[Qemu-devel] [5957] linux-user: Fix h2g usage in page_find_alloc

[Aurelien Jarno]

Revision: 5957
          http://svn.sv.gnu.org/viewvc/?view=rev&root=qemu&revision=5957
Author:   aurel32
Date:     2008-12-08 18:12:26 +0000 (Mon, 08 Dec 2008)

Log Message:
-----------
linux-user: Fix h2g usage in page_find_alloc

Paul's comment on my first approach to fix the h2g usage in
page_find_alloc finally open my eyes about what the code is actually
supposed to do:

With the help of h2g_valid we can no cleanly check if a freshly allocate
page (for host usage) is guest-reachable and, in case it is, mark it
reserved in the guest's address range.

Signed-off-by: Jan Kiszka <address@hidden>
Signed-off-by: Kirill A. Shutemov <address@hidden>
Acked-by: Edgar E. Iglesias <address@hidden>
Signed-off-by: Aurelien Jarno <address@hidden>

Modified Paths:
--------------
    trunk/exec.c

Modified: trunk/exec.c
===================================================================
--- trunk/exec.c        2008-12-08 18:12:18 UTC (rev 5956)
+++ trunk/exec.c        2008-12-08 18:12:26 UTC (rev 5957)
@@ -305,14 +305,13 @@
     if (!p) {
         /* allocate if not found */
 #if defined(CONFIG_USER_ONLY)
-        unsigned long addr;
         size_t len = sizeof(PageDesc) * L2_SIZE;
         /* Don't use qemu_malloc because it may recurse.  */
         p = mmap(0, len, PROT_READ | PROT_WRITE,
                  MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
         *lp = p;
-        addr = h2g(p);
-        if (addr == (target_ulong)addr) {
+        if (h2g_valid(p)) {
+            unsigned long addr = h2g(p);
             page_set_flags(addr & TARGET_PAGE_MASK,
                            TARGET_PAGE_ALIGN(addr + len),
                            PAGE_RESERVED);