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

["Kirill A. Shutemov" <kirill@shutemov.name>]

From: Jan Kiszka <jan.kiszka@web.de>

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 <jan.kiszka@web.de>
Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
---
 exec.c |    5 ++---
 1 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/exec.c b/exec.c
index 58a0cff..105812f 100644
--- a/exec.c
+++ b/exec.c
@@ -305,14 +305,13 @@ static inline PageDesc *page_find_alloc(target_ulong index)
     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); 
-- 
1.6.0.2.GIT