Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next

Resolve conflict between d2912cb15bdd ("treewide: Replace GPLv2
boilerplate/reference with SPDX - rule 500") removing the GPL disclaimer
and fe03d4745675 ("Update my email address") which updates Jozsef
Kadlecsik's email.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

94 files changed, 1270 insertions, 715 deletions

diff --git a/kernel/Makefile b/kernel/Makefile
index 33824f0385b3..a8d923b5481b 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -71,7 +71,7 @@ obj-$(CONFIG_UTS_NS) += utsname.o
 obj-$(CONFIG_USER_NS) += user_namespace.o
 obj-$(CONFIG_PID_NS) += pid_namespace.o
 obj-$(CONFIG_IKCONFIG) += configs.o
-obj-$(CONFIG_IKHEADERS_PROC) += kheaders.o
+obj-$(CONFIG_IKHEADERS) += kheaders.o
 obj-$(CONFIG_SMP) += stop_machine.o
 obj-$(CONFIG_KPROBES_SANITY_TEST) += test_kprobes.o
 obj-$(CONFIG_AUDIT) += audit.o auditfilter.o
@@ -127,7 +127,7 @@ $(obj)/config_data.gz: $(KCONFIG_CONFIG) FORCE
 $(obj)/kheaders.o: $(obj)/kheaders_data.tar.xz
 
 quiet_cmd_genikh = CHK     $(obj)/kheaders_data.tar.xz
-cmd_genikh = $(CONFIG_SHELL) $(srctree)/kernel/gen_ikh_data.sh $@
+cmd_genikh = $(CONFIG_SHELL) $(srctree)/kernel/gen_kheaders.sh $@
 $(obj)/kheaders_data.tar.xz: FORCE
 	$(call cmd,genikh)
 
diff --git a/kernel/async.c b/kernel/async.c
index 12c332e4e13e..4f9c1d614016 100644
--- a/kernel/async.c
+++ b/kernel/async.c
@@ -1,13 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * async.c: Asynchronous function calls for boot performance
  *
  * (C) Copyright 2009 Intel Corporation
  * Author: Arjan van de Ven <arjan@linux.intel.com>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; version 2
- * of the License.
  */
 
 
diff --git a/kernel/audit.c b/kernel/audit.c
index b96bf69183f4..486c968214d9 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /* audit.c -- Auditing support
  * Gateway between the kernel (e.g., selinux) and the user-space audit daemon.
  * System-call specific features have moved to auditsc.c
@@ -5,20 +6,6 @@
  * Copyright 2003-2007 Red Hat Inc., Durham, North Carolina.
  * All Rights Reserved.
  *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
- *
  * Written by Rickard E. (Rik) Faith <faith@redhat.com>
  *
  * Goals: 1) Integrate fully with Security Modules.
diff --git a/kernel/audit.h b/kernel/audit.h
index 2071725a999f..6c076d4982da 100644
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -1,22 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
 /* audit -- definition of audit_context structure and supporting types 
  *
  * Copyright 2003-2004 Red Hat, Inc.
  * Copyright 2005 Hewlett-Packard Development Company, L.P.
  * Copyright 2005 IBM Corporation
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
 #include <linux/fs.h>
diff --git a/kernel/audit_fsnotify.c b/kernel/audit_fsnotify.c
index b5737b826951..f0d243318452 100644
--- a/kernel/audit_fsnotify.c
+++ b/kernel/audit_fsnotify.c
@@ -1,18 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /* audit_fsnotify.c -- tracking inodes
  *
  * Copyright 2003-2009,2014-2015 Red Hat, Inc.
  * Copyright 2005 Hewlett-Packard Development Company, L.P.
  * Copyright 2005 IBM Corporation
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
  */
 
 #include <linux/kernel.h>
diff --git a/kernel/audit_watch.c b/kernel/audit_watch.c
index b50c574223fa..1f31c2f1e6fc 100644
--- a/kernel/audit_watch.c
+++ b/kernel/audit_watch.c
@@ -1,22 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /* audit_watch.c -- watching inodes
  *
  * Copyright 2003-2009 Red Hat, Inc.
  * Copyright 2005 Hewlett-Packard Development Company, L.P.
  * Copyright 2005 IBM Corporation
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
 #include <linux/file.h>
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index 303fb04770ce..9f8e190e3bea 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -1,22 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /* auditfilter.c -- filtering of audit events
  *
  * Copyright 2003-2004 Red Hat, Inc.
  * Copyright 2005 Hewlett-Packard Development Company, L.P.
  * Copyright 2005 IBM Corporation
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
diff --git a/kernel/backtracetest.c b/kernel/backtracetest.c
index a563c8fdad0d..a2a97fa3071b 100644
--- a/kernel/backtracetest.c
+++ b/kernel/backtracetest.c
@@ -1,13 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Simple stack backtrace regression test module
  *
  * (C) Copyright 2008 Intel Corporation
  * Author: Arjan van de Ven <arjan@linux.intel.com>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; version 2
- * of the License.
  */
 
 #include <linux/completion.h>
diff --git a/kernel/bpf/Makefile b/kernel/bpf/Makefile
index 4c2fa3ac56f6..29d781061cd5 100644
--- a/kernel/bpf/Makefile
+++ b/kernel/bpf/Makefile
@@ -1,5 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0
 obj-y := core.o
+CFLAGS_core.o += $(call cc-disable-warning, override-init)
 
 obj-$(CONFIG_BPF_SYSCALL) += syscall.o verifier.o inode.o helpers.o tnum.o
 obj-$(CONFIG_BPF_SYSCALL) += hashtab.o arraymap.o percpu_freelist.o bpf_lru_list.o lpm_trie.o map_in_map.o
diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c
index 0349cbf23cdb..1c65ce0098a9 100644
--- a/kernel/bpf/arraymap.c
+++ b/kernel/bpf/arraymap.c
@@ -1,14 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
  * Copyright (c) 2016,2017 Facebook
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
  */
 #include <linux/bpf.h>
 #include <linux/btf.h>
diff --git a/kernel/bpf/bpf_lru_list.c b/kernel/bpf/bpf_lru_list.c
index e6ef4401a138..1b6b9349cb85 100644
--- a/kernel/bpf/bpf_lru_list.c
+++ b/kernel/bpf/bpf_lru_list.c
@@ -1,8 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /* Copyright (c) 2016 Facebook
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
  */
 #include <linux/cpumask.h>
 #include <linux/spinlock.h>
diff --git a/kernel/bpf/bpf_lru_list.h b/kernel/bpf/bpf_lru_list.h
index 7d4f89b7cb84..f02504640e18 100644
--- a/kernel/bpf/bpf_lru_list.h
+++ b/kernel/bpf/bpf_lru_list.h
@@ -1,8 +1,5 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
 /* Copyright (c) 2016 Facebook
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
  */
 #ifndef __BPF_LRU_LIST_H_
 #define __BPF_LRU_LIST_H_
diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index 1b65ab0df457..c225c42e114a 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -1,11 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Functions to manage eBPF programs attached to cgroups
  *
  * Copyright (c) 2016 Daniel Mack
- *
- * This file is subject to the terms and conditions of version 2 of the GNU
- * General Public License.  See the file COPYING in the main directory of the
- * Linux distribution for more details.
  */
 
 #include <linux/kernel.h>
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 33fb292f2e30..ad3be85f1411 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Linux Socket Filter - Kernel level socket filtering
  *
@@ -12,11 +13,6 @@
  *	Alexei Starovoitov <ast@plumgrid.com>
  *	Daniel Borkmann <dborkman@redhat.com>
  *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
- *
  * Andi Kleen - Fix a few bad bugs and races.
  * Kris Katterjohn - Added many additional checks in bpf_check_classic()
  */
@@ -2099,7 +2095,6 @@ int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to,
 
 DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key);
 EXPORT_SYMBOL(bpf_stats_enabled_key);
-int sysctl_bpf_stats_enabled __read_mostly;
 
 /* All definitions of tracepoints related to BPF. */
 #define CREATE_TRACE_POINTS
diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c
index b31a71909307..8dff08768087 100644
--- a/kernel/bpf/cpumap.c
+++ b/kernel/bpf/cpumap.c
@@ -1,7 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /* bpf/cpumap.c
  *
  * Copyright (c) 2017 Jesper Dangaard Brouer, Red Hat Inc.
- * Released under terms in GPL version 2.  See COPYING.
  */
 
 /* The 'cpumap' is primarily used as a backend map for XDP BPF helper
@@ -208,6 +208,9 @@ static struct sk_buff *cpu_map_build_skb(struct bpf_cpu_map_entry *rcpu,
 	 * - RX ring dev queue index	(skb_record_rx_queue)
 	 */
 
+	/* Until page_pool get SKB return path, release DMA here */
+	xdp_release_frame(xdpf);
+
 	/* Allow SKB to reuse area used by xdp_frame */
 	xdp_scrub_frame(xdpf);
 
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index 5ae7cce5ef16..40e86a7e0ef0 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -1,13 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /* Copyright (c) 2017 Covalent IO, Inc. http://covalent.io
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
  */
 
 /* Devmaps primary use is as a backend map for XDP BPF helper call
@@ -88,8 +80,8 @@ static u64 dev_map_bitmap_size(const union bpf_attr *attr)
 static struct bpf_map *dev_map_alloc(union bpf_attr *attr)
 {
 	struct bpf_dtab *dtab;
-	int err = -EINVAL;
 	u64 cost;
+	int err;
 
 	if (!capable(CAP_NET_ADMIN))
 		return ERR_PTR(-EPERM);
@@ -184,6 +176,7 @@ static void dev_map_free(struct bpf_map *map)
 		if (!dev)
 			continue;
 
+		free_percpu(dev->bulkq);
 		dev_put(dev->dev);
 		kfree(dev);
 	}
@@ -279,6 +272,7 @@ void __dev_map_flush(struct bpf_map *map)
 	unsigned long *bitmap = this_cpu_ptr(dtab->flush_needed);
 	u32 bit;
 
+	rcu_read_lock();
 	for_each_set_bit(bit, bitmap, map->max_entries) {
 		struct bpf_dtab_netdev *dev = READ_ONCE(dtab->netdev_map[bit]);
 		struct xdp_bulk_queue *bq;
@@ -289,11 +283,12 @@ void __dev_map_flush(struct bpf_map *map)
 		if (unlikely(!dev))
 			continue;
 
-		__clear_bit(bit, bitmap);
-
 		bq = this_cpu_ptr(dev->bulkq);
 		bq_xmit_all(dev, bq, XDP_XMIT_FLUSH, true);
+
+		__clear_bit(bit, bitmap);
 	}
+	rcu_read_unlock();
 }
 
 /* rcu_read_lock (from syscall and BPF contexts) ensures that if a delete and/or
@@ -386,6 +381,7 @@ static void dev_map_flush_old(struct bpf_dtab_netdev *dev)
 
 		int cpu;
 
+		rcu_read_lock();
 		for_each_online_cpu(cpu) {
 			bitmap = per_cpu_ptr(dev->dtab->flush_needed, cpu);
 			__clear_bit(dev->bit, bitmap);
@@ -393,6 +389,7 @@ static void dev_map_flush_old(struct bpf_dtab_netdev *dev)
 			bq = per_cpu_ptr(dev->bulkq, cpu);
 			bq_xmit_all(dev, bq, XDP_XMIT_FLUSH, false);
 		}
+		rcu_read_unlock();
 	}
 }
 
diff --git a/kernel/bpf/disasm.c b/kernel/bpf/disasm.c
index d9ce383c0f9c..b44d8c447afd 100644
--- a/kernel/bpf/disasm.c
+++ b/kernel/bpf/disasm.c
@@ -1,14 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
  * Copyright (c) 2016 Facebook
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
  */
 
 #include <linux/bpf.h>
diff --git a/kernel/bpf/disasm.h b/kernel/bpf/disasm.h
index e1324a834a24..e546b18d27da 100644
--- a/kernel/bpf/disasm.h
+++ b/kernel/bpf/disasm.h
@@ -1,14 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
  * Copyright (c) 2016 Facebook
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
  */
 
 #ifndef __BPF_DISASM_H__
diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
index d92e05d9979b..22066a62c8c9 100644
--- a/kernel/bpf/hashtab.c
+++ b/kernel/bpf/hashtab.c
@@ -1,14 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
  * Copyright (c) 2016 Facebook
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
  */
 #include <linux/bpf.h>
 #include <linux/btf.h>
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index 4266ffde07ca..5e28718928ca 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -1,13 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
  */
 #include <linux/bpf.h>
 #include <linux/rcupdate.h>
diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c
index 84a80b02db99..cc0d0cf114e3 100644
--- a/kernel/bpf/inode.c
+++ b/kernel/bpf/inode.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Minimal file system backend for holding eBPF maps and programs,
  * used by bpf(2) object pinning.
@@ -5,10 +6,6 @@
  * Authors:
  *
  *	Daniel Borkmann <daniel@iogearbox.net>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * version 2 as published by the Free Software Foundation.
  */
 
 #include <linux/init.h>
diff --git a/kernel/bpf/lpm_trie.c b/kernel/bpf/lpm_trie.c
index 09334f13a8a0..56e6c75d354d 100644
--- a/kernel/bpf/lpm_trie.c
+++ b/kernel/bpf/lpm_trie.c
@@ -1,12 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Longest prefix match list implementation
  *
  * Copyright (c) 2016,2017 Daniel Mack
  * Copyright (c) 2016 David Herrmann
- *
- * This file is subject to the terms and conditions of version 2 of the GNU
- * General Public License.  See the file COPYING in the main directory of the
- * Linux distribution for more details.
  */
 
 #include <linux/bpf.h>
@@ -710,9 +707,14 @@ find_leftmost:
 	 * have exact two children, so this function will never return NULL.
 	 */
 	for (node = search_root; node;) {
-		if (!(node->flags & LPM_TREE_NODE_FLAG_IM))
+		if (node->flags & LPM_TREE_NODE_FLAG_IM) {
+			node = rcu_dereference(node->child[0]);
+		} else {
 			next_node = node;
-		node = rcu_dereference(node->child[0]);
+			node = rcu_dereference(node->child[0]);
+			if (!node)
+				node = rcu_dereference(next_node->child[1]);
+		}
 	}
 do_copy:
 	next_key->prefixlen = next_node->prefixlen;
diff --git a/kernel/bpf/map_in_map.c b/kernel/bpf/map_in_map.c
index 3dff41403583..fab4fb134547 100644
--- a/kernel/bpf/map_in_map.c
+++ b/kernel/bpf/map_in_map.c
@@ -1,8 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /* Copyright (c) 2017 Facebook
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
  */
 #include <linux/slab.h>
 #include <linux/bpf.h>
diff --git a/kernel/bpf/map_in_map.h b/kernel/bpf/map_in_map.h
index 6183db9ec08c..a507bf6ef8b9 100644
--- a/kernel/bpf/map_in_map.h
+++ b/kernel/bpf/map_in_map.h
@@ -1,8 +1,5 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
 /* Copyright (c) 2017 Facebook
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
  */
 #ifndef __MAP_IN_MAP_H__
 #define __MAP_IN_MAP_H__
diff --git a/kernel/bpf/percpu_freelist.c b/kernel/bpf/percpu_freelist.c
index 0c1b4ba9e90e..6e090140b924 100644
--- a/kernel/bpf/percpu_freelist.c
+++ b/kernel/bpf/percpu_freelist.c
@@ -1,8 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /* Copyright (c) 2016 Facebook
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
  */
 #include "percpu_freelist.h"
 
diff --git a/kernel/bpf/percpu_freelist.h b/kernel/bpf/percpu_freelist.h
index c3960118e617..fbf8a8a28979 100644
--- a/kernel/bpf/percpu_freelist.h
+++ b/kernel/bpf/percpu_freelist.h
@@ -1,8 +1,5 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
 /* Copyright (c) 2016 Facebook
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
  */
 #ifndef __PERCPU_FREELIST_H__
 #define __PERCPU_FREELIST_H__
diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c
index 3d86072d8e32..052580c33d26 100644
--- a/kernel/bpf/stackmap.c
+++ b/kernel/bpf/stackmap.c
@@ -1,8 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /* Copyright (c) 2016 Facebook
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
  */
 #include <linux/bpf.h>
 #include <linux/jhash.h>
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 4c53cbd3329d..7713cf39795a 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1,13 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
  */
 #include <linux/bpf.h>
 #include <linux/bpf_trace.h>
@@ -1584,6 +1576,8 @@ bpf_prog_load_check_attach_type(enum bpf_prog_type prog_type,
 		case BPF_CGROUP_INET6_CONNECT:
 		case BPF_CGROUP_UDP4_SENDMSG:
 		case BPF_CGROUP_UDP6_SENDMSG:
+		case BPF_CGROUP_UDP4_RECVMSG:
+		case BPF_CGROUP_UDP6_RECVMSG:
 			return 0;
 		default:
 			return -EINVAL;
@@ -1892,6 +1886,8 @@ static int bpf_prog_attach(const union bpf_attr *attr)
 	case BPF_CGROUP_INET6_CONNECT:
 	case BPF_CGROUP_UDP4_SENDMSG:
 	case BPF_CGROUP_UDP6_SENDMSG:
+	case BPF_CGROUP_UDP4_RECVMSG:
+	case BPF_CGROUP_UDP6_RECVMSG:
 		ptype = BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
 		break;
 	case BPF_CGROUP_SOCK_OPS:
@@ -1977,6 +1973,8 @@ static int bpf_prog_detach(const union bpf_attr *attr)
 	case BPF_CGROUP_INET6_CONNECT:
 	case BPF_CGROUP_UDP4_SENDMSG:
 	case BPF_CGROUP_UDP6_SENDMSG:
+	case BPF_CGROUP_UDP4_RECVMSG:
+	case BPF_CGROUP_UDP6_RECVMSG:
 		ptype = BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
 		break;
 	case BPF_CGROUP_SOCK_OPS:
@@ -2028,6 +2026,8 @@ static int bpf_prog_query(const union bpf_attr *attr,
 	case BPF_CGROUP_INET6_CONNECT:
 	case BPF_CGROUP_UDP4_SENDMSG:
 	case BPF_CGROUP_UDP6_SENDMSG:
+	case BPF_CGROUP_UDP4_RECVMSG:
+	case BPF_CGROUP_UDP6_RECVMSG:
 	case BPF_CGROUP_SOCK_OPS:
 	case BPF_CGROUP_DEVICE:
 	case BPF_CGROUP_SYSCTL:
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 5c2cb5bd84ce..0e079b2298f8 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -1,15 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
  * Copyright (c) 2016 Facebook
  * Copyright (c) 2018 Covalent IO, Inc. http://covalent.io
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
  */
 #include <uapi/linux/btf.h>
 #include <linux/kernel.h>
@@ -334,7 +326,8 @@ static bool type_is_sk_pointer(enum bpf_reg_type type)
 {
 	return type == PTR_TO_SOCKET ||
 		type == PTR_TO_SOCK_COMMON ||
-		type == PTR_TO_TCP_SOCK;
+		type == PTR_TO_TCP_SOCK ||
+		type == PTR_TO_XDP_SOCK;
 }
 
 static bool reg_type_may_be_null(enum bpf_reg_type type)
@@ -406,6 +399,7 @@ static const char * const reg_type_str[] = {
 	[PTR_TO_TCP_SOCK]	= "tcp_sock",
 	[PTR_TO_TCP_SOCK_OR_NULL] = "tcp_sock_or_null",
 	[PTR_TO_TP_BUFFER]	= "tp_buffer",
+	[PTR_TO_XDP_SOCK]	= "xdp_sock",
 };
 
 static char slot_type_char[] = {
@@ -453,12 +447,12 @@ static void print_verifier_state(struct bpf_verifier_env *env,
 		verbose(env, " R%d", i);
 		print_liveness(env, reg->live);
 		verbose(env, "=%s", reg_type_str[t]);
+		if (t == SCALAR_VALUE && reg->precise)
+			verbose(env, "P");
 		if ((t == SCALAR_VALUE || t == PTR_TO_STACK) &&
 		    tnum_is_const(reg->var_off)) {
 			/* reg->off should be 0 for SCALAR_VALUE */
 			verbose(env, "%lld", reg->var_off.value + reg->off);
-			if (t == PTR_TO_STACK)
-				verbose(env, ",call_%d", func(env, reg)->callsite);
 		} else {
 			verbose(env, "(id=%d", reg->id);
 			if (reg_type_may_be_refcounted_or_null(t))
@@ -520,11 +514,17 @@ static void print_verifier_state(struct bpf_verifier_env *env,
 			continue;
 		verbose(env, " fp%d", (-i - 1) * BPF_REG_SIZE);
 		print_liveness(env, state->stack[i].spilled_ptr.live);
-		if (state->stack[i].slot_type[0] == STACK_SPILL)
-			verbose(env, "=%s",
-				reg_type_str[state->stack[i].spilled_ptr.type]);
-		else
+		if (state->stack[i].slot_type[0] == STACK_SPILL) {
+			reg = &state->stack[i].spilled_ptr;
+			t = reg->type;
+			verbose(env, "=%s", reg_type_str[t]);
+			if (t == SCALAR_VALUE && reg->precise)
+				verbose(env, "P");
+			if (t == SCALAR_VALUE && tnum_is_const(reg->var_off))
+				verbose(env, "%lld", reg->var_off.value + reg->off);
+		} else {
 			verbose(env, "=%s", types_buf);
+		}
 	}
 	if (state->acquired_refs && state->refs[0].id) {
 		verbose(env, " refs=%d", state->refs[0].id);
@@ -673,6 +673,13 @@ static void free_func_state(struct bpf_func_state *state)
 	kfree(state);
 }
 
+static void clear_jmp_history(struct bpf_verifier_state *state)
+{
+	kfree(state->jmp_history);
+	state->jmp_history = NULL;
+	state->jmp_history_cnt = 0;
+}
+
 static void free_verifier_state(struct bpf_verifier_state *state,
 				bool free_self)
 {
@@ -682,6 +689,7 @@ static void free_verifier_state(struct bpf_verifier_state *state,
 		free_func_state(state->frame[i]);
 		state->frame[i] = NULL;
 	}
+	clear_jmp_history(state);
 	if (free_self)
 		kfree(state);
 }
@@ -709,8 +717,18 @@ static int copy_verifier_state(struct bpf_verifier_state *dst_state,
 			       const struct bpf_verifier_state *src)
 {
 	struct bpf_func_state *dst;
+	u32 jmp_sz = sizeof(struct bpf_idx_pair) * src->jmp_history_cnt;
 	int i, err;
 
+	if (dst_state->jmp_history_cnt < src->jmp_history_cnt) {
+		kfree(dst_state->jmp_history);
+		dst_state->jmp_history = kmalloc(jmp_sz, GFP_USER);
+		if (!dst_state->jmp_history)
+			return -ENOMEM;
+	}
+	memcpy(dst_state->jmp_history, src->jmp_history, jmp_sz);
+	dst_state->jmp_history_cnt = src->jmp_history_cnt;
+
 	/* if dst has more stack frames then src frame, free them */
 	for (i = src->curframe + 1; i <= dst_state->curframe; i++) {
 		free_func_state(dst_state->frame[i]);
@@ -719,6 +737,10 @@ static int copy_verifier_state(struct bpf_verifier_state *dst_state,
 	dst_state->speculative = src->speculative;
 	dst_state->curframe = src->curframe;
 	dst_state->active_spin_lock = src->active_spin_lock;
+	dst_state->branches = src->branches;
+	dst_state->parent = src->parent;
+	dst_state->first_insn_idx = src->first_insn_idx;
+	dst_state->last_insn_idx = src->last_insn_idx;
 	for (i = 0; i <= src->curframe; i++) {
 		dst = dst_state->frame[i];
 		if (!dst) {
@@ -734,6 +756,23 @@ static int copy_verifier_state(struct bpf_verifier_state *dst_state,
 	return 0;
 }
 
+static void update_branch_counts(struct bpf_verifier_env *env, struct bpf_verifier_state *st)
+{
+	while (st) {
+		u32 br = --st->branches;
+
+		/* WARN_ON(br > 1) technically makes sense here,
+		 * but see comment in push_stack(), hence:
+		 */
+		WARN_ONCE((int)br < 0,
+			  "BUG update_branch_counts:branches_to_explore=%d\n",
+			  br);
+		if (br)
+			break;
+		st = st->parent;
+	}
+}
+
 static int pop_stack(struct bpf_verifier_env *env, int *prev_insn_idx,
 		     int *insn_idx)
 {
@@ -787,6 +826,18 @@ static struct bpf_verifier_state *push_stack(struct bpf_verifier_env *env,
 			env->stack_size);
 		goto err;
 	}
+	if (elem->st.parent) {
+		++elem->st.parent->branches;
+		/* WARN_ON(branches > 2) technically makes sense here,
+		 * but
+		 * 1. speculative states will bump 'branches' for non-branch
+		 * instructions
+		 * 2. is_state_visited() heuristics may decide not to create
+		 * a new state for a sequence of branches and all such current
+		 * and cloned states will be pointing to a single parent state
+		 * which might have large 'branches' count.
+		 */
+	}
 	return &elem->st;
 err:
 	free_verifier_state(env->cur_state, true);
@@ -934,6 +985,9 @@ static void __mark_reg_unbounded(struct bpf_reg_state *reg)
 	reg->smax_value = S64_MAX;
 	reg->umin_value = 0;
 	reg->umax_value = U64_MAX;
+
+	/* constant backtracking is enabled for root only for now */
+	reg->precise = capable(CAP_SYS_ADMIN) ? false : true;
 }
 
 /* Mark a register as having a completely unknown (scalar) value. */
@@ -1345,6 +1399,389 @@ static int check_reg_arg(struct bpf_verifier_env *env, u32 regno,
 	return 0;
 }
 
+/* for any branch, call, exit record the history of jmps in the given state */
+static int push_jmp_history(struct bpf_verifier_env *env,
+			    struct bpf_verifier_state *cur)
+{
+	u32 cnt = cur->jmp_history_cnt;
+	struct bpf_idx_pair *p;
+
+	cnt++;
+	p = krealloc(cur->jmp_history, cnt * sizeof(*p), GFP_USER);
+	if (!p)
+		return -ENOMEM;
+	p[cnt - 1].idx = env->insn_idx;
+	p[cnt - 1].prev_idx = env->prev_insn_idx;
+	cur->jmp_history = p;
+	cur->jmp_history_cnt = cnt;
+	return 0;
+}
+
+/* Backtrack one insn at a time. If idx is not at the top of recorded
+ * history then previous instruction came from straight line execution.
+ */
+static int get_prev_insn_idx(struct bpf_verifier_state *st, int i,
+			     u32 *history)
+{
+	u32 cnt = *history;
+
+	if (cnt && st->jmp_history[cnt - 1].idx == i) {
+		i = st->jmp_history[cnt - 1].prev_idx;
+		(*history)--;
+	} else {
+		i--;
+	}
+	return i;
+}
+
+/* For given verifier state backtrack_insn() is called from the last insn to
+ * the first insn. Its purpose is to compute a bitmask of registers and
+ * stack slots that needs precision in the parent verifier state.
+ */
+static int backtrack_insn(struct bpf_verifier_env *env, int idx,
+			  u32 *reg_mask, u64 *stack_mask)
+{
+	const struct bpf_insn_cbs cbs = {
+		.cb_print	= verbose,
+		.private_data	= env,
+	};
+	struct bpf_insn *insn = env->prog->insnsi + idx;
+	u8 class = BPF_CLASS(insn->code);
+	u8 opcode = BPF_OP(insn->code);
+	u8 mode = BPF_MODE(insn->code);
+	u32 dreg = 1u << insn->dst_reg;
+	u32 sreg = 1u << insn->src_reg;
+	u32 spi;
+
+	if (insn->code == 0)
+		return 0;
+	if (env->log.level & BPF_LOG_LEVEL) {
+		verbose(env, "regs=%x stack=%llx before ", *reg_mask, *stack_mask);
+		verbose(env, "%d: ", idx);
+		print_bpf_insn(&cbs, insn, env->allow_ptr_leaks);
+	}
+
+	if (class == BPF_ALU || class == BPF_ALU64) {
+		if (!(*reg_mask & dreg))
+			return 0;
+		if (opcode == BPF_MOV) {
+			if (BPF_SRC(insn->code) == BPF_X) {
+				/* dreg = sreg
+				 * dreg needs precision after this insn
+				 * sreg needs precision before this insn
+				 */
+				*reg_mask &= ~dreg;
+				*reg_mask |= sreg;
+			} else {
+				/* dreg = K
+				 * dreg needs precision after this insn.
+				 * Corresponding register is already marked
+				 * as precise=true in this verifier state.
+				 * No further markings in parent are necessary
+				 */
+				*reg_mask &= ~dreg;
+			}
+		} else {
+			if (BPF_SRC(insn->code) == BPF_X) {
+				/* dreg += sreg
+				 * both dreg and sreg need precision
+				 * before this insn
+				 */
+				*reg_mask |= sreg;
+			} /* else dreg += K
+			   * dreg still needs precision before this insn
+			   */
+		}
+	} else if (class == BPF_LDX) {
+		if (!(*reg_mask & dreg))
+			return 0;
+		*reg_mask &= ~dreg;
+
+		/* scalars can only be spilled into stack w/o losing precision.
+		 * Load from any other memory can be zero extended.
+		 * The desire to keep that precision is already indicated
+		 * by 'precise' mark in corresponding register of this state.
+		 * No further tracking necessary.
+		 */
+		if (insn->src_reg != BPF_REG_FP)
+			return 0;
+		if (BPF_SIZE(insn->code) != BPF_DW)
+			return 0;
+
+		/* dreg = *(u64 *)[fp - off] was a fill from the stack.
+		 * that [fp - off] slot contains scalar that needs to be
+		 * tracked with precision
+		 */
+		spi = (-insn->off - 1) / BPF_REG_SIZE;
+		if (spi >= 64) {
+			verbose(env, "BUG spi %d\n", spi);
+			WARN_ONCE(1, "verifier backtracking bug");
+			return -EFAULT;
+		}
+		*stack_mask |= 1ull << spi;
+	} else if (class == BPF_STX) {
+		if (*reg_mask & dreg)
+			/* stx shouldn't be using _scalar_ dst_reg
+			 * to access memory. It means backtracking
+			 * encountered a case of pointer subtraction.
+			 */
+			return -ENOTSUPP;
+		/* scalars can only be spilled into stack */
+		if (insn->dst_reg != BPF_REG_FP)
+			return 0;
+		if (BPF_SIZE(insn->code) != BPF_DW)
+			return 0;
+		spi = (-insn->off - 1) / BPF_REG_SIZE;
+		if (spi >= 64) {
+			verbose(env, "BUG spi %d\n", spi);
+			WARN_ONCE(1, "verifier backtracking bug");
+			return -EFAULT;
+		}
+		if (!(*stack_mask & (1ull << spi)))
+			return 0;
+		*stack_mask &= ~(1ull << spi);
+		*reg_mask |= sreg;
+	} else if (class == BPF_JMP || class == BPF_JMP32) {
+		if (opcode == BPF_CALL) {
+			if (insn->src_reg == BPF_PSEUDO_CALL)
+				return -ENOTSUPP;
+			/* regular helper call sets R0 */
+			*reg_mask &= ~1;
+			if (*reg_mask & 0x3f) {
+				/* if backtracing was looking for registers R1-R5
+				 * they should have been found already.
+				 */
+				verbose(env, "BUG regs %x\n", *reg_mask);
+				WARN_ONCE(1, "verifier backtracking bug");
+				return -EFAULT;
+			}
+		} else if (opcode == BPF_EXIT) {
+			return -ENOTSUPP;
+		}
+	} else if (class == BPF_LD) {
+		if (!(*reg_mask & dreg))
+			return 0;
+		*reg_mask &= ~dreg;
+		/* It's ld_imm64 or ld_abs or ld_ind.
+		 * For ld_imm64 no further tracking of precision
+		 * into parent is necessary
+		 */
+		if (mode == BPF_IND || mode == BPF_ABS)
+			/* to be analyzed */
+			return -ENOTSUPP;
+	} else if (class == BPF_ST) {
+		if (*reg_mask & dreg)
+			/* likely pointer subtraction */
+			return -ENOTSUPP;
+	}
+	return 0;
+}
+
+/* the scalar precision tracking algorithm:
+ * . at the start all registers have precise=false.
+ * . scalar ranges are tracked as normal through alu and jmp insns.
+ * . once precise value of the scalar register is used in:
+ *   .  ptr + scalar alu
+ *   . if (scalar cond K|scalar)
+ *   .  helper_call(.., scalar, ...) where ARG_CONST is expected
+ *   backtrack through the verifier states and mark all registers and
+ *   stack slots with spilled constants that these scalar regisers
+ *   should be precise.
+ * . during state pruning two registers (or spilled stack slots)
+ *   are equivalent if both are not precise.
+ *
+ * Note the verifier cannot simply walk register parentage chain,
+ * since many different registers and stack slots could have been
+ * used to compute single precise scalar.
+ *
+ * The approach of starting with precise=true for all registers and then
+ * backtrack to mark a register as not precise when the verifier detects
+ * that program doesn't care about specific value (e.g., when helper
+ * takes register as ARG_ANYTHING parameter) is not safe.
+ *
+ * It's ok to walk single parentage chain of the verifier states.
+ * It's possible that this backtracking will go all the way till 1st insn.
+ * All other branches will be explored for needing precision later.
+ *
+ * The backtracking needs to deal with cases like:
+ *   R8=map_value(id=0,off=0,ks=4,vs=1952,imm=0) R9_w=map_value(id=0,off=40,ks=4,vs=1952,imm=0)
+ * r9 -= r8
+ * r5 = r9
+ * if r5 > 0x79f goto pc+7
+ *    R5_w=inv(id=0,umax_value=1951,var_off=(0x0; 0x7ff))
+ * r5 += 1
+ * ...
+ * call bpf_perf_event_output#25
+ *   where .arg5_type = ARG_CONST_SIZE_OR_ZERO
+ *
+ * and this case:
+ * r6 = 1
+ * call foo // uses callee's r6 inside to compute r0
+ * r0 += r6
+ * if r0 == 0 goto
+ *
+ * to track above reg_mask/stack_mask needs to be independent for each frame.
+ *
+ * Also if parent's curframe > frame where backtracking started,
+ * the verifier need to mark registers in both frames, otherwise callees
+ * may incorrectly prune callers. This is similar to
+ * commit 7640ead93924 ("bpf: verifier: make sure callees don't prune with caller differences")
+ *
+ * For now backtracking falls back into conservative marking.
+ */
+static void mark_all_scalars_precise(struct bpf_verifier_env *env,
+				     struct bpf_verifier_state *st)
+{
+	struct bpf_func_state *func;
+	struct bpf_reg_state *reg;
+	int i, j;
+
+	/* big hammer: mark all scalars precise in this path.
+	 * pop_stack may still get !precise scalars.
+	 */
+	for (; st; st = st->parent)
+		for (i = 0; i <= st->curframe; i++) {
+			func = st->frame[i];
+			for (j = 0; j < BPF_REG_FP; j++) {
+				reg = &func->regs[j];
+				if (reg->type != SCALAR_VALUE)
+					continue;
+				reg->precise = true;
+			}
+			for (j = 0; j < func->allocated_stack / BPF_REG_SIZE; j++) {
+				if (func->stack[j].slot_type[0] != STACK_SPILL)
+					continue;
+				reg = &func->stack[j].spilled_ptr;
+				if (reg->type != SCALAR_VALUE)
+					continue;
+				reg->precise = true;
+			}
+		}
+}
+
+static int mark_chain_precision(struct bpf_verifier_env *env, int regno)
+{
+	struct bpf_verifier_state *st = env->cur_state;
+	int first_idx = st->first_insn_idx;
+	int last_idx = env->insn_idx;
+	struct bpf_func_state *func;
+	struct bpf_reg_state *reg;
+	u32 reg_mask = 1u << regno;
+	u64 stack_mask = 0;
+	bool skip_first = true;
+	int i, err;
+
+	if (!env->allow_ptr_leaks)
+		/* backtracking is root only for now */
+		return 0;
+
+	func = st->frame[st->curframe];
+	reg = &func->regs[regno];
+	if (reg->type != SCALAR_VALUE) {
+		WARN_ONCE(1, "backtracing misuse");
+		return -EFAULT;
+	}
+	if (reg->precise)
+		return 0;
+	func->regs[regno].precise = true;
+
+	for (;;) {
+		DECLARE_BITMAP(mask, 64);
+		bool new_marks = false;
+		u32 history = st->jmp_history_cnt;
+
+		if (env->log.level & BPF_LOG_LEVEL)
+			verbose(env, "last_idx %d first_idx %d\n", last_idx, first_idx);
+		for (i = last_idx;;) {
+			if (skip_first) {
+				err = 0;
+				skip_first = false;
+			} else {
+				err = backtrack_insn(env, i, &reg_mask, &stack_mask);
+			}
+			if (err == -ENOTSUPP) {
+				mark_all_scalars_precise(env, st);
+				return 0;
+			} else if (err) {
+				return err;
+			}
+			if (!reg_mask && !stack_mask)
+				/* Found assignment(s) into tracked register in this state.
+				 * Since this state is already marked, just return.
+				 * Nothing to be tracked further in the parent state.
+				 */
+				return 0;
+			if (i == first_idx)
+				break;
+			i = get_prev_insn_idx(st, i, &history);
+			if (i >= env->prog->len) {
+				/* This can happen if backtracking reached insn 0
+				 * and there are still reg_mask or stack_mask
+				 * to backtrack.
+				 * It means the backtracking missed the spot where
+				 * particular register was initialized with a constant.
+				 */
+				verbose(env, "BUG backtracking idx %d\n", i);
+				WARN_ONCE(1, "verifier backtracking bug");
+				return -EFAULT;
+			}
+		}
+		st = st->parent;
+		if (!st)
+			break;
+
+		func = st->frame[st->curframe];
+		bitmap_from_u64(mask, reg_mask);
+		for_each_set_bit(i, mask, 32) {
+			reg = &func->regs[i];
+			if (reg->type != SCALAR_VALUE)
+				continue;
+			if (!reg->precise)
+				new_marks = true;
+			reg->precise = true;
+		}
+
+		bitmap_from_u64(mask, stack_mask);
+		for_each_set_bit(i, mask, 64) {
+			if (i >= func->allocated_stack / BPF_REG_SIZE) {
+				/* This can happen if backtracking
+				 * is propagating stack precision where
+				 * caller has larger stack frame
+				 * than callee, but backtrack_insn() should
+				 * have returned -ENOTSUPP.
+				 */
+				verbose(env, "BUG spi %d stack_size %d\n",
+					i, func->allocated_stack);
+				WARN_ONCE(1, "verifier backtracking bug");
+				return -EFAULT;
+			}
+
+			if (func->stack[i].slot_type[0] != STACK_SPILL)
+				continue;
+			reg = &func->stack[i].spilled_ptr;
+			if (reg->type != SCALAR_VALUE)
+				continue;
+			if (!reg->precise)
+				new_marks = true;
+			reg->precise = true;
+		}
+		if (env->log.level & BPF_LOG_LEVEL) {
+			print_verifier_state(env, func);
+			verbose(env, "parent %s regs=%x stack=%llx marks\n",
+				new_marks ? "didn't have" : "already had",
+				reg_mask, stack_mask);
+		}
+
+		if (!new_marks)
+			break;
+
+		last_idx = st->last_insn_idx;
+		first_idx = st->first_insn_idx;
+	}
+	return 0;
+}
+
+
 static bool is_spillable_regtype(enum bpf_reg_type type)
 {
 	switch (type) {
@@ -1363,6 +1800,7 @@ static bool is_spillable_regtype(enum bpf_reg_type type)
 	case PTR_TO_SOCK_COMMON_OR_NULL:
 	case PTR_TO_TCP_SOCK:
 	case PTR_TO_TCP_SOCK_OR_NULL:
+	case PTR_TO_XDP_SOCK:
 		return true;
 	default:
 		return false;
@@ -1375,6 +1813,23 @@ static bool register_is_null(struct bpf_reg_state *reg)
 	return reg->type == SCALAR_VALUE && tnum_equals_const(reg->var_off, 0);
 }
 
+static bool register_is_const(struct bpf_reg_state *reg)
+{
+	return reg->type == SCALAR_VALUE && tnum_is_const(reg->var_off);
+}
+
+static void save_register_state(struct bpf_func_state *state,
+				int spi, struct bpf_reg_state *reg)
+{
+	int i;
+
+	state->stack[spi].spilled_ptr = *reg;
+	state->stack[spi].spilled_ptr.live |= REG_LIVE_WRITTEN;
+
+	for (i = 0; i < BPF_REG_SIZE; i++)
+		state->stack[spi].slot_type[i] = STACK_SPILL;
+}
+
 /* check_stack_read/write functions track spill/fill of registers,
  * stack boundary and alignment are checked in check_mem_access()
  */
@@ -1384,7 +1839,8 @@ static int check_stack_write(struct bpf_verifier_env *env,
 {
 	struct bpf_func_state *cur; /* state of the current function */
 	int i, slot = -off - 1, spi = slot / BPF_REG_SIZE, err;
-	enum bpf_reg_type type;
+	u32 dst_reg = env->prog->insnsi[insn_idx].dst_reg;
+	struct bpf_reg_state *reg = NULL;
 
 	err = realloc_func_state(state, round_up(slot + 1, BPF_REG_SIZE),
 				 state->acquired_refs, true);
@@ -1401,27 +1857,48 @@ static int check_stack_write(struct bpf_verifier_env *env,
 	}
 
 	cur = env->cur_state->frame[env->cur_state->curframe];
-	if (value_regno >= 0 &&
-	    is_spillable_regtype((type = cur->regs[value_regno].type))) {
+	if (value_regno >= 0)
+		reg = &cur->regs[value_regno];
 
+	if (reg && size == BPF_REG_SIZE && register_is_const(reg) &&
+	    !register_is_null(reg) && env->allow_ptr_leaks) {
+		if (dst_reg != BPF_REG_FP) {
+			/* The backtracking logic can only recognize explicit
+			 * stack slot address like [fp - 8]. Other spill of
+			 * scalar via different register has to be conervative.
+			 * Backtrack from here and mark all registers as precise
+			 * that contributed into 'reg' being a constant.
+			 */
+			err = mark_chain_precision(env, value_regno);
+			if (err)
+				return err;
+		}
+		save_register_state(state, spi, reg);
+	} else if (reg && is_spillable_regtype(reg->type)) {
 		/* register containing pointer is being spilled into stack */
 		if (size != BPF_REG_SIZE) {
+			verbose_linfo(env, insn_idx, "; ");
 			verbose(env, "invalid size of register spill\n");
 			return -EACCES;
 		}
 
-		if (state != cur && type == PTR_TO_STACK) {
+		if (state != cur && reg->type == PTR_TO_STACK) {
 			verbose(env, "cannot spill pointers to stack into stack frame of the caller\n");
 			return -EINVAL;
 		}
 
-		/* save register state */
-		state->stack[spi].spilled_ptr = cur->regs[value_regno];
-		state->stack[spi].spilled_ptr.live |= REG_LIVE_WRITTEN;
+		if (!env->allow_ptr_leaks) {
+			bool sanitize = false;
 
-		for (i = 0; i < BPF_REG_SIZE; i++) {
-			if (state->stack[spi].slot_type[i] == STACK_MISC &&
-			    !env->allow_ptr_leaks) {
+			if (state->stack[spi].slot_type[0] == STACK_SPILL &&
+			    register_is_const(&state->stack[spi].spilled_ptr))
+				sanitize = true;
+			for (i = 0; i < BPF_REG_SIZE; i++)
+				if (state->stack[spi].slot_type[i] == STACK_MISC) {
+					sanitize = true;
+					break;
+				}
+			if (sanitize) {
 				int *poff = &env->insn_aux_data[insn_idx].sanitize_stack_off;
 				int soff = (-spi - 1) * BPF_REG_SIZE;
 
@@ -1444,8 +1921,8 @@ static int check_stack_write(struct bpf_verifier_env *env,
 				}
 				*poff = soff;
 			}
-			state->stack[spi].slot_type[i] = STACK_SPILL;
 		}
+		save_register_state(state, spi, reg);
 	} else {
 		u8 type = STACK_MISC;
 
@@ -1468,9 +1945,13 @@ static int check_stack_write(struct bpf_verifier_env *env,
 			state->stack[spi].spilled_ptr.live |= REG_LIVE_WRITTEN;
 
 		/* when we zero initialize stack slots mark them as such */
-		if (value_regno >= 0 &&
-		    register_is_null(&cur->regs[value_regno]))
+		if (reg && register_is_null(reg)) {
+			/* backtracking doesn't work for STACK_ZERO yet. */
+			err = mark_chain_precision(env, value_regno);
+			if (err)
+				return err;
 			type = STACK_ZERO;
+		}
 
 		/* Mark slots affected by this stack write. */
 		for (i = 0; i < size; i++)
@@ -1487,6 +1968,7 @@ static int check_stack_read(struct bpf_verifier_env *env,
 	struct bpf_verifier_state *vstate = env->cur_state;
 	struct bpf_func_state *state = vstate->frame[vstate->curframe];
 	int i, slot = -off - 1, spi = slot / BPF_REG_SIZE;
+	struct bpf_reg_state *reg;
 	u8 *stype;
 
 	if (reg_state->allocated_stack <= slot) {
@@ -1495,11 +1977,21 @@ static int check_stack_read(struct bpf_verifier_env *env,
 		return -EACCES;
 	}
 	stype = reg_state->stack[spi].slot_type;
+	reg = &reg_state->stack[spi].spilled_ptr;
 
 	if (stype[0] == STACK_SPILL) {
 		if (size != BPF_REG_SIZE) {
-			verbose(env, "invalid size of register spill\n");
-			return -EACCES;
+			if (reg->type != SCALAR_VALUE) {
+				verbose_linfo(env, env->insn_idx, "; ");
+				verbose(env, "invalid size of register fill\n");
+				return -EACCES;
+			}
+			if (value_regno >= 0) {
+				mark_reg_unknown(env, state->regs, value_regno);
+				state->regs[value_regno].live |= REG_LIVE_WRITTEN;
+			}
+			mark_reg_read(env, reg, reg->parent, REG_LIVE_READ64);
+			return 0;
 		}
 		for (i = 1; i < BPF_REG_SIZE; i++) {
 			if (stype[(slot - i) % BPF_REG_SIZE] != STACK_SPILL) {
@@ -1510,17 +2002,14 @@ static int check_stack_read(struct bpf_verifier_env *env,
 
 		if (value_regno >= 0) {
 			/* restore register state from stack */
-			state->regs[value_regno] = reg_state->stack[spi].spilled_ptr;
+			state->regs[value_regno] = *reg;
 			/* mark reg as written since spilled pointer state likely
 			 * has its liveness marks cleared by is_state_visited()
 			 * which resets stack/reg liveness for state transitions
 			 */
 			state->regs[value_regno].live |= REG_LIVE_WRITTEN;
 		}
-		mark_reg_read(env, &reg_state->stack[spi].spilled_ptr,
-			      reg_state->stack[spi].spilled_ptr.parent,
-			      REG_LIVE_READ64);
-		return 0;
+		mark_reg_read(env, reg, reg->parent, REG_LIVE_READ64);
 	} else {
 		int zeros = 0;
 
@@ -1535,23 +2024,32 @@ static int check_stack_read(struct bpf_verifier_env *env,
 				off, i, size);
 			return -EACCES;
 		}
-		mark_reg_read(env, &reg_state->stack[spi].spilled_ptr,
-			      reg_state->stack[spi].spilled_ptr.parent,
-			      REG_LIVE_READ64);
+		mark_reg_read(env, reg, reg->parent, REG_LIVE_READ64);
 		if (value_regno >= 0) {
 			if (zeros == size) {
 				/* any size read into register is zero extended,
 				 * so the whole register == const_zero
 				 */
 				__mark_reg_const_zero(&state->regs[value_regno]);
+				/* backtracking doesn't support STACK_ZERO yet,
+				 * so mark it precise here, so that later
+				 * backtracking can stop here.
+				 * Backtracking may not need this if this register
+				 * doesn't participate in pointer adjustment.
+				 * Forward propagation of precise flag is not
+				 * necessary either. This mark is only to stop
+				 * backtracking. Any register that contributed
+				 * to const 0 was marked precise before spill.
+				 */
+				state->regs[value_regno].precise = true;
 			} else {
 				/* have read misc data from the stack */
 				mark_reg_unknown(env, state->regs, value_regno);
 			}
 			state->regs[value_regno].live |= REG_LIVE_WRITTEN;
 		}
-		return 0;
 	}
+	return 0;
 }
 
 static int check_stack_access(struct bpf_verifier_env *env,
@@ -1843,6 +2341,9 @@ static int check_sock_access(struct bpf_verifier_env *env, int insn_idx,
 	case PTR_TO_TCP_SOCK:
 		valid = bpf_tcp_sock_is_valid_access(off, size, t, &info);
 		break;
+	case PTR_TO_XDP_SOCK:
+		valid = bpf_xdp_sock_is_valid_access(off, size, t, &info);
+		break;
 	default:
 		valid = false;
 	}
@@ -2007,6 +2508,9 @@ static int check_ptr_alignment(struct bpf_verifier_env *env,
 	case PTR_TO_TCP_SOCK:
 		pointer_desc = "tcp_sock ";
 		break;
+	case PTR_TO_XDP_SOCK:
+		pointer_desc = "xdp_sock ";
+		break;
 	default:
 		break;
 	}
@@ -2406,7 +2910,7 @@ static int check_stack_boundary(struct bpf_verifier_env *env, int regno,
 {
 	struct bpf_reg_state *reg = reg_state(env, regno);
 	struct bpf_func_state *state = func(env, reg);
-	int err, min_off, max_off, i, slot, spi;
+	int err, min_off, max_off, i, j, slot, spi;
 
 	if (reg->type != PTR_TO_STACK) {
 		/* Allow zero-byte read from NULL, regardless of pointer type */
@@ -2494,6 +2998,14 @@ static int check_stack_boundary(struct bpf_verifier_env *env, int regno,
 			*stype = STACK_MISC;
 			goto mark;
 		}
+		if (state->stack[spi].slot_type[0] == STACK_SPILL &&
+		    state->stack[spi].spilled_ptr.type == SCALAR_VALUE) {
+			__mark_reg_unknown(&state->stack[spi].spilled_ptr);
+			for (j = 0; j < BPF_REG_SIZE; j++)
+				state->stack[spi].slot_type[j] = STACK_MISC;
+			goto mark;
+		}
+
 err:
 		if (tnum_is_const(reg->var_off)) {
 			verbose(env, "invalid indirect read from stack off %d+%d size %d\n",
@@ -2845,6 +3357,8 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 regno,
 		err = check_helper_mem_access(env, regno - 1,
 					      reg->umax_value,
 					      zero_size_allowed, meta);
+		if (!err)
+			err = mark_chain_precision(env, regno);
 	} else if (arg_type_is_int_ptr(arg_type)) {
 		int size = int_ptr_type_to_size(arg_type);
 
@@ -2905,10 +3419,14 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env,
 	 * appear.
 	 */
 	case BPF_MAP_TYPE_CPUMAP:
-	case BPF_MAP_TYPE_XSKMAP:
 		if (func_id != BPF_FUNC_redirect_map)
 			goto error;
 		break;
+	case BPF_MAP_TYPE_XSKMAP:
+		if (func_id != BPF_FUNC_redirect_map &&
+		    func_id != BPF_FUNC_map_lookup_elem)
+			goto error;
+		break;
 	case BPF_MAP_TYPE_ARRAY_OF_MAPS:
 	case BPF_MAP_TYPE_HASH_OF_MAPS:
 		if (func_id != BPF_FUNC_map_lookup_elem)
@@ -3799,6 +4317,7 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env,
 	case PTR_TO_SOCK_COMMON_OR_NULL:
 	case PTR_TO_TCP_SOCK:
 	case PTR_TO_TCP_SOCK_OR_NULL:
+	case PTR_TO_XDP_SOCK:
 		verbose(env, "R%d pointer arithmetic on %s prohibited\n",
 			dst, reg_type_str[ptr_reg->type]);
 		return -EACCES;
@@ -4276,6 +4795,7 @@ static int adjust_reg_min_max_vals(struct bpf_verifier_env *env,
 	struct bpf_reg_state *regs = state->regs, *dst_reg, *src_reg;
 	struct bpf_reg_state *ptr_reg = NULL, off_reg = {0};
 	u8 opcode = BPF_OP(insn->code);
+	int err;
 
 	dst_reg = &regs[insn->dst_reg];
 	src_reg = NULL;
@@ -4302,11 +4822,17 @@ static int adjust_reg_min_max_vals(struct bpf_verifier_env *env,
 				 * This is legal, but we have to reverse our
 				 * src/dest handling in computing the range
 				 */
+				err = mark_chain_precision(env, insn->dst_reg);
+				if (err)
+					return err;
 				return adjust_ptr_min_max_vals(env, insn,
 							       src_reg, dst_reg);
 			}
 		} else if (ptr_reg) {
 			/* pointer += scalar */
+			err = mark_chain_precision(env, insn->src_reg);
+			if (err)
+				return err;
 			return adjust_ptr_min_max_vals(env, insn,
 						       dst_reg, src_reg);
 		}
@@ -5038,6 +5564,9 @@ static void mark_ptr_or_null_reg(struct bpf_func_state *state,
 			if (reg->map_ptr->inner_map_meta) {
 				reg->type = CONST_PTR_TO_MAP;
 				reg->map_ptr = reg->map_ptr->inner_map_meta;
+			} else if (reg->map_ptr->map_type ==
+				   BPF_MAP_TYPE_XSKMAP) {
+				reg->type = PTR_TO_XDP_SOCK;
 			} else {
 				reg->type = PTR_TO_MAP_VALUE;
 			}
@@ -5209,9 +5738,10 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env,
 	struct bpf_verifier_state *this_branch = env->cur_state;
 	struct bpf_verifier_state *other_branch;
 	struct bpf_reg_state *regs = this_branch->frame[this_branch->curframe]->regs;
-	struct bpf_reg_state *dst_reg, *other_branch_regs;
+	struct bpf_reg_state *dst_reg, *other_branch_regs, *src_reg = NULL;
 	u8 opcode = BPF_OP(insn->code);
 	bool is_jmp32;
+	int pred = -1;
 	int err;
 
 	/* Only conditional jumps are expected to reach here. */
@@ -5236,6 +5766,7 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env,
 				insn->src_reg);
 			return -EACCES;
 		}
+		src_reg = &regs[insn->src_reg];
 	} else {
 		if (insn->src_reg != BPF_REG_0) {
 			verbose(env, "BPF_JMP/JMP32 uses reserved fields\n");
@@ -5251,20 +5782,29 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env,
 	dst_reg = &regs[insn->dst_reg];
 	is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32;
 
-	if (BPF_SRC(insn->code) == BPF_K) {
-		int pred = is_branch_taken(dst_reg, insn->imm, opcode,
-					   is_jmp32);
-
-		if (pred == 1) {
-			 /* only follow the goto, ignore fall-through */
-			*insn_idx += insn->off;
-			return 0;
-		} else if (pred == 0) {
-			/* only follow fall-through branch, since
-			 * that's where the program will go
-			 */
-			return 0;
-		}
+	if (BPF_SRC(insn->code) == BPF_K)
+		pred = is_branch_taken(dst_reg, insn->imm,
+				       opcode, is_jmp32);
+	else if (src_reg->type == SCALAR_VALUE &&
+		 tnum_is_const(src_reg->var_off))
+		pred = is_branch_taken(dst_reg, src_reg->var_off.value,
+				       opcode, is_jmp32);
+	if (pred >= 0) {
+		err = mark_chain_precision(env, insn->dst_reg);
+		if (BPF_SRC(insn->code) == BPF_X && !err)
+			err = mark_chain_precision(env, insn->src_reg);
+		if (err)
+			return err;
+	}
+	if (pred == 1) {
+		/* only follow the goto, ignore fall-through */
+		*insn_idx += insn->off;
+		return 0;
+	} else if (pred == 0) {
+		/* only follow fall-through branch, since
+		 * that's where the program will go
+		 */
+		return 0;
 	}
 
 	other_branch = push_stack(env, *insn_idx + insn->off + 1, *insn_idx,
@@ -5513,13 +6053,16 @@ static int check_return_code(struct bpf_verifier_env *env)
 	struct tnum range = tnum_range(0, 1);
 
 	switch (env->prog->type) {
+	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
+		if (env->prog->expected_attach_type == BPF_CGROUP_UDP4_RECVMSG ||
+		    env->prog->expected_attach_type == BPF_CGROUP_UDP6_RECVMSG)
+			range = tnum_range(1, 1);
 	case BPF_PROG_TYPE_CGROUP_SKB:
 		if (env->prog->expected_attach_type == BPF_CGROUP_INET_EGRESS) {
 			range = tnum_range(0, 3);
 			enforce_attach_type_range = tnum_range(2, 3);
 		}
 	case BPF_PROG_TYPE_CGROUP_SOCK:
-	case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
 	case BPF_PROG_TYPE_SOCK_OPS:
 	case BPF_PROG_TYPE_CGROUP_DEVICE:
 	case BPF_PROG_TYPE_CGROUP_SYSCTL:
@@ -5546,7 +6089,7 @@ static int check_return_code(struct bpf_verifier_env *env)
 			verbose(env, "has unknown scalar value");
 		}
 		tnum_strn(tn_buf, sizeof(tn_buf), range);
-		verbose(env, " should have been %s\n", tn_buf);
+		verbose(env, " should have been in %s\n", tn_buf);
 		return -EINVAL;
 	}
 
@@ -5621,7 +6164,8 @@ static void init_explored_state(struct bpf_verifier_env *env, int idx)
  * w - next instruction
  * e - edge
  */
-static int push_insn(int t, int w, int e, struct bpf_verifier_env *env)
+static int push_insn(int t, int w, int e, struct bpf_verifier_env *env,
+		     bool loop_ok)
 {
 	int *insn_stack = env->cfg.insn_stack;
 	int *insn_state = env->cfg.insn_state;
@@ -5651,6 +6195,8 @@ static int push_insn(int t, int w, int e, struct bpf_verifier_env *env)
 		insn_stack[env->cfg.cur_stack++] = w;
 		return 1;
 	} else if ((insn_state[w] & 0xF0) == DISCOVERED) {
+		if (loop_ok && env->allow_ptr_leaks)
+			return 0;
 		verbose_linfo(env, t, "%d: ", t);
 		verbose_linfo(env, w, "%d: ", w);
 		verbose(env, "back-edge from insn %d to %d\n", t, w);
@@ -5702,7 +6248,7 @@ peek_stack:
 		if (opcode == BPF_EXIT) {
 			goto mark_explored;
 		} else if (opcode == BPF_CALL) {
-			ret = push_insn(t, t + 1, FALLTHROUGH, env);
+			ret = push_insn(t, t + 1, FALLTHROUGH, env, false);
 			if (ret == 1)
 				goto peek_stack;
 			else if (ret < 0)
@@ -5711,7 +6257,8 @@ peek_stack:
 				init_explored_state(env, t + 1);
 			if (insns[t].src_reg == BPF_PSEUDO_CALL) {
 				init_explored_state(env, t);
-				ret = push_insn(t, t + insns[t].imm + 1, BRANCH, env);
+				ret = push_insn(t, t + insns[t].imm + 1, BRANCH,
+						env, false);
 				if (ret == 1)
 					goto peek_stack;
 				else if (ret < 0)
@@ -5724,11 +6271,16 @@ peek_stack:
 			}
 			/* unconditional jump with single edge */
 			ret = push_insn(t, t + insns[t].off + 1,
-					FALLTHROUGH, env);
+					FALLTHROUGH, env, true);
 			if (ret == 1)
 				goto peek_stack;
 			else if (ret < 0)
 				goto err_free;
+			/* unconditional jmp is not a good pruning point,
+			 * but it's marked, since backtracking needs
+			 * to record jmp history in is_state_visited().
+			 */
+			init_explored_state(env, t + insns[t].off + 1);
 			/* tell verifier to check for equivalent states
 			 * after every call and jump
 			 */
@@ -5737,13 +6289,13 @@ peek_stack:
 		} else {
 			/* conditional jump with two edges */
 			init_explored_state(env, t);
-			ret = push_insn(t, t + 1, FALLTHROUGH, env);
+			ret = push_insn(t, t + 1, FALLTHROUGH, env, true);
 			if (ret == 1)
 				goto peek_stack;
 			else if (ret < 0)
 				goto err_free;
 
-			ret = push_insn(t, t + insns[t].off + 1, BRANCH, env);
+			ret = push_insn(t, t + insns[t].off + 1, BRANCH, env, true);
 			if (ret == 1)
 				goto peek_stack;
 			else if (ret < 0)
@@ -5753,7 +6305,7 @@ peek_stack:
 		/* all other non-branch instructions with single
 		 * fall-through edge
 		 */
-		ret = push_insn(t, t + 1, FALLTHROUGH, env);
+		ret = push_insn(t, t + 1, FALLTHROUGH, env, false);
 		if (ret == 1)
 			goto peek_stack;
 		else if (ret < 0)
@@ -6186,6 +6738,8 @@ static void clean_live_states(struct bpf_verifier_env *env, int insn,
 
 	sl = *explored_state(env, insn);
 	while (sl) {
+		if (sl->state.branches)
+			goto next;
 		if (sl->state.insn_idx != insn ||
 		    sl->state.curframe != cur->curframe)
 			goto next;
@@ -6227,6 +6781,8 @@ static bool regsafe(struct bpf_reg_state *rold, struct bpf_reg_state *rcur,
 	switch (rold->type) {
 	case SCALAR_VALUE:
 		if (rcur->type == SCALAR_VALUE) {
+			if (!rold->precise && !rcur->precise)
+				return true;
 			/* new val must satisfy old val knowledge */
 			return range_within(rold, rcur) &&
 			       tnum_in(rold->var_off, rcur->var_off);
@@ -6299,6 +6855,7 @@ static bool regsafe(struct bpf_reg_state *rold, struct bpf_reg_state *rcur,
 	case PTR_TO_SOCK_COMMON_OR_NULL:
 	case PTR_TO_TCP_SOCK:
 	case PTR_TO_TCP_SOCK_OR_NULL:
+	case PTR_TO_XDP_SOCK:
 		/* Only valid matches are exact, which memcmp() above
 		 * would have accepted
 		 */
@@ -6549,19 +7106,52 @@ static int propagate_liveness(struct bpf_verifier_env *env,
 	return 0;
 }
 
+static bool states_maybe_looping(struct bpf_verifier_state *old,
+				 struct bpf_verifier_state *cur)
+{
+	struct bpf_func_state *fold, *fcur;
+	int i, fr = cur->curframe;
+
+	if (old->curframe != fr)
+		return false;
+
+	fold = old->frame[fr];
+	fcur = cur->frame[fr];
+	for (i = 0; i < MAX_BPF_REG; i++)
+		if (memcmp(&fold->regs[i], &fcur->regs[i],
+			   offsetof(struct bpf_reg_state, parent)))
+			return false;
+	return true;
+}
+
+
 static int is_state_visited(struct bpf_verifier_env *env, int insn_idx)
 {
 	struct bpf_verifier_state_list *new_sl;
 	struct bpf_verifier_state_list *sl, **pprev;
 	struct bpf_verifier_state *cur = env->cur_state, *new;
 	int i, j, err, states_cnt = 0;
+	bool add_new_state = false;
 
+	cur->last_insn_idx = env->prev_insn_idx;
 	if (!env->insn_aux_data[insn_idx].prune_point)
 		/* this 'insn_idx' instruction wasn't marked, so we will not
 		 * be doing state search here
 		 */
 		return 0;
 
+	/* bpf progs typically have pruning point every 4 instructions
+	 * http://vger.kernel.org/bpfconf2019.html#session-1
+	 * Do not add new state for future pruning if the verifier hasn't seen
+	 * at least 2 jumps and at least 8 instructions.
+	 * This heuristics helps decrease 'total_states' and 'peak_states' metric.
+	 * In tests that amounts to up to 50% reduction into total verifier
+	 * memory consumption and 20% verifier time speedup.
+	 */
+	if (env->jmps_processed - env->prev_jmps_processed >= 2 &&
+	    env->insn_processed - env->prev_insn_processed >= 8)
+		add_new_state = true;
+
 	pprev = explored_state(env, insn_idx);
 	sl = *pprev;
 
@@ -6571,6 +7161,30 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx)
 		states_cnt++;
 		if (sl->state.insn_idx != insn_idx)
 			goto next;
+		if (sl->state.branches) {
+			if (states_maybe_looping(&sl->state, cur) &&
+			    states_equal(env, &sl->state, cur)) {
+				verbose_linfo(env, insn_idx, "; ");
+				verbose(env, "infinite loop detected at insn %d\n", insn_idx);
+				return -EINVAL;
+			}
+			/* if the verifier is processing a loop, avoid adding new state
+			 * too often, since different loop iterations have distinct
+			 * states and may not help future pruning.
+			 * This threshold shouldn't be too low to make sure that
+			 * a loop with large bound will be rejected quickly.
+			 * The most abusive loop will be:
+			 * r1 += 1
+			 * if r1 < 1000000 goto pc-2
+			 * 1M insn_procssed limit / 100 == 10k peak states.
+			 * This threshold shouldn't be too high either, since states
+			 * at the end of the loop are likely to be useful in pruning.
+			 */
+			if (env->jmps_processed - env->prev_jmps_processed < 20 &&
+			    env->insn_processed - env->prev_insn_processed < 100)
+				add_new_state = false;
+			goto miss;
+		}
 		if (states_equal(env, &sl->state, cur)) {
 			sl->hit_cnt++;
 			/* reached equivalent register/stack state,
@@ -6588,7 +7202,15 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx)
 				return err;
 			return 1;
 		}
-		sl->miss_cnt++;
+miss:
+		/* when new state is not going to be added do not increase miss count.
+		 * Otherwise several loop iterations will remove the state
+		 * recorded earlier. The goal of these heuristics is to have
+		 * states from some iterations of the loop (some in the beginning
+		 * and some at the end) to help pruning.
+		 */
+		if (add_new_state)
+			sl->miss_cnt++;
 		/* heuristic to determine whether this state is beneficial
 		 * to keep checking from state equivalence point of view.
 		 * Higher numbers increase max_states_per_insn and verification time,
@@ -6600,6 +7222,11 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx)
 			 */
 			*pprev = sl->next;
 			if (sl->state.frame[0]->regs[0].live & REG_LIVE_DONE) {
+				u32 br = sl->state.branches;
+
+				WARN_ONCE(br,
+					  "BUG live_done but branches_to_explore %d\n",
+					  br);
 				free_verifier_state(&sl->state, false);
 				kfree(sl);
 				env->peak_states--;
@@ -6623,20 +7250,27 @@ next:
 		env->max_states_per_insn = states_cnt;
 
 	if (!env->allow_ptr_leaks && states_cnt > BPF_COMPLEXITY_LIMIT_STATES)
-		return 0;
+		return push_jmp_history(env, cur);
 
-	/* there were no equivalent states, remember current one.
-	 * technically the current state is not proven to be safe yet,
+	if (!add_new_state)
+		return push_jmp_history(env, cur);
+
+	/* There were no equivalent states, remember the current one.
+	 * Technically the current state is not proven to be safe yet,
 	 * but it will either reach outer most bpf_exit (which means it's safe)
-	 * or it will be rejected. Since there are no loops, we won't be
+	 * or it will be rejected. When there are no loops the verifier won't be
 	 * seeing this tuple (frame[0].callsite, frame[1].callsite, .. insn_idx)
-	 * again on the way to bpf_exit
+	 * again on the way to bpf_exit.
+	 * When looping the sl->state.branches will be > 0 and this state
+	 * will not be considered for equivalence until branches == 0.
 	 */
 	new_sl = kzalloc(sizeof(struct bpf_verifier_state_list), GFP_KERNEL);
 	if (!new_sl)
 		return -ENOMEM;
 	env->total_states++;
 	env->peak_states++;
+	env->prev_jmps_processed = env->jmps_processed;
+	env->prev_insn_processed = env->insn_processed;
 
 	/* add new state to the head of linked list */
 	new = &new_sl->state;
@@ -6647,6 +7281,12 @@ next:
 		return err;
 	}
 	new->insn_idx = insn_idx;
+	WARN_ONCE(new->branches != 1,
+		  "BUG is_state_visited:branches_to_explore=%d insn %d\n", new->branches, insn_idx);
+
+	cur->parent = new;
+	cur->first_insn_idx = insn_idx;
+	clear_jmp_history(cur);
 	new_sl->next = *explored_state(env, insn_idx);
 	*explored_state(env, insn_idx) = new_sl;
 	/* connect new state to parentage chain. Current frame needs all
@@ -6656,17 +7296,18 @@ next:
 	 * the state of the call instruction (with WRITTEN set), and r0 comes
 	 * from callee with its full parentage chain, anyway.
 	 */
-	for (j = 0; j <= cur->curframe; j++)
-		for (i = j < cur->curframe ? BPF_REG_6 : 0; i < BPF_REG_FP; i++)
-			cur->frame[j]->regs[i].parent = &new->frame[j]->regs[i];
 	/* clear write marks in current state: the writes we did are not writes
 	 * our child did, so they don't screen off its reads from us.
 	 * (There are no read marks in current state, because reads always mark
 	 * their parent and current state never has children yet.  Only
 	 * explored_states can get read marks.)
 	 */
-	for (i = 0; i < BPF_REG_FP; i++)
-		cur->frame[cur->curframe]->regs[i].live = REG_LIVE_NONE;
+	for (j = 0; j <= cur->curframe; j++) {
+		for (i = j < cur->curframe ? BPF_REG_6 : 0; i < BPF_REG_FP; i++)
+			cur->frame[j]->regs[i].parent = &new->frame[j]->regs[i];
+		for (i = 0; i < BPF_REG_FP; i++)
+			cur->frame[j]->regs[i].live = REG_LIVE_NONE;
+	}
 
 	/* all stack frames are accessible from callee, clear them all */
 	for (j = 0; j <= cur->curframe; j++) {
@@ -6693,6 +7334,7 @@ static bool reg_type_mismatch_ok(enum bpf_reg_type type)
 	case PTR_TO_SOCK_COMMON_OR_NULL:
 	case PTR_TO_TCP_SOCK:
 	case PTR_TO_TCP_SOCK_OR_NULL:
+	case PTR_TO_XDP_SOCK:
 		return false;
 	default:
 		return true;
@@ -6724,6 +7366,7 @@ static int do_check(struct bpf_verifier_env *env)
 	struct bpf_reg_state *regs;
 	int insn_cnt = env->prog->len;
 	bool do_print_state = false;
+	int prev_insn_idx = -1;
 
 	env->prev_linfo = NULL;
 
@@ -6732,6 +7375,7 @@ static int do_check(struct bpf_verifier_env *env)
 		return -ENOMEM;
 	state->curframe = 0;
 	state->speculative = false;
+	state->branches = 1;
 	state->frame[0] = kzalloc(sizeof(struct bpf_func_state), GFP_KERNEL);
 	if (!state->frame[0]) {
 		kfree(state);
@@ -6748,6 +7392,7 @@ static int do_check(struct bpf_verifier_env *env)
 		u8 class;
 		int err;
 
+		env->prev_insn_idx = prev_insn_idx;
 		if (env->insn_idx >= insn_cnt) {
 			verbose(env, "invalid insn idx %d insn_cnt %d\n",
 				env->insn_idx, insn_cnt);
@@ -6820,6 +7465,7 @@ static int do_check(struct bpf_verifier_env *env)
 
 		regs = cur_regs(env);
 		env->insn_aux_data[env->insn_idx].seen = true;
+		prev_insn_idx = env->insn_idx;
 
 		if (class == BPF_ALU || class == BPF_ALU64) {
 			err = check_alu_op(env, insn);
@@ -6938,6 +7584,7 @@ static int do_check(struct bpf_verifier_env *env)
 		} else if (class == BPF_JMP || class == BPF_JMP32) {
 			u8 opcode = BPF_OP(insn->code);
 
+			env->jmps_processed++;
 			if (opcode == BPF_CALL) {
 				if (BPF_SRC(insn->code) != BPF_K ||
 				    insn->off != 0 ||
@@ -6992,7 +7639,6 @@ static int do_check(struct bpf_verifier_env *env)
 
 				if (state->curframe) {
 					/* exit from nested function */
-					env->prev_insn_idx = env->insn_idx;
 					err = prepare_func_exit(env, &env->insn_idx);
 					if (err)
 						return err;
@@ -7023,7 +7669,8 @@ static int do_check(struct bpf_verifier_env *env)
 				if (err)
 					return err;
 process_bpf_exit:
-				err = pop_stack(env, &env->prev_insn_idx,
+				update_branch_counts(env, env->cur_state);
+				err = pop_stack(env, &prev_insn_idx,
 						&env->insn_idx);
 				if (err < 0) {
 					if (err != -ENOENT)
@@ -7826,6 +8473,9 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env)
 		case PTR_TO_TCP_SOCK:
 			convert_ctx_access = bpf_tcp_sock_convert_ctx_access;
 			break;
+		case PTR_TO_XDP_SOCK:
+			convert_ctx_access = bpf_xdp_sock_convert_ctx_access;
+			break;
 		default:
 			continue;
 		}
diff --git a/kernel/bpf/xskmap.c b/kernel/bpf/xskmap.c
index 22066c28ba61..ef7338cebd18 100644
--- a/kernel/bpf/xskmap.c
+++ b/kernel/bpf/xskmap.c
@@ -17,8 +17,8 @@ struct xsk_map {
 
 static struct bpf_map *xsk_map_alloc(union bpf_attr *attr)
 {
-	int cpu, err = -EINVAL;
 	struct xsk_map *m;
+	int cpu, err;
 	u64 cost;
 
 	if (!capable(CAP_NET_ADMIN))
@@ -152,6 +152,12 @@ void __xsk_map_flush(struct bpf_map *map)
 
 static void *xsk_map_lookup_elem(struct bpf_map *map, void *key)
 {
+	WARN_ON_ONCE(!rcu_read_lock_held());
+	return __xsk_map_lookup_elem(map, *(u32 *)key);
+}
+
+static void *xsk_map_lookup_elem_sys_only(struct bpf_map *map, void *key)
+{
 	return ERR_PTR(-EOPNOTSUPP);
 }
 
@@ -218,6 +224,7 @@ const struct bpf_map_ops xsk_map_ops = {
 	.map_free = xsk_map_free,
 	.map_get_next_key = xsk_map_get_next_key,
 	.map_lookup_elem = xsk_map_lookup_elem,
+	.map_lookup_elem_sys_only = xsk_map_lookup_elem_sys_only,
 	.map_update_elem = xsk_map_update_elem,
 	.map_delete_elem = xsk_map_delete_elem,
 	.map_check_btf = map_check_no_btf,
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index ef9cfbfc82a9..daa567728251 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -215,7 +215,8 @@ static struct cftype cgroup_base_files[];
 
 static int cgroup_apply_control(struct cgroup *cgrp);
 static void cgroup_finalize_control(struct cgroup *cgrp, int ret);
-static void css_task_iter_advance(struct css_task_iter *it);
+static void css_task_iter_skip(struct css_task_iter *it,
+			       struct task_struct *task);
 static int cgroup_destroy_locked(struct cgroup *cgrp);
 static struct cgroup_subsys_state *css_create(struct cgroup *cgrp,
 					      struct cgroup_subsys *ss);
@@ -738,6 +739,7 @@ struct css_set init_css_set = {
 	.dom_cset		= &init_css_set,
 	.tasks			= LIST_HEAD_INIT(init_css_set.tasks),
 	.mg_tasks		= LIST_HEAD_INIT(init_css_set.mg_tasks),
+	.dying_tasks		= LIST_HEAD_INIT(init_css_set.dying_tasks),
 	.task_iters		= LIST_HEAD_INIT(init_css_set.task_iters),
 	.threaded_csets		= LIST_HEAD_INIT(init_css_set.threaded_csets),
 	.cgrp_links		= LIST_HEAD_INIT(init_css_set.cgrp_links),
@@ -843,6 +845,21 @@ static void css_set_update_populated(struct css_set *cset, bool populated)
 		cgroup_update_populated(link->cgrp, populated);
 }
 
+/*
+ * @task is leaving, advance task iterators which are pointing to it so
+ * that they can resume at the next position.  Advancing an iterator might
+ * remove it from the list, use safe walk.  See css_task_iter_skip() for
+ * details.
+ */
+static void css_set_skip_task_iters(struct css_set *cset,
+				    struct task_struct *task)
+{
+	struct css_task_iter *it, *pos;
+
+	list_for_each_entry_safe(it, pos, &cset->task_iters, iters_node)
+		css_task_iter_skip(it, task);
+}
+
 /**
  * css_set_move_task - move a task from one css_set to another
  * @task: task being moved
@@ -868,22 +885,9 @@ static void css_set_move_task(struct task_struct *task,
 		css_set_update_populated(to_cset, true);
 
 	if (from_cset) {
-		struct css_task_iter *it, *pos;
-
 		WARN_ON_ONCE(list_empty(&task->cg_list));
 
-		/*
-		 * @task is leaving, advance task iterators which are
-		 * pointing to it so that they can resume at the next
-		 * position.  Advancing an iterator might remove it from
-		 * the list, use safe walk.  See css_task_iter_advance*()
-		 * for details.
-		 */
-		list_for_each_entry_safe(it, pos, &from_cset->task_iters,
-					 iters_node)
-			if (it->task_pos == &task->cg_list)
-				css_task_iter_advance(it);
-
+		css_set_skip_task_iters(from_cset, task);
 		list_del_init(&task->cg_list);
 		if (!css_set_populated(from_cset))
 			css_set_update_populated(from_cset, false);
@@ -1210,6 +1214,7 @@ static struct css_set *find_css_set(struct css_set *old_cset,
 	cset->dom_cset = cset;
 	INIT_LIST_HEAD(&cset->tasks);
 	INIT_LIST_HEAD(&cset->mg_tasks);
+	INIT_LIST_HEAD(&cset->dying_tasks);
 	INIT_LIST_HEAD(&cset->task_iters);
 	INIT_LIST_HEAD(&cset->threaded_csets);
 	INIT_HLIST_NODE(&cset->hlist);
@@ -1810,11 +1815,13 @@ int cgroup_show_path(struct seq_file *sf, struct kernfs_node *kf_node,
 
 enum cgroup2_param {
 	Opt_nsdelegate,
+	Opt_memory_localevents,
 	nr__cgroup2_params
 };
 
 static const struct fs_parameter_spec cgroup2_param_specs[] = {
-	fsparam_flag  ("nsdelegate",		Opt_nsdelegate),
+	fsparam_flag("nsdelegate",		Opt_nsdelegate),
+	fsparam_flag("memory_localevents",	Opt_memory_localevents),
 	{}
 };
 
@@ -1837,6 +1844,9 @@ static int cgroup2_parse_param(struct fs_context *fc, struct fs_parameter *param
 	case Opt_nsdelegate:
 		ctx->flags |= CGRP_ROOT_NS_DELEGATE;
 		return 0;
+	case Opt_memory_localevents:
+		ctx->flags |= CGRP_ROOT_MEMORY_LOCAL_EVENTS;
+		return 0;
 	}
 	return -EINVAL;
 }
@@ -1848,6 +1858,11 @@ static void apply_cgroup_root_flags(unsigned int root_flags)
 			cgrp_dfl_root.flags |= CGRP_ROOT_NS_DELEGATE;
 		else
 			cgrp_dfl_root.flags &= ~CGRP_ROOT_NS_DELEGATE;
+
+		if (root_flags & CGRP_ROOT_MEMORY_LOCAL_EVENTS)
+			cgrp_dfl_root.flags |= CGRP_ROOT_MEMORY_LOCAL_EVENTS;
+		else
+			cgrp_dfl_root.flags &= ~CGRP_ROOT_MEMORY_LOCAL_EVENTS;
 	}
 }
 
@@ -1855,6 +1870,8 @@ static int cgroup_show_options(struct seq_file *seq, struct kernfs_root *kf_root
 {
 	if (cgrp_dfl_root.flags & CGRP_ROOT_NS_DELEGATE)
 		seq_puts(seq, ",nsdelegate");
+	if (cgrp_dfl_root.flags & CGRP_ROOT_MEMORY_LOCAL_EVENTS)
+		seq_puts(seq, ",memory_localevents");
 	return 0;
 }
 
@@ -4396,15 +4413,18 @@ static void css_task_iter_advance_css_set(struct css_task_iter *it)
 			it->task_pos = NULL;
 			return;
 		}
-	} while (!css_set_populated(cset));
+	} while (!css_set_populated(cset) && list_empty(&cset->dying_tasks));
 
 	if (!list_empty(&cset->tasks))
 		it->task_pos = cset->tasks.next;
-	else
+	else if (!list_empty(&cset->mg_tasks))
 		it->task_pos = cset->mg_tasks.next;
+	else
+		it->task_pos = cset->dying_tasks.next;
 
 	it->tasks_head = &cset->tasks;
 	it->mg_tasks_head = &cset->mg_tasks;
+	it->dying_tasks_head = &cset->dying_tasks;
 
 	/*
 	 * We don't keep css_sets locked across iteration steps and thus
@@ -4430,9 +4450,20 @@ static void css_task_iter_advance_css_set(struct css_task_iter *it)
 	list_add(&it->iters_node, &cset->task_iters);
 }
 
+static void css_task_iter_skip(struct css_task_iter *it,
+			       struct task_struct *task)
+{
+	lockdep_assert_held(&css_set_lock);
+
+	if (it->task_pos == &task->cg_list) {
+		it->task_pos = it->task_pos->next;
+		it->flags |= CSS_TASK_ITER_SKIPPED;
+	}
+}
+
 static void css_task_iter_advance(struct css_task_iter *it)
 {
-	struct list_head *next;
+	struct task_struct *task;
 
 	lockdep_assert_held(&css_set_lock);
 repeat:
@@ -4442,25 +4473,40 @@ repeat:
 		 * consumed first and then ->mg_tasks.  After ->mg_tasks,
 		 * we move onto the next cset.
 		 */
-		next = it->task_pos->next;
-
-		if (next == it->tasks_head)
-			next = it->mg_tasks_head->next;
+		if (it->flags & CSS_TASK_ITER_SKIPPED)
+			it->flags &= ~CSS_TASK_ITER_SKIPPED;
+		else
+			it->task_pos = it->task_pos->next;
 
-		if (next == it->mg_tasks_head)
+		if (it->task_pos == it->tasks_head)
+			it->task_pos = it->mg_tasks_head->next;
+		if (it->task_pos == it->mg_tasks_head)
+			it->task_pos = it->dying_tasks_head->next;
+		if (it->task_pos == it->dying_tasks_head)
 			css_task_iter_advance_css_set(it);
-		else
-			it->task_pos = next;
 	} else {
 		/* called from start, proceed to the first cset */
 		css_task_iter_advance_css_set(it);
 	}
 
-	/* if PROCS, skip over tasks which aren't group leaders */
-	if ((it->flags & CSS_TASK_ITER_PROCS) && it->task_pos &&
-	    !thread_group_leader(list_entry(it->task_pos, struct task_struct,
-					    cg_list)))
-		goto repeat;
+	if (!it->task_pos)
+		return;
+
+	task = list_entry(it->task_pos, struct task_struct, cg_list);
+
+	if (it->flags & CSS_TASK_ITER_PROCS) {
+		/* if PROCS, skip over tasks which aren't group leaders */
+		if (!thread_group_leader(task))
+			goto repeat;
+
+		/* and dying leaders w/o live member threads */
+		if (!atomic_read(&task->signal->live))
+			goto repeat;
+	} else {
+		/* skip all dying ones */
+		if (task->flags & PF_EXITING)
+			goto repeat;
+	}
 }
 
 /**
@@ -4516,6 +4562,10 @@ struct task_struct *css_task_iter_next(struct css_task_iter *it)
 
 	spin_lock_irq(&css_set_lock);
 
+	/* @it may be half-advanced by skips, finish advancing */
+	if (it->flags & CSS_TASK_ITER_SKIPPED)
+		css_task_iter_advance(it);
+
 	if (it->task_pos) {
 		it->cur_task = list_entry(it->task_pos, struct task_struct,
 					  cg_list);
@@ -5997,6 +6047,7 @@ void cgroup_exit(struct task_struct *tsk)
 	if (!list_empty(&tsk->cg_list)) {
 		spin_lock_irq(&css_set_lock);
 		css_set_move_task(tsk, cset, NULL, false);
+		list_add_tail(&tsk->cg_list, &cset->dying_tasks);
 		cset->nr_tasks--;
 
 		WARN_ON_ONCE(cgroup_task_frozen(tsk));
@@ -6022,6 +6073,13 @@ void cgroup_release(struct task_struct *task)
 	do_each_subsys_mask(ss, ssid, have_release_callback) {
 		ss->release(task);
 	} while_each_subsys_mask();
+
+	if (use_task_css_set_links) {
+		spin_lock_irq(&css_set_lock);
+		css_set_skip_task_iters(task_css_set(task), task);
+		list_del_init(&task->cg_list);
+		spin_unlock_irq(&css_set_lock);
+	}
 }
 
 void cgroup_free(struct task_struct *task)
@@ -6330,7 +6388,7 @@ static struct kobj_attribute cgroup_delegate_attr = __ATTR_RO(delegate);
 static ssize_t features_show(struct kobject *kobj, struct kobj_attribute *attr,
 			     char *buf)
 {
-	return snprintf(buf, PAGE_SIZE, "nsdelegate\n");
+	return snprintf(buf, PAGE_SIZE, "nsdelegate\nmemory_localevents\n");
 }
 static struct kobj_attribute cgroup_features_attr = __ATTR_RO(features);
 
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index 6a1942ed781c..515525ff1cfd 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -3254,10 +3254,23 @@ void cpuset_cpus_allowed(struct task_struct *tsk, struct cpumask *pmask)
 	spin_unlock_irqrestore(&callback_lock, flags);
 }
 
+/**
+ * cpuset_cpus_allowed_fallback - final fallback before complete catastrophe.
+ * @tsk: pointer to task_struct with which the scheduler is struggling
+ *
+ * Description: In the case that the scheduler cannot find an allowed cpu in
+ * tsk->cpus_allowed, we fall back to task_cs(tsk)->cpus_allowed. In legacy
+ * mode however, this value is the same as task_cs(tsk)->effective_cpus,
+ * which will not contain a sane cpumask during cases such as cpu hotplugging.
+ * This is the absolute last resort for the scheduler and it is only used if
+ * _every_ other avenue has been traveled.
+ **/
+
 void cpuset_cpus_allowed_fallback(struct task_struct *tsk)
 {
 	rcu_read_lock();
-	do_set_cpus_allowed(tsk, task_cs(tsk)->effective_cpus);
+	do_set_cpus_allowed(tsk, is_in_v2_mode() ?
+		task_cs(tsk)->cpus_allowed : cpu_possible_mask);
 	rcu_read_unlock();
 
 	/*
diff --git a/kernel/cgroup/pids.c b/kernel/cgroup/pids.c
index c9960baaa14f..8e513a573fe9 100644
--- a/kernel/cgroup/pids.c
+++ b/kernel/cgroup/pids.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Process number limiting controller for cgroups.
  *
@@ -25,10 +26,6 @@
  * a superset of parent/child/pids.current.
  *
  * Copyright (C) 2015 Aleksa Sarai <cyphar@cyphar.com>
- *
- * This file is subject to the terms and conditions of version 2 of the GNU
- * General Public License.  See the file COPYING in the main directory of the
- * Linux distribution for more details.
  */
 
 #include <linux/kernel.h>
diff --git a/kernel/cgroup/rdma.c b/kernel/cgroup/rdma.c
index 1d75ae7f1cb7..ae042c347c64 100644
--- a/kernel/cgroup/rdma.c
+++ b/kernel/cgroup/rdma.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * RDMA resource limiting controller for cgroups.
  *
@@ -5,10 +6,6 @@
  * additional RDMA resources after a certain limit is reached.
  *
  * Copyright (C) 2016 Parav Pandit <pandit.parav@gmail.com>
- *
- * This file is subject to the terms and conditions of version 2 of the GNU
- * General Public License. See the file COPYING in the main directory of the
- * Linux distribution for more details.
  */
 
 #include <linux/bitops.h>
diff --git a/kernel/compat.c b/kernel/compat.c
index b5f7063c0db6..a2bc1d6ceb57 100644
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  *  linux/kernel/compat.c
  *
@@ -5,10 +6,6 @@
  *  on 64 bit kernels.
  *
  *  Copyright (C) 2002-2003 Stephen Rothwell, IBM Corporation
- *
- *  This program is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License version 2 as
- *  published by the Free Software Foundation.
  */
 
 #include <linux/linkage.h>
diff --git a/kernel/cpu.c b/kernel/cpu.c
index f2ef10460698..077fde6fb953 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -2061,7 +2061,7 @@ static void cpuhp_online_cpu_device(unsigned int cpu)
 	kobject_uevent(&dev->kobj, KOBJ_ONLINE);
 }
 
-static int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval)
+int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval)
 {
 	int cpu, ret = 0;
 
@@ -2093,7 +2093,7 @@ static int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval)
 	return ret;
 }
 
-static int cpuhp_smt_enable(void)
+int cpuhp_smt_enable(void)
 {
 	int cpu, ret = 0;
 
diff --git a/kernel/cpu_pm.c b/kernel/cpu_pm.c
index 67b02e138a47..cbca6879ab7d 100644
--- a/kernel/cpu_pm.c
+++ b/kernel/cpu_pm.c
@@ -1,18 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2011 Google, Inc.
  *
  * Author:
  *	Colin Cross <ccross@android.com>
- *
- * This software is licensed under the terms of the GNU General Public
- * License version 2, as published by the Free Software Foundation, and
- * may be copied, distributed, and modified under those terms.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
  */
 
 #include <linux/kernel.h>
diff --git a/kernel/crash_core.c b/kernel/crash_core.c
index 093c9f917ed0..9f1557b98468 100644
--- a/kernel/crash_core.c
+++ b/kernel/crash_core.c
@@ -1,9 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * crash.c - kernel crash support code.
  * Copyright (C) 2002-2004 Eric Biederman  <ebiederm@xmission.com>
- *
- * This source code is licensed under the GNU General Public License,
- * Version 2.  See the file COPYING for more details.
  */
 
 #include <linux/crash_core.h>
diff --git a/kernel/cred.c b/kernel/cred.c
index e74ffdc98a92..c73a87a4df13 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -446,6 +446,15 @@ int commit_creds(struct cred *new)
 		if (task->mm)
 			set_dumpable(task->mm, suid_dumpable);
 		task->pdeath_signal = 0;
+		/*
+		 * If a task drops privileges and becomes nondumpable,
+		 * the dumpability change must become visible before
+		 * the credential change; otherwise, a __ptrace_may_access()
+		 * racing with this change may be able to attach to a task it
+		 * shouldn't be able to attach to (as if the task had dropped
+		 * privileges without becoming nondumpable).
+		 * Pairs with a read barrier in __ptrace_may_access().
+		 */
 		smp_wmb();
 	}
 
diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c
index badd77670d00..099002d84f46 100644
--- a/kernel/dma/debug.c
+++ b/kernel/dma/debug.c
@@ -1,20 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2008 Advanced Micro Devices, Inc.
  *
  * Author: Joerg Roedel <joerg.roedel@amd.com>
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 as published
- * by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  */
 
 #define pr_fmt(fmt)	"DMA-API: " fmt
diff --git a/kernel/events/internal.h b/kernel/events/internal.h
index 79c47076700a..3aef4191798c 100644
--- a/kernel/events/internal.h
+++ b/kernel/events/internal.h
@@ -24,7 +24,7 @@ struct ring_buffer {
 	atomic_t			poll;		/* POLL_ for wakeups */
 
 	local_t				head;		/* write position    */
-	local_t				nest;		/* nested writers    */
+	unsigned int			nest;		/* nested writers    */
 	local_t				events;		/* event limit       */
 	local_t				wakeup;		/* wakeup stamp      */
 	local_t				lost;		/* nr records lost   */
@@ -41,7 +41,7 @@ struct ring_buffer {
 
 	/* AUX area */
 	long				aux_head;
-	local_t				aux_nest;
+	unsigned int			aux_nest;
 	long				aux_wakeup;	/* last aux_watermark boundary crossed by aux_head */
 	unsigned long			aux_pgoff;
 	int				aux_nr_pages;
diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
index 674b35383491..ffb59a4ef4ff 100644
--- a/kernel/events/ring_buffer.c
+++ b/kernel/events/ring_buffer.c
@@ -38,7 +38,12 @@ static void perf_output_get_handle(struct perf_output_handle *handle)
 	struct ring_buffer *rb = handle->rb;
 
 	preempt_disable();
-	local_inc(&rb->nest);
+
+	/*
+	 * Avoid an explicit LOAD/STORE such that architectures with memops
+	 * can use them.
+	 */
+	(*(volatile unsigned int *)&rb->nest)++;
 	handle->wakeup = local_read(&rb->wakeup);
 }
 
@@ -46,17 +51,35 @@ static void perf_output_put_handle(struct perf_output_handle *handle)
 {
 	struct ring_buffer *rb = handle->rb;
 	unsigned long head;
+	unsigned int nest;
+
+	/*
+	 * If this isn't the outermost nesting, we don't have to update
+	 * @rb->user_page->data_head.
+	 */
+	nest = READ_ONCE(rb->nest);
+	if (nest > 1) {
+		WRITE_ONCE(rb->nest, nest - 1);
+		goto out;
+	}
 
 again:
+	/*
+	 * In order to avoid publishing a head value that goes backwards,
+	 * we must ensure the load of @rb->head happens after we've
+	 * incremented @rb->nest.
+	 *
+	 * Otherwise we can observe a @rb->head value before one published
+	 * by an IRQ/NMI happening between the load and the increment.
+	 */
+	barrier();
 	head = local_read(&rb->head);
 
 	/*
-	 * IRQ/NMI can happen here, which means we can miss a head update.
+	 * IRQ/NMI can happen here and advance @rb->head, causing our
+	 * load above to be stale.
 	 */
 
-	if (!local_dec_and_test(&rb->nest))
-		goto out;
-
 	/*
 	 * Since the mmap() consumer (userspace) can run on a different CPU:
 	 *
@@ -84,14 +107,23 @@ again:
 	 * See perf_output_begin().
 	 */
 	smp_wmb(); /* B, matches C */
-	rb->user_page->data_head = head;
+	WRITE_ONCE(rb->user_page->data_head, head);
 
 	/*
-	 * Now check if we missed an update -- rely on previous implied
-	 * compiler barriers to force a re-read.
+	 * We must publish the head before decrementing the nest count,
+	 * otherwise an IRQ/NMI can publish a more recent head value and our
+	 * write will (temporarily) publish a stale value.
 	 */
+	barrier();
+	WRITE_ONCE(rb->nest, 0);
+
+	/*
+	 * Ensure we decrement @rb->nest before we validate the @rb->head.
+	 * Otherwise we cannot be sure we caught the 'last' nested update.
+	 */
+	barrier();
 	if (unlikely(head != local_read(&rb->head))) {
-		local_inc(&rb->nest);
+		WRITE_ONCE(rb->nest, 1);
 		goto again;
 	}
 
@@ -330,6 +362,7 @@ void *perf_aux_output_begin(struct perf_output_handle *handle,
 	struct perf_event *output_event = event;
 	unsigned long aux_head, aux_tail;
 	struct ring_buffer *rb;
+	unsigned int nest;
 
 	if (output_event->parent)
 		output_event = output_event->parent;
@@ -360,13 +393,16 @@ void *perf_aux_output_begin(struct perf_output_handle *handle,
 	if (!refcount_inc_not_zero(&rb->aux_refcount))
 		goto err;
 
+	nest = READ_ONCE(rb->aux_nest);
 	/*
 	 * Nesting is not supported for AUX area, make sure nested
 	 * writers are caught early
 	 */
-	if (WARN_ON_ONCE(local_xchg(&rb->aux_nest, 1)))
+	if (WARN_ON_ONCE(nest))
 		goto err_put;
 
+	WRITE_ONCE(rb->aux_nest, nest + 1);
+
 	aux_head = rb->aux_head;
 
 	handle->rb = rb;
@@ -394,7 +430,7 @@ void *perf_aux_output_begin(struct perf_output_handle *handle,
 		if (!handle->size) { /* A, matches D */
 			event->pending_disable = smp_processor_id();
 			perf_output_wakeup(handle);
-			local_set(&rb->aux_nest, 0);
+			WRITE_ONCE(rb->aux_nest, 0);
 			goto err_put;
 		}
 	}
@@ -471,7 +507,7 @@ void perf_aux_output_end(struct perf_output_handle *handle, unsigned long size)
 		perf_event_aux_event(handle->event, aux_head, size,
 				     handle->aux_flags);
 
-	rb->user_page->aux_head = rb->aux_head;
+	WRITE_ONCE(rb->user_page->aux_head, rb->aux_head);
 	if (rb_need_aux_wakeup(rb))
 		wakeup = true;
 
@@ -483,7 +519,7 @@ void perf_aux_output_end(struct perf_output_handle *handle, unsigned long size)
 
 	handle->event = NULL;
 
-	local_set(&rb->aux_nest, 0);
+	WRITE_ONCE(rb->aux_nest, 0);
 	/* can't be last */
 	rb_free_aux(rb);
 	ring_buffer_put(rb);
@@ -503,7 +539,7 @@ int perf_aux_output_skip(struct perf_output_handle *handle, unsigned long size)
 
 	rb->aux_head += size;
 
-	rb->user_page->aux_head = rb->aux_head;
+	WRITE_ONCE(rb->user_page->aux_head, rb->aux_head);
 	if (rb_need_aux_wakeup(rb)) {
 		perf_output_wakeup(handle);
 		handle->wakeup = rb->aux_wakeup + rb->aux_watermark;
diff --git a/kernel/exit.c b/kernel/exit.c
index 1803efb2922f..a75b6a7f458a 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -195,6 +195,7 @@ repeat:
 	rcu_read_unlock();
 
 	proc_flush_task(p);
+	cgroup_release(p);
 
 	write_lock_irq(&tasklist_lock);
 	ptrace_release_task(p);
@@ -220,7 +221,6 @@ repeat:
 	}
 
 	write_unlock_irq(&tasklist_lock);
-	cgroup_release(p);
 	release_thread(p);
 	call_rcu(&p->rcu, delayed_put_task_struct);
 
diff --git a/kernel/extable.c b/kernel/extable.c
index 6a5b61ebc66c..e23cce6e6092 100644
--- a/kernel/extable.c
+++ b/kernel/extable.c
@@ -1,19 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /* Rewritten by Rusty Russell, on the backs of many others...
    Copyright (C) 2001 Rusty Russell, 2002 Rusty Russell IBM.
 
-    This program is free software; you can redistribute it and/or modify
-    it under the terms of the GNU General Public License as published by
-    the Free Software Foundation; either version 2 of the License, or
-    (at your option) any later version.
-
-    This program is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU General Public License for more details.
-
-    You should have received a copy of the GNU General Public License
-    along with this program; if not, write to the Free Software
-    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
 #include <linux/ftrace.h>
 #include <linux/memory.h>
diff --git a/kernel/fork.c b/kernel/fork.c
index b2b87d450b80..75675b9bf6df 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -123,7 +123,7 @@
 unsigned long total_forks;	/* Handle normal Linux uptimes. */
 int nr_threads;			/* The idle threads do not count.. */
 
-int max_threads;		/* tunable limit on nr_threads */
+static int max_threads;		/* tunable limit on nr_threads */
 
 DEFINE_PER_CPU(unsigned long, process_counts) = 0;
 
diff --git a/kernel/futex.c b/kernel/futex.c
index 2268b97d5439..4b5b468c58b6 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  *  Fast Userspace Mutexes (which I call "Futexes!").
  *  (C) Rusty Russell, IBM 2002
@@ -29,20 +30,6 @@
  *
  *  "The futexes are also cursed."
  *  "But they come in a choice of three flavours!"
- *
- *  This program is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License as published by
- *  the Free Software Foundation; either version 2 of the License, or
- *  (at your option) any later version.
- *
- *  This program is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License
- *  along with this program; if not, write to the Free Software
- *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 #include <linux/compat.h>
 #include <linux/slab.h>
diff --git a/kernel/gen_ikh_data.sh b/kernel/gen_kheaders.sh
index 591a94f7b387..9a34e1d9bd7f 100755
--- a/kernel/gen_ikh_data.sh
+++ b/kernel/gen_kheaders.sh
@@ -2,7 +2,7 @@
 # SPDX-License-Identifier: GPL-2.0
 
 # This script generates an archive consisting of kernel headers
-# for CONFIG_IKHEADERS_PROC.
+# for CONFIG_IKHEADERS.
 set -e
 spath="$(dirname "$(readlink -f "$0")")"
 kroot="$spath/.."
@@ -31,9 +31,8 @@ arch/$SRCARCH/include/
 
 # This block is useful for debugging the incremental builds.
 # Uncomment it for debugging.
-# iter=1
-# if [ ! -f /tmp/iter ]; then echo 1 > /tmp/iter;
-# else; 	iter=$(($(cat /tmp/iter) + 1)); fi
+# if [ ! -f /tmp/iter ]; then iter=1; echo 1 > /tmp/iter;
+# else iter=$(($(cat /tmp/iter) + 1)); echo $iter > /tmp/iter; fi
 # find $src_file_list -type f | xargs ls -lR > /tmp/src-ls-$iter
 # find $obj_file_list -type f | xargs ls -lR > /tmp/obj-ls-$iter
 
@@ -43,10 +42,18 @@ arch/$SRCARCH/include/
 pushd $kroot > /dev/null
 src_files_md5="$(find $src_file_list -type f                       |
 		grep -v "include/generated/compile.h"		   |
+		grep -v "include/generated/autoconf.h"		   |
+		grep -v "include/config/auto.conf"		   |
+		grep -v "include/config/auto.conf.cmd"		   |
+		grep -v "include/config/tristate.conf"		   |
 		xargs ls -lR | md5sum | cut -d ' ' -f1)"
 popd > /dev/null
 obj_files_md5="$(find $obj_file_list -type f                       |
 		grep -v "include/generated/compile.h"		   |
+		grep -v "include/generated/autoconf.h"		   |
+		grep -v "include/config/auto.conf"                 |
+		grep -v "include/config/auto.conf.cmd"		   |
+		grep -v "include/config/tristate.conf"		   |
 		xargs ls -lR | md5sum | cut -d ' ' -f1)"
 
 if [ -f $tarfile ]; then tarfile_md5="$(md5sum $tarfile | cut -d ' ' -f1)"; fi
@@ -82,7 +89,7 @@ find $cpio_dir -type f -print0 |
 
 tar -Jcf $tarfile -C $cpio_dir/ . > /dev/null
 
-echo "$src_files_md5" > kernel/kheaders.md5
+echo "$src_files_md5" >  kernel/kheaders.md5
 echo "$obj_files_md5" >> kernel/kheaders.md5
 echo "$(md5sum $tarfile | cut -d ' ' -f1)" >> kernel/kheaders.md5
 
diff --git a/kernel/kexec.c b/kernel/kexec.c
index 68559808fdfa..1b018f1a6e0d 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -1,9 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * kexec.c - kexec_load system call
  * Copyright (C) 2002-2004 Eric Biederman  <ebiederm@xmission.com>
- *
- * This source code is licensed under the GNU General Public License,
- * Version 2.  See the file COPYING for more details.
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index fd5c95ff9251..d5870723b8ad 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -1,9 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * kexec.c - kexec system call core code.
  * Copyright (C) 2002-2004 Eric Biederman  <ebiederm@xmission.com>
- *
- * This source code is licensed under the GNU General Public License,
- * Version 2.  See the file COPYING for more details.
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index 072b6ee55e3f..ef7b951a8087 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -1,12 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * kexec: kexec_file_load system call
  *
  * Copyright (C) 2014 Red Hat Inc.
  * Authors:
  *      Vivek Goyal <vgoyal@redhat.com>
- *
- * This source code is licensed under the GNU General Public License,
- * Version 2.  See the file COPYING for more details.
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
diff --git a/kernel/kheaders.c b/kernel/kheaders.c
index 70ae6052920d..8f69772af77b 100644
--- a/kernel/kheaders.c
+++ b/kernel/kheaders.c
@@ -8,9 +8,8 @@
 
 #include <linux/kernel.h>
 #include <linux/module.h>
-#include <linux/proc_fs.h>
+#include <linux/kobject.h>
 #include <linux/init.h>
-#include <linux/uaccess.h>
 
 /*
  * Define kernel_headers_data and kernel_headers_data_end, within which the
@@ -31,39 +30,32 @@ extern char kernel_headers_data;
 extern char kernel_headers_data_end;
 
 static ssize_t
-ikheaders_read_current(struct file *file, char __user *buf,
-		      size_t len, loff_t *offset)
+ikheaders_read(struct file *file,  struct kobject *kobj,
+	       struct bin_attribute *bin_attr,
+	       char *buf, loff_t off, size_t len)
 {
-	return simple_read_from_buffer(buf, len, offset,
-				       &kernel_headers_data,
-				       &kernel_headers_data_end -
-				       &kernel_headers_data);
+	memcpy(buf, &kernel_headers_data + off, len);
+	return len;
 }
 
-static const struct file_operations ikheaders_file_ops = {
-	.read = ikheaders_read_current,
-	.llseek = default_llseek,
+static struct bin_attribute kheaders_attr __ro_after_init = {
+	.attr = {
+		.name = "kheaders.tar.xz",
+		.mode = 0444,
+	},
+	.read = &ikheaders_read,
 };
 
 static int __init ikheaders_init(void)
 {
-	struct proc_dir_entry *entry;
-
-	/* create the current headers file */
-	entry = proc_create("kheaders.tar.xz", S_IRUGO, NULL,
-			    &ikheaders_file_ops);
-	if (!entry)
-		return -ENOMEM;
-
-	proc_set_size(entry,
-		      &kernel_headers_data_end -
-		      &kernel_headers_data);
-	return 0;
+	kheaders_attr.size = (&kernel_headers_data_end -
+			      &kernel_headers_data);
+	return sysfs_create_bin_file(kernel_kobj, &kheaders_attr);
 }
 
 static void __exit ikheaders_cleanup(void)
 {
-	remove_proc_entry("kheaders.tar.xz", NULL);
+	sysfs_remove_bin_file(kernel_kobj, &kheaders_attr);
 }
 
 module_init(ikheaders_init);
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index b1ea30a5540e..445337c107e0 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1,21 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  *  Kernel Probes (KProbes)
  *  kernel/kprobes.c
  *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
- *
  * Copyright (C) IBM Corporation, 2002, 2004
  *
  * 2002-Oct	Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel
diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c
index 46ba853656f6..35859da8bd4f 100644
--- a/kernel/ksysfs.c
+++ b/kernel/ksysfs.c
@@ -1,11 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * kernel/ksysfs.c - sysfs attributes in /sys/kernel, which
  * 		     are not related to any other subsystem
  *
  * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
- * 
- * This file is release under the GPLv2
- *
  */
 
 #include <linux/kobject.h>
diff --git a/kernel/latencytop.c b/kernel/latencytop.c
index 871734ea2f04..e3acead004e6 100644
--- a/kernel/latencytop.c
+++ b/kernel/latencytop.c
@@ -1,13 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * latencytop.c: Latency display infrastructure
  *
  * (C) Copyright 2008 Intel Corporation
  * Author: Arjan van de Ven <arjan@linux.intel.com>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; version 2
- * of the License.
  */
 
 /*
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index 2398832947c6..c4ce08f43bd6 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -18,6 +18,7 @@
 #include <linux/elf.h>
 #include <linux/moduleloader.h>
 #include <linux/completion.h>
+#include <linux/memory.h>
 #include <asm/cacheflush.h>
 #include "core.h"
 #include "patch.h"
@@ -718,16 +719,21 @@ static int klp_init_object_loaded(struct klp_patch *patch,
 	struct klp_func *func;
 	int ret;
 
+	mutex_lock(&text_mutex);
+
 	module_disable_ro(patch->mod);
 	ret = klp_write_object_relocations(patch->mod, obj);
 	if (ret) {
 		module_enable_ro(patch->mod, true);
+		mutex_unlock(&text_mutex);
 		return ret;
 	}
 
 	arch_klp_init_object_loaded(patch, obj);
 	module_enable_ro(patch->mod, true);
 
+	mutex_unlock(&text_mutex);
+
 	klp_for_each_func(obj, func) {
 		ret = klp_find_object_symbol(obj->name, func->old_name,
 					     func->old_sympos,
diff --git a/kernel/locking/qrwlock.c b/kernel/locking/qrwlock.c
index c7471c3fb798..fe9ca92faa2a 100644
--- a/kernel/locking/qrwlock.c
+++ b/kernel/locking/qrwlock.c
@@ -1,16 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Queued read/write locks
  *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
  * (C) Copyright 2013-2014 Hewlett-Packard Development Company, L.P.
  *
  * Authors: Waiman Long <waiman.long@hp.com>
diff --git a/kernel/locking/qspinlock.c b/kernel/locking/qspinlock.c
index e14b32c69639..2473f10c6956 100644
--- a/kernel/locking/qspinlock.c
+++ b/kernel/locking/qspinlock.c
@@ -1,16 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Queued spinlock
  *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
  * (C) Copyright 2013-2015 Hewlett-Packard Development Company, L.P.
  * (C) Copyright 2013-2014,2018 Red Hat, Inc.
  * (C) Copyright 2015 Intel Corp.
diff --git a/kernel/locking/qspinlock_stat.h b/kernel/locking/qspinlock_stat.h
index 54152670ff24..e625bb410aa2 100644
--- a/kernel/locking/qspinlock_stat.h
+++ b/kernel/locking/qspinlock_stat.h
@@ -1,13 +1,5 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
 /*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
  *
  * Authors: Waiman Long <longman@redhat.com>
  */
diff --git a/kernel/locking/semaphore.c b/kernel/locking/semaphore.c
index 561acdd39960..d9dd94defc0a 100644
--- a/kernel/locking/semaphore.c
+++ b/kernel/locking/semaphore.c
@@ -1,9 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (c) 2008 Intel Corporation
  * Author: Matthew Wilcox <willy@linux.intel.com>
  *
- * Distributed under the terms of the GNU GPL, version 2
- *
  * This file implements counting semaphores.
  * A counting semaphore may be acquired 'n' times before sleeping.
  * See mutex.c for single-acquisition sleeping locks which enforce
diff --git a/kernel/memremap.c b/kernel/memremap.c
index 1490e63f69a9..6e1970719dc2 100644
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -95,6 +95,7 @@ static void devm_memremap_pages_release(void *data)
 	pgmap->kill(pgmap->ref);
 	for_each_device_pfn(pfn, pgmap)
 		put_page(pfn_to_page(pfn));
+	pgmap->cleanup(pgmap->ref);
 
 	/* pages are dead and unused, undo the arch mapping */
 	align_start = res->start & ~(SECTION_SIZE - 1);
@@ -133,8 +134,8 @@ static void devm_memremap_pages_release(void *data)
  * 2/ The altmap field may optionally be initialized, in which case altmap_valid
  *    must be set to true
  *
- * 3/ pgmap->ref must be 'live' on entry and will be killed at
- *    devm_memremap_pages_release() time, or if this routine fails.
+ * 3/ pgmap->ref must be 'live' on entry and will be killed and reaped
+ *    at devm_memremap_pages_release() time, or if this routine fails.
  *
  * 4/ res is expected to be a host memory range that could feasibly be
  *    treated as a "System RAM" range, i.e. not a device mmio range, but
@@ -156,8 +157,10 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
 	pgprot_t pgprot = PAGE_KERNEL;
 	int error, nid, is_ram;
 
-	if (!pgmap->ref || !pgmap->kill)
+	if (!pgmap->ref || !pgmap->kill || !pgmap->cleanup) {
+		WARN(1, "Missing reference count teardown definition\n");
 		return ERR_PTR(-EINVAL);
+	}
 
 	align_start = res->start & ~(SECTION_SIZE - 1);
 	align_size = ALIGN(res->start + resource_size(res), SECTION_SIZE)
@@ -168,14 +171,16 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
 	if (conflict_pgmap) {
 		dev_WARN(dev, "Conflicting mapping in same section\n");
 		put_dev_pagemap(conflict_pgmap);
-		return ERR_PTR(-ENOMEM);
+		error = -ENOMEM;
+		goto err_array;
 	}
 
 	conflict_pgmap = get_dev_pagemap(PHYS_PFN(align_end), NULL);
 	if (conflict_pgmap) {
 		dev_WARN(dev, "Conflicting mapping in same section\n");
 		put_dev_pagemap(conflict_pgmap);
-		return ERR_PTR(-ENOMEM);
+		error = -ENOMEM;
+		goto err_array;
 	}
 
 	is_ram = region_intersects(align_start, align_size,
@@ -267,10 +272,18 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
 	pgmap_array_delete(res);
  err_array:
 	pgmap->kill(pgmap->ref);
+	pgmap->cleanup(pgmap->ref);
+
 	return ERR_PTR(error);
 }
 EXPORT_SYMBOL_GPL(devm_memremap_pages);
 
+void devm_memunmap_pages(struct device *dev, struct dev_pagemap *pgmap)
+{
+	devm_release_action(dev, devm_memremap_pages_release, pgmap);
+}
+EXPORT_SYMBOL_GPL(devm_memunmap_pages);
+
 unsigned long vmem_altmap_offset(struct vmem_altmap *altmap)
 {
 	/* number of pfns from base where pfn_to_page() is valid */
diff --git a/kernel/module.c b/kernel/module.c
index 6e6712b3aaf5..80c7c09584cf 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1,20 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
    Copyright (C) 2002 Richard Henderson
    Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
 
-    This program is free software; you can redistribute it and/or modify
-    it under the terms of the GNU General Public License as published by
-    the Free Software Foundation; either version 2 of the License, or
-    (at your option) any later version.
-
-    This program is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU General Public License for more details.
-
-    You should have received a copy of the GNU General Public License
-    along with this program; if not, write to the Free Software
-    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
 #include <linux/export.h>
 #include <linux/extable.h>
diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index f6c5d330059a..c815f58e6bc0 100644
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -1,13 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  *  Copyright (C) 2006 IBM Corporation
  *
  *  Author: Serge Hallyn <serue@us.ibm.com>
  *
- *  This program is free software; you can redistribute it and/or
- *  modify it under the terms of the GNU General Public License as
- *  published by the Free Software Foundation, version 2 of the
- *  License.
- *
  *  Jun 2006 - namespaces support
  *             OpenVZ, SWsoft Inc.
  *             Pavel Emelianov <xemul@openvz.org>
diff --git a/kernel/params.c b/kernel/params.c
index ce89f757e6da..cf448785d058 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -1,19 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /* Helpers for initial module or kernel cmdline parsing
    Copyright (C) 2001 Rusty Russell.
 
-    This program is free software; you can redistribute it and/or modify
-    it under the terms of the GNU General Public License as published by
-    the Free Software Foundation; either version 2 of the License, or
-    (at your option) any later version.
-
-    This program is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU General Public License for more details.
-
-    You should have received a copy of the GNU General Public License
-    along with this program; if not, write to the Free Software
-    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
 #include <linux/kernel.h>
 #include <linux/string.h>
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index c8c272df7154..cd7434e6000d 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * kernel/power/hibernate.c - Hibernation (a.k.a suspend-to-disk) support.
  *
@@ -6,8 +7,6 @@
  * Copyright (c) 2004 Pavel Machek <pavel@ucw.cz>
  * Copyright (c) 2009 Rafael J. Wysocki, Novell Inc.
  * Copyright (C) 2012 Bojan Smojver <bojan@rexursive.com>
- *
- * This file is released under the GPLv2.
  */
 
 #define pr_fmt(fmt) "PM: " fmt
@@ -129,7 +128,7 @@ static int hibernation_test(int level) { return 0; }
 static int platform_begin(int platform_mode)
 {
 	return (platform_mode && hibernation_ops) ?
-		hibernation_ops->begin() : 0;
+		hibernation_ops->begin(PMSG_FREEZE) : 0;
 }
 
 /**
@@ -257,6 +256,11 @@ void swsusp_show_speed(ktime_t start, ktime_t stop,
 		(kps % 1000) / 10);
 }
 
+__weak int arch_resume_nosmt(void)
+{
+	return 0;
+}
+
 /**
  * create_image - Create a hibernation image.
  * @platform_mode: Whether or not to use the platform driver.
@@ -324,6 +328,10 @@ static int create_image(int platform_mode)
  Enable_cpus:
 	suspend_enable_secondary_cpus();
 
+	/* Allow architectures to do nosmt-specific post-resume dances */
+	if (!in_suspend)
+		error = arch_resume_nosmt();
+
  Platform_finish:
 	platform_finish(platform_mode);
 
@@ -542,7 +550,7 @@ int hibernation_platform_enter(void)
 	 * hibernation_ops->finish() before saving the image, so we should let
 	 * the firmware know that we're going to enter the sleep state after all
 	 */
-	error = hibernation_ops->begin();
+	error = hibernation_ops->begin(PMSG_HIBERNATE);
 	if (error)
 		goto Close;
 
diff --git a/kernel/power/main.c b/kernel/power/main.c
index 4f43e724f6eb..bdbd605c4215 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -1,11 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * kernel/power/main.c - PM subsystem core functionality.
  *
  * Copyright (c) 2003 Patrick Mochel
  * Copyright (c) 2003 Open Source Development Lab
- *
- * This file is released under the GPLv2
- *
  */
 
 #include <linux/export.h>
diff --git a/kernel/power/poweroff.c b/kernel/power/poweroff.c
index 7ef6866b521d..6d475281c730 100644
--- a/kernel/power/poweroff.c
+++ b/kernel/power/poweroff.c
@@ -1,7 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * poweroff.c - sysrq handler to gracefully power down machine.
- *
- * This file is released under the GPL v2
  */
 
 #include <linux/kernel.h>
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index bc9558ab1e5b..83105874f255 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * linux/kernel/power/snapshot.c
  *
@@ -5,9 +6,6 @@
  *
  * Copyright (C) 1998-2005 Pavel Machek <pavel@ucw.cz>
  * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
- *
- * This file is released under the GPLv2.
- *
  */
 
 #define pr_fmt(fmt) "PM: " fmt
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index ef908c134b34..9505101ed2bc 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -1,11 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * kernel/power/suspend.c - Suspend to RAM and standby functionality.
  *
  * Copyright (c) 2003 Patrick Mochel
  * Copyright (c) 2003 Open Source Development Lab
  * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
- *
- * This file is released under the GPLv2.
  */
 
 #define pr_fmt(fmt) "PM: " fmt
@@ -62,6 +61,12 @@ static DECLARE_SWAIT_QUEUE_HEAD(s2idle_wait_head);
 enum s2idle_states __read_mostly s2idle_state;
 static DEFINE_RAW_SPINLOCK(s2idle_lock);
 
+/**
+ * pm_suspend_via_s2idle - Check if suspend-to-idle is the default suspend.
+ *
+ * Return 'true' if suspend-to-idle has been selected as the default system
+ * suspend method.
+ */
 bool pm_suspend_via_s2idle(void)
 {
 	return mem_sleep_current == PM_SUSPEND_TO_IDLE;
diff --git a/kernel/power/suspend_test.c b/kernel/power/suspend_test.c
index 6a897e8b2a88..60564b58de07 100644
--- a/kernel/power/suspend_test.c
+++ b/kernel/power/suspend_test.c
@@ -1,9 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * kernel/power/suspend_test.c - Suspend to RAM and standby test facility.
  *
  * Copyright (c) 2009 Pavel Machek <pavel@ucw.cz>
- *
- * This file is released under the GPLv2.
  */
 
 #include <linux/init.h>
diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index d7f6c1a288d3..e1912ad13bdc 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * linux/kernel/power/swap.c
  *
@@ -7,9 +8,6 @@
  * Copyright (C) 1998,2001-2005 Pavel Machek <pavel@ucw.cz>
  * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
  * Copyright (C) 2010-2012 Bojan Smojver <bojan@rexursive.com>
- *
- * This file is released under the GPLv2.
- *
  */
 
 #define pr_fmt(fmt) "PM: " fmt
diff --git a/kernel/power/user.c b/kernel/power/user.c
index cb24e840a3e6..77438954cc2b 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -1,12 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * linux/kernel/power/user.c
  *
  * This file provides the user space interface for software suspend/resume.
  *
  * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
- *
- * This file is released under the GPLv2.
- *
  */
 
 #include <linux/suspend.h>
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 5710d07e67cf..8456b6e2205f 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -324,6 +324,16 @@ static int __ptrace_may_access(struct task_struct *task, unsigned int mode)
 	return -EPERM;
 ok:
 	rcu_read_unlock();
+	/*
+	 * If a task drops privileges and becomes nondumpable (through a syscall
+	 * like setresuid()) while we are trying to access it, we must ensure
+	 * that the dumpability is read after the credentials; otherwise,
+	 * we may be able to attach to a task that we shouldn't be able to
+	 * attach to (as if the task had dropped privileges without becoming
+	 * nondumpable).
+	 * Pairs with a write barrier in commit_creds().
+	 */
+	smp_rmb();
 	mm = task->mm;
 	if (mm &&
 	    ((get_dumpable(mm) != SUID_DUMP_USER) &&
@@ -705,6 +715,10 @@ static int ptrace_peek_siginfo(struct task_struct *child,
 	if (arg.nr < 0)
 		return -EINVAL;
 
+	/* Ensure arg.off fits in an unsigned long */
+	if (arg.off > ULONG_MAX)
+		return 0;
+
 	if (arg.flags & PTRACE_PEEKSIGINFO_SHARED)
 		pending = &child->signal->shared_pending;
 	else
@@ -712,18 +726,20 @@ static int ptrace_peek_siginfo(struct task_struct *child,
 
 	for (i = 0; i < arg.nr; ) {
 		kernel_siginfo_t info;
-		s32 off = arg.off + i;
+		unsigned long off = arg.off + i;
+		bool found = false;
 
 		spin_lock_irq(&child->sighand->siglock);
 		list_for_each_entry(q, &pending->list, list) {
 			if (!off--) {
+				found = true;
 				copy_siginfo(&info, &q->info);
 				break;
 			}
 		}
 		spin_unlock_irq(&child->sighand->siglock);
 
-		if (off >= 0) /* beyond the end of the list */
+		if (!found) /* beyond the end of the list */
 			break;
 
 #ifdef CONFIG_COMPAT
diff --git a/kernel/sched/cpudeadline.c b/kernel/sched/cpudeadline.c
index 50316455ea66..ec4e4a9aab5f 100644
--- a/kernel/sched/cpudeadline.c
+++ b/kernel/sched/cpudeadline.c
@@ -1,14 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  *  kernel/sched/cpudl.c
  *
  *  Global CPU deadline management
  *
  *  Author: Juri Lelli <j.lelli@sssup.it>
- *
- *  This program is free software; you can redistribute it and/or
- *  modify it under the terms of the GNU General Public License
- *  as published by the Free Software Foundation; version 2
- *  of the License.
  */
 #include "sched.h"
 
diff --git a/kernel/sched/cpupri.c b/kernel/sched/cpupri.c
index daaadf939ccb..9c6480e6d62d 100644
--- a/kernel/sched/cpupri.c
+++ b/kernel/sched/cpupri.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  *  kernel/sched/cpupri.c
  *
@@ -20,11 +21,6 @@
  *  searches).  For tasks with affinity restrictions, the algorithm has a
  *  worst case complexity of O(min(102, nr_domcpus)), though the scenario that
  *  yields the worst case search is fairly contrived.
- *
- *  This program is free software; you can redistribute it and/or
- *  modify it under the terms of the GNU General Public License
- *  as published by the Free Software Foundation; version 2
- *  of the License.
  */
 #include "sched.h"
 
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index 678bfb9bd87f..14c6a8716ba1 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -1,13 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * kernel/sched/debug.c
  *
  * Print the CFS rbtree and other debugging details
  *
  * Copyright(C) 2007, Red Hat, Inc., Ingo Molnar
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
  */
 #include "sched.h"
 
diff --git a/kernel/sched/membarrier.c b/kernel/sched/membarrier.c
index 3cd8a3a795d2..aa8d75804108 100644
--- a/kernel/sched/membarrier.c
+++ b/kernel/sched/membarrier.c
@@ -1,17 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Copyright (C) 2010-2017 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  *
  * membarrier system call
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
  */
 #include "sched.h"
 
diff --git a/kernel/signal.c b/kernel/signal.c
index d7b9d14ac80d..d622eac9d169 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2485,6 +2485,8 @@ relock:
 	if (signal_group_exit(signal)) {
 		ksig->info.si_signo = signr = SIGKILL;
 		sigdelset(&current->pending.signal, SIGKILL);
+		trace_signal_deliver(SIGKILL, SEND_SIG_NOINFO,
+				&sighand->action[SIGKILL - 1]);
 		recalc_sigpending();
 		goto fatal;
 	}
@@ -3619,12 +3621,11 @@ static struct pid *pidfd_to_pid(const struct file *file)
 }
 
 /**
- * sys_pidfd_send_signal - send a signal to a process through a task file
- *                          descriptor
- * @pidfd:  the file descriptor of the process
- * @sig:    signal to be sent
- * @info:   the signal info
- * @flags:  future flags to be passed
+ * sys_pidfd_send_signal - Signal a process through a pidfd
+ * @pidfd:  file descriptor of the process
+ * @sig:    signal to send
+ * @info:   signal info
+ * @flags:  future flags
  *
  * The syscall currently only signals via PIDTYPE_PID which covers
  * kill(<positive-pid>, <signal>. It does not signal threads or process
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 2c3382378d94..a6b81c6b6bff 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -1,10 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  *	linux/kernel/softirq.c
  *
  *	Copyright (C) 1992 Linus Torvalds
  *
- *	Distribute under GPLv2.
- *
  *	Rewritten. Old one was good in 2.2, but in 2.3 it was immoral. --ANK (990903)
  */
 
diff --git a/kernel/stacktrace.c b/kernel/stacktrace.c
index 5667f1da3ede..36139de0a3c4 100644
--- a/kernel/stacktrace.c
+++ b/kernel/stacktrace.c
@@ -207,7 +207,7 @@ int stack_trace_save_tsk_reliable(struct task_struct *tsk, unsigned long *store,
 
 	ret = arch_stack_walk_reliable(consume_entry, &c, tsk);
 	put_task_stack(tsk);
-	return ret;
+	return ret ? ret : c.len;
 }
 #endif
 
diff --git a/kernel/sys.c b/kernel/sys.c
index bdbfe8d37418..2969304c29fe 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1882,13 +1882,14 @@ exit_err:
 }
 
 /*
+ * Check arithmetic relations of passed addresses.
+ *
  * WARNING: we don't require any capability here so be very careful
  * in what is allowed for modification from userspace.
  */
-static int validate_prctl_map(struct prctl_mm_map *prctl_map)
+static int validate_prctl_map_addr(struct prctl_mm_map *prctl_map)
 {
 	unsigned long mmap_max_addr = TASK_SIZE;
-	struct mm_struct *mm = current->mm;
 	int error = -EINVAL, i;
 
 	static const unsigned char offsets[] = {
@@ -1949,24 +1950,6 @@ static int validate_prctl_map(struct prctl_mm_map *prctl_map)
 			      prctl_map->start_data))
 			goto out;
 
-	/*
-	 * Someone is trying to cheat the auxv vector.
-	 */
-	if (prctl_map->auxv_size) {
-		if (!prctl_map->auxv || prctl_map->auxv_size > sizeof(mm->saved_auxv))
-			goto out;
-	}
-
-	/*
-	 * Finally, make sure the caller has the rights to
-	 * change /proc/pid/exe link: only local sys admin should
-	 * be allowed to.
-	 */
-	if (prctl_map->exe_fd != (u32)-1) {
-		if (!ns_capable(current_user_ns(), CAP_SYS_ADMIN))
-			goto out;
-	}
-
 	error = 0;
 out:
 	return error;
@@ -1993,11 +1976,18 @@ static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data
 	if (copy_from_user(&prctl_map, addr, sizeof(prctl_map)))
 		return -EFAULT;
 
-	error = validate_prctl_map(&prctl_map);
+	error = validate_prctl_map_addr(&prctl_map);
 	if (error)
 		return error;
 
 	if (prctl_map.auxv_size) {
+		/*
+		 * Someone is trying to cheat the auxv vector.
+		 */
+		if (!prctl_map.auxv ||
+				prctl_map.auxv_size > sizeof(mm->saved_auxv))
+			return -EINVAL;
+
 		memset(user_auxv, 0, sizeof(user_auxv));
 		if (copy_from_user(user_auxv,
 				   (const void __user *)prctl_map.auxv,
@@ -2010,6 +2000,14 @@ static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data
 	}
 
 	if (prctl_map.exe_fd != (u32)-1) {
+		/*
+		 * Make sure the caller has the rights to
+		 * change /proc/pid/exe link: only local sys admin should
+		 * be allowed to.
+		 */
+		if (!ns_capable(current_user_ns(), CAP_SYS_ADMIN))
+			return -EINVAL;
+
 		error = prctl_set_mm_exe_file(mm, prctl_map.exe_fd);
 		if (error)
 			return error;
@@ -2097,7 +2095,11 @@ static int prctl_set_mm(int opt, unsigned long addr,
 			unsigned long arg4, unsigned long arg5)
 {
 	struct mm_struct *mm = current->mm;
-	struct prctl_mm_map prctl_map;
+	struct prctl_mm_map prctl_map = {
+		.auxv = NULL,
+		.auxv_size = 0,
+		.exe_fd = -1,
+	};
 	struct vm_area_struct *vma;
 	int error;
 
@@ -2125,9 +2127,15 @@ static int prctl_set_mm(int opt, unsigned long addr,
 
 	error = -EINVAL;
 
-	down_write(&mm->mmap_sem);
+	/*
+	 * arg_lock protects concurent updates of arg boundaries, we need
+	 * mmap_sem for a) concurrent sys_brk, b) finding VMA for addr
+	 * validation.
+	 */
+	down_read(&mm->mmap_sem);
 	vma = find_vma(mm, addr);
 
+	spin_lock(&mm->arg_lock);
 	prctl_map.start_code	= mm->start_code;
 	prctl_map.end_code	= mm->end_code;
 	prctl_map.start_data	= mm->start_data;
@@ -2139,9 +2147,6 @@ static int prctl_set_mm(int opt, unsigned long addr,
 	prctl_map.arg_end	= mm->arg_end;
 	prctl_map.env_start	= mm->env_start;
 	prctl_map.env_end	= mm->env_end;
-	prctl_map.auxv		= NULL;
-	prctl_map.auxv_size	= 0;
-	prctl_map.exe_fd	= -1;
 
 	switch (opt) {
 	case PR_SET_MM_START_CODE:
@@ -2181,7 +2186,7 @@ static int prctl_set_mm(int opt, unsigned long addr,
 		goto out;
 	}
 
-	error = validate_prctl_map(&prctl_map);
+	error = validate_prctl_map_addr(&prctl_map);
 	if (error)
 		goto out;
 
@@ -2218,7 +2223,8 @@ static int prctl_set_mm(int opt, unsigned long addr,
 
 	error = 0;
 out:
-	up_write(&mm->mmap_sem);
+	spin_unlock(&mm->arg_lock);
+	up_read(&mm->mmap_sem);
 	return error;
 }
 
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 7d1008be6173..1beca96fb625 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -230,11 +230,6 @@ static int proc_dostring_coredump(struct ctl_table *table, int write,
 #endif
 static int proc_dopipe_max_size(struct ctl_table *table, int write,
 		void __user *buffer, size_t *lenp, loff_t *ppos);
-#ifdef CONFIG_BPF_SYSCALL
-static int proc_dointvec_minmax_bpf_stats(struct ctl_table *table, int write,
-					  void __user *buffer, size_t *lenp,
-					  loff_t *ppos);
-#endif
 
 #ifdef CONFIG_MAGIC_SYSRQ
 /* Note: sysrq code uses its own private copy */
@@ -1253,12 +1248,10 @@ static struct ctl_table kern_table[] = {
 	},
 	{
 		.procname	= "bpf_stats_enabled",
-		.data		= &sysctl_bpf_stats_enabled,
-		.maxlen		= sizeof(sysctl_bpf_stats_enabled),
+		.data		= &bpf_stats_enabled_key.key,
+		.maxlen		= sizeof(bpf_stats_enabled_key),
 		.mode		= 0644,
-		.proc_handler	= proc_dointvec_minmax_bpf_stats,
-		.extra1		= &zero,
-		.extra2		= &one,
+		.proc_handler	= proc_do_static_key,
 	},
 #endif
 #if defined(CONFIG_TREE_RCU) || defined(CONFIG_PREEMPT_RCU)
@@ -3374,26 +3367,35 @@ int proc_do_large_bitmap(struct ctl_table *table, int write,
 
 #endif /* CONFIG_PROC_SYSCTL */
 
-#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_SYSCTL)
-static int proc_dointvec_minmax_bpf_stats(struct ctl_table *table, int write,
-					  void __user *buffer, size_t *lenp,
-					  loff_t *ppos)
+#if defined(CONFIG_SYSCTL)
+int proc_do_static_key(struct ctl_table *table, int write,
+		       void __user *buffer, size_t *lenp,
+		       loff_t *ppos)
 {
-	int ret, bpf_stats = *(int *)table->data;
-	struct ctl_table tmp = *table;
+	struct static_key *key = (struct static_key *)table->data;
+	static DEFINE_MUTEX(static_key_mutex);
+	int val, ret;
+	struct ctl_table tmp = {
+		.data   = &val,
+		.maxlen = sizeof(val),
+		.mode   = table->mode,
+		.extra1 = &zero,
+		.extra2 = &one,
+	};
 
 	if (write && !capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
-	tmp.data = &bpf_stats;
+	mutex_lock(&static_key_mutex);
+	val = static_key_enabled(key);
 	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
 	if (write && !ret) {
-		*(int *)table->data = bpf_stats;
-		if (bpf_stats)
-			static_branch_enable(&bpf_stats_enabled_key);
+		if (val)
+			static_key_enable(key);
 		else
-			static_branch_disable(&bpf_stats_enabled_key);
+			static_key_disable(key);
 	}
+	mutex_unlock(&static_key_mutex);
 	return ret;
 }
 #endif
diff --git a/kernel/taskstats.c b/kernel/taskstats.c
index 5f852b8f59f7..13a0f2e6ebc2 100644
--- a/kernel/taskstats.c
+++ b/kernel/taskstats.c
@@ -1,19 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * taskstats.c - Export per-task statistics to userland
  *
  * Copyright (C) Shailabh Nagar, IBM Corp. 2006
  *           (C) Balbir Singh,   IBM Corp. 2006
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
  */
 
 #include <linux/kernel.h>
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 85f5912d8f70..44b726bab4bd 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -808,17 +808,18 @@ ktime_t ktime_get_coarse_with_offset(enum tk_offsets offs)
 	struct timekeeper *tk = &tk_core.timekeeper;
 	unsigned int seq;
 	ktime_t base, *offset = offsets[offs];
+	u64 nsecs;
 
 	WARN_ON(timekeeping_suspended);
 
 	do {
 		seq = read_seqcount_begin(&tk_core.seq);
 		base = ktime_add(tk->tkr_mono.base, *offset);
+		nsecs = tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift;
 
 	} while (read_seqcount_retry(&tk_core.seq, seq));
 
-	return base;
-
+	return base + nsecs;
 }
 EXPORT_SYMBOL_GPL(ktime_get_coarse_with_offset);
 
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 3994a231eb92..c102c240bb0b 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -413,8 +413,6 @@ static const struct bpf_func_proto bpf_perf_event_read_value_proto = {
 	.arg4_type	= ARG_CONST_SIZE,
 };
 
-static DEFINE_PER_CPU(struct perf_sample_data, bpf_trace_sd);
-
 static __always_inline u64
 __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map,
 			u64 flags, struct perf_sample_data *sd)
@@ -445,24 +443,50 @@ __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map,
 	return perf_event_output(event, sd, regs);
 }
 
+/*
+ * Support executing tracepoints in normal, irq, and nmi context that each call
+ * bpf_perf_event_output
+ */
+struct bpf_trace_sample_data {
+	struct perf_sample_data sds[3];
+};
+
+static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds);
+static DEFINE_PER_CPU(int, bpf_trace_nest_level);
 BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map,
 	   u64, flags, void *, data, u64, size)
 {
-	struct perf_sample_data *sd = this_cpu_ptr(&bpf_trace_sd);
+	struct bpf_trace_sample_data *sds = this_cpu_ptr(&bpf_trace_sds);
+	int nest_level = this_cpu_inc_return(bpf_trace_nest_level);
 	struct perf_raw_record raw = {
 		.frag = {
 			.size = size,
 			.data = data,
 		},
 	};
+	struct perf_sample_data *sd;
+	int err;
 
-	if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
-		return -EINVAL;
+	if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) {
+		err = -EBUSY;
+		goto out;
+	}
+
+	sd = &sds->sds[nest_level - 1];
+
+	if (unlikely(flags & ~(BPF_F_INDEX_MASK))) {
+		err = -EINVAL;
+		goto out;
+	}
 
 	perf_sample_data_init(sd, 0, 0);
 	sd->raw = &raw;
 
-	return __bpf_perf_event_output(regs, map, flags, sd);
+	err = __bpf_perf_event_output(regs, map, flags, sd);
+
+out:
+	this_cpu_dec(bpf_trace_nest_level);
+	return err;
 }
 
 static const struct bpf_func_proto bpf_perf_event_output_proto = {
@@ -890,16 +914,48 @@ pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 /*
  * bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp
  * to avoid potential recursive reuse issue when/if tracepoints are added
- * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack
+ * inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack.
+ *
+ * Since raw tracepoints run despite bpf_prog_active, support concurrent usage
+ * in normal, irq, and nmi context.
  */
-static DEFINE_PER_CPU(struct pt_regs, bpf_raw_tp_regs);
+struct bpf_raw_tp_regs {
+	struct pt_regs regs[3];
+};
+static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs);
+static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level);
+static struct pt_regs *get_bpf_raw_tp_regs(void)
+{
+	struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs);
+	int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level);
+
+	if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) {
+		this_cpu_dec(bpf_raw_tp_nest_level);
+		return ERR_PTR(-EBUSY);
+	}
+
+	return &tp_regs->regs[nest_level - 1];
+}
+
+static void put_bpf_raw_tp_regs(void)
+{
+	this_cpu_dec(bpf_raw_tp_nest_level);
+}
+
 BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args,
 	   struct bpf_map *, map, u64, flags, void *, data, u64, size)
 {
-	struct pt_regs *regs = this_cpu_ptr(&bpf_raw_tp_regs);
+	struct pt_regs *regs = get_bpf_raw_tp_regs();
+	int ret;
+
+	if (IS_ERR(regs))
+		return PTR_ERR(regs);
 
 	perf_fetch_caller_regs(regs);
-	return ____bpf_perf_event_output(regs, map, flags, data, size);
+	ret = ____bpf_perf_event_output(regs, map, flags, data, size);
+
+	put_bpf_raw_tp_regs();
+	return ret;
 }
 
 static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = {
@@ -916,12 +972,18 @@ static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = {
 BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args,
 	   struct bpf_map *, map, u64, flags)
 {
-	struct pt_regs *regs = this_cpu_ptr(&bpf_raw_tp_regs);
+	struct pt_regs *regs = get_bpf_raw_tp_regs();
+	int ret;
+
+	if (IS_ERR(regs))
+		return PTR_ERR(regs);
 
 	perf_fetch_caller_regs(regs);
 	/* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */
-	return bpf_get_stackid((unsigned long) regs, (unsigned long) map,
-			       flags, 0, 0);
+	ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map,
+			      flags, 0, 0);
+	put_bpf_raw_tp_regs();
+	return ret;
 }
 
 static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = {
@@ -936,11 +998,17 @@ static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = {
 BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args,
 	   void *, buf, u32, size, u64, flags)
 {
-	struct pt_regs *regs = this_cpu_ptr(&bpf_raw_tp_regs);
+	struct pt_regs *regs = get_bpf_raw_tp_regs();
+	int ret;
+
+	if (IS_ERR(regs))
+		return PTR_ERR(regs);
 
 	perf_fetch_caller_regs(regs);
-	return bpf_get_stack((unsigned long) regs, (unsigned long) buf,
-			     (unsigned long) size, flags, 0);
+	ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf,
+			    (unsigned long) size, flags, 0);
+	put_bpf_raw_tp_regs();
+	return ret;
 }
 
 static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = {
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index a12aff849c04..38277af44f5c 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -34,6 +34,7 @@
 #include <linux/hash.h>
 #include <linux/rcupdate.h>
 #include <linux/kprobes.h>
+#include <linux/memory.h>
 
 #include <trace/events/sched.h>
 
@@ -2610,10 +2611,12 @@ static void ftrace_run_update_code(int command)
 {
 	int ret;
 
+	mutex_lock(&text_mutex);
+
 	ret = ftrace_arch_code_modify_prepare();
 	FTRACE_WARN_ON(ret);
 	if (ret)
-		return;
+		goto out_unlock;
 
 	/*
 	 * By default we use stop_machine() to modify the code.
@@ -2625,6 +2628,9 @@ static void ftrace_run_update_code(int command)
 
 	ret = ftrace_arch_code_modify_post_process();
 	FTRACE_WARN_ON(ret);
+
+out_unlock:
+	mutex_unlock(&text_mutex);
 }
 
 static void ftrace_run_modify_code(struct ftrace_ops *ops, int command,
@@ -2935,14 +2941,13 @@ static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs)
 			p = &pg->records[i];
 			p->flags = rec_flags;
 
-#ifndef CC_USING_NOP_MCOUNT
 			/*
 			 * Do the initial record conversion from mcount jump
 			 * to the NOP instructions.
 			 */
-			if (!ftrace_code_disable(mod, p))
+			if (!__is_defined(CC_USING_NOP_MCOUNT) &&
+			    !ftrace_code_disable(mod, p))
 				break;
-#endif
 
 			update_cnt++;
 		}
@@ -4221,10 +4226,13 @@ void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
 	struct ftrace_func_entry *entry;
 	struct ftrace_func_map *map;
 	struct hlist_head *hhd;
-	int size = 1 << mapper->hash.size_bits;
-	int i;
+	int size, i;
+
+	if (!mapper)
+		return;
 
 	if (free_func && mapper->hash.count) {
+		size = 1 << mapper->hash.size_bits;
 		for (i = 0; i < size; i++) {
 			hhd = &mapper->hash.buckets[i];
 			hlist_for_each_entry(entry, hhd, hlist) {
@@ -5776,6 +5784,7 @@ void ftrace_module_enable(struct module *mod)
 	struct ftrace_page *pg;
 
 	mutex_lock(&ftrace_lock);
+	mutex_lock(&text_mutex);
 
 	if (ftrace_disabled)
 		goto out_unlock;
@@ -5837,6 +5846,7 @@ void ftrace_module_enable(struct module *mod)
 		ftrace_arch_code_modify_post_process();
 
  out_unlock:
+	mutex_unlock(&text_mutex);
 	mutex_unlock(&ftrace_lock);
 
 	process_cached_mods(mod->name);
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 1c80521fd436..83e08b78dbee 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -6923,7 +6923,7 @@ struct tracing_log_err {
 
 static DEFINE_MUTEX(tracing_err_log_lock);
 
-struct tracing_log_err *get_tracing_log_err(struct trace_array *tr)
+static struct tracing_log_err *get_tracing_log_err(struct trace_array *tr)
 {
 	struct tracing_log_err *err;
 
@@ -8192,7 +8192,7 @@ static const struct file_operations buffer_percent_fops = {
 	.llseek		= default_llseek,
 };
 
-struct dentry *trace_instance_dir;
+static struct dentry *trace_instance_dir;
 
 static void
 init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer);
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 54373d93e251..ba751f993c3b 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -1057,7 +1057,7 @@ static enum print_line_t trace_stack_print(struct trace_iterator *iter,
 
 	trace_seq_puts(s, "<stack trace>\n");
 
-	for (p = field->caller; p && *p != ULONG_MAX && p < end; p++) {
+	for (p = field->caller; p && p < end && *p != ULONG_MAX; p++) {
 
 		if (trace_seq_has_overflowed(s))
 			break;
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index eb7e06b54741..b55906c77ce0 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -426,8 +426,6 @@ end:
 /*
  * Argument syntax:
  *  - Add uprobe: p|r[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS]
- *
- *  - Remove uprobe: -:[GRP/]EVENT
  */
 static int trace_uprobe_create(int argc, const char **argv)
 {
@@ -443,10 +441,17 @@ static int trace_uprobe_create(int argc, const char **argv)
 	ret = 0;
 	ref_ctr_offset = 0;
 
-	/* argc must be >= 1 */
-	if (argv[0][0] == 'r')
+	switch (argv[0][0]) {
+	case 'r':
 		is_return = true;
-	else if (argv[0][0] != 'p' || argc < 2)
+		break;
+	case 'p':
+		break;
+	default:
+		return -ECANCELED;
+	}
+
+	if (argc < 2)
 		return -ECANCELED;
 
 	if (argv[0][1] == ':')
diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
index 46f2ab1e08a9..df3ade14ccbd 100644
--- a/kernel/tracepoint.c
+++ b/kernel/tracepoint.c
@@ -1,19 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Copyright (C) 2008-2014 Mathieu Desnoyers
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
 #include <linux/module.h>
 #include <linux/mutex.h>
diff --git a/kernel/tsacct.c b/kernel/tsacct.c
index 370724b45391..7be3e7530841 100644
--- a/kernel/tsacct.c
+++ b/kernel/tsacct.c
@@ -1,19 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * tsacct.c - System accounting over taskstats interface
  *
  * Copyright (C) Jay Lan,	<jlan@sgi.com>
- *
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
  */
 
 #include <linux/kernel.h>
diff --git a/kernel/ucount.c b/kernel/ucount.c
index f48d1b6376a4..feb128c7b5d9 100644
--- a/kernel/ucount.c
+++ b/kernel/ucount.c
@@ -1,9 +1,4 @@
-/*
- *  This program is free software; you can redistribute it and/or
- *  modify it under the terms of the GNU General Public License as
- *  published by the Free Software Foundation, version 2 of the
- *  License.
- */
+// SPDX-License-Identifier: GPL-2.0-only
 
 #include <linux/stat.h>
 #include <linux/sysctl.h>
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index 923414a246e9..0eff45ce7703 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -1,9 +1,4 @@
-/*
- *  This program is free software; you can redistribute it and/or
- *  modify it under the terms of the GNU General Public License as
- *  published by the Free Software Foundation, version 2 of the
- *  License.
- */
+// SPDX-License-Identifier: GPL-2.0-only
 
 #include <linux/export.h>
 #include <linux/nsproxy.h>
diff --git a/kernel/utsname.c b/kernel/utsname.c
index dcd6be1996fe..f0e491193009 100644
--- a/kernel/utsname.c
+++ b/kernel/utsname.c
@@ -1,12 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  *  Copyright (C) 2004 IBM Corporation
  *
  *  Author: Serge Hallyn <serue@us.ibm.com>
- *
- *  This program is free software; you can redistribute it and/or
- *  modify it under the terms of the GNU General Public License as
- *  published by the Free Software Foundation, version 2 of the
- *  License.
  */
 
 #include <linux/export.h>
diff --git a/kernel/utsname_sysctl.c b/kernel/utsname_sysctl.c
index 258033d62cb3..3732c888a949 100644
--- a/kernel/utsname_sysctl.c
+++ b/kernel/utsname_sysctl.c
@@ -1,12 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  *  Copyright (C) 2007
  *
  *  Author: Eric Biederman <ebiederm@xmision.com>
- *
- *  This program is free software; you can redistribute it and/or
- *  modify it under the terms of the GNU General Public License as
- *  published by the Free Software Foundation, version 2 of the
- *  License.
  */
 
 #include <linux/export.h>