WebSVN – HelenOS – Diff – /trunk/kernel/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.
 */
 
/** @addtogroup genericmm
 * @{
 */
 
/**
 * @file
 * @brief   Backend for address space areas backed by an ELF image.
 */
 
#include <lib/elf.h>
#include <debug.h>
#include <arch/types.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>
 
#ifdef CONFIG_VIRT_IDX_DCACHE
#include <arch/mm/cache.h>
#endif
 
static int elf_page_fault(as_area_t *area, uintptr_t addr, pf_access_t access);
static void elf_frame_free(as_area_t *area, uintptr_t page, uintptr_t 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, uintptr_t 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;
    uintptr_t base, frame, page, start_anon;
    index_t i;
    bool dirty = false;
 
    if (!as_area_check_access(area, access))
        return AS_PF_FAULT;
 
    ASSERT((addr >= ALIGN_DOWN(entry->p_vaddr, PAGE_SIZE)) &&
        (addr < entry->p_vaddr + entry->p_memsz));
    i = (addr - ALIGN_DOWN(entry->p_vaddr, PAGE_SIZE)) >> PAGE_WIDTH;
    base = (uintptr_t)
        (((void *) elf) + ALIGN_DOWN(entry->p_offset, PAGE_SIZE));
 
    /* Virtual address of faulting page*/
    page = ALIGN_DOWN(addr, PAGE_SIZE);
 
    /* Virtual address of the end of initialized part of segment */
    start_anon = entry->p_vaddr + entry->p_filesz;
 
    if (area->sh_info) {
        bool found = false;
 
        /*
         * The address space area is shared.
         */
       
        mutex_lock(&area->sh_info->lock);
        frame = (uintptr_t) btree_search(&area->sh_info->pagemap,
            page - area->base, &leaf);
        if (!frame) {
            unsigned int i;
 
            /*
             * Workaround for valid NULL address.
             */
 
            for (i = 0; i < leaf->keys; i++) {
                if (leaf->key[i] == page) {
                    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, page, 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 (page >= entry->p_vaddr && page + PAGE_SIZE <= start_anon) {
        /*
         * 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 = (uintptr_t)frame_alloc(ONE_FRAME, 0);
            memcpy((void *) PA2KA(frame),
                (void *) (base + i * FRAME_SIZE), FRAME_SIZE);
            dirty = true;
        } else {
            frame = KA2PA(base + i * FRAME_SIZE);
        }  
    } else if (page >= start_anon) {
        /*
         * 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 = (uintptr_t)frame_alloc(ONE_FRAME, 0);
        memsetb((void *) PA2KA(frame), FRAME_SIZE, 0);
        dirty = true;
    } else {
        size_t pad_lo, pad_hi;
        /*
         * The mixed case.
         *
         * The middle part is backed by the ELF image and
         * the lower and upper parts are anonymous memory.
         * (The segment can be and often is shorter than 1 page).
         */
        if (page < entry->p_vaddr)
            pad_lo = entry->p_vaddr - page;
        else
            pad_lo = 0;
 
        if (start_anon < page + PAGE_SIZE)
            pad_hi = page + PAGE_SIZE - start_anon;
        else
            pad_hi = 0;
 
        frame = (uintptr_t)frame_alloc(ONE_FRAME, 0);
        memcpy((void *) (PA2KA(frame) + pad_lo),
            (void *) (base + i * FRAME_SIZE + pad_lo),
            FRAME_SIZE - pad_lo - pad_hi);
        memsetb((void *) PA2KA(frame), pad_lo, 0);
        memsetb((void *) (PA2KA(frame) + FRAME_SIZE - pad_hi), pad_hi, 0);
        dirty = true;
    }
 
    if (dirty && area->sh_info) {
        frame_reference_add(ADDR2PFN(frame));
        btree_insert(&area->sh_info->pagemap, page - 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, page, 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, uintptr_t page, uintptr_t frame)
{
    elf_header_t *elf = area->backend_data.elf;
    elf_segment_header_t *entry = area->backend_data.segment;
    uintptr_t base, start_anon;
    index_t i;
 
    ASSERT((page >= ALIGN_DOWN(entry->p_vaddr, PAGE_SIZE)) &&
        (page < entry->p_vaddr + entry->p_memsz));
    i = (page - ALIGN_DOWN(entry->p_vaddr, PAGE_SIZE)) >> PAGE_WIDTH;
    base = (uintptr_t) (((void *) elf) +
        ALIGN_DOWN(entry->p_offset, FRAME_SIZE));
    start_anon = entry->p_vaddr + entry->p_filesz;
 
    if (page >= entry->p_vaddr && page + PAGE_SIZE <= start_anon) {
        if (entry->p_flags & PF_W) {
            /*
             * Free the frame with the copy of writable segment
             * data.
             */
            frame_free(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(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;
    uintptr_t 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) {
        unsigned int i;
       
        node = list_get_instance(cur, btree_node_t, leaf_link);
       
        for (i = 0; i < node->keys; i++) {
            uintptr_t base = node->key[i];
            count_t count = (count_t) node->value[i];
            unsigned int j;
           
            /*
             * Skip read-only areas of used space that are backed
             * by the ELF image.
             */
            if (!(area->flags & AS_AREA_WRITE))
                if (base >= entry->p_vaddr &&
                    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 >= entry->p_vaddr &&
                        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);
 
                pfn_t pfn = ADDR2PFN(PTE_GET_FRAME(pte));
                frame_reference_add(pfn);
            }
               
        }
    }
    mutex_unlock(&area->sh_info->lock);
}
 
/** @}
 */
 

Rev 3007	Rev 3104
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	/** @addtogroup genericmm	29	/** @addtogroup genericmm
30	* @{	30	* @{
31	*/	31	*/
32		32
33	/**	33	/**
34	* @file	34	* @file
35	* @brief Backend for address space areas backed by an ELF image.	35	* @brief Backend for address space areas backed by an ELF image.
36	*/	36	*/
37		37
38	#include <lib/elf.h>	38	#include <lib/elf.h>
39	#include <debug.h>	39	#include <debug.h>
40	#include <arch/types.h>	40	#include <arch/types.h>
41	#include <mm/as.h>	41	#include <mm/as.h>
42	#include <mm/frame.h>	42	#include <mm/frame.h>
43	#include <mm/slab.h>	43	#include <mm/slab.h>
44	#include <mm/page.h>	44	#include <mm/page.h>
45	#include <genarch/mm/page_pt.h>	45	#include <genarch/mm/page_pt.h>
46	#include <genarch/mm/page_ht.h>	46	#include <genarch/mm/page_ht.h>
47	#include <align.h>	47	#include <align.h>
48	#include <memstr.h>	48	#include <memstr.h>
49	#include <macros.h>	49	#include <macros.h>
50	#include <arch.h>	50	#include <arch.h>
51		51
52	#ifdef CONFIG_VIRT_IDX_DCACHE	52	#ifdef CONFIG_VIRT_IDX_DCACHE
53	#include <arch/mm/cache.h>	53	#include <arch/mm/cache.h>
54	#endif	54	#endif
55		55
56	static int elf_page_fault(as_area_t *area, uintptr_t addr, pf_access_t access);	56	static int elf_page_fault(as_area_t *area, uintptr_t addr, pf_access_t access);
57	static void elf_frame_free(as_area_t *area, uintptr_t page, uintptr_t frame);	57	static void elf_frame_free(as_area_t *area, uintptr_t page, uintptr_t frame);
58	static void elf_share(as_area_t *area);	58	static void elf_share(as_area_t *area);
59		59
60	mem_backend_t elf_backend = {	60	mem_backend_t elf_backend = {
61	.page_fault = elf_page_fault,	61	.page_fault = elf_page_fault,
62	.frame_free = elf_frame_free,	62	.frame_free = elf_frame_free,
63	.share = elf_share	63	.share = elf_share
64	};	64	};
65		65
66	/** Service a page fault in the ELF backend address space area.	66	/** Service a page fault in the ELF backend address space area.
67	*	67	*
68	* The address space area and page tables must be already locked.	68	* The address space area and page tables must be already locked.
69	*	69	*
70	* @param area Pointer to the address space area.	70	* @param area Pointer to the address space area.
71	* @param addr Faulting virtual address.	71	* @param addr Faulting virtual address.
72	* @param access Access mode that caused the fault (i.e. read/write/exec).	72	* @param access Access mode that caused the fault (i.e. read/write/exec).
73	*	73	*
74	* @return AS_PF_FAULT on failure (i.e. page fault) or AS_PF_OK on success (i.e.	74	* @return AS_PF_FAULT on failure (i.e. page fault) or AS_PF_OK on success (i.e.
75	* serviced).	75	* serviced).
76	*/	76	*/
77	int elf_page_fault(as_area_t *area, uintptr_t addr, pf_access_t access)	77	int elf_page_fault(as_area_t *area, uintptr_t addr, pf_access_t access)
78	{	78	{
79	elf_header_t *elf = area->backend_data.elf;	79	elf_header_t *elf = area->backend_data.elf;
80	elf_segment_header_t *entry = area->backend_data.segment;	80	elf_segment_header_t *entry = area->backend_data.segment;
81	btree_node_t *leaf;	81	btree_node_t *leaf;
82	uintptr_t base, frame, page, start_anon;	82	uintptr_t base, frame, page, start_anon;
83	index_t i;	83	index_t i;
84	bool dirty = false;	84	bool dirty = false;
85		85
86	if (!as_area_check_access(area, access))	86	if (!as_area_check_access(area, access))
87	return AS_PF_FAULT;	87	return AS_PF_FAULT;
88		88
89	ASSERT((addr >= ALIGN_DOWN(entry->p_vaddr, PAGE_SIZE)) &&	89	ASSERT((addr >= ALIGN_DOWN(entry->p_vaddr, PAGE_SIZE)) &&
90	(addr < entry->p_vaddr + entry->p_memsz));	90	(addr < entry->p_vaddr + entry->p_memsz));
91	i = (addr - ALIGN_DOWN(entry->p_vaddr, PAGE_SIZE)) >> PAGE_WIDTH;	91	i = (addr - ALIGN_DOWN(entry->p_vaddr, PAGE_SIZE)) >> PAGE_WIDTH;
92	base = (uintptr_t)	92	base = (uintptr_t)
93	(((void *) elf) + ALIGN_DOWN(entry->p_offset, PAGE_SIZE));	93	(((void *) elf) + ALIGN_DOWN(entry->p_offset, PAGE_SIZE));
94		94
95	/* Virtual address of faulting page*/	95	/* Virtual address of faulting page*/
96	page = ALIGN_DOWN(addr, PAGE_SIZE);	96	page = ALIGN_DOWN(addr, PAGE_SIZE);
97		97
98	/* Virtual address of the end of initialized part of segment */	98	/* Virtual address of the end of initialized part of segment */
99	start_anon = entry->p_vaddr + entry->p_filesz;	99	start_anon = entry->p_vaddr + entry->p_filesz;
100		100
101	if (area->sh_info) {	101	if (area->sh_info) {
102	bool found = false;	102	bool found = false;
103		103
104	/*	104	/*
105	* The address space area is shared.	105	* The address space area is shared.
106	*/	106	*/
107		107
108	mutex_lock(&area->sh_info->lock);	108	mutex_lock(&area->sh_info->lock);
109	frame = (uintptr_t) btree_search(&area->sh_info->pagemap,	109	frame = (uintptr_t) btree_search(&area->sh_info->pagemap,
110	page - area->base, &leaf);	110	page - area->base, &leaf);
111	if (!frame) {	111	if (!frame) {
112	unsigned int i;	112	unsigned int i;
113		113
114	/*	114	/*
115	* Workaround for valid NULL address.	115	* Workaround for valid NULL address.
116	*/	116	*/
117		117
118	for (i = 0; i < leaf->keys; i++) {	118	for (i = 0; i < leaf->keys; i++) {
119	if (leaf->key[i] == page) {	119	if (leaf->key[i] == page) {
120	found = true;	120	found = true;
121	break;	121	break;
122	}	122	}
123	}	123	}
124	}	124	}
125	if (frame \|\| found) {	125	if (frame \|\| found) {
126	frame_reference_add(ADDR2PFN(frame));	126	frame_reference_add(ADDR2PFN(frame));
127	page_mapping_insert(AS, addr, frame,	127	page_mapping_insert(AS, addr, frame,
128	as_area_get_flags(area));	128	as_area_get_flags(area));
129	if (!used_space_insert(area, page, 1))	129	if (!used_space_insert(area, page, 1))
130	panic("Could not insert used space.\n");	130	panic("Could not insert used space.\n");
131	mutex_unlock(&area->sh_info->lock);	131	mutex_unlock(&area->sh_info->lock);
132	return AS_PF_OK;	132	return AS_PF_OK;
133	}	133	}
134	}	134	}
135		135
136	/*	136	/*
137	* The area is either not shared or the pagemap does not contain the	137	* The area is either not shared or the pagemap does not contain the
138	* mapping.	138	* mapping.
139	*/	139	*/
140	if (page >= entry->p_vaddr && page + PAGE_SIZE <= start_anon) {	140	if (page >= entry->p_vaddr && page + PAGE_SIZE <= start_anon) {
141	/*	141	/*
142	* Initialized portion of the segment. The memory is backed	142	* Initialized portion of the segment. The memory is backed
143	* directly by the content of the ELF image. Pages are	143	* directly by the content of the ELF image. Pages are
144	* only copied if the segment is writable so that there	144	* only copied if the segment is writable so that there
145	* can be more instantions of the same memory ELF image	145	* can be more instantions of the same memory ELF image
146	* used at a time. Note that this could be later done	146	* used at a time. Note that this could be later done
147	* as COW.	147	* as COW.
148	*/	148	*/
149	if (entry->p_flags & PF_W) {	149	if (entry->p_flags & PF_W) {
150	frame = (uintptr_t)frame_alloc(ONE_FRAME, 0);	150	frame = (uintptr_t)frame_alloc(ONE_FRAME, 0);
151	memcpy((void *) PA2KA(frame),	151	memcpy((void *) PA2KA(frame),
152	(void ) (base + i FRAME_SIZE), FRAME_SIZE);	152	(void ) (base + i FRAME_SIZE), FRAME_SIZE);
153	dirty = true;	153	dirty = true;
154	} else {	154	} else {
155	frame = KA2PA(base + i * FRAME_SIZE);	155	frame = KA2PA(base + i * FRAME_SIZE);
156	}	156	}
157	} else if (page >= start_anon) {	157	} else if (page >= start_anon) {
158	/*	158	/*
159	* This is the uninitialized portion of the segment.	159	* This is the uninitialized portion of the segment.
160	* It is not physically present in the ELF image.	160	* It is not physically present in the ELF image.
161	* To resolve the situation, a frame must be allocated	161	* To resolve the situation, a frame must be allocated
162	* and cleared.	162	* and cleared.
163	*/	163	*/
164	frame = (uintptr_t)frame_alloc(ONE_FRAME, 0);	164	frame = (uintptr_t)frame_alloc(ONE_FRAME, 0);
165	memsetb(PA2KA(frame), FRAME_SIZE, 0);	165	memsetb((void *) PA2KA(frame), FRAME_SIZE, 0);
166	dirty = true;	166	dirty = true;
167	} else {	167	} else {
168	size_t pad_lo, pad_hi;	168	size_t pad_lo, pad_hi;
169	/*	169	/*
170	* The mixed case.	170	* The mixed case.
171	*	171	*
172	* The middle part is backed by the ELF image and	172	* The middle part is backed by the ELF image and
173	* the lower and upper parts are anonymous memory.	173	* the lower and upper parts are anonymous memory.
174	* (The segment can be and often is shorter than 1 page).	174	* (The segment can be and often is shorter than 1 page).
175	*/	175	*/
176	if (page < entry->p_vaddr)	176	if (page < entry->p_vaddr)
177	pad_lo = entry->p_vaddr - page;	177	pad_lo = entry->p_vaddr - page;
178	else	178	else
179	pad_lo = 0;	179	pad_lo = 0;
180		180
181	if (start_anon < page + PAGE_SIZE)	181	if (start_anon < page + PAGE_SIZE)
182	pad_hi = page + PAGE_SIZE - start_anon;	182	pad_hi = page + PAGE_SIZE - start_anon;
183	else	183	else
184	pad_hi = 0;	184	pad_hi = 0;
185		185
186	frame = (uintptr_t)frame_alloc(ONE_FRAME, 0);	186	frame = (uintptr_t)frame_alloc(ONE_FRAME, 0);
187	memcpy((void *) (PA2KA(frame) + pad_lo),	187	memcpy((void *) (PA2KA(frame) + pad_lo),
188	(void ) (base + i FRAME_SIZE + pad_lo),	188	(void ) (base + i FRAME_SIZE + pad_lo),
189	FRAME_SIZE - pad_lo - pad_hi);	189	FRAME_SIZE - pad_lo - pad_hi);
190	memsetb(PA2KA(frame), pad_lo, 0);	190	memsetb((void *) PA2KA(frame), pad_lo, 0);
191	memsetb(PA2KA(frame) + FRAME_SIZE - pad_hi, pad_hi, 0);	191	memsetb((void *) (PA2KA(frame) + FRAME_SIZE - pad_hi), pad_hi, 0);
192	dirty = true;	192	dirty = true;
193	}	193	}
194		194
195	if (dirty && area->sh_info) {	195	if (dirty && area->sh_info) {
196	frame_reference_add(ADDR2PFN(frame));	196	frame_reference_add(ADDR2PFN(frame));
197	btree_insert(&area->sh_info->pagemap, page - area->base,	197	btree_insert(&area->sh_info->pagemap, page - area->base,
198	(void *) frame, leaf);	198	(void *) frame, leaf);
199	}	199	}
200		200
201	if (area->sh_info)	201	if (area->sh_info)
202	mutex_unlock(&area->sh_info->lock);	202	mutex_unlock(&area->sh_info->lock);
203		203
204	page_mapping_insert(AS, addr, frame, as_area_get_flags(area));	204	page_mapping_insert(AS, addr, frame, as_area_get_flags(area));
205	if (!used_space_insert(area, page, 1))	205	if (!used_space_insert(area, page, 1))
206	panic("Could not insert used space.\n");	206	panic("Could not insert used space.\n");
207		207
208	return AS_PF_OK;	208	return AS_PF_OK;
209	}	209	}
210		210
211	/** Free a frame that is backed by the ELF backend.	211	/** Free a frame that is backed by the ELF backend.
212	*	212	*
213	* The address space area and page tables must be already locked.	213	* The address space area and page tables must be already locked.
214	*	214	*
215	* @param area Pointer to the address space area.	215	* @param area Pointer to the address space area.
216	* @param page Page that is mapped to frame. Must be aligned to PAGE_SIZE.	216	* @param page Page that is mapped to frame. Must be aligned to PAGE_SIZE.
217	* @param frame Frame to be released.	217	* @param frame Frame to be released.
218	*	218	*
219	*/	219	*/
220	void elf_frame_free(as_area_t *area, uintptr_t page, uintptr_t frame)	220	void elf_frame_free(as_area_t *area, uintptr_t page, uintptr_t frame)
221	{	221	{
222	elf_header_t *elf = area->backend_data.elf;	222	elf_header_t *elf = area->backend_data.elf;
223	elf_segment_header_t *entry = area->backend_data.segment;	223	elf_segment_header_t *entry = area->backend_data.segment;
224	uintptr_t base, start_anon;	224	uintptr_t base, start_anon;
225	index_t i;	225	index_t i;
226		226
227	ASSERT((page >= ALIGN_DOWN(entry->p_vaddr, PAGE_SIZE)) &&	227	ASSERT((page >= ALIGN_DOWN(entry->p_vaddr, PAGE_SIZE)) &&
228	(page < entry->p_vaddr + entry->p_memsz));	228	(page < entry->p_vaddr + entry->p_memsz));
229	i = (page - ALIGN_DOWN(entry->p_vaddr, PAGE_SIZE)) >> PAGE_WIDTH;	229	i = (page - ALIGN_DOWN(entry->p_vaddr, PAGE_SIZE)) >> PAGE_WIDTH;
230	base = (uintptr_t) (((void *) elf) +	230	base = (uintptr_t) (((void *) elf) +
231	ALIGN_DOWN(entry->p_offset, FRAME_SIZE));	231	ALIGN_DOWN(entry->p_offset, FRAME_SIZE));
232	start_anon = entry->p_vaddr + entry->p_filesz;	232	start_anon = entry->p_vaddr + entry->p_filesz;
233		233
234	if (page >= entry->p_vaddr && page + PAGE_SIZE <= start_anon) {	234	if (page >= entry->p_vaddr && page + PAGE_SIZE <= start_anon) {
235	if (entry->p_flags & PF_W) {	235	if (entry->p_flags & PF_W) {
236	/*	236	/*
237	* Free the frame with the copy of writable segment	237	* Free the frame with the copy of writable segment
238	* data.	238	* data.
239	*/	239	*/
240	frame_free(frame);	240	frame_free(frame);
241	}	241	}
242	} else {	242	} else {
243	/*	243	/*
244	* The frame is either anonymous memory or the mixed case (i.e.	244	* The frame is either anonymous memory or the mixed case (i.e.
245	* lower part is backed by the ELF image and the upper is	245	* lower part is backed by the ELF image and the upper is
246	* anonymous). In any case, a frame needs to be freed.	246	* anonymous). In any case, a frame needs to be freed.
247	*/	247	*/
248	frame_free(frame);	248	frame_free(frame);
249	}	249	}
250	}	250	}
251		251
252	/** Share ELF image backed address space area.	252	/** Share ELF image backed address space area.
253	*	253	*
254	* If the area is writable, then all mapped pages are duplicated in the pagemap.	254	* If the area is writable, then all mapped pages are duplicated in the pagemap.
255	* Otherwise only portions of the area that are not backed by the ELF image	255	* Otherwise only portions of the area that are not backed by the ELF image
256	* are put into the pagemap.	256	* are put into the pagemap.
257	*	257	*
258	* The address space and address space area must be locked prior to the call.	258	* The address space and address space area must be locked prior to the call.
259	*	259	*
260	* @param area Address space area.	260	* @param area Address space area.
261	*/	261	*/
262	void elf_share(as_area_t *area)	262	void elf_share(as_area_t *area)
263	{	263	{
264	elf_segment_header_t *entry = area->backend_data.segment;	264	elf_segment_header_t *entry = area->backend_data.segment;
265	link_t *cur;	265	link_t *cur;
266	btree_node_t leaf, node;	266	btree_node_t leaf, node;
267	uintptr_t start_anon = entry->p_vaddr + entry->p_filesz;	267	uintptr_t start_anon = entry->p_vaddr + entry->p_filesz;
268		268
269	/*	269	/*
270	* Find the node in which to start linear search.	270	* Find the node in which to start linear search.
271	*/	271	*/
272	if (area->flags & AS_AREA_WRITE) {	272	if (area->flags & AS_AREA_WRITE) {
273	node = list_get_instance(area->used_space.leaf_head.next,	273	node = list_get_instance(area->used_space.leaf_head.next,
274	btree_node_t, leaf_link);	274	btree_node_t, leaf_link);
275	} else {	275	} else {
276	(void) btree_search(&area->sh_info->pagemap, start_anon, &leaf);	276	(void) btree_search(&area->sh_info->pagemap, start_anon, &leaf);
277	node = btree_leaf_node_left_neighbour(&area->sh_info->pagemap,	277	node = btree_leaf_node_left_neighbour(&area->sh_info->pagemap,
278	leaf);	278	leaf);
279	if (!node)	279	if (!node)
280	node = leaf;	280	node = leaf;
281	}	281	}
282		282
283	/*	283	/*
284	* Copy used anonymous portions of the area to sh_info's page map.	284	* Copy used anonymous portions of the area to sh_info's page map.
285	*/	285	*/
286	mutex_lock(&area->sh_info->lock);	286	mutex_lock(&area->sh_info->lock);
287	for (cur = &node->leaf_link; cur != &area->used_space.leaf_head;	287	for (cur = &node->leaf_link; cur != &area->used_space.leaf_head;
288	cur = cur->next) {	288	cur = cur->next) {
289	unsigned int i;	289	unsigned int i;
290		290
291	node = list_get_instance(cur, btree_node_t, leaf_link);	291	node = list_get_instance(cur, btree_node_t, leaf_link);
292		292
293	for (i = 0; i < node->keys; i++) {	293	for (i = 0; i < node->keys; i++) {
294	uintptr_t base = node->key[i];	294	uintptr_t base = node->key[i];
295	count_t count = (count_t) node->value[i];	295	count_t count = (count_t) node->value[i];
296	unsigned int j;	296	unsigned int j;
297		297
298	/*	298	/*
299	* Skip read-only areas of used space that are backed	299	* Skip read-only areas of used space that are backed
300	* by the ELF image.	300	* by the ELF image.
301	*/	301	*/
302	if (!(area->flags & AS_AREA_WRITE))	302	if (!(area->flags & AS_AREA_WRITE))
303	if (base >= entry->p_vaddr &&	303	if (base >= entry->p_vaddr &&
304	base + count * PAGE_SIZE <= start_anon)	304	base + count * PAGE_SIZE <= start_anon)
305	continue;	305	continue;
306		306
307	for (j = 0; j < count; j++) {	307	for (j = 0; j < count; j++) {
308	pte_t *pte;	308	pte_t *pte;
309		309
310	/*	310	/*
311	* Skip read-only pages that are backed by the	311	* Skip read-only pages that are backed by the
312	* ELF image.	312	* ELF image.
313	*/	313	*/
314	if (!(area->flags & AS_AREA_WRITE))	314	if (!(area->flags & AS_AREA_WRITE))
315	if (base >= entry->p_vaddr &&	315	if (base >= entry->p_vaddr &&
316	base + (j + 1) * PAGE_SIZE <=	316	base + (j + 1) * PAGE_SIZE <=
317	start_anon)	317	start_anon)
318	continue;	318	continue;
319		319
320	page_table_lock(area->as, false);	320	page_table_lock(area->as, false);
321	pte = page_mapping_find(area->as,	321	pte = page_mapping_find(area->as,
322	base + j * PAGE_SIZE);	322	base + j * PAGE_SIZE);
323	ASSERT(pte && PTE_VALID(pte) &&	323	ASSERT(pte && PTE_VALID(pte) &&
324	PTE_PRESENT(pte));	324	PTE_PRESENT(pte));
325	btree_insert(&area->sh_info->pagemap,	325	btree_insert(&area->sh_info->pagemap,
326	(base + j * PAGE_SIZE) - area->base,	326	(base + j * PAGE_SIZE) - area->base,
327	(void *) PTE_GET_FRAME(pte), NULL);	327	(void *) PTE_GET_FRAME(pte), NULL);
328	page_table_unlock(area->as, false);	328	page_table_unlock(area->as, false);
329		329
330	pfn_t pfn = ADDR2PFN(PTE_GET_FRAME(pte));	330	pfn_t pfn = ADDR2PFN(PTE_GET_FRAME(pte));
331	frame_reference_add(pfn);	331	frame_reference_add(pfn);
332	}	332	}
333		333
334	}	334	}
335	}	335	}
336	mutex_unlock(&area->sh_info->lock);	336	mutex_unlock(&area->sh_info->lock);
337	}	337	}
338		338
339	/** @}	339	/** @}
340	*/	340	*/
341		341

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(root)/trunk/kernel/generic/src/mm/backend_elf.c – Rev 3007 → 3104