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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 11/17] of: overlay: check prevents multiple fragments add or delete same node
Date: Thu,  8 Nov 2018 22:05:59 -0800	[thread overview]
Message-ID: <1541743565-23163-12-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>

Multiple overlay fragments adding or deleting the same node is not
supported.  Replace code comment of such, with check to detect the
attempt and fail the overlay apply.

Devicetree unittest where multiple fragments added the same node was
added in the previous patch in the series.  After applying this patch
the unittest messages will no longer include:

   Duplicate name in motor-1, renamed to "controller#1"
   OF: overlay: of_overlay_apply() err=0
   ### dt-test ### of_overlay_fdt_apply() expected -22, ret=0, overlay_bad_add_dup_node
   ### dt-test ### FAIL of_unittest_overlay_high_level():2419 Adding overlay 'overlay_bad_add_dup_node' failed

   ...

   ### dt-test ### end of unittest - 210 passed, 1 failed

but will instead include:

   OF: overlay: ERROR: multiple overlay fragments add and/or delete node /testcase-data-2/substation@100/motor-1/controller

   ...

   ### dt-test ### end of unittest - 211 passed, 0 failed

Tested-by: Alan Tull <atull@kernel.org>
Signed-off-by: Frank Rowand <frank.rowand@sony.com>
---

checkpatch errors "line over 80 characters" and "Too many leading tabs"
are ok, they will be fixed later in this series

 drivers/of/overlay.c | 58 ++++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 49 insertions(+), 9 deletions(-)

diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
index c8f88b0836a3..8af8115bd36e 100644
--- a/drivers/of/overlay.c
+++ b/drivers/of/overlay.c
@@ -392,14 +392,6 @@ static int add_changeset_property(struct overlay_changeset *ovcs,
  *       a live devicetree created from Open Firmware.
  *
  * NOTE_2: Multiple mods of created nodes not supported.
- *       If more than one fragment contains a node that does not already exist
- *       in the live tree, then for each fragment of_changeset_attach_node()
- *       will add a changeset entry to add the node.  When the changeset is
- *       applied, __of_attach_node() will attach the node twice (once for
- *       each fragment).  At this point the device tree will be corrupted.
- *
- *       TODO: add integrity check to ensure that multiple fragments do not
- *             create the same node.
  *
  * Returns 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if
  * invalid @overlay.
@@ -517,6 +509,54 @@ static int build_changeset_symbols_node(struct overlay_changeset *ovcs,
 }
 
 /**
+ * check_changeset_dup_add_node() - changeset validation: duplicate add node
+ * @ovcs:	Overlay changeset
+ *
+ * Check changeset @ovcs->cset for multiple add node entries for the same
+ * node.
+ *
+ * Returns 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if
+ * invalid overlay in @ovcs->fragments[].
+ */
+static int check_changeset_dup_add_node(struct overlay_changeset *ovcs)
+{
+	struct of_changeset_entry *ce_1, *ce_2;
+	char *fn_1, *fn_2;
+	int name_match;
+
+	list_for_each_entry(ce_1, &ovcs->cset.entries, node) {
+
+		if (ce_1->action == OF_RECONFIG_ATTACH_NODE ||
+		    ce_1->action == OF_RECONFIG_DETACH_NODE) {
+
+			ce_2 = ce_1;
+			list_for_each_entry_continue(ce_2, &ovcs->cset.entries, node) {
+				if (ce_2->action == OF_RECONFIG_ATTACH_NODE ||
+				    ce_2->action == OF_RECONFIG_DETACH_NODE) {
+					/* inexpensive name compare */
+					if (!of_node_cmp(ce_1->np->full_name,
+					    ce_2->np->full_name)) {
+						/* expensive full path name compare */
+						fn_1 = kasprintf(GFP_KERNEL, "%pOF", ce_1->np);
+						fn_2 = kasprintf(GFP_KERNEL, "%pOF", ce_2->np);
+						name_match = !strcmp(fn_1, fn_2);
+						kfree(fn_1);
+						kfree(fn_2);
+						if (name_match) {
+							pr_err("ERROR: multiple overlay fragments add and/or delete node %pOF\n",
+							       ce_1->np);
+							return -EINVAL;
+						}
+					}
+				}
+			}
+		}
+	}
+
+	return 0;
+}
+
+/**
  * build_changeset() - populate overlay changeset in @ovcs from @ovcs->fragments
  * @ovcs:	Overlay changeset
  *
@@ -571,7 +611,7 @@ static int build_changeset(struct overlay_changeset *ovcs)
 		}
 	}
 
-	return 0;
+	return check_changeset_dup_add_node(ovcs);
 }
 
 /*
-- 
Frank Rowand <frank.rowand@sony.com>


  parent reply	other threads:[~2018-11-09  6:08 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 ` [PATCH v7 08/17] of: overlay: validate overlay properties #address-cells and #size-cells frowand.list
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 ` frowand.list [this message]
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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