Commit f19412a2a6346ff4976d57c2692464f7cd8fa7eb

Authored by aurel32
1 parent 45bc1f52

linux-user: mremap(): handle MREMAP_FIXED and MREMAP_MAYMOVE correctly

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Acked-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5959 c046a42c-6fe2-441c-8c8c-71466251a162
Showing 1 changed file with 28 additions and 6 deletions
linux-user/mmap.c
... ... @@ -537,19 +537,41 @@ int target_munmap(abi_ulong start, abi_ulong len)
537 537 return ret;
538 538 }
539 539  
540   -/* XXX: currently, we only handle MAP_ANONYMOUS and not MAP_FIXED
541   - blocks which have been allocated starting on a host page */
542 540 abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size,
543 541 abi_ulong new_size, unsigned long flags,
544 542 abi_ulong new_addr)
545 543 {
546 544 int prot;
547   - unsigned long host_addr;
  545 + void *host_addr;
548 546  
549 547 mmap_lock();
550   - /* XXX: use 5 args syscall */
551   - host_addr = (long)mremap(g2h(old_addr), old_size, new_size, flags);
552   - if (host_addr == -1) {
  548 +
  549 + if (flags & MREMAP_FIXED)
  550 + host_addr = mremap(g2h(old_addr), old_size, new_size,
  551 + flags, new_addr);
  552 + else if (flags & MREMAP_MAYMOVE) {
  553 + abi_ulong mmap_start;
  554 +
  555 + mmap_start = mmap_find_vma(0, new_size);
  556 +
  557 + if (mmap_start == -1) {
  558 + errno = ENOMEM;
  559 + host_addr = MAP_FAILED;
  560 + } else
  561 + host_addr = mremap(g2h(old_addr), old_size, new_size,
  562 + flags | MREMAP_FIXED, g2h(mmap_start));
  563 + } else {
  564 + host_addr = mremap(g2h(old_addr), old_size, new_size, flags);
  565 + /* Check if address fits target address space */
  566 + if ((unsigned long)host_addr + new_size > (abi_ulong)-1) {
  567 + /* Revert mremap() changes */
  568 + host_addr = mremap(g2h(old_addr), new_size, old_size, flags);
  569 + errno = ENOMEM;
  570 + host_addr = MAP_FAILED;
  571 + }
  572 + }
  573 +
  574 + if (host_addr == MAP_FAILED) {
553 575 new_addr = -1;
554 576 } else {
555 577 new_addr = h2g(host_addr);
... ...