[Qemu-devel] [5958] linux-user: mmap: add check if requested memory area fits target address space

[Qemu-devel] [5958] linux-user: mmap: add check if requested memory area fits target address space

[Aurelien Jarno]

Revision: 5958
          http://svn.sv.gnu.org/viewvc/?view=rev&root=qemu&revision=5958
Author:   aurel32
Date:     2008-12-08 18:12:33 +0000 (Mon, 08 Dec 2008)

Log Message:
-----------
linux-user: mmap: add check if requested memory area fits target address space

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>

Modified Paths:
--------------
    trunk/linux-user/mmap.c

Modified: trunk/linux-user/mmap.c
===================================================================
--- trunk/linux-user/mmap.c	2008-12-08 18:12:26 UTC (rev 5957)
+++ trunk/linux-user/mmap.c	2008-12-08 18:12:33 UTC (rev 5958)
@@ -382,6 +382,16 @@
         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) {