示例#1
0
abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size,
                       abi_ulong new_size, unsigned long flags,
                       abi_ulong new_addr)
{
    int prot;
    void *host_addr;

    mmap_lock();

    if (flags & MREMAP_FIXED)
        host_addr = (void *) syscall(__NR_mremap, g2h(old_addr),
                                     old_size, new_size,
                                     flags,
                                     new_addr);
    else if (flags & MREMAP_MAYMOVE) {
        abi_ulong mmap_start;

        mmap_start = mmap_find_vma(0, new_size);

        if (mmap_start == -1) {
            errno = ENOMEM;
            host_addr = MAP_FAILED;
        } else
            host_addr = (void *) syscall(__NR_mremap, g2h(old_addr),
                                         old_size, new_size,
                                         flags | MREMAP_FIXED,
                                         g2h(mmap_start));
    } else {
        host_addr = mremap(g2h(old_addr), old_size, new_size, flags);
        /* Check if address fits target address space */
        if ((unsigned long)host_addr + new_size > (abi_ulong)-1) {
            /* Revert mremap() changes */
            host_addr = mremap(g2h(old_addr), new_size, old_size, flags);
            errno = ENOMEM;
            host_addr = MAP_FAILED;
        }
    }

    if (host_addr == MAP_FAILED) {
        new_addr = -1;
    } else {
        new_addr = h2g(host_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);
    }
    mmap_unlock();
    return new_addr;
}
示例#2
0
/*
 * Find and reserve a free memory area of size 'size'. The search
 * starts at 'start'.
 * It must be called with mmap_lock() held.
 * Return -1 if error.
 */
abi_ulong mmap_find_vma(abi_ulong start, abi_ulong size)
{
    void *ptr;
    abi_ulong addr;

    size = HOST_PAGE_ALIGN(size);
    start &= qemu_host_page_mask;

    /* If 'start' == 0, then a default start address is used. */
    if (start == 0)
        start = mmap_next_start;

    addr = start;

    for(;;) {
        /*
         * Reserve needed memory area to avoid a race.
         * It should be discarded using:
         *  - mmap() with MAP_FIXED flag
         *  - mremap() with MREMAP_FIXED flag
         *  - shmat() with SHM_REMAP flag
         */
        ptr = mmap((void *)(unsigned long)addr, size, PROT_NONE,
                   MAP_ANONYMOUS|MAP_PRIVATE|MAP_NORESERVE, -1, 0);

        /* ENOMEM, if host address space has no memory */
        if (ptr == MAP_FAILED)
            return (abi_ulong)-1;

        /* If address fits target address space we've found what we need */
        if ((unsigned long)ptr + size - 1 <= (abi_ulong)-1)
            break;

        /* Unmap and try again with new page */
        munmap(ptr, size);
        addr += qemu_host_page_size;

        /* ENOMEM if we check whole of target address space */
        if (addr == start)
            return (abi_ulong)-1;
    }

    /* Update default start address */
    if (start == mmap_next_start)
        mmap_next_start = (unsigned long)ptr + size;

    return h2g(ptr);
}
示例#3
0
文件: mmap.c 项目: iggy/qemu
void *qemu_vmalloc(size_t size)
{
    void *p;

    mmap_lock();
    /* Use map and mark the pages as used.  */
    p = mmap(NULL, size, PROT_READ | PROT_WRITE,
             MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);

    if (h2g_valid(p)) {
        /* Allocated region overlaps guest address space. This may recurse.  */
        abi_ulong addr = h2g(p);
        page_set_flags(addr & TARGET_PAGE_MASK, TARGET_PAGE_ALIGN(addr + size),
                       PAGE_RESERVED);
    }

    mmap_unlock();
    return p;
}
示例#4
0
/* 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_ANONYMOUS)
            printf("MAP_ANON ");
        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=" 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(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_ANONYMOUS))
            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);

	/*
	 * Test if requested memory area fits target address space
	 * It can fail only on 64-bit host with 32-bit target.
	 * On any other target/host host mmap() handles this error correctly.
	 */
        if ((unsigned long)start + len - 1 > (abi_ulong) -1) {
            errno = EINVAL;
            goto fail;
        }

        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_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 */
            if ((flags & MAP_TYPE) == MAP_SHARED &&
                (prot & PROT_WRITE)) {
                errno = EINVAL;
                goto fail;
            }
            retaddr = target_mmap(start, len, prot | PROT_WRITE,
                                  MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS,
                                  -1, 0);
            if (retaddr == -1)
                goto fail;
            pread(fd, g2h(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_ANONYMOUS)
                offset1 = 0;
            else
                offset1 = offset + real_start - start;
            p = mmap(g2h(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;
}
示例#5
0
文件: mmap.c 项目: LingxiaoJIA/qemu
abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size,
                       abi_ulong new_size, unsigned long flags,
                       abi_ulong new_addr)
{
    int prot;
    void *host_addr;

    mmap_lock();

    if (flags & MREMAP_FIXED) {
        host_addr = (void *) syscall(__NR_mremap, g2h(old_addr),
                                     old_size, new_size,
                                     flags,
                                     g2h(new_addr));

        if (RESERVED_VA && host_addr != MAP_FAILED) {
            /* If new and old addresses overlap then the above mremap will
               already have failed with EINVAL.  */
            mmap_reserve(old_addr, old_size);
        }
    } else if (flags & MREMAP_MAYMOVE) {
        abi_ulong mmap_start;

        mmap_start = mmap_find_vma(0, new_size);

        if (mmap_start == -1) {
            errno = ENOMEM;
            host_addr = MAP_FAILED;
        } else {
            host_addr = (void *) syscall(__NR_mremap, g2h(old_addr),
                                         old_size, new_size,
                                         flags | MREMAP_FIXED,
                                         g2h(mmap_start));
            if ( RESERVED_VA ) {
                mmap_reserve(old_addr, old_size);
            }
        }
    } else {
        int prot = 0;
        if (RESERVED_VA && old_size < new_size) {
            abi_ulong addr;
            for (addr = old_addr + old_size;
                 addr < old_addr + new_size;
                 addr++) {
                prot |= page_get_flags(addr);
            }
        }
        if (prot == 0) {
            host_addr = mremap(g2h(old_addr), old_size, new_size, flags);
            if (host_addr != MAP_FAILED && RESERVED_VA && old_size > new_size) {
                mmap_reserve(old_addr + old_size, new_size - old_size);
            }
        } else {
            errno = ENOMEM;
            host_addr = MAP_FAILED;
        }
        /* Check if address fits target address space */
        if ((unsigned long)host_addr + new_size > (abi_ulong)-1) {
            /* Revert mremap() changes */
            host_addr = mremap(g2h(old_addr), new_size, old_size, flags);
            errno = ENOMEM;
            host_addr = MAP_FAILED;
        }
    }

    if (host_addr == MAP_FAILED) {
        new_addr = -1;
    } else {
        new_addr = h2g(host_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);
    }
    tb_invalidate_phys_range(new_addr, new_addr + new_size);
    mmap_unlock();
    return new_addr;
}
示例#6
0
文件: mmap.c 项目: LingxiaoJIA/qemu
/* 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;

    mmap_lock();
#ifdef DEBUG_MMAP
    {
        printf("mmap: start=0x" TARGET_ABI_FMT_lx
               " len=0x" TARGET_ABI_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_ANONYMOUS)
            printf("MAP_ANON ");
        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=" TARGET_ABI_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;
    host_offset = offset & qemu_host_page_mask;

    /* If the user is asking for the kernel to find a location, do that
       before we truncate the length for mapping files below.  */
    if (!(flags & MAP_FIXED)) {
        host_len = len + offset - host_offset;
        host_len = HOST_PAGE_ALIGN(host_len);
        start = mmap_find_vma(real_start, host_len);
        if (start == (abi_ulong)-1) {
            errno = ENOMEM;
            goto fail;
        }
    }

    /* When mapping files into a memory area larger than the file, accesses
       to pages beyond the file size will cause a SIGBUS. 

       For example, if mmaping a file of 100 bytes on a host with 4K pages
       emulating a target with 8K pages, the target expects to be able to
       access the first 8K. But the host will trap us on any access beyond
       4K.  

       When emulating a target with a larger page-size than the hosts, we
       may need to truncate file maps at EOF and add extra anonymous pages
       up to the targets page boundary.  */

    if ((qemu_real_host_page_size < TARGET_PAGE_SIZE)
        && !(flags & MAP_ANONYMOUS)) {
       struct stat sb;

       if (fstat (fd, &sb) == -1)
           goto fail;

       /* Are we trying to create a map beyond EOF?.  */
       if (offset + len > sb.st_size) {
           /* If so, truncate the file map at eof aligned with 
              the hosts real pagesize. Additional anonymous maps
              will be created beyond EOF.  */
           len = (sb.st_size - offset);
           len += qemu_real_host_page_size - 1;
           len &= ~(qemu_real_host_page_size - 1);
       }
    }

    if (!(flags & MAP_FIXED)) {
        unsigned long host_start;
        void *p;

        host_len = len + offset - host_offset;
        host_len = HOST_PAGE_ALIGN(host_len);

        /* 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(start), host_len, prot,
                 flags | MAP_FIXED | MAP_ANONYMOUS, -1, 0);
        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_ANONYMOUS)) {
            p = mmap(g2h(start), len, prot,
                     flags | MAP_FIXED, fd, host_offset);
            if (p == MAP_FAILED) {
                munmap(g2h(start), host_len);
                goto fail;
            }
            host_start += offset - host_offset;
        }
        start = h2g(host_start);
    } else {
        if (start & ~TARGET_PAGE_MASK) {
            errno = EINVAL;
            goto fail;
        }
        end = start + len;
        real_end = HOST_PAGE_ALIGN(end);

	/*
	 * Test if requested memory area fits target address space
	 * It can fail only on 64-bit host with 32-bit target.
	 * On any other target/host host mmap() handles this error correctly.
	 */
        if ((unsigned long)start + len - 1 > (abi_ulong) -1) {
            errno = EINVAL;
            goto fail;
        }

        /* 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 */
            if ((flags & MAP_TYPE) == MAP_SHARED &&
                (prot & PROT_WRITE)) {
                errno = EINVAL;
                goto fail;
            }
            retaddr = target_mmap(start, len, prot | PROT_WRITE,
                                  MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS,
                                  -1, 0);
            if (retaddr == -1)
                goto fail;
            if (pread(fd, g2h(start), len, offset) == -1)
                goto fail;
            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_ANONYMOUS)
                offset1 = 0;
            else
                offset1 = offset + real_start - start;
            p = mmap(g2h(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_ABI_FMT_lx "\n", start);
    page_dump(stdout);
    printf("\n");
#endif
    tb_invalidate_phys_range(start, start + len);
    mmap_unlock();
    return start;
fail:
    mmap_unlock();
    return -1;
}
示例#7
0
文件: mmap.c 项目: LingxiaoJIA/qemu
/*
 * Find and reserve a free memory area of size 'size'. The search
 * starts at 'start'.
 * It must be called with mmap_lock() held.
 * Return -1 if error.
 */
abi_ulong mmap_find_vma(abi_ulong start, abi_ulong size)
{
    void *ptr, *prev;
    abi_ulong addr;
    int wrapped, repeat;

    /* If 'start' == 0, then a default start address is used. */
    if (start == 0) {
        start = mmap_next_start;
    } else {
        start &= qemu_host_page_mask;
    }

    size = HOST_PAGE_ALIGN(size);

#ifdef CONFIG_USE_GUEST_BASE
    if (RESERVED_VA) {
        return mmap_find_vma_reserved(start, size);
    }
#endif

    addr = start;
    wrapped = repeat = 0;
    prev = 0;

    for (;; prev = ptr) {
        /*
         * Reserve needed memory area to avoid a race.
         * It should be discarded using:
         *  - mmap() with MAP_FIXED flag
         *  - mremap() with MREMAP_FIXED flag
         *  - shmat() with SHM_REMAP flag
         */
        ptr = mmap(g2h(addr), size, PROT_NONE,
                   MAP_ANONYMOUS|MAP_PRIVATE|MAP_NORESERVE, -1, 0);

        /* ENOMEM, if host address space has no memory */
        if (ptr == MAP_FAILED) {
            return (abi_ulong)-1;
        }

        /* Count the number of sequential returns of the same address.
           This is used to modify the search algorithm below.  */
        repeat = (ptr == prev ? repeat + 1 : 0);

        if (h2g_valid(ptr + size - 1)) {
            addr = h2g(ptr);

            if ((addr & ~TARGET_PAGE_MASK) == 0) {
                /* Success.  */
                if (start == mmap_next_start && addr >= TASK_UNMAPPED_BASE) {
                    mmap_next_start = addr + size;
                }
                return addr;
            }

            /* The address is not properly aligned for the target.  */
            switch (repeat) {
            case 0:
                /* Assume the result that the kernel gave us is the
                   first with enough free space, so start again at the
                   next higher target page.  */
                addr = TARGET_PAGE_ALIGN(addr);
                break;
            case 1:
                /* Sometimes the kernel decides to perform the allocation
                   at the top end of memory instead.  */
                addr &= TARGET_PAGE_MASK;
                break;
            case 2:
                /* Start over at low memory.  */
                addr = 0;
                break;
            default:
                /* Fail.  This unaligned block must the last.  */
                addr = -1;
                break;
            }
        } else {
            /* Since the result the kernel gave didn't fit, start
               again at low memory.  If any repetition, fail.  */
            addr = (repeat ? -1 : 0);
        }

        /* Unmap and try again.  */
        munmap(ptr, size);

        /* ENOMEM if we checked the whole of the target address space.  */
        if (addr == (abi_ulong)-1) {
            return (abi_ulong)-1;
        } else if (addr == 0) {
            if (wrapped) {
                return (abi_ulong)-1;
            }
            wrapped = 1;
            /* Don't actually use 0 when wrapping, instead indicate
               that we'd truly like an allocation in low memory.  */
            addr = (mmap_min_addr > TARGET_PAGE_SIZE
                     ? TARGET_PAGE_ALIGN(mmap_min_addr)
                     : TARGET_PAGE_SIZE);
        } else if (wrapped && addr >= start) {
            return (abi_ulong)-1;
        }
    }
}