcpy((void *) PA2KA(frame), (void *) (base + i*FRAME_SIZE), size);
 
        if (area->sh_info) {
            frame_reference_add(ADDR2PFN(frame));
            btree_insert(&area->sh_info->pagemap, ALIGN_DOWN(addr, PAGE_SIZE) - area->base,
                (void *) frame, leaf);
        }
 
    }
   
    if (area->sh_info)
        mutex_unlock(&area->sh_info->lock);
   
    page_mapping_insert(AS, addr, frame, as_area_get_flags(area));
    if (!used_space_insert(area, ALIGN_DOWN(addr, PAGE_SIZE), 1))
        panic("Could not insert used space.\n");
 
    return AS_PF_OK;
}
 
/** Free a frame that is backed by the ELF backend.
 *
 * The address space area and page tables must be already locked.
 *
 * @param area Pointer to the address space area.
 * @param page Page that is mapped to frame. Must be aligned to PAGE_SIZE.
 * @param frame Frame to be released.
 *
 */
void elf_frame_free(as_area_t *area, __address page, __address frame)
{
    elf_header_t *elf = area->backend_data.elf;
    elf_segment_header_t *entry = area->backend_data.segment;
    __address base;
    index_t i;
   
    ASSERT((page >= entry->p_vaddr) && (page < entry->p_vaddr + entry->p_memsz));
    i = (page - entry->p_vaddr) >> PAGE_WIDTH;
    base = (__address) (((void *) elf) + entry->p_offset);
    ASSERT(ALIGN_UP(base, FRAME_SIZE) == base);
   
    if (page + PAGE_SIZE < ALIGN_UP(entry->p_vaddr + entry->p_filesz, PAGE_SIZE)) {
        if (entry->p_flags & PF_W) {
            /*
             * Free the frame with the copy of writable segment data.
             */
            frame_free(ADDR2PFN(frame));
        }
    } else {
        /*
         * The frame is either anonymous memory or the mixed case (i.e. lower
         * part is backed by the ELF image and the upper is anonymous).
         * In any case, a frame needs to be freed.
         */
        frame_free(ADDR2PFN(frame));
    }
}
 
/** Share ELF image backed address space area.
 *
 * If the area is writable, then all mapped pages are duplicated in the pagemap.
 * Otherwise only portions of the area that are not backed by the ELF image
 * are put into the pagemap.
 *
 * The address space and address space area must be locked prior to the call.
 *
 * @param area Address space area.
 */
void elf_share(as_area_t *area)
{
    elf_segment_header_t *entry = area->backend_data.segment;
    link_t *cur;
    btree_node_t *leaf, *node;
    __address start_anon = entry->p_vaddr + entry->p_filesz;
 
    /*
     * Find the node in which to start linear search.
     */
    if (area->flags & AS_AREA_WRITE) {
        node = list_get_instance(area->used_space.leaf_head.next, btree_node_t, leaf_link);
    } else {
        (void) btree_search(&area->sh_info->pagemap, start_anon, &leaf);
        node = btree_leaf_node_left_neighbour(&area->sh_info->pagemap, leaf);
        if (!node)
            node = leaf;
    }
 
    /*
     * Copy used anonymous portions of the area to sh_info's page map.
     */
    mutex_lock(&area->sh_info->lock);
    for (cur = &node->leaf_link; cur != &area->used_space.leaf_head; cur = cur->next) {
        int i;
       
        node = list_get_instance(cur, btree_node_t, leaf_link);
       
        for (i = 0; i < node->keys; i++) {
            __address base = node->key[i];
            count_t count = (count_t) node->value[i];
            int j;
           
            /*
             * Skip read-only areas of used space that are backed
             * by the ELF image.
             */
            if (!(area->flags & AS_AREA_WRITE))
                if (base + count*PAGE_SIZE <= start_anon)
                    continue;
           
            for (j = 0; j < count; j++) {
                pte_t *pte;
           
                /*
                 * Skip read-only pages that are backed by the ELF image.
                 */
                if (!(area->flags & AS_AREA_WRITE))
                    if (base + (j + 1)*PAGE_SIZE <= start_anon)
                        continue;
               
                page_table_lock(area->as, false);
                pte = page_mapping_find(area->as, base + j*PAGE_SIZE);
                ASSERT(pte && PTE_VALID(pte) && PTE_PRESENT(pte));
                btree_insert(&area->sh_info->pagemap, (base + j*PAGE_SIZE) - area->base,
                    (void *) PTE_GET_FRAME(pte), NULL);
                page_table_unlock(area->as, false);
                frame_reference_add(ADDR2PFN(PTE_GET_FRAME(pte)));
            }
               
        }
    }
    mutex_unlock(&area->sh_info->lock);
}
 

Subversion Repositories HelenOS-historic

(root)/kernel/trunk/generic/src/mm/backend_elf.c – Rev 1546 → 1550

Rev 1546		Rev 1550
1	/*	1	/*
2	* Copyright (C) 2006 Jakub Jermar	2	* Copyright (C) 2006 Jakub Jermar
3	* All rights reserved.	3	* All rights reserved.
4	*	4	*
5	* Redistribution and use in source and binary forms, with or without	5	* Redistribution and use in source and binary forms, with or without
6	* modification, are permitted provided that the following conditions	6	* modification, are permitted provided that the following conditions
7	* are met:	7	* are met:
8	*	8	*
9	* - Redistributions of source code must retain the above copyright	9	* - Redistributions of source code must retain the above copyright
10	* notice, this list of conditions and the following disclaimer.	10	* notice, this list of conditions and the following disclaimer.
11	* - Redistributions in binary form must reproduce the above copyright	11	* - Redistributions in binary form must reproduce the above copyright
12	* notice, this list of conditions and the following disclaimer in the	12	* notice, this list of conditions and the following disclaimer in the
13	* documentation and/or other materials provided with the distribution.	13	* documentation and/or other materials provided with the distribution.
14	* - The name of the author may not be used to endorse or promote products	14	* - The name of the author may not be used to endorse or promote products
15	* derived from this software without specific prior written permission.	15	* derived from this software without specific prior written permission.
16	*	16	*
17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR	17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES	18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.	19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,	20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT	21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,	22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY	23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT	24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF	25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.	26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27	*/	27	*/
28		28
29	/**	29	/**
30	* @file backend_elf.c	30	* @file backend_elf.c
31	* @brief Backend for address space areas backed by an ELF image.	31	* @brief Backend for address space areas backed by an ELF image.
32	*/	32	*/
33		33
34	#include <elf.h>	34	#include <elf.h>
35	#include <debug.h>	35	#include <debug.h>
36	#include <arch/types.h>	36	#include <arch/types.h>
37	#include <typedefs.h>	37	#include <typedefs.h>
38	#include <mm/as.h>	38	#include <mm/as.h>
39	#include <mm/frame.h>	39	#include <mm/frame.h>
40	#include <mm/slab.h>	40	#include <mm/slab.h>
41	#include <mm/page.h>	41	#include <mm/page.h>
42	#include <genarch/mm/page_pt.h>	42	#include <genarch/mm/page_pt.h>
43	#include <genarch/mm/page_ht.h>	43	#include <genarch/mm/page_ht.h>
44	#include <align.h>	44	#include <align.h>
45	#include <memstr.h>	45	#include <memstr.h>
46	#include <macros.h>	46	#include <macros.h>
47	#include <arch.h>	47	#include <arch.h>
48		48
49	static int elf_page_fault(as_area_t *area, __address addr, pf_access_t access);	49	static int elf_page_fault(as_area_t *area, __address addr, pf_access_t access);
50	static void elf_frame_free(as_area_t *area, __address page, __address frame);	50	static void elf_frame_free(as_area_t *area, __address page, __address frame);
51	static void elf_share(as_area_t *area);	51	static void elf_share(as_area_t *area);
52		52
53	mem_backend_t elf_backend = {	53	mem_backend_t elf_backend = {
54	.page_fault = elf_page_fault,	54	.page_fault = elf_page_fault,
55	.frame_free = elf_frame_free,	55	.frame_free = elf_frame_free,
56	.share = elf_share	56	.share = elf_share
57	};	57	};
58		58
59	/** Service a page fault in the ELF backend address space area.	59	/** Service a page fault in the ELF backend address space area.
60	*	60	*
61	* The address space area and page tables must be already locked.	61	* The address space area and page tables must be already locked.
62	*	62	*
63	* @param area Pointer to the address space area.	63	* @param area Pointer to the address space area.
64	* @param addr Faulting virtual address.	64	* @param addr Faulting virtual address.
65	* @param access Access mode that caused the fault (i.e. read/write/exec).	65	* @param access Access mode that caused the fault (i.e. read/write/exec).
66	*	66	*
67	* @return AS_PF_FAULT on failure (i.e. page fault) or AS_PF_OK on success (i.e. serviced).	67	* @return AS_PF_FAULT on failure (i.e. page fault) or AS_PF_OK on success (i.e. serviced).
68	*/	68	*/
69	int elf_page_fault(as_area_t *area, __address addr, pf_access_t access)	69	int elf_page_fault(as_area_t *area, __address addr, pf_access_t access)
70	{	70	{
71	elf_header_t *elf = area->backend_data.elf;	71	elf_header_t *elf = area->backend_data.elf;
72	elf_segment_header_t *entry = area->backend_data.segment;	72	elf_segment_header_t *entry = area->backend_data.segment;
73	btree_node_t *leaf;	73	btree_node_t *leaf;
74	__address base, frame;	74	__address base, frame;
75	index_t i;	75	index_t i;
76		76
77	if (!as_area_check_access(area, access))	77	if (!as_area_check_access(area, access))
78	return AS_PF_FAULT;	78	return AS_PF_FAULT;
79		79
80	ASSERT((addr >= entry->p_vaddr) && (addr < entry->p_vaddr + entry->p_memsz));	80	ASSERT((addr >= entry->p_vaddr) && (addr < entry->p_vaddr + entry->p_memsz));
81	i = (addr - entry->p_vaddr) >> PAGE_WIDTH;	81	i = (addr - entry->p_vaddr) >> PAGE_WIDTH;
82	base = (__address) (((void *) elf) + entry->p_offset);	82	base = (__address) (((void *) elf) + entry->p_offset);
83	ASSERT(ALIGN_UP(base, FRAME_SIZE) == base);	83	ASSERT(ALIGN_UP(base, FRAME_SIZE) == base);
84		84
85	if (area->sh_info) {	85	if (area->sh_info) {
86	bool found = false;	86	bool found = false;
87		87
88	/*	88	/*
89	* The address space area is shared.	89	* The address space area is shared.
90	*/	90	*/
91		91
92	mutex_lock(&area->sh_info->lock);	92	mutex_lock(&area->sh_info->lock);
93	frame = (__address) btree_search(&area->sh_info->pagemap,	93	frame = (__address) btree_search(&area->sh_info->pagemap,
94	ALIGN_DOWN(addr, PAGE_SIZE) - area->base, &leaf);	94	ALIGN_DOWN(addr, PAGE_SIZE) - area->base, &leaf);
95	if (!frame) {	95	if (!frame) {
96	int i;	96	int i;
97		97
98	/*	98	/*
99	* Workaround for valid NULL address.	99	* Workaround for valid NULL address.
100	*/	100	*/
101		101
102	for (i = 0; i < leaf->keys; i++) {	102	for (i = 0; i < leaf->keys; i++) {
103	if (leaf->key[i] == ALIGN_DOWN(addr, PAGE_SIZE)) {	103	if (leaf->key[i] == ALIGN_DOWN(addr, PAGE_SIZE)) {
104	found = true;	104	found = true;
105	break;	105	break;
106	}	106	}
107	}	107	}
108	}	108	}
109	if (frame \|\| found) {	109	if (frame \|\| found) {
110	frame_reference_add(ADDR2PFN(frame));	110	frame_reference_add(ADDR2PFN(frame));
111	page_mapping_insert(AS, addr, frame, as_area_get_flags(area));	111	page_mapping_insert(AS, addr, frame, as_area_get_flags(area));
112	frame_reference_add(ADDR2PFN(PTE_GET_FRAME(pte)));	-
113	if (!used_space_insert(area, ALIGN_DOWN(addr, PAGE_SIZE), 1))	112	if (!used_space_insert(area, ALIGN_DOWN(addr, PAGE_SIZE), 1))
114	panic("Could not insert used space.\n");	113	panic("Could not insert used space.\n");
115	mutex_unlock(&area->sh_info->lock);	114	mutex_unlock(&area->sh_info->lock);
116	return AS_PF_OK;	115	return AS_PF_OK;
117	}	116	}
118	}	117	}
119		118
120	/*	119	/*
121	* The area is either not shared or the pagemap does not contain the mapping.	120	* The area is either not shared or the pagemap does not contain the mapping.
122	*/	121	*/
123		122
124	if (ALIGN_DOWN(addr, PAGE_SIZE) + PAGE_SIZE < entry->p_vaddr + entry->p_filesz) {	123	if (ALIGN_DOWN(addr, PAGE_SIZE) + PAGE_SIZE < entry->p_vaddr + entry->p_filesz) {
125	/*	124	/*
126	* Initialized portion of the segment. The memory is backed	125	* Initialized portion of the segment. The memory is backed
127	* directly by the content of the ELF image. Pages are	126	* directly by the content of the ELF image. Pages are
128	* only copied if the segment is writable so that there	127	* only copied if the segment is writable so that there
129	* can be more instantions of the same memory ELF image	128	* can be more instantions of the same memory ELF image
130	* used at a time. Note that this could be later done	129	* used at a time. Note that this could be later done
131	* as COW.	130	* as COW.
132	*/	131	*/
133	if (entry->p_flags & PF_W) {	132	if (entry->p_flags & PF_W) {
134	frame = PFN2ADDR(frame_alloc(ONE_FRAME, 0));	133	frame = PFN2ADDR(frame_alloc(ONE_FRAME, 0));
135	memcpy((void ) PA2KA(frame), (void ) (base + i*FRAME_SIZE), FRAME_SIZE);	134	memcpy((void ) PA2KA(frame), (void ) (base + i*FRAME_SIZE), FRAME_SIZE);
136		135
137	if (area->sh_info) {	136	if (area->sh_info) {
138	frame_reference_add(ADDR2PFN(frame));	137	frame_reference_add(ADDR2PFN(frame));
139	btree_insert(&area->sh_info->pagemap, ALIGN_DOWN(addr, PAGE_SIZE) - area->base,	138	btree_insert(&area->sh_info->pagemap, ALIGN_DOWN(addr, PAGE_SIZE) - area->base,
140	(void *) frame, leaf);	139	(void *) frame, leaf);
141	}	140	}
142		141
143	} else {	142	} else {
144	frame = KA2PA(base + i*FRAME_SIZE);	143	frame = KA2PA(base + i*FRAME_SIZE);
145	}	144	}
146	} else if (ALIGN_DOWN(addr, PAGE_SIZE) >= ALIGN_UP(entry->p_vaddr + entry->p_filesz, PAGE_SIZE)) {	145	} else if (ALIGN_DOWN(addr, PAGE_SIZE) >= ALIGN_UP(entry->p_vaddr + entry->p_filesz, PAGE_SIZE)) {
147	/*	146	/*
148	* This is the uninitialized portion of the segment.	147	* This is the uninitialized portion of the segment.
149	* It is not physically present in the ELF image.	148	* It is not physically present in the ELF image.
150	* To resolve the situation, a frame must be allocated	149	* To resolve the situation, a frame must be allocated
151	* and cleared.	150	* and cleared.
152	*/	151	*/
153	frame = PFN2ADDR(frame_alloc(ONE_FRAME, 0));	152	frame = PFN2ADDR(frame_alloc(ONE_FRAME, 0));
154	memsetb(PA2KA(frame), FRAME_SIZE, 0);	153	memsetb(PA2KA(frame), FRAME_SIZE, 0);
155		154
156	if (area->sh_info) {	155	if (area->sh_info) {
157	frame_reference_add(ADDR2PFN(frame));	156	frame_reference_add(ADDR2PFN(frame));
158	btree_insert(&area->sh_info->pagemap, ALIGN_DOWN(addr, PAGE_SIZE) - area->base,	157	btree_insert(&area->sh_info->pagemap, ALIGN_DOWN(addr, PAGE_SIZE) - area->base,
159	(void *) frame, leaf);	158	(void *) frame, leaf);
160	}	159	}
161		160
162	} else {	161	} else {
163	size_t size;	162	size_t size;
164	/*	163	/*
165	* The mixed case.	164	* The mixed case.
166	* The lower part is backed by the ELF image and	165	* The lower part is backed by the ELF image and
167	* the upper part is anonymous memory.	166	* the upper part is anonymous memory.
168	*/	167	*/
169	size = entry->p_filesz - (i<<PAGE_WIDTH);	168	size = entry->p_filesz - (i<<PAGE_WIDTH);
170	frame = PFN2ADDR(frame_alloc(ONE_FRAME, 0));	169	frame = PFN2ADDR(frame_alloc(ONE_FRAME, 0));
171	memsetb(PA2KA(frame) + size, FRAME_SIZE - size, 0);	170	memsetb(PA2KA(frame) + size, FRAME_SIZE - size, 0);
172	memcpy((void ) PA2KA(frame), (void ) (base + i*FRAME_SIZE), size);	171	memcpy((void ) PA2KA(frame), (void ) (base + i*FRAME_SIZE), size);
173		172
174	if (area->sh_info) {	173	if (area->sh_info) {
175	frame_reference_add(ADDR2PFN(frame));	174	frame_reference_add(ADDR2PFN(frame));
176	btree_insert(&area->sh_info->pagemap, ALIGN_DOWN(addr, PAGE_SIZE) - area->base,	175	btree_insert(&area->sh_info->pagemap, ALIGN_DOWN(addr, PAGE_SIZE) - area->base,
177	(void *) frame, leaf);	176	(void *) frame, leaf);
178	}	177	}
179		178
180	}	179	}
181		180
182	if (area->sh_info)	181	if (area->sh_info)
183	mutex_unlock(&area->sh_info->lock);	182	mutex_unlock(&area->sh_info->lock);
184		183
185	page_mapping_insert(AS, addr, frame, as_area_get_flags(area));	184	page_mapping_insert(AS, addr, frame, as_area_get_flags(area));
186	if (!used_space_insert(area, ALIGN_DOWN(addr, PAGE_SIZE), 1))	185	if (!used_space_insert(area, ALIGN_DOWN(addr, PAGE_SIZE), 1))
187	panic("Could not insert used space.\n");	186	panic("Could not insert used space.\n");
188		187
189	return AS_PF_OK;	188	return AS_PF_OK;
190	}	189	}
191		190
192	/** Free a frame that is backed by the ELF backend.	191	/** Free a frame that is backed by the ELF backend.
193	*	192	*
194	* The address space area and page tables must be already locked.	193	* The address space area and page tables must be already locked.
195	*	194	*
196	* @param area Pointer to the address space area.	195	* @param area Pointer to the address space area.
197	* @param page Page that is mapped to frame. Must be aligned to PAGE_SIZE.	196	* @param page Page that is mapped to frame. Must be aligned to PAGE_SIZE.
198	* @param frame Frame to be released.	197	* @param frame Frame to be released.
199	*	198	*
200	*/	199	*/
201	void elf_frame_free(as_area_t *area, __address page, __address frame)	200	void elf_frame_free(as_area_t *area, __address page, __address frame)
202	{	201	{
203	elf_header_t *elf = area->backend_data.elf;	202	elf_header_t *elf = area->backend_data.elf;
204	elf_segment_header_t *entry = area->backend_data.segment;	203	elf_segment_header_t *entry = area->backend_data.segment;
205	__address base;	204	__address base;
206	index_t i;	205	index_t i;
207		206
208	ASSERT((page >= entry->p_vaddr) && (page < entry->p_vaddr + entry->p_memsz));	207	ASSERT((page >= entry->p_vaddr) && (page < entry->p_vaddr + entry->p_memsz));
209	i = (page - entry->p_vaddr) >> PAGE_WIDTH;	208	i = (page - entry->p_vaddr) >> PAGE_WIDTH;
210	base = (__address) (((void *) elf) + entry->p_offset);	209	base = (__address) (((void *) elf) + entry->p_offset);
211	ASSERT(ALIGN_UP(base, FRAME_SIZE) == base);	210	ASSERT(ALIGN_UP(base, FRAME_SIZE) == base);
212		211
213	if (page + PAGE_SIZE < ALIGN_UP(entry->p_vaddr + entry->p_filesz, PAGE_SIZE)) {	212	if (page + PAGE_SIZE < ALIGN_UP(entry->p_vaddr + entry->p_filesz, PAGE_SIZE)) {
214	if (entry->p_flags & PF_W) {	213	if (entry->p_flags & PF_W) {
215	/*	214	/*
216	* Free the frame with the copy of writable segment data.	215	* Free the frame with the copy of writable segment data.
217	*/	216	*/
218	frame_free(ADDR2PFN(frame));	217	frame_free(ADDR2PFN(frame));
219	}	218	}
220	} else {	219	} else {
221	/*	220	/*
222	* The frame is either anonymous memory or the mixed case (i.e. lower	221	* The frame is either anonymous memory or the mixed case (i.e. lower
223	* part is backed by the ELF image and the upper is anonymous).	222	* part is backed by the ELF image and the upper is anonymous).
224	* In any case, a frame needs to be freed.	223	* In any case, a frame needs to be freed.
225	*/	224	*/
226	frame_free(ADDR2PFN(frame));	225	frame_free(ADDR2PFN(frame));
227	}	226	}
228	}	227	}
229		228
230	/** Share ELF image backed address space area.	229	/** Share ELF image backed address space area.
231	*	230	*
232	* If the area is writable, then all mapped pages are duplicated in the pagemap.	231	* If the area is writable, then all mapped pages are duplicated in the pagemap.
233	* Otherwise only portions of the area that are not backed by the ELF image	232	* Otherwise only portions of the area that are not backed by the ELF image
234	* are put into the pagemap.	233	* are put into the pagemap.
235	*	234	*
236	* The address space and address space area must be locked prior to the call.	235	* The address space and address space area must be locked prior to the call.
237	*	236	*
238	* @param area Address space area.	237	* @param area Address space area.
239	*/	238	*/
240	void elf_share(as_area_t *area)	239	void elf_share(as_area_t *area)
241	{	240	{
242	elf_segment_header_t *entry = area->backend_data.segment;	241	elf_segment_header_t *entry = area->backend_data.segment;
243	link_t *cur;	242	link_t *cur;
244	btree_node_t leaf, node;	243	btree_node_t leaf, node;
245	__address start_anon = entry->p_vaddr + entry->p_filesz;	244	__address start_anon = entry->p_vaddr + entry->p_filesz;
246		245
247	/*	246	/*
248	* Find the node in which to start linear search.	247	* Find the node in which to start linear search.
249	*/	248	*/
250	if (area->flags & AS_AREA_WRITE) {	249	if (area->flags & AS_AREA_WRITE) {
251	node = list_get_instance(area->used_space.leaf_head.next, btree_node_t, leaf_link);	250	node = list_get_instance(area->used_space.leaf_head.next, btree_node_t, leaf_link);
252	} else {	251	} else {
253	(void) btree_search(&area->sh_info->pagemap, start_anon, &leaf);	252	(void) btree_search(&area->sh_info->pagemap, start_anon, &leaf);
254	node = btree_leaf_node_left_neighbour(&area->sh_info->pagemap, leaf);	253	node = btree_leaf_node_left_neighbour(&area->sh_info->pagemap, leaf);
255	if (!node)	254	if (!node)
256	node = leaf;	255	node = leaf;
257	}	256	}
258		257
259	/*	258	/*
260	* Copy used anonymous portions of the area to sh_info's page map.	259	* Copy used anonymous portions of the area to sh_info's page map.
261	*/	260	*/
262	mutex_lock(&area->sh_info->lock);	261	mutex_lock(&area->sh_info->lock);
263	for (cur = &node->leaf_link; cur != &area->used_space.leaf_head; cur = cur->next) {	262	for (cur = &node->leaf_link; cur != &area->used_space.leaf_head; cur = cur->next) {
264	int i;	263	int i;
265		264
266	node = list_get_instance(cur, btree_node_t, leaf_link);	265	node = list_get_instance(cur, btree_node_t, leaf_link);
267		266
268	for (i = 0; i < node->keys; i++) {	267	for (i = 0; i < node->keys; i++) {
269	__address base = node->key[i];	268	__address base = node->key[i];
270	count_t count = (count_t) node->value[i];	269	count_t count = (count_t) node->value[i];
271	int j;	270	int j;
272		271
273	/*	272	/*
274	* Skip read-only areas of used space that are backed	273	* Skip read-only areas of used space that are backed
275	* by the ELF image.	274	* by the ELF image.
276	*/	275	*/
277	if (!(area->flags & AS_AREA_WRITE))	276	if (!(area->flags & AS_AREA_WRITE))
278	if (base + count*PAGE_SIZE <= start_anon)	277	if (base + count*PAGE_SIZE <= start_anon)
279	continue;	278	continue;
280		279
281	for (j = 0; j < count; j++) {	280	for (j = 0; j < count; j++) {
282	pte_t *pte;	281	pte_t *pte;
283		282
284	/*	283	/*
285	* Skip read-only pages that are backed by the ELF image.	284	* Skip read-only pages that are backed by the ELF image.
286	*/	285	*/
287	if (!(area->flags & AS_AREA_WRITE))	286	if (!(area->flags & AS_AREA_WRITE))
288	if (base + (j + 1)*PAGE_SIZE <= start_anon)	287	if (base + (j + 1)*PAGE_SIZE <= start_anon)
289	continue;	288	continue;
290		289
291	page_table_lock(area->as, false);	290	page_table_lock(area->as, false);
292	pte = page_mapping_find(area->as, base + j*PAGE_SIZE);	291	pte = page_mapping_find(area->as, base + j*PAGE_SIZE);
293	ASSERT(pte && PTE_VALID(pte) && PTE_PRESENT(pte));	292	ASSERT(pte && PTE_VALID(pte) && PTE_PRESENT(pte));
294	btree_insert(&area->sh_info->pagemap, (base + j*PAGE_SIZE) - area->base,	293	btree_insert(&area->sh_info->pagemap, (base + j*PAGE_SIZE) - area->base,
295	(void *) PTE_GET_FRAME(pte), NULL);	294	(void *) PTE_GET_FRAME(pte), NULL);
296	page_table_unlock(area->as, false);	295	page_table_unlock(area->as, false);
297	frame_reference_add(ADDR2PFN(PTE_GET_FRAME(pte)));	296	frame_reference_add(ADDR2PFN(PTE_GET_FRAME(pte)));
298	}	297	}
299		298
300	}	299	}
301	}	300	}
302	mutex_unlock(&area->sh_info->lock);	301	mutex_unlock(&area->sh_info->lock);
303	}	302	}
304		303