[PATCH 05.1/16] of:overlay: missing name, phandle, linux, phandle in new nodes
Frank Rowand
frowand.list at gmail.com
Thu Oct 11 08:03:00 AEDT 2018
On 10/10/18 13:40, Alan Tull wrote:
> On Wed, Oct 10, 2018 at 1:49 AM Frank Rowand <frowand.list at gmail.com> wrote:
>>
>> On 10/09/18 23:04, frowand.list at gmail.com wrote:
>>> From: Frank Rowand <frank.rowand at 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.rowand at 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.
>
> I wasn't clear if you still could use the testing so I did re-run my
> test. This patch adds back some of the missing properties, but the
> the kobject names aren't set as dev_name() returns NULL:
>
> * without this patch some of_node properties don't show up in sysfs:
> root at arria10:~# ls
> /sys/bus/platform/drivers/altera_freeze_br/ff200450.\<NULL\>/of_node
> clocks compatible interrupt-parent interrupts reg
>
> * with this patch, the of_node properties phandle and name are back:
> root at arria10:~# ls
> /sys/bus/platform/drivers/altera_freeze_br/ff200450.\<NULL\>/of_node
> clocks compatible interrupt-parent interrupts
> name phandle reg
Thanks for the testing. I'll keep chasing after this problem today.
This is useful data for me as I was not looking under the /sys/bus/...
tree that you reported, but was instead looking at /proc/device-tree/...
which showed the same type of problem since the overlay I was using
does not show up under /sys/bus/...
I'll have to create a useful overlay test case that will show up under
/sys/bus/...
In the meantime, can you send me the base FDT and the overlay FDT for
your test case?
Thanks,
Frank
>
> root at arria10:~# cat
> /sys/bus/platform/drivers/altera_freeze_br/ff200450.\<NULL\>/of_node/name
> freeze_controllerroot at arria10:~# ("freeze_controller" w/o the \n so
> the name is correct)
>
> * with or without the patch I see the behavior I reported yesterday,
> kobj names are NULL.
> root at arria10:~# ls /sys/bus/platform/drivers/altera_freeze_br/
> bind ff200450.<NULL> uevent unbind
>
> root at arria10:~# ls /sys/bus/platform/drivers/altera_gpio/
> bind ff200010.<NULL> ff200020.<NULL> ff200030.<NULL>
> uevent unbind
>
> Alan
>
> Alan
>
>>
>> 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;
>>> +
>>> }
>>>
>>> /*
>>>
>>
>
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