mirror of https://gitee.com/openkylin/qemu.git
fixed target_mmap() if host page size < TARGET_PAGE_SIZE
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@3642 c046a42c-6fe2-441c-8c8c-71466251a162
This commit is contained in:
bellard
parent
dae3270c6e
commit
a03e2d421e
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@ -151,19 +151,53 @@ static int mmap_frag(abi_ulong real_start,
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return 0;
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}
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#if defined(__CYGWIN__)
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/* Cygwin doesn't have a whole lot of address space. */
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static abi_ulong mmap_next_start = 0x18000000;
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#else
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static abi_ulong mmap_next_start = 0x40000000;
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#endif
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/* find a free memory area of size 'size'. The search starts at
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'start'. If 'start' == 0, then a default start address is used.
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Return -1 if error.
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*/
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/* XXX: should mark pages used by the host as reserved to be sure not
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to use them. */
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static abi_ulong mmap_find_vma(abi_ulong start, abi_ulong size)
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{
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abi_ulong addr, addr1, addr_start;
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int prot;
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size = HOST_PAGE_ALIGN(size);
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start = start & qemu_host_page_mask;
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addr = start;
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if (addr == 0)
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addr = mmap_next_start;
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addr_start = addr;
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for(;;) {
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prot = 0;
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for(addr1 = addr; addr1 < (addr + size); addr1 += TARGET_PAGE_SIZE) {
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prot |= page_get_flags(addr1);
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}
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if (prot == 0)
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break;
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addr += qemu_host_page_size;
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/* we found nothing */
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if (addr == addr_start)
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return (abi_ulong)-1;
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}
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if (start == 0)
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mmap_next_start = addr + size;
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return addr;
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}
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/* NOTE: all the constants are the HOST ones */
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abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
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int flags, int fd, abi_ulong offset)
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{
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abi_ulong ret, end, real_start, real_end, retaddr, host_offset, host_len;
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unsigned long host_start;
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#if defined(__alpha__) || defined(__sparc__) || defined(__x86_64__) || \
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defined(__ia64) || defined(__mips__)
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static abi_ulong last_start = 0x40000000;
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#elif defined(__CYGWIN__)
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/* Cygwin doesn't have a whole lot of address space. */
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static abi_ulong last_start = 0x18000000;
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#endif
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#ifdef DEBUG_MMAP
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{
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@ -203,147 +237,101 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
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real_start = start & qemu_host_page_mask;
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if (!(flags & MAP_FIXED)) {
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#if defined(__alpha__) || defined(__sparc__) || defined(__x86_64__) || \
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defined(__ia64) || defined(__mips__) || defined(__CYGWIN__)
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/* tell the kernel to search at the same place as i386 */
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if (real_start == 0) {
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real_start = last_start;
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last_start += HOST_PAGE_ALIGN(len);
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abi_ulong mmap_start;
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void *p;
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host_offset = offset & qemu_host_page_mask;
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host_len = len + offset - host_offset;
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host_len = HOST_PAGE_ALIGN(host_len);
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mmap_start = mmap_find_vma(real_start, host_len);
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if (mmap_start == (abi_ulong)-1) {
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errno = ENOMEM;
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return -1;
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}
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#endif
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host_offset = offset & qemu_host_page_mask;
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host_len = len + offset - host_offset;
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if (qemu_host_page_size > qemu_real_host_page_size) {
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/*
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* The guest expects to see mmapped areas aligned to it's pagesize.
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* If the host's real page size is smaller than the guest's, we need
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* to fixup the maps. It is done by allocating a larger area,
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* displacing the map (if needed) and finally chopping off the spare
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* room at the edges.
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*/
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/*
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* We assume qemu_host_page_size is always the same as
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* TARGET_PAGE_SIZE, see exec.c. qemu_real_host_page_size is the
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* hosts real page size.
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*/
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abi_ulong host_end;
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unsigned long host_aligned_start;
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void *p;
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host_len = HOST_PAGE_ALIGN(host_len + qemu_host_page_size
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- qemu_real_host_page_size);
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p = mmap(real_start ? g2h(real_start) : NULL,
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host_len, prot, flags, fd, host_offset);
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if (p == MAP_FAILED)
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return -1;
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host_start = (unsigned long)p;
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host_end = host_start + host_len;
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/* Find start and end, aligned to the targets pagesize with-in the
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large mmaped area. */
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host_aligned_start = TARGET_PAGE_ALIGN(host_start);
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if (!(flags & MAP_ANONYMOUS))
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host_aligned_start += offset - host_offset;
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start = h2g(host_aligned_start);
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end = start + TARGET_PAGE_ALIGN(len);
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/* Chop off the leftovers, if any. */
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if (host_aligned_start > host_start)
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munmap((void *)host_start, host_aligned_start - host_start);
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if (end < host_end)
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munmap((void *)g2h(end), host_end - end);
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goto the_end1;
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} else {
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/* if not fixed, no need to do anything */
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void *p = mmap(real_start ? g2h(real_start) : NULL,
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host_len, prot, flags, fd, host_offset);
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if (p == MAP_FAILED)
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return -1;
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/* update start so that it points to the file position at 'offset' */
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host_start = (unsigned long)p;
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if (!(flags & MAP_ANONYMOUS))
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host_start += offset - host_offset;
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start = h2g(host_start);
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goto the_end1;
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}
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}
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if (start & ~TARGET_PAGE_MASK) {
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errno = EINVAL;
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return -1;
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}
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end = start + len;
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real_end = HOST_PAGE_ALIGN(end);
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/* worst case: we cannot map the file because the offset is not
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aligned, so we read it */
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if (!(flags & MAP_ANONYMOUS) &&
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(offset & ~qemu_host_page_mask) != (start & ~qemu_host_page_mask)) {
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/* msync() won't work here, so we return an error if write is
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possible while it is a shared mapping */
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if ((flags & MAP_TYPE) == MAP_SHARED &&
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(prot & PROT_WRITE)) {
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/* Note: we prefer to control the mapping address. It is
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especially important if qemu_host_page_size >
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qemu_real_host_page_size */
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p = mmap(g2h(mmap_start),
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host_len, prot, flags | MAP_FIXED, fd, host_offset);
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if (p == MAP_FAILED)
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return -1;
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/* update start so that it points to the file position at 'offset' */
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host_start = (unsigned long)p;
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if (!(flags & MAP_ANONYMOUS))
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host_start += offset - host_offset;
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start = h2g(host_start);
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} else {
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if (start & ~TARGET_PAGE_MASK) {
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errno = EINVAL;
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return -1;
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}
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retaddr = target_mmap(start, len, prot | PROT_WRITE,
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MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS,
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-1, 0);
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if (retaddr == -1)
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return -1;
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pread(fd, g2h(start), len, offset);
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if (!(prot & PROT_WRITE)) {
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ret = target_mprotect(start, len, prot);
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if (ret != 0)
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return ret;
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end = start + len;
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real_end = HOST_PAGE_ALIGN(end);
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/* worst case: we cannot map the file because the offset is not
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aligned, so we read it */
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if (!(flags & MAP_ANONYMOUS) &&
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(offset & ~qemu_host_page_mask) != (start & ~qemu_host_page_mask)) {
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/* msync() won't work here, so we return an error if write is
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possible while it is a shared mapping */
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if ((flags & MAP_TYPE) == MAP_SHARED &&
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(prot & PROT_WRITE)) {
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errno = EINVAL;
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return -1;
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}
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retaddr = target_mmap(start, len, prot | PROT_WRITE,
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MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS,
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-1, 0);
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if (retaddr == -1)
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return -1;
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pread(fd, g2h(start), len, offset);
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if (!(prot & PROT_WRITE)) {
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ret = target_mprotect(start, len, prot);
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if (ret != 0)
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return ret;
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}
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goto the_end;
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}
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goto the_end;
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}
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/* handle the start of the mapping */
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if (start > real_start) {
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if (real_end == real_start + qemu_host_page_size) {
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/* one single host page */
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ret = mmap_frag(real_start, start, end,
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/* handle the start of the mapping */
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if (start > real_start) {
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if (real_end == real_start + qemu_host_page_size) {
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/* one single host page */
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ret = mmap_frag(real_start, start, end,
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prot, flags, fd, offset);
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if (ret == -1)
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return ret;
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goto the_end1;
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}
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ret = mmap_frag(real_start, start, real_start + qemu_host_page_size,
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prot, flags, fd, offset);
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if (ret == -1)
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return ret;
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goto the_end1;
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real_start += qemu_host_page_size;
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}
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/* handle the end of the mapping */
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if (end < real_end) {
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ret = mmap_frag(real_end - qemu_host_page_size,
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real_end - qemu_host_page_size, real_end,
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prot, flags, fd,
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offset + real_end - qemu_host_page_size - start);
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if (ret == -1)
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return -1;
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real_end -= qemu_host_page_size;
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}
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ret = mmap_frag(real_start, start, real_start + qemu_host_page_size,
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prot, flags, fd, offset);
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if (ret == -1)
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return ret;
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real_start += qemu_host_page_size;
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}
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/* handle the end of the mapping */
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if (end < real_end) {
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ret = mmap_frag(real_end - qemu_host_page_size,
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real_end - qemu_host_page_size, real_end,
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prot, flags, fd,
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offset + real_end - qemu_host_page_size - start);
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if (ret == -1)
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return -1;
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real_end -= qemu_host_page_size;
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}
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/* map the middle (easier) */
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if (real_start < real_end) {
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void *p;
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unsigned long offset1;
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if (flags & MAP_ANONYMOUS)
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offset1 = 0;
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else
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offset1 = offset + real_start - start;
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p = mmap(g2h(real_start), real_end - real_start,
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prot, flags, fd, offset1);
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if (p == MAP_FAILED)
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return -1;
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/* map the middle (easier) */
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if (real_start < real_end) {
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void *p;
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unsigned long offset1;
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if (flags & MAP_ANONYMOUS)
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offset1 = 0;
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else
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offset1 = offset + real_start - start;
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p = mmap(g2h(real_start), real_end - real_start,
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prot, flags, fd, offset1);
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if (p == MAP_FAILED)
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return -1;
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}
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}
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the_end1:
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page_set_flags(start, start + len, prot | PAGE_VALID);
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