diff --git a/poky/bitbake/lib/bb/COW.py b/poky/bitbake/lib/bb/COW.py
index 23c22b6..76bc08a 100644
--- a/poky/bitbake/lib/bb/COW.py
+++ b/poky/bitbake/lib/bb/COW.py
@@ -3,6 +3,8 @@
 #
 # Copyright (C) 2006 Tim Ansell
 #
+# SPDX-License-Identifier: GPL-2.0-only
+#
 # Please Note:
 # Be careful when using mutable types (ie Dict and Lists) - operations involving these are SLOW.
 # Assign a file to __warn__ to get warnings about slow operations.
diff --git a/poky/bitbake/lib/bb/asyncrpc/__init__.py b/poky/bitbake/lib/bb/asyncrpc/__init__.py
index c2f2b3c..9a85e99 100644
--- a/poky/bitbake/lib/bb/asyncrpc/__init__.py
+++ b/poky/bitbake/lib/bb/asyncrpc/__init__.py
@@ -1,4 +1,6 @@
 #
+# Copyright BitBake Contributors
+#
 # SPDX-License-Identifier: GPL-2.0-only
 #
 
diff --git a/poky/bitbake/lib/bb/asyncrpc/client.py b/poky/bitbake/lib/bb/asyncrpc/client.py
index 3496019..881434d 100644
--- a/poky/bitbake/lib/bb/asyncrpc/client.py
+++ b/poky/bitbake/lib/bb/asyncrpc/client.py
@@ -1,4 +1,6 @@
 #
+# Copyright BitBake Contributors
+#
 # SPDX-License-Identifier: GPL-2.0-only
 #
 
diff --git a/poky/bitbake/lib/bb/asyncrpc/serv.py b/poky/bitbake/lib/bb/asyncrpc/serv.py
index 585bc12..5cf45f9 100644
--- a/poky/bitbake/lib/bb/asyncrpc/serv.py
+++ b/poky/bitbake/lib/bb/asyncrpc/serv.py
@@ -1,4 +1,6 @@
 #
+# Copyright BitBake Contributors
+#
 # SPDX-License-Identifier: GPL-2.0-only
 #
 
diff --git a/poky/bitbake/lib/bb/build.py b/poky/bitbake/lib/bb/build.py
index 55f68b9..b8c1099 100644
--- a/poky/bitbake/lib/bb/build.py
+++ b/poky/bitbake/lib/bb/build.py
@@ -20,6 +20,7 @@
 import time
 import re
 import stat
+import datetime
 import bb
 import bb.msg
 import bb.process
@@ -618,7 +619,8 @@
     logorder = os.path.join(tempdir, 'log.task_order')
     try:
         with open(logorder, 'a') as logorderfile:
-            logorderfile.write('{0} ({1}): {2}\n'.format(task, os.getpid(), logbase))
+            timestamp = datetime.datetime.now().strftime("%Y%m%d-%H%M%S.%f")
+            logorderfile.write('{0} {1} ({2}): {3}\n'.format(timestamp, task, os.getpid(), logbase))
     except OSError:
         logger.exception("Opening log file '%s'", logorder)
         pass
diff --git a/poky/bitbake/lib/bb/codeparser.py b/poky/bitbake/lib/bb/codeparser.py
index 3b3c3b4..9d66d3a 100644
--- a/poky/bitbake/lib/bb/codeparser.py
+++ b/poky/bitbake/lib/bb/codeparser.py
@@ -1,4 +1,6 @@
 #
+# Copyright BitBake Contributors
+#
 # SPDX-License-Identifier: GPL-2.0-only
 #
 
diff --git a/poky/bitbake/lib/bb/compress/_pipecompress.py b/poky/bitbake/lib/bb/compress/_pipecompress.py
index 5de17a8..4a403d6 100644
--- a/poky/bitbake/lib/bb/compress/_pipecompress.py
+++ b/poky/bitbake/lib/bb/compress/_pipecompress.py
@@ -1,4 +1,6 @@
 #
+# Copyright BitBake Contributors
+#
 # SPDX-License-Identifier: GPL-2.0-only
 #
 # Helper library to implement streaming compression and decompression using an
diff --git a/poky/bitbake/lib/bb/compress/lz4.py b/poky/bitbake/lib/bb/compress/lz4.py
index 0f6bc51..88b0989 100644
--- a/poky/bitbake/lib/bb/compress/lz4.py
+++ b/poky/bitbake/lib/bb/compress/lz4.py
@@ -1,4 +1,6 @@
 #
+# Copyright BitBake Contributors
+#
 # SPDX-License-Identifier: GPL-2.0-only
 #
 
diff --git a/poky/bitbake/lib/bb/compress/zstd.py b/poky/bitbake/lib/bb/compress/zstd.py
index 50c4213..cdbbe9d 100644
--- a/poky/bitbake/lib/bb/compress/zstd.py
+++ b/poky/bitbake/lib/bb/compress/zstd.py
@@ -1,4 +1,6 @@
 #
+# Copyright BitBake Contributors
+#
 # SPDX-License-Identifier: GPL-2.0-only
 #
 
diff --git a/poky/bitbake/lib/bb/cooker.py b/poky/bitbake/lib/bb/cooker.py
index 2adf4d2..1b6ee30 100644
--- a/poky/bitbake/lib/bb/cooker.py
+++ b/poky/bitbake/lib/bb/cooker.py
@@ -402,6 +402,7 @@
         for mc in self.databuilder.mcdata.values():
             mc.renameVar("__depends", "__base_depends")
             self.add_filewatch(mc.getVar("__base_depends", False), self.configwatcher)
+            mc.setVar("__bbclasstype", "recipe")
 
         self.baseconfig_valid = True
         self.parsecache_valid = False
diff --git a/poky/bitbake/lib/bb/cookerdata.py b/poky/bitbake/lib/bb/cookerdata.py
index d54ac93..9706948 100644
--- a/poky/bitbake/lib/bb/cookerdata.py
+++ b/poky/bitbake/lib/bb/cookerdata.py
@@ -254,6 +254,7 @@
         filtered_keys = bb.utils.approved_variables()
         bb.data.inheritFromOS(self.basedata, self.savedenv, filtered_keys)
         self.basedata.setVar("BB_ORIGENV", self.savedenv)
+        self.basedata.setVar("__bbclasstype", "global")
 
         if worker:
             self.basedata.setVar("BB_WORKERCONTEXT", "1")
diff --git a/poky/bitbake/lib/bb/daemonize.py b/poky/bitbake/lib/bb/daemonize.py
index 4957bfd..7689404 100644
--- a/poky/bitbake/lib/bb/daemonize.py
+++ b/poky/bitbake/lib/bb/daemonize.py
@@ -1,4 +1,6 @@
 #
+# Copyright BitBake Contributors
+#
 # SPDX-License-Identifier: GPL-2.0-only
 #
 
diff --git a/poky/bitbake/lib/bb/data.py b/poky/bitbake/lib/bb/data.py
index c09d9b0..53fe348 100644
--- a/poky/bitbake/lib/bb/data.py
+++ b/poky/bitbake/lib/bb/data.py
@@ -441,7 +441,7 @@
 
 def inherits_class(klass, d):
     val = d.getVar('__inherit_cache', False) or []
-    needle = os.path.join('classes', '%s.bbclass' % klass)
+    needle = '/%s.bbclass' % klass
     for v in val:
         if v.endswith(needle):
             return True
diff --git a/poky/bitbake/lib/bb/exceptions.py b/poky/bitbake/lib/bb/exceptions.py
index ecbad59..801db9c 100644
--- a/poky/bitbake/lib/bb/exceptions.py
+++ b/poky/bitbake/lib/bb/exceptions.py
@@ -1,4 +1,6 @@
 #
+# Copyright BitBake Contributors
+#
 # SPDX-License-Identifier: GPL-2.0-only
 #
 
diff --git a/poky/bitbake/lib/bb/fetch2/gitsm.py b/poky/bitbake/lib/bb/fetch2/gitsm.py
index c1950e4..25d5db0 100644
--- a/poky/bitbake/lib/bb/fetch2/gitsm.py
+++ b/poky/bitbake/lib/bb/fetch2/gitsm.py
@@ -115,6 +115,9 @@
                     # This has to be a file reference
                     proto = "file"
                     url = "gitsm://" + uris[module]
+            if "{}{}".format(ud.host, ud.path) in url:
+                raise bb.fetch2.FetchError("Submodule refers to the parent repository. This will cause deadlock situation in current version of Bitbake." \
+                                           "Consider using git fetcher instead.")
 
             url += ';protocol=%s' % proto
             url += ";name=%s" % module
diff --git a/poky/bitbake/lib/bb/fetch2/npm.py b/poky/bitbake/lib/bb/fetch2/npm.py
index 8f7c10a..8a179a3 100644
--- a/poky/bitbake/lib/bb/fetch2/npm.py
+++ b/poky/bitbake/lib/bb/fetch2/npm.py
@@ -156,7 +156,7 @@
             raise ParameterError("Invalid 'version' parameter", ud.url)
 
         # Extract the 'registry' part of the url
-        ud.registry = re.sub(r"^npm://", "http://", ud.url.split(";")[0])
+        ud.registry = re.sub(r"^npm://", "https://", ud.url.split(";")[0])
 
         # Using the 'downloadfilename' parameter as local filename
         # or the npm package name.
diff --git a/poky/bitbake/lib/bb/fetch2/osc.py b/poky/bitbake/lib/bb/fetch2/osc.py
index 86f8ddf..495ac8a 100644
--- a/poky/bitbake/lib/bb/fetch2/osc.py
+++ b/poky/bitbake/lib/bb/fetch2/osc.py
@@ -1,4 +1,6 @@
 #
+# Copyright BitBake Contributors
+#
 # SPDX-License-Identifier: GPL-2.0-only
 #
 """
diff --git a/poky/bitbake/lib/bb/parse/parse_py/BBHandler.py b/poky/bitbake/lib/bb/parse/parse_py/BBHandler.py
index 6841573..18e6868 100644
--- a/poky/bitbake/lib/bb/parse/parse_py/BBHandler.py
+++ b/poky/bitbake/lib/bb/parse/parse_py/BBHandler.py
@@ -44,23 +44,36 @@
     __inherit_cache = d.getVar('__inherit_cache', False) or []
     files = d.expand(files).split()
     for file in files:
-        if not os.path.isabs(file) and not file.endswith(".bbclass"):
-            file = os.path.join('classes', '%s.bbclass' % file)
+        classtype = d.getVar("__bbclasstype", False)
+        origfile = file
+        for t in ["classes-" + classtype, "classes"]:
+            file = origfile
+            if not os.path.isabs(file) and not file.endswith(".bbclass"):
+                file = os.path.join(t, '%s.bbclass' % file)
 
-        if not os.path.isabs(file):
-            bbpath = d.getVar("BBPATH")
-            abs_fn, attempts = bb.utils.which(bbpath, file, history=True)
-            for af in attempts:
-                if af != abs_fn:
-                    bb.parse.mark_dependency(d, af)
-            if abs_fn:
-                file = abs_fn
+            if not os.path.isabs(file):
+                bbpath = d.getVar("BBPATH")
+                abs_fn, attempts = bb.utils.which(bbpath, file, history=True)
+                for af in attempts:
+                    if af != abs_fn:
+                        bb.parse.mark_dependency(d, af)
+                if abs_fn:
+                    file = abs_fn
+
+            if os.path.exists(file):
+                break
+
+        if not os.path.exists(file):
+            raise ParseError("Could not inherit file %s" % (file), fn, lineno)
 
         if not file in __inherit_cache:
             logger.debug("Inheriting %s (from %s:%d)" % (file, fn, lineno))
             __inherit_cache.append( file )
             d.setVar('__inherit_cache', __inherit_cache)
-            include(fn, file, lineno, d, "inherit")
+            try:
+                bb.parse.handle(file, d, True)
+            except (IOError, OSError) as exc:
+                raise ParseError("Could not inherit file %s: %s" % (fn, exc.strerror), fn, lineno)
             __inherit_cache = d.getVar('__inherit_cache', False) or []
 
 def get_statements(filename, absolute_filename, base_name):
diff --git a/poky/bitbake/lib/bb/process.py b/poky/bitbake/lib/bb/process.py
index be2c15a..4c7b6d3 100644
--- a/poky/bitbake/lib/bb/process.py
+++ b/poky/bitbake/lib/bb/process.py
@@ -1,4 +1,6 @@
 #
+# Copyright BitBake Contributors
+#
 # SPDX-License-Identifier: GPL-2.0-only
 #
 
diff --git a/poky/bitbake/lib/bb/runqueue.py b/poky/bitbake/lib/bb/runqueue.py
index 359b503..48e2540 100644
--- a/poky/bitbake/lib/bb/runqueue.py
+++ b/poky/bitbake/lib/bb/runqueue.py
@@ -168,15 +168,19 @@
         openSUSE /proc/pressure/* files have readable file permissions but when read the error EOPNOTSUPP (Operation not supported)
         is returned.
         """
-        if self.rq.max_cpu_pressure or self.rq.max_io_pressure:
+        if self.rq.max_cpu_pressure or self.rq.max_io_pressure or self.rq.max_memory_pressure:
             try:
-                with open("/proc/pressure/cpu") as cpu_pressure_fds, open("/proc/pressure/io") as io_pressure_fds:
+                with open("/proc/pressure/cpu") as cpu_pressure_fds, \
+                    open("/proc/pressure/io") as io_pressure_fds, \
+                    open("/proc/pressure/memory") as memory_pressure_fds:
+
                     self.prev_cpu_pressure = cpu_pressure_fds.readline().split()[4].split("=")[1]
                     self.prev_io_pressure = io_pressure_fds.readline().split()[4].split("=")[1]
+                    self.prev_memory_pressure = memory_pressure_fds.readline().split()[4].split("=")[1]
                     self.prev_pressure_time = time.time()
                 self.check_pressure = True
             except:
-                bb.warn("The /proc/pressure files can't be read. Continuing build without monitoring pressure")
+                bb.note("The /proc/pressure files can't be read. Continuing build without monitoring pressure")
                 self.check_pressure = False
         else:
             self.check_pressure = False
@@ -184,21 +188,26 @@
     def exceeds_max_pressure(self):
         """
         Monitor the difference in total pressure at least once per second, if
-        BB_PRESSURE_MAX_{CPU|IO} are set, return True if above threshold.
+        BB_PRESSURE_MAX_{CPU|IO|MEMORY} are set, return True if above threshold.
         """
         if self.check_pressure:
-            with open("/proc/pressure/cpu") as cpu_pressure_fds, open("/proc/pressure/io") as io_pressure_fds:
+            with open("/proc/pressure/cpu") as cpu_pressure_fds, \
+                open("/proc/pressure/io") as io_pressure_fds, \
+                open("/proc/pressure/memory") as memory_pressure_fds:
                 # extract "total" from /proc/pressure/{cpu|io}
                 curr_cpu_pressure = cpu_pressure_fds.readline().split()[4].split("=")[1]
                 curr_io_pressure = io_pressure_fds.readline().split()[4].split("=")[1]
+                curr_memory_pressure = memory_pressure_fds.readline().split()[4].split("=")[1]
                 exceeds_cpu_pressure =  self.rq.max_cpu_pressure and (float(curr_cpu_pressure) - float(self.prev_cpu_pressure)) > self.rq.max_cpu_pressure
                 exceeds_io_pressure =  self.rq.max_io_pressure and (float(curr_io_pressure) - float(self.prev_io_pressure)) > self.rq.max_io_pressure
+                exceeds_memory_pressure = self.rq.max_memory_pressure and (float(curr_memory_pressure) - float(self.prev_memory_pressure)) > self.rq.max_memory_pressure
                 now = time.time()
                 if now - self.prev_pressure_time > 1.0:
                     self.prev_cpu_pressure = curr_cpu_pressure
                     self.prev_io_pressure = curr_io_pressure
+                    self.prev_memory_pressure = curr_memory_pressure
                     self.prev_pressure_time = now
-            return (exceeds_cpu_pressure or exceeds_io_pressure)
+            return (exceeds_cpu_pressure or exceeds_io_pressure or exceeds_memory_pressure)
         return False
 
     def next_buildable_task(self):
@@ -1748,6 +1757,7 @@
         self.scheduler = self.cfgData.getVar("BB_SCHEDULER") or "speed"
         self.max_cpu_pressure = self.cfgData.getVar("BB_PRESSURE_MAX_CPU")
         self.max_io_pressure = self.cfgData.getVar("BB_PRESSURE_MAX_IO")
+        self.max_memory_pressure = self.cfgData.getVar("BB_PRESSURE_MAX_MEMORY")
 
         self.sq_buildable = set()
         self.sq_running = set()
@@ -1798,6 +1808,13 @@
             if self.max_io_pressure > upper_limit:
                 bb.warn("Your build will be largely unregulated since BB_PRESSURE_MAX_IO is set to %s. It is very unlikely that such high pressure will be experienced." % (self.max_io_pressure))
 
+        if self.max_memory_pressure:
+            self.max_memory_pressure = float(self.max_memory_pressure)
+            if self.max_memory_pressure < lower_limit:
+                bb.fatal("Invalid BB_PRESSURE_MAX_MEMORY %s, minimum value is %s." % (self.max_memory_pressure, lower_limit))
+            if self.max_memory_pressure > upper_limit:
+                bb.warn("Your build will be largely unregulated since BB_PRESSURE_MAX_MEMORY is set to %s. It is very unlikely that such high pressure will be experienced." % (self.max_io_pressure))
+            
         # List of setscene tasks which we've covered
         self.scenequeue_covered = set()
         # List of tasks which are covered (including setscene ones)
@@ -2237,10 +2254,9 @@
 
         # No more tasks can be run. If we have deferred setscene tasks we should run them.
         if self.sq_deferred:
-            tid = self.sq_deferred.pop(list(self.sq_deferred.keys())[0])
-            logger.warning("Runqeueue deadlocked on deferred tasks, forcing task %s" % tid)
-            if tid not in self.runq_complete:
-                self.sq_task_failoutright(tid)
+            deferred_tid = list(self.sq_deferred.keys())[0]
+            blocking_tid = self.sq_deferred.pop(deferred_tid)
+            logger.warning("Runqeueue deadlocked on deferred tasks, forcing task %s blocked by %s" % (deferred_tid, blocking_tid))
             return True
 
         if self.failed_tids:
@@ -2506,11 +2522,14 @@
 
         if update_tasks:
             self.sqdone = False
-            for tid in [t[0] for t in update_tasks]:
-                h = pending_hash_index(tid, self.rqdata)
-                if h in self.sqdata.hashes and tid != self.sqdata.hashes[h]:
-                    self.sq_deferred[tid] = self.sqdata.hashes[h]
-                    bb.note("Deferring %s after %s" % (tid, self.sqdata.hashes[h]))
+            for mc in sorted(self.sqdata.multiconfigs):
+                for tid in sorted([t[0] for t in update_tasks]):
+                    if mc_from_tid(tid) != mc:
+                        continue
+                    h = pending_hash_index(tid, self.rqdata)
+                    if h in self.sqdata.hashes and tid != self.sqdata.hashes[h]:
+                        self.sq_deferred[tid] = self.sqdata.hashes[h]
+                        bb.note("Deferring %s after %s" % (tid, self.sqdata.hashes[h]))
             update_scenequeue_data([t[0] for t in update_tasks], self.sqdata, self.rqdata, self.rq, self.cooker, self.stampcache, self, summary=False)
 
         for (tid, harddepfail, origvalid) in update_tasks:
diff --git a/poky/bitbake/lib/bb/siggen.py b/poky/bitbake/lib/bb/siggen.py
index 3f3d6df..07bb529 100644
--- a/poky/bitbake/lib/bb/siggen.py
+++ b/poky/bitbake/lib/bb/siggen.py
@@ -1,4 +1,6 @@
 #
+# Copyright BitBake Contributors
+#
 # SPDX-License-Identifier: GPL-2.0-only
 #
 
@@ -425,7 +427,7 @@
                 bb.error("Taskhash mismatch %s versus %s for %s" % (computed_taskhash, self.taskhash[tid], tid))
                 sigfile = sigfile.replace(self.taskhash[tid], computed_taskhash)
 
-        fd, tmpfile = tempfile.mkstemp(dir=os.path.dirname(sigfile), prefix="sigtask.")
+        fd, tmpfile = bb.utils.mkstemp(dir=os.path.dirname(sigfile), prefix="sigtask.")
         try:
             with bb.compress.zstd.open(fd, "wt", encoding="utf-8", num_threads=1) as f:
                 json.dump(data, f, sort_keys=True, separators=(",", ":"), cls=SetEncoder)
diff --git a/poky/bitbake/lib/bb/tests/compression.py b/poky/bitbake/lib/bb/tests/compression.py
index d3ddf67..95af3f9 100644
--- a/poky/bitbake/lib/bb/tests/compression.py
+++ b/poky/bitbake/lib/bb/tests/compression.py
@@ -1,4 +1,6 @@
 #
+# Copyright BitBake Contributors
+#
 # SPDX-License-Identifier: GPL-2.0-only
 #
 
diff --git a/poky/bitbake/lib/bb/tests/cooker.py b/poky/bitbake/lib/bb/tests/cooker.py
index c82d4b7..9e524ae 100644
--- a/poky/bitbake/lib/bb/tests/cooker.py
+++ b/poky/bitbake/lib/bb/tests/cooker.py
@@ -1,6 +1,8 @@
 #
 # BitBake Tests for cooker.py
 #
+# Copyright BitBake Contributors
+#
 # SPDX-License-Identifier: GPL-2.0-only
 #
 
diff --git a/poky/bitbake/lib/bb/tests/fetch.py b/poky/bitbake/lib/bb/tests/fetch.py
index 7fcf57e..b4ed691 100644
--- a/poky/bitbake/lib/bb/tests/fetch.py
+++ b/poky/bitbake/lib/bb/tests/fetch.py
@@ -11,6 +11,7 @@
 import tempfile
 import collections
 import os
+import signal
 import tarfile
 from bb.fetch2 import URI
 from bb.fetch2 import FetchMethod
@@ -22,6 +23,24 @@
         return unittest.skip("network test")
     return lambda f: f
 
+class TestTimeout(Exception):
+    pass
+
+class Timeout():
+
+    def __init__(self, seconds):
+        self.seconds = seconds
+
+    def handle_timeout(self, signum, frame):
+        raise TestTimeout("Test failed: timeout reached")
+
+    def __enter__(self):
+        signal.signal(signal.SIGALRM, self.handle_timeout)
+        signal.alarm(self.seconds)
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        signal.alarm(0)
+
 class URITest(unittest.TestCase):
     test_uris = {
         "http://www.google.com/index.html" : {
@@ -1172,6 +1191,15 @@
         self.assertTrue(os.path.exists(os.path.join(repo_path, 'edgelet/hsm-sys/azure-iot-hsm-c/deps/utpm/deps/c-utility/testtools/umock-c/deps/ctest/README.md')), msg='Missing submodule checkout')
         self.assertTrue(os.path.exists(os.path.join(repo_path, 'edgelet/hsm-sys/azure-iot-hsm-c/deps/utpm/deps/c-utility/testtools/umock-c/deps/testrunner/readme.md')), msg='Missing submodule checkout')
 
+    @skipIfNoNetwork()
+    def test_git_submodule_reference_to_parent(self):
+        self.recipe_url = "gitsm://github.com/gflags/gflags.git;protocol=https;branch=master"
+        self.d.setVar("SRCREV", "14e1138441bbbb584160cb1c0a0426ec1bac35f1")
+        with Timeout(60):
+            fetcher = bb.fetch.Fetch([self.recipe_url], self.d)
+            with self.assertRaises(bb.fetch2.FetchError):
+                fetcher.download()
+
 class SVNTest(FetcherTest):
     def skipIfNoSvn():
         import shutil
diff --git a/poky/bitbake/lib/bb/tests/parse.py b/poky/bitbake/lib/bb/tests/parse.py
index 1a3b749..ee7f253 100644
--- a/poky/bitbake/lib/bb/tests/parse.py
+++ b/poky/bitbake/lib/bb/tests/parse.py
@@ -164,6 +164,7 @@
     # become unset/disappear.
     #
     def test_parse_classextend_contamination(self):
+        self.d.setVar("__bbclasstype", "recipe")
         cls = self.parsehelper(self.classextend_bbclass, suffix=".bbclass")
         #clsname = os.path.basename(cls.name).replace(".bbclass", "")
         self.classextend = self.classextend.replace("###CLASS###", cls.name)
diff --git a/poky/bitbake/lib/bb/utils.py b/poky/bitbake/lib/bb/utils.py
index 19ed68e..92d44c5 100644
--- a/poky/bitbake/lib/bb/utils.py
+++ b/poky/bitbake/lib/bb/utils.py
@@ -28,6 +28,8 @@
 import collections
 import copy
 import ctypes
+import random
+import tempfile
 from subprocess import getstatusoutput
 from contextlib import contextmanager
 from ctypes import cdll
@@ -429,12 +431,14 @@
     return eval(source, ctx, locals)
 
 @contextmanager
-def fileslocked(files):
+def fileslocked(files, *args, **kwargs):
     """Context manager for locking and unlocking file locks."""
     locks = []
     if files:
         for lockfile in files:
-            locks.append(bb.utils.lockfile(lockfile))
+            l = bb.utils.lockfile(lockfile, *args, **kwargs)
+            if l is not None:
+                locks.append(l)
 
     try:
         yield
@@ -1754,3 +1758,22 @@
             if str(uid) == line_split[2]:
                 return True
     return False
+
+def mkstemp(suffix=None, prefix=None, dir=None, text=False):
+    """
+    Generates a unique filename, independent of time.
+
+    mkstemp() in glibc (at least) generates unique file names based on the
+    current system time. When combined with highly parallel builds, and
+    operating over NFS (e.g. shared sstate/downloads) this can result in
+    conflicts and race conditions.
+
+    This function adds additional entropy to the file name so that a collision
+    is independent of time and thus extremely unlikely.
+    """
+    entropy = "".join(random.choices("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890", k=20))
+    if prefix:
+        prefix = prefix + entropy
+    else:
+        prefix = tempfile.gettempprefix() + entropy
+    return tempfile.mkstemp(suffix=suffix, prefix=prefix, dir=dir, text=text)
diff --git a/poky/bitbake/lib/bblayers/__init__.py b/poky/bitbake/lib/bblayers/__init__.py
index 4e7c09d..78efd29 100644
--- a/poky/bitbake/lib/bblayers/__init__.py
+++ b/poky/bitbake/lib/bblayers/__init__.py
@@ -1,4 +1,6 @@
 #
+# Copyright BitBake Contributors
+#
 # SPDX-License-Identifier: GPL-2.0-only
 #
 
diff --git a/poky/bitbake/lib/bblayers/action.py b/poky/bitbake/lib/bblayers/action.py
index 6723e2c..454c251 100644
--- a/poky/bitbake/lib/bblayers/action.py
+++ b/poky/bitbake/lib/bblayers/action.py
@@ -1,4 +1,6 @@
 #
+# Copyright BitBake Contributors
+#
 # SPDX-License-Identifier: GPL-2.0-only
 #
 
diff --git a/poky/bitbake/lib/bblayers/common.py b/poky/bitbake/lib/bblayers/common.py
index 6c76ef3..f7b9cee 100644
--- a/poky/bitbake/lib/bblayers/common.py
+++ b/poky/bitbake/lib/bblayers/common.py
@@ -1,4 +1,6 @@
 #
+# Copyright BitBake Contributors
+#
 # SPDX-License-Identifier: GPL-2.0-only
 #
 
diff --git a/poky/bitbake/lib/bblayers/layerindex.py b/poky/bitbake/lib/bblayers/layerindex.py
index 7936516..0ac8fd2 100644
--- a/poky/bitbake/lib/bblayers/layerindex.py
+++ b/poky/bitbake/lib/bblayers/layerindex.py
@@ -1,4 +1,6 @@
 #
+# Copyright BitBake Contributors
+#
 # SPDX-License-Identifier: GPL-2.0-only
 #
 
diff --git a/poky/bitbake/lib/bblayers/query.py b/poky/bitbake/lib/bblayers/query.py
index 525d4f0..afd3951 100644
--- a/poky/bitbake/lib/bblayers/query.py
+++ b/poky/bitbake/lib/bblayers/query.py
@@ -1,4 +1,6 @@
 #
+# Copyright BitBake Contributors
+#
 # SPDX-License-Identifier: GPL-2.0-only
 #
 
@@ -55,11 +57,12 @@
         # Check for overlayed .bbclass files
         classes = collections.defaultdict(list)
         for layerdir in self.bblayers:
-            classdir = os.path.join(layerdir, 'classes')
-            if os.path.exists(classdir):
-                for classfile in os.listdir(classdir):
-                    if os.path.splitext(classfile)[1] == '.bbclass':
-                        classes[classfile].append(classdir)
+            for c in ["classes-global", "classes-recipe", "classes"]:
+                classdir = os.path.join(layerdir, c)
+                if os.path.exists(classdir):
+                    for classfile in os.listdir(classdir):
+                        if os.path.splitext(classfile)[1] == '.bbclass':
+                            classes[classfile].append(classdir)
 
         # Locating classes and other files is a bit more complicated than recipes -
         # layer priority is not a factor; instead BitBake uses the first matching
@@ -122,9 +125,14 @@
         if inherits:
             bbpath = str(self.tinfoil.config_data.getVar('BBPATH'))
             for classname in inherits:
-                classfile = 'classes/%s.bbclass' % classname
-                if not bb.utils.which(bbpath, classfile, history=False):
-                    logger.error('No class named %s found in BBPATH', classfile)
+                found = False
+                for c in ["classes-global", "classes-recipe", "classes"]:
+                    cfile = c + '/%s.bbclass' % classname
+                    if bb.utils.which(bbpath, cfile, history=False):
+                        found = True
+                        break
+                if not found:
+                    logger.error('No class named %s found in BBPATH', classname)
                     sys.exit(1)
 
         pkg_pn = self.tinfoil.cooker.recipecaches[mc].pkg_pn
@@ -172,7 +180,7 @@
                     logger.plain("  %s %s%s", layer.ljust(20), ver, skipped)
 
         global_inherit = (self.tinfoil.config_data.getVar('INHERIT') or "").split()
-        cls_re = re.compile('classes/')
+        cls_re = re.compile('classes.*/')
 
         preffiles = []
         show_unique_pn = []
@@ -405,7 +413,7 @@
                     self.check_cross_depends("RRECOMMENDS", layername, f, best, args.filenames, ignore_layers)
 
             # The inherit class
-            cls_re = re.compile('classes/')
+            cls_re = re.compile('classes.*/')
             if f in self.tinfoil.cooker_data.inherits:
                 inherits = self.tinfoil.cooker_data.inherits[f]
                 for cls in inherits:
diff --git a/poky/bitbake/lib/prserv/__init__.py b/poky/bitbake/lib/prserv/__init__.py
index 9961040..38ced81 100644
--- a/poky/bitbake/lib/prserv/__init__.py
+++ b/poky/bitbake/lib/prserv/__init__.py
@@ -1,4 +1,6 @@
 #
+# Copyright BitBake Contributors
+#
 # SPDX-License-Identifier: GPL-2.0-only
 #
 
diff --git a/poky/bitbake/lib/prserv/client.py b/poky/bitbake/lib/prserv/client.py
index a3f19dd..69ab7a4 100644
--- a/poky/bitbake/lib/prserv/client.py
+++ b/poky/bitbake/lib/prserv/client.py
@@ -1,4 +1,6 @@
 #
+# Copyright BitBake Contributors
+#
 # SPDX-License-Identifier: GPL-2.0-only
 #
 
diff --git a/poky/bitbake/lib/prserv/db.py b/poky/bitbake/lib/prserv/db.py
index 2710d4a..b4bda70 100644
--- a/poky/bitbake/lib/prserv/db.py
+++ b/poky/bitbake/lib/prserv/db.py
@@ -1,4 +1,6 @@
 #
+# Copyright BitBake Contributors
+#
 # SPDX-License-Identifier: GPL-2.0-only
 #
 
diff --git a/poky/bitbake/lib/prserv/serv.py b/poky/bitbake/lib/prserv/serv.py
index 0a20b92..c686b20 100644
--- a/poky/bitbake/lib/prserv/serv.py
+++ b/poky/bitbake/lib/prserv/serv.py
@@ -1,4 +1,6 @@
 #
+# Copyright BitBake Contributors
+#
 # SPDX-License-Identifier: GPL-2.0-only
 #
 
diff --git a/poky/bitbake/lib/toaster/manage.py b/poky/bitbake/lib/toaster/manage.py
index ae32619..f8de49c 100755
--- a/poky/bitbake/lib/toaster/manage.py
+++ b/poky/bitbake/lib/toaster/manage.py
@@ -1,5 +1,7 @@
 #!/usr/bin/env python3
 #
+# Copyright BitBake Contributors
+#
 # SPDX-License-Identifier: GPL-2.0-only
 #