adding cc: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
On 4/10/22 16:08, frowand.list@xxxxxxxxx wrote:
> From: Frank Rowand <frank.rowand@xxxxxxxx>
>
> Variables change name across function calls when there is not a good
> reason to do so. Fix by changing "fdt" to "new_fdt" and "tree" to
> "overlay_tree".
>
> The name disparity was confusing when creating the following commit.
> The name changes are in this separate commit to make review of the
> following commmit less complex.
>
> Signed-off-by: Frank Rowand <frank.rowand@xxxxxxxx>
> ---
> Changes since v1:
> - This patch is added to the series.
>
> drivers/of/overlay.c | 94 ++++++++++++++++++++++----------------------
> 1 file changed, 47 insertions(+), 47 deletions(-)
>
> diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
> index d80160cf34bb..f74aa9ff67aa 100644
> --- a/drivers/of/overlay.c
> +++ b/drivers/of/overlay.c
> @@ -57,7 +57,7 @@ struct fragment {
> * struct overlay_changeset
> * @id: changeset identifier
> * @ovcs_list: list on which we are located
> - * @fdt: base of memory allocated to hold aligned FDT that was unflattened to create @overlay_tree
> + * @new_fdt: Memory allocated to hold unflattened aligned FDT
> * @overlay_tree: expanded device tree that contains the fragment nodes
> * @count: count of fragment structures
> * @fragments: fragment nodes in the overlay expanded device tree
> @@ -67,7 +67,7 @@ struct fragment {
> struct overlay_changeset {
> int id;
> struct list_head ovcs_list;
> - const void *fdt;
> + const void *new_fdt;
> struct device_node *overlay_tree;
> int count;
> struct fragment *fragments;
> @@ -718,19 +718,20 @@ static struct device_node *find_target(struct device_node *info_node)
>
> /**
> * init_overlay_changeset() - initialize overlay changeset from overlay tree
> - * @ovcs: Overlay changeset to build
> - * @fdt: base of memory allocated to hold aligned FDT that was unflattened to create @tree
> - * @tree: Contains the overlay fragments and overlay fixup nodes
> + * @ovcs: Overlay changeset to build
> + * @new_fdt: Memory allocated to hold unflattened aligned FDT
> + * @overlay_tree: Contains the overlay fragments and overlay fixup nodes
> *
> * Initialize @ovcs. Populate @ovcs->fragments with node information from
> - * the top level of @tree. The relevant top level nodes are the fragment
> - * nodes and the __symbols__ node. Any other top level node will be ignored.
> + * the top level of @overlay_tree. The relevant top level nodes are the
> + * fragment nodes and the __symbols__ node. Any other top level node will
> + * be ignored.
> *
> * Return: 0 on success, -ENOMEM if memory allocation failure, -EINVAL if error
> - * detected in @tree, or -ENOSPC if idr_alloc() error.
> + * detected in @overlay_tree, or -ENOSPC if idr_alloc() error.
> */
> static int init_overlay_changeset(struct overlay_changeset *ovcs,
> - const void *fdt, struct device_node *tree)
> + const void *new_fdt, struct device_node *overlay_tree)
> {
> struct device_node *node, *overlay_node;
> struct fragment *fragment;
> @@ -741,17 +742,17 @@ static int init_overlay_changeset(struct overlay_changeset *ovcs,
> * Warn for some issues. Can not return -EINVAL for these until
> * of_unittest_apply_overlay() is fixed to pass these checks.
> */
> - if (!of_node_check_flag(tree, OF_DYNAMIC))
> - pr_debug("%s() tree is not dynamic\n", __func__);
> + if (!of_node_check_flag(overlay_tree, OF_DYNAMIC))
> + pr_debug("%s() overlay_tree is not dynamic\n", __func__);
>
> - if (!of_node_check_flag(tree, OF_DETACHED))
> - pr_debug("%s() tree is not detached\n", __func__);
> + if (!of_node_check_flag(overlay_tree, OF_DETACHED))
> + pr_debug("%s() overlay_tree is not detached\n", __func__);
>
> - if (!of_node_is_root(tree))
> - pr_debug("%s() tree is not root\n", __func__);
> + if (!of_node_is_root(overlay_tree))
> + pr_debug("%s() overlay_tree is not root\n", __func__);
>
> - ovcs->overlay_tree = tree;
> - ovcs->fdt = fdt;
> + ovcs->overlay_tree = overlay_tree;
> + ovcs->new_fdt = new_fdt;
>
> INIT_LIST_HEAD(&ovcs->ovcs_list);
>
> @@ -764,7 +765,7 @@ static int init_overlay_changeset(struct overlay_changeset *ovcs,
> cnt = 0;
>
> /* fragment nodes */
> - for_each_child_of_node(tree, node) {
> + for_each_child_of_node(overlay_tree, node) {
> overlay_node = of_get_child_by_name(node, "__overlay__");
> if (overlay_node) {
> cnt++;
> @@ -772,7 +773,7 @@ static int init_overlay_changeset(struct overlay_changeset *ovcs,
> }
> }
>
> - node = of_get_child_by_name(tree, "__symbols__");
> + node = of_get_child_by_name(overlay_tree, "__symbols__");
> if (node) {
> cnt++;
> of_node_put(node);
> @@ -785,7 +786,7 @@ static int init_overlay_changeset(struct overlay_changeset *ovcs,
> }
>
> cnt = 0;
> - for_each_child_of_node(tree, node) {
> + for_each_child_of_node(overlay_tree, node) {
> overlay_node = of_get_child_by_name(node, "__overlay__");
> if (!overlay_node)
> continue;
> @@ -807,7 +808,7 @@ static int init_overlay_changeset(struct overlay_changeset *ovcs,
> * if there is a symbols fragment in ovcs->fragments[i] it is
> * the final element in the array
> */
> - node = of_get_child_by_name(tree, "__symbols__");
> + node = of_get_child_by_name(overlay_tree, "__symbols__");
> if (node) {
> ovcs->symbols_fragment = 1;
> fragment = &fragments[cnt];
> @@ -862,11 +863,11 @@ static void free_overlay_changeset(struct overlay_changeset *ovcs)
> kfree(ovcs->fragments);
> /*
> * There should be no live pointers into ovcs->overlay_tree and
> - * ovcs->fdt due to the policy that overlay notifiers are not allowed
> - * to retain pointers into the overlay devicetree.
> + * ovcs->new_fdt due to the policy that overlay notifiers are not
> + * allowed to retain pointers into the overlay devicetree.
> */
> kfree(ovcs->overlay_tree);
> - kfree(ovcs->fdt);
> + kfree(ovcs->new_fdt);
> kfree(ovcs);
> }
>
> @@ -874,16 +875,15 @@ static void free_overlay_changeset(struct overlay_changeset *ovcs)
> * internal documentation
> *
> * of_overlay_apply() - Create and apply an overlay changeset
> - * @fdt: base of memory allocated to hold the aligned FDT
> - * @tree: Expanded overlay device tree
> - * @ovcs_id: Pointer to overlay changeset id
> + * @new_fdt: Memory allocated to hold the aligned FDT
> + * @overlay_tree: Expanded overlay device tree
> + * @ovcs_id: Pointer to overlay changeset id
> *
> * Creates and applies an overlay changeset.
> *
> * If an error occurs in a pre-apply notifier, then no changes are made
> * to the device tree.
> *
> -
> * A non-zero return value will not have created the changeset if error is from:
> * - parameter checks
> * - building the changeset
> @@ -913,29 +913,29 @@ static void free_overlay_changeset(struct overlay_changeset *ovcs)
> * id is returned to *ovcs_id.
> */
>
> -static int of_overlay_apply(const void *fdt, struct device_node *tree,
> - int *ovcs_id)
> +static int of_overlay_apply(const void *new_fdt,
> + struct device_node *overlay_tree, int *ovcs_id)
> {
> struct overlay_changeset *ovcs;
> int ret = 0, ret_revert, ret_tmp;
>
> /*
> - * As of this point, fdt and tree belong to the overlay changeset.
> - * overlay changeset code is responsible for freeing them.
> + * As of this point, new_fdt and overlay_tree belong to the overlay
> + * changeset. overlay changeset code is responsible for freeing them.
> */
>
> if (devicetree_corrupt()) {
> pr_err("devicetree state suspect, refuse to apply overlay\n");
> - kfree(fdt);
> - kfree(tree);
> + kfree(new_fdt);
> + kfree(overlay_tree);
> ret = -EBUSY;
> goto out;
> }
>
> ovcs = kzalloc(sizeof(*ovcs), GFP_KERNEL);
> if (!ovcs) {
> - kfree(fdt);
> - kfree(tree);
> + kfree(new_fdt);
> + kfree(overlay_tree);
> ret = -ENOMEM;
> goto out;
> }
> @@ -943,20 +943,20 @@ static int of_overlay_apply(const void *fdt, struct device_node *tree,
> of_overlay_mutex_lock();
> mutex_lock(&of_mutex);
>
> - ret = of_resolve_phandles(tree);
> + ret = of_resolve_phandles(overlay_tree);
> if (ret)
> - goto err_free_tree;
> + goto err_free_overlay_tree;
>
> - ret = init_overlay_changeset(ovcs, fdt, tree);
> + ret = init_overlay_changeset(ovcs, new_fdt, overlay_tree);
> if (ret)
> - goto err_free_tree;
> + goto err_free_overlay_tree;
>
> /*
> * after overlay_notify(), ovcs->overlay_tree related pointers may have
> - * leaked to drivers, so can not kfree() tree, aka ovcs->overlay_tree;
> - * and can not free memory containing aligned fdt. The aligned fdt
> - * is contained within the memory at ovcs->fdt, possibly at an offset
> - * from ovcs->fdt.
> + * leaked to drivers, so can not kfree() overlay_tree,
> + * aka ovcs->overlay_tree; and can not free memory containing aligned
> + * fdt. The aligned fdt is contained within the memory at
> + * ovcs->new_fdt, possibly at an offset from ovcs->new_fdt.
> */
> ret = overlay_notify(ovcs, OF_OVERLAY_PRE_APPLY);
> if (ret) {
> @@ -997,9 +997,9 @@ static int of_overlay_apply(const void *fdt, struct device_node *tree,
>
> goto out_unlock;
>
> -err_free_tree:
> - kfree(fdt);
> - kfree(tree);
> +err_free_overlay_tree:
> + kfree(new_fdt);
> + kfree(overlay_tree);
>
> err_free_overlay_changeset:
> free_overlay_changeset(ovcs);
