[mirror_qemu.git] / bsd-user / mmap.c

/*
 *  mmap support for qemu
 *
 *  Copyright (c) 2003 - 2008 Fabrice Bellard
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, see <http://www.gnu.org/licenses/>.
 */
#include "qemu/osdep.h"

#include "qemu.h"
#include "qemu-common.h"

//#define DEBUG_MMAP

static pthread_mutex_t mmap_mutex = PTHREAD_MUTEX_INITIALIZER;
static __thread int mmap_lock_count;

void mmap_lock(void)
{
    if (mmap_lock_count++ == 0) {
        pthread_mutex_lock(&mmap_mutex);
    }
}

void mmap_unlock(void)
{
    if (--mmap_lock_count == 0) {
        pthread_mutex_unlock(&mmap_mutex);
    }
}

bool have_mmap_lock(void)
{
    return mmap_lock_count > 0 ? true : false;
}

/* Grab lock to make sure things are in a consistent state after fork().  */
void mmap_fork_start(void)
{
    if (mmap_lock_count)
        abort();
    pthread_mutex_lock(&mmap_mutex);
}

void mmap_fork_end(int child)
{
    if (child)
        pthread_mutex_init(&mmap_mutex, NULL);
    else
        pthread_mutex_unlock(&mmap_mutex);
}

/* NOTE: all the constants are the HOST ones, but addresses are target. */
int target_mprotect(abi_ulong start, abi_ulong len, int prot)
{
    abi_ulong end, host_start, host_end, addr;
    int prot1, ret;

#ifdef DEBUG_MMAP
    printf("mprotect: start=0x" TARGET_FMT_lx
           " len=0x" TARGET_FMT_lx " prot=%c%c%c\n", start, len,
           prot & PROT_READ ? 'r' : '-',
           prot & PROT_WRITE ? 'w' : '-',
           prot & PROT_EXEC ? 'x' : '-');
#endif

    if ((start & ~TARGET_PAGE_MASK) != 0)
        return -EINVAL;
    len = TARGET_PAGE_ALIGN(len);
    end = start + len;
    if (end < start)
        return -EINVAL;
    prot &= PROT_READ | PROT_WRITE | PROT_EXEC;
    if (len == 0)
        return 0;

    mmap_lock();
    host_start = start & qemu_host_page_mask;
    host_end = HOST_PAGE_ALIGN(end);
    if (start > host_start) {
        /* handle host page containing start */
        prot1 = prot;
        for (addr = host_start; addr < start; addr += TARGET_PAGE_SIZE) {
            prot1 |= page_get_flags(addr);
        }
        if (host_end == host_start + qemu_host_page_size) {
            for (addr = end; addr < host_end; addr += TARGET_PAGE_SIZE) {
                prot1 |= page_get_flags(addr);
            }
            end = host_end;
        }
        ret = mprotect(g2h_untagged(host_start),
                       qemu_host_page_size, prot1 & PAGE_BITS);
        if (ret != 0)
            goto error;
        host_start += qemu_host_page_size;
    }
    if (end < host_end) {
        prot1 = prot;
        for (addr = end; addr < host_end; addr += TARGET_PAGE_SIZE) {
            prot1 |= page_get_flags(addr);
        }
        ret = mprotect(g2h_untagged(host_end - qemu_host_page_size),
                       qemu_host_page_size, prot1 & PAGE_BITS);
        if (ret != 0)
            goto error;
        host_end -= qemu_host_page_size;
    }

    /* handle the pages in the middle */
    if (host_start < host_end) {
        ret = mprotect(g2h_untagged(host_start), host_end - host_start, prot);
        if (ret != 0)
            goto error;
    }
    page_set_flags(start, start + len, prot | PAGE_VALID);
    mmap_unlock();
    return 0;
error:
    mmap_unlock();
    return ret;
}

/* map an incomplete host page */
static int mmap_frag(abi_ulong real_start,
                     abi_ulong start, abi_ulong end,
                     int prot, int flags, int fd, abi_ulong offset)
{
    abi_ulong real_end, addr;
    void *host_start;
    int prot1, prot_new;

    real_end = real_start + qemu_host_page_size;
    host_start = g2h_untagged(real_start);

    /* get the protection of the target pages outside the mapping */
    prot1 = 0;
    for (addr = real_start; addr < real_end; addr++) {
        if (addr < start || addr >= end)
            prot1 |= page_get_flags(addr);
    }

    if (prot1 == 0) {
        /* no page was there, so we allocate one */
        void *p = mmap(host_start, qemu_host_page_size, prot,
                       flags | MAP_ANON, -1, 0);
        if (p == MAP_FAILED)
            return -1;
        prot1 = prot;
    }
    prot1 &= PAGE_BITS;

    prot_new = prot | prot1;
    if (!(flags & MAP_ANON)) {
        /* msync() won't work here, so we return an error if write is
           possible while it is a shared mapping */
        if ((flags & TARGET_BSD_MAP_FLAGMASK) == MAP_SHARED &&
            (prot & PROT_WRITE))
            return -1;

        /* adjust protection to be able to read */
        if (!(prot1 & PROT_WRITE))
            mprotect(host_start, qemu_host_page_size, prot1 | PROT_WRITE);

        /* read the corresponding file data */
        pread(fd, g2h_untagged(start), end - start, offset);

        /* put final protection */
        if (prot_new != (prot1 | PROT_WRITE))
            mprotect(host_start, qemu_host_page_size, prot_new);
    } else {
        /* just update the protection */
        if (prot_new != prot1) {
            mprotect(host_start, qemu_host_page_size, prot_new);
        }
    }
    return 0;
}

static abi_ulong mmap_next_start = 0x40000000;

unsigned long last_brk;

/* find a free memory area of size 'size'. The search starts at
   'start'. If 'start' == 0, then a default start address is used.
   Return -1 if error.
*/
/* page_init() marks pages used by the host as reserved to be sure not
   to use them. */
static abi_ulong mmap_find_vma(abi_ulong start, abi_ulong size)
{
    abi_ulong addr, addr1, addr_start;
    int prot;
    unsigned long new_brk;

    new_brk = (unsigned long)sbrk(0);
    if (last_brk && last_brk < new_brk && last_brk == (target_ulong)last_brk) {
        /* This is a hack to catch the host allocating memory with brk().
           If it uses mmap then we loose.
           FIXME: We really want to avoid the host allocating memory in
           the first place, and maybe leave some slack to avoid switching
           to mmap.  */
        page_set_flags(last_brk & TARGET_PAGE_MASK,
                       TARGET_PAGE_ALIGN(new_brk),
                       PAGE_RESERVED);
    }
    last_brk = new_brk;

    size = HOST_PAGE_ALIGN(size);
    start = start & qemu_host_page_mask;
    addr = start;
    if (addr == 0)
        addr = mmap_next_start;
    addr_start = addr;
    for (;;) {
        prot = 0;
        for (addr1 = addr; addr1 < (addr + size); addr1 += TARGET_PAGE_SIZE) {
            prot |= page_get_flags(addr1);
        }
        if (prot == 0)
            break;
        addr += qemu_host_page_size;
        /* we found nothing */
        if (addr == addr_start)
            return (abi_ulong)-1;
    }
    if (start == 0)
        mmap_next_start = addr + size;
    return addr;
}

/* NOTE: all the constants are the HOST ones */
abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
                     int flags, int fd, abi_ulong offset)
{
    abi_ulong ret, end, real_start, real_end, retaddr, host_offset, host_len;
    unsigned long host_start;

    mmap_lock();
#ifdef DEBUG_MMAP
    {
        printf("mmap: start=0x" TARGET_FMT_lx
               " len=0x" TARGET_FMT_lx " prot=%c%c%c flags=",
               start, len,
               prot & PROT_READ ? 'r' : '-',
               prot & PROT_WRITE ? 'w' : '-',
               prot & PROT_EXEC ? 'x' : '-');
        if (flags & MAP_FIXED)
            printf("MAP_FIXED ");
        if (flags & MAP_ANON)
            printf("MAP_ANON ");
        switch (flags & TARGET_BSD_MAP_FLAGMASK) {
        case MAP_PRIVATE:
            printf("MAP_PRIVATE ");
            break;
        case MAP_SHARED:
            printf("MAP_SHARED ");
            break;
        default:
            printf("[MAP_FLAGMASK=0x%x] ", flags & TARGET_BSD_MAP_FLAGMASK);
            break;
        }
        printf("fd=%d offset=" TARGET_FMT_lx "\n", fd, offset);
    }
#endif

    if (offset & ~TARGET_PAGE_MASK) {
        errno = EINVAL;
        goto fail;
    }

    len = TARGET_PAGE_ALIGN(len);
    if (len == 0)
        goto the_end;
    real_start = start & qemu_host_page_mask;

    if (!(flags & MAP_FIXED)) {
        abi_ulong mmap_start;
        void *p;
        host_offset = offset & qemu_host_page_mask;
        host_len = len + offset - host_offset;
        host_len = HOST_PAGE_ALIGN(host_len);
        mmap_start = mmap_find_vma(real_start, host_len);
        if (mmap_start == (abi_ulong)-1) {
            errno = ENOMEM;
            goto fail;
        }
        /* Note: we prefer to control the mapping address. It is
           especially important if qemu_host_page_size >
           qemu_real_host_page_size */
        p = mmap(g2h_untagged(mmap_start),
                 host_len, prot, flags | MAP_FIXED, fd, host_offset);
        if (p == MAP_FAILED)
            goto fail;
        /* update start so that it points to the file position at 'offset' */
        host_start = (unsigned long)p;
        if (!(flags & MAP_ANON))
            host_start += offset - host_offset;
        start = h2g(host_start);
    } else {
        int flg;
        target_ulong addr;

        if (start & ~TARGET_PAGE_MASK) {
            errno = EINVAL;
            goto fail;
        }
        end = start + len;
        real_end = HOST_PAGE_ALIGN(end);

        for (addr = real_start; addr < real_end; addr += TARGET_PAGE_SIZE) {
            flg = page_get_flags(addr);
            if (flg & PAGE_RESERVED) {
                errno = ENXIO;
                goto fail;
            }
        }

        /* worst case: we cannot map the file because the offset is not
           aligned, so we read it */
        if (!(flags & MAP_ANON) &&
            (offset & ~qemu_host_page_mask) != (start & ~qemu_host_page_mask)) {
            /* msync() won't work here, so we return an error if write is
               possible while it is a shared mapping */
            if ((flags & TARGET_BSD_MAP_FLAGMASK) == MAP_SHARED &&
                (prot & PROT_WRITE)) {
                errno = EINVAL;
                goto fail;
            }
            retaddr = target_mmap(start, len, prot | PROT_WRITE,
                                  MAP_FIXED | MAP_PRIVATE | MAP_ANON,
                                  -1, 0);
            if (retaddr == -1)
                goto fail;
            pread(fd, g2h_untagged(start), len, offset);
            if (!(prot & PROT_WRITE)) {
                ret = target_mprotect(start, len, prot);
                if (ret != 0) {
                    start = ret;
                    goto the_end;
                }
            }
            goto the_end;
        }

        /* handle the start of the mapping */
        if (start > real_start) {
            if (real_end == real_start + qemu_host_page_size) {
                /* one single host page */
                ret = mmap_frag(real_start, start, end,
                                prot, flags, fd, offset);
                if (ret == -1)
                    goto fail;
                goto the_end1;
            }
            ret = mmap_frag(real_start, start, real_start + qemu_host_page_size,
                            prot, flags, fd, offset);
            if (ret == -1)
                goto fail;
            real_start += qemu_host_page_size;
        }
        /* handle the end of the mapping */
        if (end < real_end) {
            ret = mmap_frag(real_end - qemu_host_page_size,
                            real_end - qemu_host_page_size, real_end,
                            prot, flags, fd,
                            offset + real_end - qemu_host_page_size - start);
            if (ret == -1)
                goto fail;
            real_end -= qemu_host_page_size;
        }

        /* map the middle (easier) */
        if (real_start < real_end) {
            void *p;
            unsigned long offset1;
            if (flags & MAP_ANON)
                offset1 = 0;
            else
                offset1 = offset + real_start - start;
            p = mmap(g2h_untagged(real_start), real_end - real_start,
                     prot, flags, fd, offset1);
            if (p == MAP_FAILED)
                goto fail;
        }
    }
 the_end1:
    page_set_flags(start, start + len, prot | PAGE_VALID);
 the_end:
#ifdef DEBUG_MMAP
    printf("ret=0x" TARGET_FMT_lx "\n", start);
    page_dump(stdout);
    printf("\n");
#endif
    mmap_unlock();
    return start;
fail:
    mmap_unlock();
    return -1;
}

int target_munmap(abi_ulong start, abi_ulong len)
{
    abi_ulong end, real_start, real_end, addr;
    int prot, ret;

#ifdef DEBUG_MMAP
    printf("munmap: start=0x%lx len=0x%lx\n", start, len);
#endif
    if (start & ~TARGET_PAGE_MASK)
        return -EINVAL;
    len = TARGET_PAGE_ALIGN(len);
    if (len == 0)
        return -EINVAL;
    mmap_lock();
    end = start + len;
    real_start = start & qemu_host_page_mask;
    real_end = HOST_PAGE_ALIGN(end);

    if (start > real_start) {
        /* handle host page containing start */
        prot = 0;
        for (addr = real_start; addr < start; addr += TARGET_PAGE_SIZE) {
            prot |= page_get_flags(addr);
        }
        if (real_end == real_start + qemu_host_page_size) {
            for (addr = end; addr < real_end; addr += TARGET_PAGE_SIZE) {
                prot |= page_get_flags(addr);
            }
            end = real_end;
        }
        if (prot != 0)
            real_start += qemu_host_page_size;
    }
    if (end < real_end) {
        prot = 0;
        for (addr = end; addr < real_end; addr += TARGET_PAGE_SIZE) {
            prot |= page_get_flags(addr);
        }
        if (prot != 0)
            real_end -= qemu_host_page_size;
    }

    ret = 0;
    /* unmap what we can */
    if (real_start < real_end) {
        ret = munmap(g2h_untagged(real_start), real_end - real_start);
    }

    if (ret == 0)
        page_set_flags(start, start + len, 0);
    mmap_unlock();
    return ret;
}

int target_msync(abi_ulong start, abi_ulong len, int flags)
{
    abi_ulong end;

    if (start & ~TARGET_PAGE_MASK)
        return -EINVAL;
    len = TARGET_PAGE_ALIGN(len);
    end = start + len;
    if (end < start)
        return -EINVAL;
    if (end == start)
        return 0;

    start &= qemu_host_page_mask;
    return msync(g2h_untagged(start), end - start, flags);
}
Commit	Line	Data
84778508 BS	1	/*
	2	* mmap support for qemu
	3	*
	4	* Copyright (c) 2003 - 2008 Fabrice Bellard
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
8167ee88	17	* along with this program; if not, see <http://www.gnu.org/licenses/>.
84778508	18	*/
2231197c	19	#include "qemu/osdep.h"
84778508 BS	20
	21	#include "qemu.h"
	22	#include "qemu-common.h"
	23
	24	//#define DEBUG_MMAP
	25
95992b67	26	static pthread_mutex_t mmap_mutex = PTHREAD_MUTEX_INITIALIZER;
06943a62	27	static __thread int mmap_lock_count;
84778508 BS	28
	29	void mmap_lock(void)
	30	{
	31	if (mmap_lock_count++ == 0) {
	32	pthread_mutex_lock(&mmap_mutex);
	33	}
	34	}
	35
	36	void mmap_unlock(void)
	37	{
	38	if (--mmap_lock_count == 0) {
	39	pthread_mutex_unlock(&mmap_mutex);
	40	}
	41	}
	42
301e40ed AB	43	bool have_mmap_lock(void)
	44	{
	45	return mmap_lock_count > 0 ? true : false;
	46	}
	47
84778508 BS	48	/* Grab lock to make sure things are in a consistent state after fork(). */
	49	void mmap_fork_start(void)
	50	{
	51	if (mmap_lock_count)
	52	abort();
	53	pthread_mutex_lock(&mmap_mutex);
	54	}
	55
	56	void mmap_fork_end(int child)
	57	{
	58	if (child)
	59	pthread_mutex_init(&mmap_mutex, NULL);
	60	else
	61	pthread_mutex_unlock(&mmap_mutex);
	62	}
84778508	63
84778508 BS	64	/* NOTE: all the constants are the HOST ones, but addresses are target. */
	65	int target_mprotect(abi_ulong start, abi_ulong len, int prot)
	66	{
	67	abi_ulong end, host_start, host_end, addr;
	68	int prot1, ret;
	69
	70	#ifdef DEBUG_MMAP
	71	printf("mprotect: start=0x" TARGET_FMT_lx
	72	" len=0x" TARGET_FMT_lx " prot=%c%c%c\n", start, len,
	73	prot & PROT_READ ? 'r' : '-',
	74	prot & PROT_WRITE ? 'w' : '-',
	75	prot & PROT_EXEC ? 'x' : '-');
	76	#endif
	77
	78	if ((start & ~TARGET_PAGE_MASK) != 0)
	79	return -EINVAL;
	80	len = TARGET_PAGE_ALIGN(len);
	81	end = start + len;
	82	if (end < start)
	83	return -EINVAL;
	84	prot &= PROT_READ \| PROT_WRITE \| PROT_EXEC;
	85	if (len == 0)
	86	return 0;
	87
	88	mmap_lock();
	89	host_start = start & qemu_host_page_mask;
	90	host_end = HOST_PAGE_ALIGN(end);
	91	if (start > host_start) {
	92	/* handle host page containing start */
	93	prot1 = prot;
5be1d0b5	94	for (addr = host_start; addr < start; addr += TARGET_PAGE_SIZE) {
84778508 BS	95	prot1 \|= page_get_flags(addr);
	96	}
	97	if (host_end == host_start + qemu_host_page_size) {
5be1d0b5	98	for (addr = end; addr < host_end; addr += TARGET_PAGE_SIZE) {
84778508 BS	99	prot1 \|= page_get_flags(addr);
	100	}
	101	end = host_end;
	102	}
3e8f1628 RH	103	ret = mprotect(g2h_untagged(host_start),
3e8f1628 RH	104	qemu_host_page_size, prot1 & PAGE_BITS);
84778508 BS	105	if (ret != 0)
	106	goto error;
	107	host_start += qemu_host_page_size;
	108	}
	109	if (end < host_end) {
	110	prot1 = prot;
5be1d0b5	111	for (addr = end; addr < host_end; addr += TARGET_PAGE_SIZE) {
84778508 BS	112	prot1 \|= page_get_flags(addr);
84778508 BS	113	}
3e8f1628 RH	114	ret = mprotect(g2h_untagged(host_end - qemu_host_page_size),
3e8f1628 RH	115	qemu_host_page_size, prot1 & PAGE_BITS);
84778508 BS	116	if (ret != 0)
	117	goto error;
	118	host_end -= qemu_host_page_size;
	119	}
	120
	121	/* handle the pages in the middle */
	122	if (host_start < host_end) {
3e8f1628	123	ret = mprotect(g2h_untagged(host_start), host_end - host_start, prot);
84778508 BS	124	if (ret != 0)
	125	goto error;
	126	}
	127	page_set_flags(start, start + len, prot \| PAGE_VALID);
	128	mmap_unlock();
	129	return 0;
	130	error:
	131	mmap_unlock();
	132	return ret;
	133	}
	134
	135	/* map an incomplete host page */
	136	static int mmap_frag(abi_ulong real_start,
	137	abi_ulong start, abi_ulong end,
	138	int prot, int flags, int fd, abi_ulong offset)
	139	{
	140	abi_ulong real_end, addr;
	141	void *host_start;
	142	int prot1, prot_new;
	143
	144	real_end = real_start + qemu_host_page_size;
3e8f1628	145	host_start = g2h_untagged(real_start);
84778508 BS	146
	147	/* get the protection of the target pages outside the mapping */
	148	prot1 = 0;
5be1d0b5	149	for (addr = real_start; addr < real_end; addr++) {
84778508 BS	150	if (addr < start \|\| addr >= end)
	151	prot1 \|= page_get_flags(addr);
	152	}
	153
	154	if (prot1 == 0) {
	155	/* no page was there, so we allocate one */
	156	void *p = mmap(host_start, qemu_host_page_size, prot,
	157	flags \| MAP_ANON, -1, 0);
	158	if (p == MAP_FAILED)
	159	return -1;
	160	prot1 = prot;
	161	}
	162	prot1 &= PAGE_BITS;
	163
	164	prot_new = prot \| prot1;
	165	if (!(flags & MAP_ANON)) {
	166	/* msync() won't work here, so we return an error if write is
	167	possible while it is a shared mapping */
6c173b3c	168	if ((flags & TARGET_BSD_MAP_FLAGMASK) == MAP_SHARED &&
84778508	169	(prot & PROT_WRITE))
059bca46	170	return -1;
84778508 BS	171
	172	/* adjust protection to be able to read */
	173	if (!(prot1 & PROT_WRITE))
	174	mprotect(host_start, qemu_host_page_size, prot1 \| PROT_WRITE);
	175
	176	/* read the corresponding file data */
3e8f1628	177	pread(fd, g2h_untagged(start), end - start, offset);
84778508 BS	178
	179	/* put final protection */
	180	if (prot_new != (prot1 \| PROT_WRITE))
	181	mprotect(host_start, qemu_host_page_size, prot_new);
	182	} else {
	183	/* just update the protection */
	184	if (prot_new != prot1) {
	185	mprotect(host_start, qemu_host_page_size, prot_new);
	186	}
	187	}
	188	return 0;
	189	}
	190
84778508	191	static abi_ulong mmap_next_start = 0x40000000;
84778508 BS	192
	193	unsigned long last_brk;
	194
	195	/* find a free memory area of size 'size'. The search starts at
	196	'start'. If 'start' == 0, then a default start address is used.
	197	Return -1 if error.
	198	*/
	199	/* page_init() marks pages used by the host as reserved to be sure not
	200	to use them. */
	201	static abi_ulong mmap_find_vma(abi_ulong start, abi_ulong size)
	202	{
	203	abi_ulong addr, addr1, addr_start;
	204	int prot;
	205	unsigned long new_brk;
	206
	207	new_brk = (unsigned long)sbrk(0);
	208	if (last_brk && last_brk < new_brk && last_brk == (target_ulong)last_brk) {
	209	/* This is a hack to catch the host allocating memory with brk().
	210	If it uses mmap then we loose.
	211	FIXME: We really want to avoid the host allocating memory in
	212	the first place, and maybe leave some slack to avoid switching
	213	to mmap. */
	214	page_set_flags(last_brk & TARGET_PAGE_MASK,
	215	TARGET_PAGE_ALIGN(new_brk),
	216	PAGE_RESERVED);
	217	}
	218	last_brk = new_brk;
	219
	220	size = HOST_PAGE_ALIGN(size);
	221	start = start & qemu_host_page_mask;
	222	addr = start;
	223	if (addr == 0)
	224	addr = mmap_next_start;
	225	addr_start = addr;
5be1d0b5	226	for (;;) {
84778508	227	prot = 0;
5be1d0b5	228	for (addr1 = addr; addr1 < (addr + size); addr1 += TARGET_PAGE_SIZE) {
84778508 BS	229	prot \|= page_get_flags(addr1);
	230	}
	231	if (prot == 0)
	232	break;
	233	addr += qemu_host_page_size;
	234	/* we found nothing */
	235	if (addr == addr_start)
	236	return (abi_ulong)-1;
	237	}
	238	if (start == 0)
	239	mmap_next_start = addr + size;
	240	return addr;
	241	}
	242
	243	/* NOTE: all the constants are the HOST ones */
	244	abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
	245	int flags, int fd, abi_ulong offset)
	246	{
	247	abi_ulong ret, end, real_start, real_end, retaddr, host_offset, host_len;
	248	unsigned long host_start;
	249
	250	mmap_lock();
	251	#ifdef DEBUG_MMAP
	252	{
	253	printf("mmap: start=0x" TARGET_FMT_lx
	254	" len=0x" TARGET_FMT_lx " prot=%c%c%c flags=",
	255	start, len,
	256	prot & PROT_READ ? 'r' : '-',
	257	prot & PROT_WRITE ? 'w' : '-',
	258	prot & PROT_EXEC ? 'x' : '-');
	259	if (flags & MAP_FIXED)
	260	printf("MAP_FIXED ");
	261	if (flags & MAP_ANON)
	262	printf("MAP_ANON ");
5be1d0b5	263	switch (flags & TARGET_BSD_MAP_FLAGMASK) {
84778508 BS	264	case MAP_PRIVATE:
	265	printf("MAP_PRIVATE ");
	266	break;
	267	case MAP_SHARED:
	268	printf("MAP_SHARED ");
	269	break;
	270	default:
6c173b3c	271	printf("[MAP_FLAGMASK=0x%x] ", flags & TARGET_BSD_MAP_FLAGMASK);
84778508 BS	272	break;
	273	}
	274	printf("fd=%d offset=" TARGET_FMT_lx "\n", fd, offset);
	275	}
	276	#endif
	277
	278	if (offset & ~TARGET_PAGE_MASK) {
	279	errno = EINVAL;
	280	goto fail;
	281	}
	282
	283	len = TARGET_PAGE_ALIGN(len);
	284	if (len == 0)
	285	goto the_end;
	286	real_start = start & qemu_host_page_mask;
	287
	288	if (!(flags & MAP_FIXED)) {
	289	abi_ulong mmap_start;
	290	void *p;
	291	host_offset = offset & qemu_host_page_mask;
	292	host_len = len + offset - host_offset;
	293	host_len = HOST_PAGE_ALIGN(host_len);
	294	mmap_start = mmap_find_vma(real_start, host_len);
	295	if (mmap_start == (abi_ulong)-1) {
	296	errno = ENOMEM;
	297	goto fail;
	298	}
	299	/* Note: we prefer to control the mapping address. It is
	300	especially important if qemu_host_page_size >
	301	qemu_real_host_page_size */
3e8f1628	302	p = mmap(g2h_untagged(mmap_start),
84778508 BS	303	host_len, prot, flags \| MAP_FIXED, fd, host_offset);
	304	if (p == MAP_FAILED)
	305	goto fail;
	306	/* update start so that it points to the file position at 'offset' */
	307	host_start = (unsigned long)p;
	308	if (!(flags & MAP_ANON))
	309	host_start += offset - host_offset;
	310	start = h2g(host_start);
	311	} else {
	312	int flg;
	313	target_ulong addr;
	314
	315	if (start & ~TARGET_PAGE_MASK) {
	316	errno = EINVAL;
	317	goto fail;
	318	}
	319	end = start + len;
	320	real_end = HOST_PAGE_ALIGN(end);
	321
5be1d0b5	322	for (addr = real_start; addr < real_end; addr += TARGET_PAGE_SIZE) {
84778508 BS	323	flg = page_get_flags(addr);
	324	if (flg & PAGE_RESERVED) {
	325	errno = ENXIO;
	326	goto fail;
	327	}
	328	}
	329
	330	/* worst case: we cannot map the file because the offset is not
	331	aligned, so we read it */
	332	if (!(flags & MAP_ANON) &&
	333	(offset & ~qemu_host_page_mask) != (start & ~qemu_host_page_mask)) {
	334	/* msync() won't work here, so we return an error if write is
	335	possible while it is a shared mapping */
6c173b3c	336	if ((flags & TARGET_BSD_MAP_FLAGMASK) == MAP_SHARED &&
84778508 BS	337	(prot & PROT_WRITE)) {
	338	errno = EINVAL;
	339	goto fail;
	340	}
	341	retaddr = target_mmap(start, len, prot \| PROT_WRITE,
	342	MAP_FIXED \| MAP_PRIVATE \| MAP_ANON,
	343	-1, 0);
	344	if (retaddr == -1)
	345	goto fail;
3e8f1628	346	pread(fd, g2h_untagged(start), len, offset);
84778508 BS	347	if (!(prot & PROT_WRITE)) {
	348	ret = target_mprotect(start, len, prot);
	349	if (ret != 0) {
	350	start = ret;
	351	goto the_end;
	352	}
	353	}
	354	goto the_end;
	355	}
	356
	357	/* handle the start of the mapping */
	358	if (start > real_start) {
	359	if (real_end == real_start + qemu_host_page_size) {
	360	/* one single host page */
	361	ret = mmap_frag(real_start, start, end,
	362	prot, flags, fd, offset);
	363	if (ret == -1)
	364	goto fail;
	365	goto the_end1;
	366	}
	367	ret = mmap_frag(real_start, start, real_start + qemu_host_page_size,
	368	prot, flags, fd, offset);
	369	if (ret == -1)
	370	goto fail;
	371	real_start += qemu_host_page_size;
	372	}
	373	/* handle the end of the mapping */
	374	if (end < real_end) {
	375	ret = mmap_frag(real_end - qemu_host_page_size,
	376	real_end - qemu_host_page_size, real_end,
	377	prot, flags, fd,
	378	offset + real_end - qemu_host_page_size - start);
	379	if (ret == -1)
	380	goto fail;
	381	real_end -= qemu_host_page_size;
	382	}
	383
	384	/* map the middle (easier) */
	385	if (real_start < real_end) {
	386	void *p;
	387	unsigned long offset1;
	388	if (flags & MAP_ANON)
	389	offset1 = 0;
	390	else
	391	offset1 = offset + real_start - start;
3e8f1628	392	p = mmap(g2h_untagged(real_start), real_end - real_start,
84778508 BS	393	prot, flags, fd, offset1);
	394	if (p == MAP_FAILED)
	395	goto fail;
	396	}
	397	}
	398	the_end1:
	399	page_set_flags(start, start + len, prot \| PAGE_VALID);
	400	the_end:
	401	#ifdef DEBUG_MMAP
	402	printf("ret=0x" TARGET_FMT_lx "\n", start);
	403	page_dump(stdout);
	404	printf("\n");
	405	#endif
	406	mmap_unlock();
	407	return start;
	408	fail:
	409	mmap_unlock();
	410	return -1;
	411	}
	412
	413	int target_munmap(abi_ulong start, abi_ulong len)
	414	{
	415	abi_ulong end, real_start, real_end, addr;
	416	int prot, ret;
	417
	418	#ifdef DEBUG_MMAP
	419	printf("munmap: start=0x%lx len=0x%lx\n", start, len);
	420	#endif
	421	if (start & ~TARGET_PAGE_MASK)
	422	return -EINVAL;
	423	len = TARGET_PAGE_ALIGN(len);
	424	if (len == 0)
	425	return -EINVAL;
	426	mmap_lock();
	427	end = start + len;
	428	real_start = start & qemu_host_page_mask;
	429	real_end = HOST_PAGE_ALIGN(end);
	430
	431	if (start > real_start) {
	432	/* handle host page containing start */
	433	prot = 0;
5be1d0b5	434	for (addr = real_start; addr < start; addr += TARGET_PAGE_SIZE) {
84778508 BS	435	prot \|= page_get_flags(addr);
	436	}
	437	if (real_end == real_start + qemu_host_page_size) {
5be1d0b5	438	for (addr = end; addr < real_end; addr += TARGET_PAGE_SIZE) {
84778508 BS	439	prot \|= page_get_flags(addr);
	440	}
	441	end = real_end;
	442	}
	443	if (prot != 0)
	444	real_start += qemu_host_page_size;
	445	}
	446	if (end < real_end) {
	447	prot = 0;
5be1d0b5	448	for (addr = end; addr < real_end; addr += TARGET_PAGE_SIZE) {
84778508 BS	449	prot \|= page_get_flags(addr);
	450	}
	451	if (prot != 0)
	452	real_end -= qemu_host_page_size;
	453	}
	454
	455	ret = 0;
	456	/* unmap what we can */
	457	if (real_start < real_end) {
3e8f1628	458	ret = munmap(g2h_untagged(real_start), real_end - real_start);
84778508 BS	459	}
	460
	461	if (ret == 0)
	462	page_set_flags(start, start + len, 0);
	463	mmap_unlock();
	464	return ret;
	465	}
	466
	467	int target_msync(abi_ulong start, abi_ulong len, int flags)
	468	{
	469	abi_ulong end;
	470
	471	if (start & ~TARGET_PAGE_MASK)
	472	return -EINVAL;
	473	len = TARGET_PAGE_ALIGN(len);
	474	end = start + len;
	475	if (end < start)
	476	return -EINVAL;
	477	if (end == start)
	478	return 0;
	479
	480	start &= qemu_host_page_mask;
3e8f1628	481	return msync(g2h_untagged(start), end - start, flags);
84778508	482	}