exec: Relax range check in ram_block_discard_range()

We want to make use of ram_block_discard_range() in the RAM block resize callback when growing a RAM block, *before* used_length is changed. Let's relax the check. As RAM blocks always mmap the whole max_length area, we cannot corrupt unrelated data. Reviewed-by: Peter Xu <[email protected]> Signed-off-by: David Hildenbrand <[email protected]> Message-Id: <[email protected]> Signed-off-by: Dr. David Alan Gilbert <[email protected]>
zhijianli88 · May 13, 2021 · dcdc460 · dcdc460
1 parent c7c0e72
commit dcdc460
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/softmmu/physmem.c b/softmmu/physmem.c
@@ -3500,7 +3500,7 @@ int ram_block_discard_range(RAMBlock *rb, uint64_t start, size_t length)
         goto err;
     }
 
-    if ((start + length) <= rb->used_length) {
+    if ((start + length) <= rb->max_length) {
         bool need_madvise, need_fallocate;
         if (!QEMU_IS_ALIGNED(length, rb->page_size)) {
             error_report("ram_block_discard_range: Unaligned length: %zx",
@@ -3567,7 +3567,7 @@ int ram_block_discard_range(RAMBlock *rb, uint64_t start, size_t length)
     } else {
         error_report("ram_block_discard_range: Overrun block '%s' (%" PRIu64
                      "/%zx/" RAM_ADDR_FMT")",
-                     rb->idstr, start, length, rb->used_length);
+                     rb->idstr, start, length, rb->max_length);
     }
 
 err: