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Message-ID: <CANk1AXQFTfdwy9n+WH2k98w6oyqLj3wLDRfaMmtTGk66sJjqUw@mail.gmail.com>
Date: Mon, 8 Oct 2018 10:57:50 -0500
From: Alan Tull <atull@...nel.org>
To: Frank Rowand <frowand.list@...il.com>
Cc: Rob Herring <robh+dt@...nel.org>,
Pantelis Antoniou <pantelis.antoniou@...sulko.com>,
Michael Ellerman <mpe@...erman.id.au>,
Benjamin Herrenschmidt <benh@...nel.crashing.org>,
Paul Mackerras <paulus@...ba.org>,
Moritz Fischer <mdf@...nel.org>,
linux-kernel <linux-kernel@...r.kernel.org>,
linuxppc-dev <linuxppc-dev@...ts.ozlabs.org>,
"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
<devicetree@...r.kernel.org>, linux-fpga@...r.kernel.org
Subject: Re: [PATCH 09/16] of: overlay: validate overlay properties
#address-cells and #size-cells
On Thu, Oct 4, 2018 at 11:14 PM <frowand.list@...il.com> wrote:
>
> From: Frank Rowand <frank.rowand@...y.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.
Hi Frank,
I'm starting some FPGA testing on this patchset applied to v4.19-rc7.
That applied cleanly; if that's not the best base to test against,
please let me know.
On a very simple overlay, I'm seeing this patch's warning catching
things other than #address-cells or #size-cells. I'm just getting
started looking at this, will spend time understanding this better and
I'll test other overlays. The warnings were:
Applying dtbo: socfpga_overlay.dtb
[ 33.117881] fpga_manager fpga0: writing soc_system.rbf to Altera
SOCFPGA FPGA Manager
[ 33.575223] OF: overlay: WARNING: add_changeset_property(), memory
leak will occur if overlay removed. Property:
/soc/base-fpga-region/firmware-name
[ 33.588584] OF: overlay: WARNING: add_changeset_property(), memory
leak will occur if overlay removed. Property:
/soc/base-fpga-region/fpga-bridges
[ 33.601856] OF: overlay: WARNING: add_changeset_property(), memory
leak will occur if overlay removed. Property:
/soc/base-fpga-region/ranges
Here's part of that overlay including the properties it's complaining about:
/dts-v1/;
/plugin/;
/ {
fragment@0 {
target = <&base_fpga_region>;
#address-cells = <1>;
#size-cells = <1>;
__overlay__ {
#address-cells = <1>;
#size-cells = <1>;
firmware-name = "soc_system.rbf";
fpga-bridges = <&fpga_bridge1>;
ranges = <0x20000 0xff200000 0x100000>,
<0x0 0xc0000000 0x20000000>;
gpio@...40 {
so on...
By the way, I didn't get any warnings when I subsequently removed this overlay.
Alan
>
> 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
>
> Signed-off-by: Frank Rowand <frank.rowand@...y.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.
> *
> * 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) {
> +
> + 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)
> + 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@...y.com>
>
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