kdbus: cmdline emptiness check fix

[ This commit re-applies change Ia925fa43bf4c50ab707be98f275b50808782f063 to new kdbus upstream version. ]
Signed-off-by: Karol Lewandowski <k.lewandowsk@samsung.com>
Change-Id: Ia03913a35dba34567c1bd99afbfe138ea7a5d133

diff --git a/ipc/kdbus/metadata.c b/ipc/kdbus/metadata.c
index 71ca475a80d5ebeb785ebe4728a51bbf12ea35c4..106ec26f2882ec854aaead7a40af7f20cc7ba780 100644 (file)
--- a/ipc/kdbus/metadata.c
+++ b/ipc/kdbus/metadata.c
@@ -244,7 +244,7 @@ static int kdbus_meta_proc_collect_cmdline(struct kdbus_meta_proc *mp)
        struct mm_struct *mm = current->mm;
        char *cmdline;
 
-       if (!mm->arg_end)
+       if (mm->arg_start >= mm->arg_end)
                return 0;
 
        cmdline = strndup_user((const char __user *)mm->arg_start,