scripts/dtc: Update to upstream version v1.6.0-2-g87a656ae5ff9

This adds the following commits from upstream:

87a656ae5ff9 check: Inform about missing ranges
73d6e9ecb417 libfdt: fix undefined behaviour in fdt_splice_()
2525da3dba9b Bump version to v1.6.0
62cb4ad286ff Execute tests on FreeBSD with Cirrus CI
1f9a41750883 tests: Allow running the testsuite on already installed binary / libraries
c5995ddf4c20 tests: Honour NO_YAML make variable
e4ce227e89d7 tests: Properly clean up .bak file from tests
9b75292c335c tests: Honour $(NO_PYTHON) flag from Makefile in run_tests.sh
6c253afd07d4 Encode $(NO_PYTHON) consistently with other variables
95ec8ef706bd tests: No need to explicitly pass $PYTHON from Make to run_tests.sh
2b5f62d109a2 tests: Let run_tests.sh run Python tests without Makefile assistance
76b43dcbd18a checks: Add 'dma-ranges' check
e5c92a4780c6 libfdt: Use VALID_INPUT for FDT_ERR_BADSTATE checks
e5cc26b68bc0 libfdt: Add support for disabling internal checks
28fd7590aad2 libfdt: Improve comments in some of the assumptions
fc207c32341b libfdt: Fix a few typos
0f61c72dedc4 libfdt: Allow exclusion of fdt_check_full()
f270f45fd5d2 libfdt: Add support for disabling ordering check/fixup
c18bae9a4c96 libfdt: Add support for disabling version checks
fc03c4a2e04e libfdt: Add support for disabling rollback handling
77563ae72b7c libfdt: Add support for disabling sanity checks
57bc6327b80b libfdt: Add support for disabling dtb checks
464962489dcc Add a way to control the level of checks in the code
0c5326cb2845 libfdt: De-inline fdt_header_size()
cc6a5a071504 Revert "yamltree: Ensure consistent bracketing of properties with phandles"
0e9225eb0dfe Remove redundant YYLOC global declaration
cab09eedd644 Move -DNO_VALGRIND into CPPFLAGS
0eb1cb0b531e Makefile: pass $(CFLAGS) also during dependency generation

Signed-off-by: Rob Herring <robh@kernel.org>

scripts/dtc/libfdt/libfdt_internal.h

@@ -48,4 +48,126 @@ static inline struct fdt_reserve_entry *fdt_mem_rsv_w_(void *fdt, int n)
 
 #define FDT_SW_MAGIC		(~FDT_MAGIC)
 
+/**********************************************************************/
+/* Checking controls                                                  */
+/**********************************************************************/
+
+#ifndef FDT_ASSUME_MASK
+#define FDT_ASSUME_MASK 0
+#endif
+
+/*
+ * Defines assumptions which can be enabled. Each of these can be enabled
+ * individually. For maximum safety, don't enable any assumptions!
+ *
+ * For minimal code size and no safety, use ASSUME_PERFECT at your own risk.
+ * You should have another method of validating the device tree, such as a
+ * signature or hash check before using libfdt.
+ *
+ * For situations where security is not a concern it may be safe to enable
+ * ASSUME_SANE.
+ */
+enum {
+	/*
+	 * This does essentially no checks. Only the latest device-tree
+	 * version is correctly handled. Inconsistencies or errors in the device
+	 * tree may cause undefined behaviour or crashes. Invalid parameters
+	 * passed to libfdt may do the same.
+	 *
+	 * If an error occurs when modifying the tree it may leave the tree in
+	 * an intermediate (but valid) state. As an example, adding a property
+	 * where there is insufficient space may result in the property name
+	 * being added to the string table even though the property itself is
+	 * not added to the struct section.
+	 *
+	 * Only use this if you have a fully validated device tree with
+	 * the latest supported version and wish to minimise code size.
+	 */
+	ASSUME_PERFECT		= 0xff,
+
+	/*
+	 * This assumes that the device tree is sane. i.e. header metadata
+	 * and basic hierarchy are correct.
+	 *
+	 * With this assumption enabled, normal device trees produced by libfdt
+	 * and the compiler should be handled safely. Malicious device trees and
+	 * complete garbage may cause libfdt to behave badly or crash. Truncated
+	 * device trees (e.g. those only partially loaded) can also cause
+	 * problems.
+	 *
+	 * Note: Only checks that relate exclusively to the device tree itself
+	 * (not the parameters passed to libfdt) are disabled by this
+	 * assumption. This includes checking headers, tags and the like.
+	 */
+	ASSUME_VALID_DTB	= 1 << 0,
+
+	/*
+	 * This builds on ASSUME_VALID_DTB and further assumes that libfdt
+	 * functions are called with valid parameters, i.e. not trigger
+	 * FDT_ERR_BADOFFSET or offsets that are out of bounds. It disables any
+	 * extensive checking of parameters and the device tree, making various
+	 * assumptions about correctness.
+	 *
+	 * It doesn't make sense to enable this assumption unless
+	 * ASSUME_VALID_DTB is also enabled.
+	 */
+	ASSUME_VALID_INPUT	= 1 << 1,
+
+	/*
+	 * This disables checks for device-tree version and removes all code
+	 * which handles older versions.
+	 *
+	 * Only enable this if you know you have a device tree with the latest
+	 * version.
+	 */
+	ASSUME_LATEST		= 1 << 2,
+
+	/*
+	 * This assumes that it is OK for a failed addition to the device tree,
+	 * due to lack of space or some other problem, to skip any rollback
+	 * steps (such as dropping the property name from the string table).
+	 * This is safe to enable in most circumstances, even though it may
+	 * leave the tree in a sub-optimal state.
+	 */
+	ASSUME_NO_ROLLBACK	= 1 << 3,
+
+	/*
+	 * This assumes that the device tree components appear in a 'convenient'
+	 * order, i.e. the memory reservation block first, then the structure
+	 * block and finally the string block.
+	 *
+	 * This order is not specified by the device-tree specification,
+	 * but is expected by libfdt. The device-tree compiler always created
+	 * device trees with this order.
+	 *
+	 * This assumption disables a check in fdt_open_into() and removes the
+	 * ability to fix the problem there. This is safe if you know that the
+	 * device tree is correctly ordered. See fdt_blocks_misordered_().
+	 */
+	ASSUME_LIBFDT_ORDER	= 1 << 4,
+
+	/*
+	 * This assumes that libfdt itself does not have any internal bugs. It
+	 * drops certain checks that should never be needed unless libfdt has an
+	 * undiscovered bug.
+	 *
+	 * This can generally be considered safe to enable.
+	 */
+	ASSUME_LIBFDT_FLAWLESS	= 1 << 5,
+};
+
+/**
+ * can_assume_() - check if a particular assumption is enabled
+ *
+ * @mask: Mask to check (ASSUME_...)
+ * @return true if that assumption is enabled, else false
+ */
+static inline bool can_assume_(int mask)
+{
+	return FDT_ASSUME_MASK & mask;
+}
+
+/** helper macros for checking assumptions */
+#define can_assume(_assume)	can_assume_(ASSUME_ ## _assume)
+
 #endif /* LIBFDT_INTERNAL_H */