From: Michael Riesch <michael.riesch@wolfvision.net>
To: Michael Tretter <m.tretter@pengutronix.de>
Cc: barebox@lists.infradead.org
Subject: Re: [PATCH 1/2] of: overlay: improve error handling in of_overlay_apply_tree
Date: Wed, 21 Sep 2022 12:00:38 +0200 [thread overview]
Message-ID: <521707bd-6b5a-af0b-1976-7f971d90a9e7@wolfvision.net> (raw)
In-Reply-To: <20220921075705.GD16312@pengutronix.de>
Hi Michael,
On 9/21/22 09:57, Michael Tretter wrote:
> On Wed, 21 Sep 2022 08:55:12 +0200, Michael Riesch wrote:
>> On 9/5/22 12:07, Michael Riesch wrote:
>>> Propagate any error from of_overlay_apply_symbols and let the user
>>> know if the provided overlay is not applicable.
>>>
>>> Signed-off-by: Michael Riesch <michael.riesch@wolfvision.net>
>>> ---
>>> drivers/of/overlay.c | 14 +++++++++-----
>>> 1 file changed, 9 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
>>> index 20a43f5170..20686db511 100644
>>> --- a/drivers/of/overlay.c
>>> +++ b/drivers/of/overlay.c
>>> @@ -115,8 +115,8 @@ static char *of_overlay_fix_path(struct device_node *root,
>>> return basprintf("%s%s", target->full_name, path_tail);
>>> }
>>>
>>> -static void of_overlay_apply_symbols(struct device_node *root,
>>> - struct device_node *overlay)
>>> +static int of_overlay_apply_symbols(struct device_node *root,
>>> + struct device_node *overlay)
>>> {
>>> const char *old_path;
>>> char *new_path;
>>> @@ -129,12 +129,12 @@ static void of_overlay_apply_symbols(struct device_node *root,
>>>
>>> if (!overlay_symbols) {
>>> pr_debug("overlay doesn't have a __symbols__ node\n");
>>> - return;
>>> + return -EINVAL;
>>
>> Come to think of it, do all overlays need to provide a __symbols__ node?
>> If not, this check is overly strict.
>
> Overlays don't need a __symbols__ node. It would be only required, if overlays
> are stacked and the second overlay refers to nodes of the first overlay by
> labels. Having no __symbols__ in the overlay is a success path and the message
> is just a debug message.
Thanks for the clarification. We need to fix this one, then.
Seeing that the patch is in next: Am I supposed to send an incremental
"fixup! ..." patch which can be squashed? Or should I send a proper
patch with a Fixes: tag?
>>> }
>>>
>>> if (!root_symbols) {
>>> pr_info("root doesn't have a __symbols__ node\n");
>>> - return;
>>> + return -EINVAL;
>>
>> Ditto for the root.
>
> I'm not sure what should happen, if the root does not have __symbols__.
> Barebox wouldn't be able to copy the __symbols__ of the overlay, but this
> still wouldn't be a problem unless overlays are stacked. In the stacking case,
> only applying the second overlay should fail.
I can reestablish the behavior before this patch, i.e., __symbols__ is
optional in both root and overlay.
> Maybe, we should add a new __symbols__ node, if the root doesn't have a
> __symbols__ node?
If this is desired, I can implement the change -- but is it desired?
>>> }
>>>
>>> list_for_each_entry(prop, &overlay_symbols->properties, list) {
>>> @@ -148,6 +148,8 @@ static void of_overlay_apply_symbols(struct device_node *root,
>>> prop->name, new_path);
>>> of_property_write_string(root_symbols, prop->name, new_path);
>>> }
>>> +
>>> + return 0;
>>> }
>>>
>>> static int of_overlay_apply_fragment(struct device_node *root,
>>> @@ -190,7 +192,9 @@ int of_overlay_apply_tree(struct device_node *root,
>>> goto out_err;
>>>
>>> /* Copy symbols from resolved overlay to base device tree */
>>> - of_overlay_apply_symbols(root, resolved);
>>> + err = of_overlay_apply_symbols(root, resolved);
>>> + if (err)
>>> + goto out_err;
>>
>> If both checks need to be relaxed, the complete patch should be reverted
>> I guess :-/
>
> What did you do to run into this error? What was your expectation?
Well I tried to apply an overlay without __symbols__ :-) (which did work
before).
Best regards,
Michael
next prev parent reply other threads:[~2022-09-21 10:02 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-05 10:07 [PATCH 0/2] of: overlay: avoid potential null pointer exception Michael Riesch
2022-09-05 10:07 ` [PATCH 1/2] of: overlay: improve error handling in of_overlay_apply_tree Michael Riesch
2022-09-21 6:55 ` Michael Riesch
2022-09-21 7:57 ` Michael Tretter
2022-09-21 10:00 ` Michael Riesch [this message]
2022-09-05 10:07 ` [PATCH 2/2] of: overlay: avoid potential null pointer exception Michael Riesch
2022-09-12 9:16 ` [PATCH 0/2] " Sascha Hauer
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=521707bd-6b5a-af0b-1976-7f971d90a9e7@wolfvision.net \
--to=michael.riesch@wolfvision.net \
--cc=barebox@lists.infradead.org \
--cc=m.tretter@pengutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox