[Qemu-devel] [PATCH v1 for 3.0 1/2] linux-user/mmap.c: handle len = 0 maps correctly

[Alex Bennée]

I've slightly re-organised the check to more closely match the
sequence that the kernel uses in do_mmap().

Signed-off-by: Alex Bennée <alex.ben...@linaro.org>
Cc: umarcor <1783...@bugs.launchpad.net>
---
 linux-user/mmap.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/linux-user/mmap.c b/linux-user/mmap.c
index d0c50e4888..3ef69fa2d0 100644
--- a/linux-user/mmap.c
+++ b/linux-user/mmap.c
@@ -391,14 +391,22 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int 
prot,
     }
 #endif
 
-    if (offset & ~TARGET_PAGE_MASK) {
+    if (!len) {
         errno = EINVAL;
         goto fail;
     }
 
     len = TARGET_PAGE_ALIGN(len);
-    if (len == 0)
-        goto the_end;
+    if (!len) {
+        errno = EINVAL;
+        goto fail;
+    }
+
+    if (offset & ~TARGET_PAGE_MASK) {
+        errno = EINVAL;
+        goto fail;
+    }
+
     real_start = start & qemu_host_page_mask;
     host_offset = offset & qemu_host_page_mask;
 
-- 
2.17.1