From patchwork Tue Sep 14 05:22:34 2010
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Subject: linux-user: mmap_reserve() not controlled by RESERVED_VA
From: amateur <tianlei.zhao@gmail.com>
X-Patchwork-Id: 64672
Message-Id: <20100914052234.GA10008@localdomain>
To: Qemu Devel <qemu-devel@nongnu.org>
Date: Tue, 14 Sep 2010 13:22:34 +0800

mmap_reserve() should be called only when RESERVED_VA is enabled.
Otherwise, unmaped virtual address space will never be reusable. This
bug will exhaust virtual address space in extreme conditions.


diff --git a/linux-user/mmap.c b/linux-user/mmap.c
index e10a6ef..50748a2 100644
--- a/linux-user/mmap.c
+++ b/linux-user/mmap.c
@@ -697,7 +697,9 @@ abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size,
                                          old_size, new_size,
                                          flags | MREMAP_FIXED,
                                          g2h(mmap_start));
-            mmap_reserve(old_addr, old_size);
+            if ( RESERVED_VA ) {
+                mmap_reserve(old_addr, old_size);
+            }
         }
     } else {
         int prot = 0;