/* *  mmap support for qemu * *  Copyright (c) 2003 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, write to the Free Software *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */#include <stdlib.h>#include <stdio.h>#include <stdarg.h>#include <string.h>#include <unistd.h>#include <errno.h>#include <sys/mman.h>#include "qemu.h"//#define DEBUG_MMAP/* NOTE: all the constants are the HOST ones */int target_mprotect(unsigned long start, unsigned long len, int prot){    unsigned long end, host_start, host_end, addr;    int prot1, ret;#ifdef DEBUG_MMAP    printf("mprotect: start=0x%lx len=0x%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;    if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC))        return -EINVAL;    if (len == 0)        return 0;    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((void *)host_start, qemu_host_page_size, prot1 & PAGE_BITS);        if (ret != 0)            return ret;        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((void *)(host_end - qemu_host_page_size), qemu_host_page_size,                       prot1 & PAGE_BITS);        if (ret != 0)            return ret;        host_end -= qemu_host_page_size;    }    /* handle the pages in the middle */    if (host_start < host_end) {        ret = mprotect((void *)host_start, host_end - host_start, prot);        if (ret != 0)            return ret;    }    page_set_flags(start, start + len, prot | PAGE_VALID);    return 0;}/* map an incomplete host page */int mmap_frag(unsigned long host_start,               unsigned long start, unsigned long end,               int prot, int flags, int fd, unsigned long offset){    unsigned long host_end, ret, addr;    int prot1, prot_new;    host_end = host_start + qemu_host_page_size;    /* get the protection of the target pages outside the mapping */    prot1 = 0;    for(addr = host_start; addr < host_end; addr++) {        if (addr < start || addr >= end)            prot1 |= page_get_flags(addr);    }    if (prot1 == 0) {        /* no page was there, so we allocate one */        ret = (long)mmap((void *)host_start, qemu_host_page_size, prot,                         flags | MAP_ANONYMOUS, -1, 0);        if (ret == -1)            return ret;    }    prot1 &= PAGE_BITS;    prot_new = prot | prot1;    if (!(flags & MAP_ANONYMOUS)) {        /* msync() won't work here, so we return an error if write is           possible while it is a shared mapping */#ifndef __APPLE__        if ((flags & MAP_TYPE) == MAP_SHARED &&#else        if ((flags &  MAP_SHARED) &&#endif            (prot & PROT_WRITE))            return -EINVAL;        /* adjust protection to be able to read */        if (!(prot1 & PROT_WRITE))            mprotect((void *)host_start, qemu_host_page_size, prot1 | PROT_WRITE);        /* read the corresponding file data */        pread(fd, (void *)start, end - start, offset);        /* put final protection */        if (prot_new != (prot1 | PROT_WRITE))            mprotect((void *)host_start, qemu_host_page_size, prot_new);    } else {        /* just update the protection */        if (prot_new != prot1) {            mprotect((void *)host_start, qemu_host_page_size, prot_new);        }    }    return 0;}/* NOTE: all the constants are the HOST ones */long target_mmap(unsigned long start, unsigned long len, int prot,                 int flags, int fd, unsigned long offset){    unsigned long ret, end, host_start, host_end, retaddr, host_offset, host_len;#if defined(__alpha__) || defined(__sparc__) || defined(__x86_64__)    static unsigned long last_start = 0x40000000;#endif#ifdef DEBUG_MMAP    {        printf("mmap: start=0x%lx len=0x%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_ANONYMOUS)            printf("MAP_ANON ");#ifndef MAP_TYPE# define MAP_TYPE 0x3#endif        switch(flags & MAP_TYPE) {        case MAP_PRIVATE:            printf("MAP_PRIVATE ");            break;        case MAP_SHARED:            printf("MAP_SHARED ");            break;        default:            printf("[MAP_TYPE=0x%x] ", flags & MAP_TYPE);            break;        }        printf("fd=%d offset=%lx\n", fd, offset);    }#endif    if (offset & ~TARGET_PAGE_MASK)        return -EINVAL;    len = TARGET_PAGE_ALIGN(len);    if (len == 0)        return start;    host_start = start & qemu_host_page_mask;    if (!(flags & MAP_FIXED)) {#if defined(__alpha__) || defined(__sparc__) || defined(__x86_64__)        /* tell the kernel to search at the same place as i386 */        if (host_start == 0) {            host_start = last_start;            last_start += HOST_PAGE_ALIGN(len);        }#endif        if (qemu_host_page_size != qemu_real_host_page_size) {            /* NOTE: this code is only for debugging with '-p' option */            /* reserve a memory area */            host_len = HOST_PAGE_ALIGN(len) + qemu_host_page_size - TARGET_PAGE_SIZE;            host_start = (long)mmap((void *)host_start, host_len, PROT_NONE,                                    MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);            if (host_start == -1)                return host_start;            host_end = host_start + host_len;            start = HOST_PAGE_ALIGN(host_start);            end = start + HOST_PAGE_ALIGN(len);            if (start > host_start)                munmap((void *)host_start, start - host_start);            if (end < host_end)                munmap((void *)end, host_end - end);            /* use it as a fixed mapping */            flags |= MAP_FIXED;        } else {            /* if not fixed, no need to do anything */            host_offset = offset & qemu_host_page_mask;            host_len = len + offset - host_offset;            start = (long)mmap((void *)host_start, host_len,                               prot, flags, fd, host_offset);            if (start == -1)                return start;            /* update start so that it points to the file position at 'offset' */            if (!(flags & MAP_ANONYMOUS))                start += offset - host_offset;            goto the_end1;        }    }    if (start & ~TARGET_PAGE_MASK)        return -EINVAL;    end = start + len;    host_end = HOST_PAGE_ALIGN(end);    /* worst case: we cannot map the file because the offset is not       aligned, so we read it */    if (!(flags & MAP_ANONYMOUS) &&        (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 */#ifndef __APPLE__        if ((flags & MAP_TYPE) == MAP_SHARED &&#else        if ((flags & MAP_SHARED) &&#endif            (prot & PROT_WRITE))            return -EINVAL;        retaddr = target_mmap(start, len, prot | PROT_WRITE,                              MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS,                              -1, 0);        if (retaddr == -1)            return retaddr;        pread(fd, (void *)start, len, offset);        if (!(prot & PROT_WRITE)) {            ret = target_mprotect(start, len, prot);            if (ret != 0)                return ret;        }        goto the_end;    }    /* handle the start of the mapping */    if (start > host_start) {        if (host_end == host_start + qemu_host_page_size) {            /* one single host page */            ret = mmap_frag(host_start, start, end,                            prot, flags, fd, offset);            if (ret == -1)                return ret;            goto the_end1;        }        ret = mmap_frag(host_start, start, host_start + qemu_host_page_size,                        prot, flags, fd, offset);        if (ret == -1)            return ret;        host_start += qemu_host_page_size;    }    /* handle the end of the mapping */    if (end < host_end) {        ret = mmap_frag(host_end - qemu_host_page_size,                        host_end - qemu_host_page_size, host_end,                        prot, flags, fd,                        offset + host_end - qemu_host_page_size - start);        if (ret == -1)            return ret;        host_end -= qemu_host_page_size;    }    /* map the middle (easier) */    if (host_start < host_end) {        unsigned long offset1;	if (flags & MAP_ANONYMOUS)	  offset1 = 0;	else	  offset1 = offset + host_start - start;        ret = (long)mmap((void *)host_start, host_end - host_start,                         prot, flags, fd, offset1);        if (ret == -1)            return ret;    } the_end1:    page_set_flags(start, start + len, prot | PAGE_VALID); the_end:#ifdef DEBUG_MMAP    printf("target_mmap: ret=0x%lx\n", (long)start);    page_dump(stdout);    printf("\n");#endif    return start;}int target_munmap(unsigned long start, unsigned long len){    unsigned long end, host_start, host_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;    end = start + len;    host_start = start & qemu_host_page_mask;    host_end = HOST_PAGE_ALIGN(end);    if (start > host_start) {        /* handle host page containing start */        prot = 0;        for(addr = host_start; addr < start; addr += TARGET_PAGE_SIZE) {            prot |= page_get_flags(addr);        }        if (host_end == host_start + qemu_host_page_size) {            for(addr = end; addr < host_end; addr += TARGET_PAGE_SIZE) {                prot |= page_get_flags(addr);            }            end = host_end;        }        if (prot != 0)            host_start += qemu_host_page_size;    }    if (end < host_end) {        prot = 0;        for(addr = end; addr < host_end; addr += TARGET_PAGE_SIZE) {            prot |= page_get_flags(addr);        }        if (prot != 0)            host_end -= qemu_host_page_size;    }    /* unmap what we can */    if (host_start < host_end) {        ret = munmap((void *)host_start, host_end - host_start);        if (ret != 0)            return ret;    }    page_set_flags(start, start + len, 0);    return 0;}/* XXX: currently, we only handle MAP_ANONYMOUS and not MAP_FIXED   blocks which have been allocated starting on a host page */long target_mremap(unsigned long old_addr, unsigned long old_size,                   unsigned long new_size, unsigned long flags,                   unsigned long new_addr){#ifndef __APPLE__    /* XXX: use 5 args syscall */    new_addr = (long)mremap((void *)old_addr, old_size, new_size, flags);    if (new_addr == -1)        return new_addr;    prot = page_get_flags(old_addr);    page_set_flags(old_addr, old_addr + old_size, 0);    page_set_flags(new_addr, new_addr + new_size, prot | PAGE_VALID);    return new_addr;#else    qerror("target_mremap: unsupported\n");#endif}int target_msync(unsigned long start, unsigned long len, int flags){    unsigned long 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((void *)start, end - start, flags);}