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From: frowand.list@gmail.com
To: Rob Herring <robh+dt@kernel.org>,
	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>
Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
	devicetree@vger.kernel.org, linux-fpga@vger.kernel.org
Subject: [PATCH v7 08/17] of: overlay: validate overlay properties #address-cells and #size-cells
Date: Thu,  8 Nov 2018 22:05:56 -0800	[thread overview]
Message-ID: <1541743565-23163-9-git-send-email-frowand.list@gmail.com> (raw)
In-Reply-To: <1541743565-23163-1-git-send-email-frowand.list@gmail.com>

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.

Tested-by: Alan Tull <atull@kernel.org>
Signed-off-by: Frank Rowand <frank.rowand@sony.com>
---
 drivers/of/overlay.c | 32 +++++++++++++++++++++++++++++---
 include/linux/of.h   |  6 ++++++
 2 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
index 15be3da34fef..72bf00adb9c8 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") ||
@@ -322,12 +328,32 @@ 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 (!of_prop_val_eq(prop, new_prop)) {
+			pr_err("ERROR: changing value of #address-cells is not allowed in %pOF\n",
+			       target->np);
+			ret = -EINVAL;
+		}
+	} else if (!of_prop_cmp(prop->name, "#size-cells")) {
+		if (!of_prop_val_eq(prop, new_prop)) {
+			pr_err("ERROR: changing value of #size-cells is not allowed in %pOF\n",
+			       target->np);
+			ret = -EINVAL;
+		}
+	} 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: memory leak will occur if overlay removed, property: %pOF/%s\n",
+		       target->np, new_prop->name);
 
 	if (ret) {
 		kfree(new_prop->name);
diff --git a/include/linux/of.h b/include/linux/of.h
index 664cd5573ae2..18ac8921e90c 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -990,6 +990,12 @@ static inline int of_map_rid(struct device_node *np, u32 rid,
 #define of_node_cmp(s1, s2)		strcasecmp((s1), (s2))
 #endif
 
+static inline int of_prop_val_eq(struct property *p1, struct property *p2)
+{
+	return p1->length == p2->length &&
+	       !memcmp(p1->value, p2->value, (size_t)p1->length);
+}
+
 #if defined(CONFIG_OF) && defined(CONFIG_NUMA)
 extern int of_node_to_nid(struct device_node *np);
 #else
-- 
Frank Rowand <frank.rowand@sony.com>


  parent reply	other threads:[~2018-11-09  6:07 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-09  6:05 [PATCH v7 00/17] of: overlay: validation checks, subsequent fixes frowand.list
2018-11-09  6:05 ` [PATCH v7 01/17] of: overlay: add tests to validate kfrees from overlay removal frowand.list
2018-11-09  6:05 ` [PATCH v7 02/17] of: overlay: add missing of_node_put() after add new node to changeset frowand.list
2018-11-09  6:05 ` [PATCH v7 03/17] of: overlay: add missing of_node_get() in __of_attach_node_sysfs frowand.list
2018-11-09  6:05 ` [PATCH v7 04/17] powerpc/pseries: add of_node_put() in dlpar_detach_node() frowand.list
2018-11-09  6:05 ` [PATCH v7 05/17] of: overlay: use prop add changeset entry for property in new nodes frowand.list
2018-11-09  6:05 ` [PATCH v7 06/17] of: overlay: do not duplicate properties from overlay for " frowand.list
2018-11-09  6:05 ` [PATCH v7 07/17] of: overlay: reorder fields in struct fragment frowand.list
2018-11-09  6:05 ` frowand.list [this message]
2018-11-09  6:05 ` [PATCH v7 09/17] of: overlay: make all pr_debug() and pr_err() messages unique frowand.list
2018-11-09  6:05 ` [PATCH v7 10/17] of: overlay: test case of two fragments adding same node frowand.list
2018-11-09  6:05 ` [PATCH v7 11/17] of: overlay: check prevents multiple fragments add or delete " frowand.list
2018-11-09  6:06 ` [PATCH v7 12/17] of: overlay: check prevents multiple fragments touching same property frowand.list
2018-11-09  6:06 ` [PATCH v7 13/17] of: unittest: remove unused of_unittest_apply_overlay() argument frowand.list
2018-11-09  6:06 ` [PATCH v7 14/17] of: overlay: set node fields from properties when add new overlay node frowand.list
2018-11-09  6:06 ` [PATCH v7 15/17] of: unittest: allow base devicetree to have symbol metadata frowand.list
2018-11-09  6:06 ` [PATCH v7 16/17] of: unittest: find overlays[] entry by name instead of index frowand.list
2018-11-09  6:06 ` [PATCH v7 17/17] of: unittest: initialize args before calling of_*parse_*() frowand.list

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