On 10/09/18 23:04, frowand.l...@gmail.com wrote:
> From: Frank Rowand <frank.row...@sony.com>
>
>
> "of: overlay: use prop add changeset entry for property in new nodes"
> fixed a problem where an 'update property' changeset entry was
> created for properties contained in nodes added by a changeset.
> The fix was to use an 'add property' changeset entry.
>
> This exposed more bugs in the apply overlay code. The properties
> 'name', 'phandle', and 'linux,phandle' were filtered out by
> add_changeset_property() as special properties. Change the filter
> to be only for existing nodes, not newly added nodes.
>
> The second bug is that the 'name' property does not exist in the
> newest FDT version, and has to be constructed from the node's
> full_name. Construct an 'add property' changeset entry for
> newly added nodes.
>
> Signed-off-by: Frank Rowand <frank.row...@sony.com>
> ---
>
>
> Hi Alan,
>
> Thanks for reporting the problem with missing node names.
>
> I was able to replicate the problem, and have created this preliminary
> version of a patch to fix the problem.
>
> I have not extensively reviewed the patch yet, but would appreciate
> if you can confirm this fixes your problem.
>
> I created this patch as patch 17 of the series, but have also
> applied it as patch 05.1, immediately after patch 05/16, and
> built the kernel, booted, and verified name and phandle for
> one of the nodes in a unittest overlay for both cases. So
> minimal testing so far on my part.
>
> I have not verified whether the series builds and boots after
> each of patches 06..16 if this patch is applied as patch 05.1.
>
> There is definitely more work needed for me to complete this
> patch because it allocates some more memory, but does not yet
> free it when the overlay is released.
>
> -Frank
>
>
> drivers/of/overlay.c | 72
> ++++++++++++++++++++++++++++++++++++++++++++++++----
> 1 file changed, 67 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
> index 0b0904f44bc7..9746cea2aa91 100644
> --- a/drivers/of/overlay.c
> +++ b/drivers/of/overlay.c
> @@ -301,10 +301,11 @@ static int add_changeset_property(struct
> overlay_changeset *ovcs,
> struct property *new_prop = NULL, *prop;
> int ret = 0;
>
> - if (!of_prop_cmp(overlay_prop->name, "name") ||
> - !of_prop_cmp(overlay_prop->name, "phandle") ||
> - !of_prop_cmp(overlay_prop->name, "linux,phandle"))
> - return 0;
> + if (target->in_livetree)
> + if (!of_prop_cmp(overlay_prop->name, "name") ||
> + !of_prop_cmp(overlay_prop->name, "phandle") ||
> + !of_prop_cmp(overlay_prop->name, "linux,phandle"))
> + return 0;
This is a big hammer patch.
Nobody should waste time reviewing this patch.
The following part should not be needed (though the above section might have
to become _slightly_ more complex).
-Frank
>
> if (target->in_livetree)
> prop = of_find_property(target->np, overlay_prop->name, NULL);
> @@ -443,10 +444,13 @@ static int build_changeset_next_level(struct
> overlay_changeset *ovcs,
> struct target *target, const struct device_node *overlay_node)
> {
> struct device_node *child;
> - struct property *prop;
> + struct property *prop, *name_prop;
> + bool has_name = false;
> int ret;
>
> for_each_property_of_node(overlay_node, prop) {
> + if (!strcmp(prop->name, "name"))
> + has_name = true;
> ret = add_changeset_property(ovcs, target, prop, 0);
> if (ret) {
> pr_debug("Failed to apply prop @%pOF/%s, err=%d\n",
> @@ -455,6 +459,57 @@ static int build_changeset_next_level(struct
> overlay_changeset *ovcs,
> }
> }
>
> + /*
> + * With FDT version 0x10 we may not have the name property,
> + * recreate it here from the unit name if absent
> + */
> +
> + if (!has_name) {
> + const char *p = target->np->full_name, *ps = p, *pa = NULL;
> + int len;
> +
> + /*
> + * zzz
> + * TODO: stash name_prop on a list in ovcs, to be freed
> + * after overlay removed
> + */
> +
> + while (*p) {
> + if ((*p) == '@')
> + pa = p;
> + else if ((*p) == '/')
> + ps = p + 1;
> + p++;
> + }
> +
> + if (pa < ps)
> + pa = p;
> + len = (pa - ps) + 1;
> +
> + name_prop = kmalloc(sizeof(*name_prop), GFP_KERNEL);
> + if (!name_prop)
> + return -ENOMEM;
> +
> + name_prop->name = kstrdup("name", GFP_KERNEL);
> + name_prop->value = kmalloc(len, GFP_KERNEL);
> + if (!name_prop->name || !name_prop->value) {
> + ret = -ENOMEM;
> + goto err_free_name_prop;
> + }
> +
> + memcpy(name_prop->value, ps, len - 1);
> + ((char *)name_prop->value)[len - 1] = 0;
> +
> + name_prop->length = strlen(name_prop->value) + 1;
> +
> + ret = add_changeset_property(ovcs, target, name_prop, 0);
> + if (ret) {
> + pr_debug("Failed to apply name_prop @%pOF/%s, err=%d\n",
> + target->np, name_prop->name, ret);
> + goto err_free_name_prop;
> + }
> + }
> +
> for_each_child_of_node(overlay_node, child) {
> ret = add_changeset_node(ovcs, target, child);
> if (ret) {
> @@ -466,6 +521,13 @@ static int build_changeset_next_level(struct
> overlay_changeset *ovcs,
> }
>
> return 0;
> +
> +err_free_name_prop:
> + kfree(name_prop->name);
> + kfree(name_prop->value);
> + kfree(name_prop);
> + return ret;
> +
> }
>
> /*
>
