thunderbolt: Use kzalloc_flex() for struct tb_path allocation

Simplifies allocation of struct tb_path by using a flexible array
member. Also added __counted_by for extra runtime analysis.

Signed-off-by: Rosen Penev <rosenp@gmail.com>
Reviewed-by: Kees Cook <kees@kernel.org>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

diff --git a/drivers/thunderbolt/path.c b/drivers/thunderbolt/path.c
index 22fb4a1e1acd1b1d1a3525f6ce19a70a4bc31a5b..8713ea0f47c1b647680121f72c5dfcd4ebfc639b 100644 (file)
--- a/drivers/thunderbolt/path.c
+++ b/drivers/thunderbolt/path.c
@@ -150,22 +150,17 @@ struct tb_path *tb_path_discover(struct tb_port *src, int src_hopid,
                num_hops++;
        }
 
-       path = kzalloc_obj(*path);
+       path = kzalloc_flex(*path, hops, num_hops);
        if (!path)
                return NULL;
 
+       path->path_length = num_hops;
+
        path->name = name;
        path->tb = src->sw->tb;
-       path->path_length = num_hops;
        path->activated = true;
        path->alloc_hopid = alloc_hopid;
 
-       path->hops = kzalloc_objs(*path->hops, num_hops);
-       if (!path->hops) {
-               kfree(path);
-               return NULL;
-       }
-
        tb_dbg(path->tb, "discovering %s path starting from %llx:%u\n",
               path->name, tb_route(src->sw), src->port);
 
@@ -245,10 +240,6 @@ struct tb_path *tb_path_alloc(struct tb *tb, struct tb_port *src, int src_hopid,
        size_t num_hops;
        int i, ret;
 
-       path = kzalloc_obj(*path);
-       if (!path)
-               return NULL;
-
        first_port = last_port = NULL;
        i = 0;
        tb_for_each_port_on_path(src, dst, in_port) {
@@ -259,20 +250,17 @@ struct tb_path *tb_path_alloc(struct tb *tb, struct tb_port *src, int src_hopid,
        }
 
        /* Check that src and dst are reachable */
-       if (first_port != src || last_port != dst) {
-               kfree(path);
+       if (first_port != src || last_port != dst)
                return NULL;
-       }
 
        /* Each hop takes two ports */
        num_hops = i / 2;
 
-       path->hops = kzalloc_objs(*path->hops, num_hops);
-       if (!path->hops) {
-               kfree(path);
+       path = kzalloc_flex(*path, hops, num_hops);
+       if (!path)
                return NULL;
-       }
 
+       path->path_length = num_hops;
        path->alloc_hopid = true;
 
        in_hopid = src_hopid;
@@ -339,7 +327,6 @@ struct tb_path *tb_path_alloc(struct tb *tb, struct tb_port *src, int src_hopid,
        }
 
        path->tb = tb;
-       path->path_length = num_hops;
        path->name = name;
 
        return path;
@@ -372,7 +359,6 @@ void tb_path_free(struct tb_path *path)
                }
        }
 
-       kfree(path->hops);
        kfree(path);
 }
 

diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index e96474f17067a3ba92d678035b24eaafc6540362..217c3114bec8ba96eaf2348de55f3ede70b6f24c 100644 (file)
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -419,9 +419,9 @@ enum tb_path_port {
  * @activated: Is the path active
  * @clear_fc: Clear all flow control from the path config space entries
  *           when deactivating this path
- * @hops: Path hops
  * @path_length: How many hops the path uses
  * @alloc_hopid: Does this path consume port HopID
+ * @hops: Path hops
  *
  * A path consists of a number of hops (see &struct tb_path_hop). To
  * establish a PCIe tunnel two paths have to be created between the two
@@ -440,9 +440,10 @@ struct tb_path {
        bool drop_packages;
        bool activated;
        bool clear_fc;
-       struct tb_path_hop *hops;
        int path_length;
        bool alloc_hopid;
+
+       struct tb_path_hop hops[] __counted_by(path_length);
 };
 
 /* HopIDs 0-7 are reserved by the Thunderbolt protocol */