From: Frank Rowand <frowand.list@gmail.com>
To: Rob Herring <robh+dt@kernel.org>
Cc: Pantelis Antoniou <pantelis.antoniou@konsulko.com>,
Michael Ellerman <mpe@ellerman.id.au>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>, Alan Tull <atull@kernel.org>,
Moritz Fischer <mdf@kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
devicetree@vger.kernel.org, linux-fpga@vger.kernel.org
Subject: Re: [PATCH 09/16] of: overlay: validate overlay properties #address-cells and #size-cells
Date: Fri, 5 Oct 2018 11:53:44 -0700 [thread overview]
Message-ID: <f39a84d3-f706-d31e-db22-4e3ebc72c447@gmail.com> (raw)
In-Reply-To: <CAL_JsqKK3f4W1DdPkzNed0=tx5Oxu9w=RKs8PnaXMfuShBpV1A@mail.gmail.com>
On 10/05/18 08:07, Rob Herring wrote:
> On Thu, Oct 4, 2018 at 11:14 PM <frowand.list@gmail.com> wrote:
>>
>> From: Frank Rowand <frank.rowand@sony.com>
>>
>> If overlay properties #address-cells or #size-cells are already in
>> the live devicetree for any given node, then the values in the
>> overlay must match the values in the live tree.
>>
>> If the properties are already in the live tree then there is no
>> need to create a changeset entry to add them since they must
>> have the same value. This reduces the memory used by the
>> changeset and eliminates a possible memory leak. This is
>> verified by 12 fewer warnings during the devicetree unittest,
>> as the possible memory leak warnings about #address-cells and
>
> and...?
#size-cells no longer occur.
(Thanks for catching that.)
>>
>> Signed-off-by: Frank Rowand <frank.rowand@sony.com>
>> ---
>> drivers/of/overlay.c | 38 +++++++++++++++++++++++++++++++++++---
>> 1 file changed, 35 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
>> index 29c33a5c533f..e6fb3ffe9d93 100644
>> --- a/drivers/of/overlay.c
>> +++ b/drivers/of/overlay.c
>> @@ -287,7 +287,12 @@ static struct property *dup_and_fixup_symbol_prop(
>> * @target may be either in the live devicetree or in a new subtree that
>> * is contained in the changeset.
>> *
>> - * Some special properties are not updated (no error returned).
>> + * Some special properties are not added or updated (no error returned):
>> + * "name", "phandle", "linux,phandle".
>> + *
>> + * Properties "#address-cells" and "#size-cells" are not updated if they
>> + * are already in the live tree, but if present in the live tree, the values
>> + * in the overlay must match the values in the live tree.
>
> Perhaps this should be generalized to apply to any property? We can't
> really deal with property values changing on the fly anyways.
That is a bigger discussion. I'd prefer to not hold up this series for that
question to be resolved. It will be easy enough to generalize in an add-on
patch later.
>> *
>> * Update of property in symbols node is not allowed.
>> *
>> @@ -300,6 +305,7 @@ static int add_changeset_property(struct overlay_changeset *ovcs,
>> {
>> struct property *new_prop = NULL, *prop;
>> int ret = 0;
>> + bool check_for_non_overlay_node = false;
>>
>> if (!of_prop_cmp(overlay_prop->name, "name") ||
>> !of_prop_cmp(overlay_prop->name, "phandle") ||
>> @@ -322,13 +328,39 @@ static int add_changeset_property(struct overlay_changeset *ovcs,
>> if (!new_prop)
>> return -ENOMEM;
>>
>> - if (!prop)
>> + if (!prop) {
>> +
>
> Remove the extra blank lines.
Will do.
>
>> + check_for_non_overlay_node = true;
>> ret = of_changeset_add_property(&ovcs->cset, target->np,
>> new_prop);
>> - else
>> +
>> + } else if (!of_prop_cmp(prop->name, "#address-cells")) {
>> +
>> + if (prop->length != 4 || new_prop->length != 4 ||
>> + *(u32 *)prop->value != *(u32 *)new_prop->value)
>
> Technically these are __be32 types. This could use a helper (of_prop_val_eq).
These are in a unpacked form, so cpu byte order, not FDT byte order.
>
> I'm not sure we really need to validate the length here as dtc does
> that (but yes, not everything is from dtc).
Since I'm accessing 4 bytes of the values, I need to be sure the lengths
are at least 4. For #address-cells and #size-cells the property is
specified as four bytes, so I could simplify the code for the specific case.
If this gets extended to any arbitrary property then a new of_prop_val_eq()
would check that the lengths are equal and the values (of size length) are
also equal.
>
>> + pr_err("ERROR: overlay and/or live tree #address-cells invalid in node %pOF\n",
>> + target->np);
>> +
>> + } else if (!of_prop_cmp(prop->name, "#size-cells")) {
>> +
>> + if (prop->length != 4 || new_prop->length != 4 ||
>> + *(u32 *)prop->value != *(u32 *)new_prop->value)
>> + pr_err("ERROR: overlay and/or live tree #size-cells invalid in node %pOF\n",
>> + target->np);
>> +
>> + } else {
>> +
>> + check_for_non_overlay_node = true;
>> ret = of_changeset_update_property(&ovcs->cset, target->np,
>> new_prop);
>>
>> + }
>> +
>> + if (check_for_non_overlay_node &&
>> + !of_node_check_flag(target->np, OF_OVERLAY))
>> + pr_err("WARNING: %s(), memory leak will occur if overlay removed. Property: %pOF/%s\n",
>> + __func__, target->np, new_prop->name);
>> +
>> if (ret) {
>> kfree(new_prop->name);
>> kfree(new_prop->value);
>> --
>> Frank Rowand <frank.rowand@sony.com>
>>
>
next prev parent reply other threads:[~2018-10-05 18:53 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-05 4:12 [PATCH 00/16] of: overlay: validation checks, subsequent fixes frowand.list
2018-10-05 4:12 ` [PATCH 01/16] of: overlay: add tests to validate kfrees from overlay removal frowand.list
2018-10-05 4:12 ` [PATCH 02/16] of: overlay: add missing of_node_put() after add new node to changeset frowand.list
2018-10-05 4:12 ` [PATCH 03/16] of: overlay: add missing of_node_get() in __of_attach_node_sysfs frowand.list
2018-10-05 4:12 ` [PATCH 04/16] powerpc/pseries: add of_node_put() in dlpar_detach_node() frowand.list
2018-10-05 4:12 ` [PATCH 05/16] of: overlay: use prop add changeset entry for property in new nodes frowand.list
2018-10-09 20:28 ` Alan Tull
2018-10-09 23:44 ` Frank Rowand
2018-10-10 6:04 ` [PATCH 05.1/16] of:overlay: missing name, phandle, linux,phandle " frowand.list
2018-10-10 6:49 ` Frank Rowand
2018-10-10 20:40 ` Alan Tull
2018-10-10 21:03 ` Frank Rowand
2018-10-11 5:39 ` Frank Rowand
2018-10-11 19:33 ` Alan Tull
2018-10-11 23:38 ` Frank Rowand
2018-10-05 4:12 ` [PATCH 06/16] of: overlay: do not duplicate properties from overlay for " frowand.list
2018-10-05 4:12 ` [PATCH 07/16] of: dynamic: change type of of_{at,de}tach_node() to void frowand.list
2018-10-05 4:12 ` [PATCH 08/16] of: overlay: reorder fields in struct fragment frowand.list
2018-10-05 4:12 ` [PATCH 09/16] of: overlay: validate overlay properties #address-cells and #size-cells frowand.list
2018-10-05 15:07 ` Rob Herring
2018-10-05 18:53 ` Frank Rowand [this message]
2018-10-05 19:04 ` Rob Herring
2018-10-05 19:09 ` Frank Rowand
2018-10-08 15:57 ` Alan Tull
2018-10-08 18:46 ` Alan Tull
2018-10-09 0:02 ` Frank Rowand
2018-10-09 18:40 ` Alan Tull
2018-10-05 4:12 ` [PATCH 10/16] of: overlay: make all pr_debug() and pr_err() messages unique frowand.list
2018-10-05 4:12 ` [PATCH 11/16] of: overlay: test case of two fragments adding same node frowand.list
2018-10-05 4:12 ` [PATCH 12/16] of: overlay: check prevents multiple fragments add or delete " frowand.list
2018-10-05 4:12 ` [PATCH 13/16] of: overlay: check prevents multiple fragments touching same property frowand.list
2018-10-05 4:12 ` [PATCH 14/16] of: unittest: remove unused of_unittest_apply_overlay() argument frowand.list
2018-10-05 4:12 ` [PATCH 15/16] of: unittest: initialize args before calling of_irq_parse_one() frowand.list
2018-10-05 13:26 ` Guenter Roeck
2018-10-05 19:05 ` Frank Rowand
2018-10-05 14:53 ` Rob Herring
2018-10-05 19:04 ` Frank Rowand
2018-10-05 4:12 ` [PATCH 16/16] of: unittest: find overlays[] entry by name instead of index frowand.list
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=f39a84d3-f706-d31e-db22-4e3ebc72c447@gmail.com \
--to=frowand.list@gmail.com \
--cc=atull@kernel.org \
--cc=benh@kernel.crashing.org \
--cc=devicetree@vger.kernel.org \
--cc=linux-fpga@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=mdf@kernel.org \
--cc=mpe@ellerman.id.au \
--cc=pantelis.antoniou@konsulko.com \
--cc=paulus@samba.org \
--cc=robh+dt@kernel.org \
/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;
as well as URLs for NNTP newsgroup(s).