[PATCH 05.1/16] of:overlay: missing name, phandle, linux, phandle in new nodes
Frank Rowand
frowand.list at gmail.com
Thu Oct 11 16:39:28 AEDT 2018
On 10/10/18 14:03, Frank Rowand wrote:
> 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?
I now have a test case that shows the problem under /sys/bus/... so I
no longer need the base FDT and overlay FDT for your test case.
I have determined the location that sets the name to "<NULL>" but do
not have the fix yet. Still working on that.
-Frank
>
> 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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