libfdt: Fix bug in fdt_subnode_offset_namelen()

There's currently an off-by-one bug in fdt_subnode_offset_namelen()
which causes it to keep searching after it's finished the subnodes of
the given parent, and into the subnodes of siblings of the original
node which come after it in the tree.

This patch fixes the bug.  It also extends the subnode_offset testcase
(updating all of the 'test_tree1' example trees in the process) to
catch it.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

9 files changed, 60 insertions, 11 deletions

diff --git a/libfdt/fdt_ro.c b/libfdt/fdt_ro.c
index 6365c26..d12c7ee 100644
--- a/libfdt/fdt_ro.c
+++ b/libfdt/fdt_ro.c
@@ -108,12 +108,12 @@ int fdt_num_mem_rsv(const void *fdt)
 int fdt_subnode_offset_namelen(const void *fdt, int offset,
 			       const char *name, int namelen)
 {
-	int depth;
+	int depth = 0;
 
 	FDT_CHECK_HEADER(fdt);
 
-	for (depth = 0;
-	     offset >= 0;
+	for (depth = 0, offset = fdt_next_node(fdt, offset, &depth);
+	     (offset >= 0) && (depth > 0);
 	     offset = fdt_next_node(fdt, offset, &depth)) {
 		if (depth < 0)
 			return -FDT_ERR_NOTFOUND;
@@ -122,7 +122,10 @@ int fdt_subnode_offset_namelen(const void *fdt, int offset,
 			return offset;
 	}
 
-	return offset; /* error */
+	if (offset < 0)
+		return offset; /* error */
+	else
+		return -FDT_ERR_NOTFOUND;
 }
 
 int fdt_subnode_offset(const void *fdt, int parentoffset,
diff --git a/tests/include1.dts b/tests/include1.dts
index 0c7f42e..8d7e747 100644
--- a/tests/include1.dts
+++ b/tests/include1.dts
@@ -19,5 +19,8 @@
 			compatible = "subsubnode2", "subsubnode";
 			prop-int = <0726746425>;
 		};
+
+		ss2 {
+		};
 	};
 };
diff --git a/tests/include7.dts b/tests/include7.dts
index fa726f9..dba5e47 100644
--- a/tests/include7.dts
+++ b/tests/include7.dts
@@ -6,4 +6,7 @@
 			compatible = "subsubnode1", "subsubnode";
 			prop-int = <0xdeadbeef>;
 		};
+
+		ss1 {
+		};
 	};
diff --git a/tests/rw_tree1.c b/tests/rw_tree1.c
index 8f335c9..f0bce88 100644
--- a/tests/rw_tree1.c
+++ b/tests/rw_tree1.c
@@ -50,7 +50,7 @@ int main(int argc, char *argv[])
 {
 	void *fdt;
 	int err;
-	int offset;
+	int offset, s1, s2;
 
 	test_init(argc, argv);
 
@@ -77,21 +77,25 @@ int main(int argc, char *argv[])
 	CHECK(fdt_setprop_string(fdt, 0, "prop-str", TEST_STRING_1));
 
 	OFF_CHECK(offset, fdt_add_subnode(fdt, 0, "subnode@1"));
-	CHECK(fdt_setprop_string(fdt, offset, "compatible", "subnode1"));
-	CHECK(fdt_setprop_cell(fdt, offset, "prop-int", TEST_VALUE_1));
-	OFF_CHECK(offset, fdt_add_subnode(fdt, offset, "subsubnode"));
+	s1 = offset;
+	CHECK(fdt_setprop_string(fdt, s1, "compatible", "subnode1"));
+	CHECK(fdt_setprop_cell(fdt, s1, "prop-int", TEST_VALUE_1));
+	OFF_CHECK(offset, fdt_add_subnode(fdt, s1, "subsubnode"));
 	CHECK(fdt_setprop(fdt, offset, "compatible",
 			  "subsubnode1\0subsubnode", 23));
 	CHECK(fdt_setprop_cell(fdt, offset, "prop-int", TEST_VALUE_1));
+	OFF_CHECK(offset, fdt_add_subnode(fdt, s1, "ss1"));
 
 	OFF_CHECK(offset, fdt_add_subnode(fdt, 0, "subnode@2"));
-	CHECK(fdt_setprop_cell(fdt, offset, "linux,phandle", PHANDLE_1));
-	CHECK(fdt_setprop_cell(fdt, offset, "prop-int", TEST_VALUE_2));
-	OFF_CHECK(offset, fdt_add_subnode(fdt, offset, "subsubnode@0"));
+	s2 = offset;
+	CHECK(fdt_setprop_cell(fdt, s2, "linux,phandle", PHANDLE_1));
+	CHECK(fdt_setprop_cell(fdt, s2, "prop-int", TEST_VALUE_2));
+	OFF_CHECK(offset, fdt_add_subnode(fdt, s2, "subsubnode@0"));
 	CHECK(fdt_setprop_cell(fdt, offset, "linux,phandle", PHANDLE_2));
 	CHECK(fdt_setprop(fdt, offset, "compatible",
 			  "subsubnode2\0subsubnode", 23));
 	CHECK(fdt_setprop_cell(fdt, offset, "prop-int", TEST_VALUE_2));
+	OFF_CHECK(offset, fdt_add_subnode(fdt, s2, "ss2"));
 
 	CHECK(fdt_pack(fdt));
 
diff --git a/tests/subnode_offset.c b/tests/subnode_offset.c
index 17be8d8..b961070 100644
--- a/tests/subnode_offset.c
+++ b/tests/subnode_offset.c
@@ -60,6 +60,7 @@ int main(int argc, char *argv[])
 	void *fdt;
 	int subnode1_offset, subnode2_offset;
 	int subsubnode1_offset, subsubnode2_offset, subsubnode2_offset2;
+	int ss11_off, ss12_off, ss21_off, ss22_off;
 
 	test_init(argc, argv);
 	fdt = load_blob_arg(argc, argv);
@@ -84,5 +85,15 @@ int main(int argc, char *argv[])
 	if (subsubnode2_offset != subsubnode2_offset2)
 		FAIL("Different offsets with and without unit address");
 
+	ss11_off = check_subnode(fdt, subnode1_offset, "ss1");
+	ss21_off = fdt_subnode_offset(fdt, subnode2_offset, "ss1");
+	if (ss21_off != -FDT_ERR_NOTFOUND)
+		FAIL("Incorrectly found ss1 in subnode2");
+
+	ss12_off = fdt_subnode_offset(fdt, subnode1_offset, "ss2");
+	if (ss12_off != -FDT_ERR_NOTFOUND)
+		FAIL("Incorrectly found ss2 in subnode1");
+	ss22_off = check_subnode(fdt, subnode2_offset, "ss2");
+
 	PASS();
 }
diff --git a/tests/sw_tree1.c b/tests/sw_tree1.c
index 2a94b63..687fb82 100644
--- a/tests/sw_tree1.c
+++ b/tests/sw_tree1.c
@@ -66,6 +66,8 @@ int main(int argc, char *argv[])
 			   23));
 	CHECK(fdt_property_cell(fdt, "prop-int", TEST_VALUE_1));
 	CHECK(fdt_end_node(fdt));
+	CHECK(fdt_begin_node(fdt, "ss1"));
+	CHECK(fdt_end_node(fdt));
 	CHECK(fdt_end_node(fdt));
 
 	CHECK(fdt_begin_node(fdt, "subnode@2"));
@@ -77,6 +79,9 @@ int main(int argc, char *argv[])
 			   23));
 	CHECK(fdt_property_cell(fdt, "prop-int", TEST_VALUE_2));
 	CHECK(fdt_end_node(fdt));
+	CHECK(fdt_begin_node(fdt, "ss2"));
+	CHECK(fdt_end_node(fdt));
+
 	CHECK(fdt_end_node(fdt));
 
 	CHECK(fdt_end_node(fdt));
diff --git a/tests/test_tree1.dts b/tests/test_tree1.dts
index 27602af..1593554 100644
--- a/tests/test_tree1.dts
+++ b/tests/test_tree1.dts
@@ -16,6 +16,9 @@
 			compatible = "subsubnode1", "subsubnode";
 			prop-int = <0xdeadbeef>;
 		};
+
+		ss1 {
+		};
 	};
 
 	subnode@2 {
@@ -27,5 +30,8 @@
 			compatible = "subsubnode2", "subsubnode";
 			prop-int = <0726746425>;
 		};
+
+		ss2 {
+		};
 	};
 };
diff --git a/tests/test_tree1_dts0.dts b/tests/test_tree1_dts0.dts
index 6b40cf5..032d540 100644
--- a/tests/test_tree1_dts0.dts
+++ b/tests/test_tree1_dts0.dts
@@ -16,6 +16,9 @@
 			compatible = "subsubnode1", "subsubnode";
 			prop-int = < 0xdeadbeef>;
 		};
+
+		ss1 {
+		};
 	};
 
 	subnode@2 {
@@ -27,5 +30,8 @@
 			compatible = "subsubnode2", "subsubnode";
 			prop-int = < 0726746425>;
 		};
+
+		ss2 {
+		};
 	};
 };
diff --git a/tests/trees.S b/tests/trees.S
index cedf5f9..609cdd6 100644
--- a/tests/trees.S
+++ b/tests/trees.S
@@ -96,6 +96,10 @@ test_tree1_struct:
 	PROP_STR(test_tree1, compatible, "subsubnode1\0subsubnode")
 	PROP_INT(test_tree1, prop_int, TEST_VALUE_1)
 	END_NODE
+
+	BEGIN_NODE("ss1")
+	END_NODE
+
 	END_NODE
 
 	BEGIN_NODE("subnode@2")
@@ -107,6 +111,10 @@ test_tree1_struct:
 	PROP_STR(test_tree1, compatible, "subsubnode2\0subsubnode")
 	PROP_INT(test_tree1, prop_int, TEST_VALUE_2)
 	END_NODE
+
+	BEGIN_NODE("ss2")
+	END_NODE
+
 	END_NODE
 
 	END_NODE