Sadly I was wrong to suggest dropping vaddrs' initializer during review
of v2 of the patch introducing this code. gcc 4.3 can't cope.
Fixes: 52531c734ea1 ("xen/gnttab: Rework resource acquisition")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
---
v2: Re-insert the other half of what Andrew had in his original patch.
--- a/xen/common/grant_table.c
+++ b/xen/common/grant_table.c
@@ -4026,7 +4026,7 @@ int gnttab_acquire_resource(
struct grant_table *gt = d->grant_table;
unsigned int i, final_frame;
mfn_t tmp;
- void **vaddrs;
+ void **vaddrs = NULL;
int rc = -EINVAL;
if ( !nr_frames )
@@ -4055,6 +4055,17 @@ int gnttab_acquire_resource(
break;
}
+ /*
+ * Some older toolchains can't spot that vaddrs won't remain uninitialized
+ * on non-error paths, and hence it needs setting to NULL at the top of the
+ * function. Leave some runtime safety.
+ */
+ if ( !vaddrs )
+ {
+ ASSERT_UNREACHABLE();
+ rc = -ENODATA;
+ }
+
/* Any errors? Bad id, or from growing the table? */
if ( rc )
goto out;