Merge tag 'v5.2-rc3' into locking/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>

44 files changed, 213 insertions, 329 deletions

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/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/core.c b/kernel/bpf/core.c
index 242a643af82f..7c473f208a10 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()
  */
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 950ab2f28922..d38e49f943a1 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/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 217cec4e22c6..426a0026225c 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -1810,11 +1810,13 @@ 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 +1839,9 @@ 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 +1853,11 @@ 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 +1865,8 @@ 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;
 }
 
@@ -6325,7 +6337,7 @@ 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/cred.c b/kernel/cred.c
index 45d77284aed0..e74ffdc98a92 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -1,12 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /* Task credentials management - see Documentation/security/credentials.rst
  *
  * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public Licence
- * as published by the Free Software Foundation; either version
- * 2 of the Licence, or (at your option) any later version.
  */
 #include <linux/export.h>
 #include <linux/cred.h>
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/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 49bf20a8c512..6d50728ef2e7 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/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/locking/lock_events.h b/kernel/locking/lock_events.h
index feb1acc54611..46b71af8eef2 100644
--- a/kernel/locking/lock_events.h
+++ b/kernel/locking/lock_events.h
@@ -31,12 +31,50 @@ enum lock_events {
 DECLARE_PER_CPU(unsigned long, lockevents[lockevent_num]);
 
 /*
+ * The purpose of the lock event counting subsystem is to provide a low
+ * overhead way to record the number of specific locking events by using
+ * percpu counters. It is the percpu sum that matters, not specifically
+ * how many of them happens in each cpu.
+ *
+ * It is possible that the same percpu counter may be modified in both
+ * the process and interrupt contexts. For architectures that perform
+ * percpu operation with multiple instructions, it is possible to lose
+ * count if a process context percpu update is interrupted in the middle
+ * and the same counter is updated in the interrupt context. Therefore,
+ * the generated percpu sum may not be precise. The error, if any, should
+ * be small and insignificant.
+ *
+ * For those architectures that do multi-instruction percpu operation,
+ * preemption in the middle and moving the task to another cpu may cause
+ * a larger error in the count. Again, this will be few and far between.
+ * Given the imprecise nature of the count and the possibility of resetting
+ * the count and doing the measurement again, this is not really a big
+ * problem.
+ *
+ * To get a better picture of what is happening under the hood, it is
+ * suggested that a few measurements should be taken with the counts
+ * reset in between to stamp out outliner because of these possible
+ * error conditions.
+ *
+ * To minimize overhead, we use __this_cpu_*() in all cases except when
+ * CONFIG_DEBUG_PREEMPT is defined. In this particular case, this_cpu_*()
+ * will be used to avoid the appearance of unwanted BUG messages.
+ */
+#ifdef CONFIG_DEBUG_PREEMPT
+#define lockevent_percpu_inc(x)         this_cpu_inc(x)
+#define lockevent_percpu_add(x, v)      this_cpu_add(x, v)
+#else
+#define lockevent_percpu_inc(x)         __this_cpu_inc(x)
+#define lockevent_percpu_add(x, v)      __this_cpu_add(x, v)
+#endif
+
+/*
  * Increment the PV qspinlock statistical counters
  */
 static inline void __lockevent_inc(enum lock_events event, bool cond)
 {
         if (cond)
-                __this_cpu_inc(lockevents[event]);
+                lockevent_percpu_inc(lockevents[event]);
 }
 
 #define lockevent_inc(ev)         __lockevent_inc(LOCKEVENT_ ##ev, true)
@@ -44,7 +82,7 @@ static inline void __lockevent_inc(enum lock_events event, bool cond)
 
 static inline void __lockevent_add(enum lock_events event, int inc)
 {
-        __this_cpu_add(lockevents[event], inc);
+        lockevent_percpu_add(lockevents[event], inc);
 }
 
 #define lockevent_add(ev, c)    __lockevent_add(LOCKEVENT_ ##ev, c)
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/module-internal.h b/kernel/module-internal.h
index d354341f8cc0..33783abc377b 100644
--- a/kernel/module-internal.h
+++ b/kernel/module-internal.h
@@ -1,12 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
 /* Module internals
  *
  * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public Licence
- * as published by the Free Software Foundation; either version
- * 2 of the Licence, or (at your option) any later version.
  */
 
 #include <linux/elf.h>
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/module_signing.c b/kernel/module_signing.c
index 6b9a926fd86b..b10fb1986ca9 100644
--- a/kernel/module_signing.c
+++ b/kernel/module_signing.c
@@ -1,12 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /* Module signature checker
  *
  * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public Licence
- * as published by the Free Software Foundation; either version
- * 2 of the Licence, or (at your option) any later version.
  */
 
 #include <linux/kernel.h>
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..97522630b1b6 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -129,7 +129,7 @@ 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;
 }
 
 /**
@@ -542,7 +542,7 @@ 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/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..328a01e1a2f0 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;
         }
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/stop_machine.c b/kernel/stop_machine.c
index 7231fb5953fc..2b5a6754646f 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * kernel/stop_machine.c
  *
@@ -5,8 +6,6 @@
  * Copyright (C) 2008, 2005     Rusty Russell rusty@rustcorp.com.au
  * Copyright (C) 2010           SUSE Linux Products GmbH
  * Copyright (C) 2010           Tejun Heo <tj@kernel.org>
- *
- * This file is released under the GPLv2 and any later version.
  */
 #include <linux/completion.h>
 #include <linux/cpu.h>
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/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/trace/trace.c b/kernel/trace/trace.c
index 2c92b3d9ea30..1c80521fd436 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -8910,12 +8910,8 @@ void ftrace_dump(enum ftrace_dump_mode oops_dump_mode)
 
                 cnt++;
 
-                /* reset all but tr, trace, and overruns */
-                memset(&iter.seq, 0,
-                       sizeof(struct trace_iterator) -
-                       offsetof(struct trace_iterator, seq));
+                trace_iterator_reset(&iter);
                 iter.iter_flags |= TRACE_FILE_LAT_FMT;
-                iter.pos = -1;
 
                 if (trace_find_next_entry_inc(&iter) != NULL) {
                         int ret;
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 1974ce818ddb..005f08629b8b 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -15,7 +15,6 @@
 #include <linux/trace_seq.h>
 #include <linux/trace_events.h>
 #include <linux/compiler.h>
-#include <linux/trace_seq.h>
 #include <linux/glob.h>
 
 #ifdef CONFIG_FTRACE_SYSCALLS
@@ -1967,4 +1966,22 @@ static inline void tracer_hardirqs_off(unsigned long a0, unsigned long a1) { }
 
 extern struct trace_iterator *tracepoint_print_iter;
 
+/*
+ * Reset the state of the trace_iterator so that it can read consumed data.
+ * Normally, the trace_iterator is used for reading the data when it is not
+ * consumed, and must retain state.
+ */
+static __always_inline void trace_iterator_reset(struct trace_iterator *iter)
+{
+        const size_t offset = offsetof(struct trace_iterator, seq);
+
+        /*
+         * Keep gcc from complaining about overwriting more than just one
+         * member in the structure.
+         */
+        memset((char *)iter + offset, 0, sizeof(struct trace_iterator) - offset);
+
+        iter->pos = -1;
+}
+
 #endif /* _LINUX_KERNEL_TRACE_H */
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index d3e59312ef40..5079d1db3754 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -428,7 +428,7 @@ predicate_parse(const char *str, int nr_parens, int nr_preds,
         op_stack = kmalloc_array(nr_parens, sizeof(*op_stack), GFP_KERNEL);
         if (!op_stack)
                 return ERR_PTR(-ENOMEM);
-        prog_stack = kmalloc_array(nr_preds, sizeof(*prog_stack), GFP_KERNEL);
+        prog_stack = kcalloc(nr_preds, sizeof(*prog_stack), GFP_KERNEL);
         if (!prog_stack) {
                 parse_error(pe, -ENOMEM, 0);
                 goto out_free;
@@ -579,7 +579,11 @@ predicate_parse(const char *str, int nr_parens, int nr_preds,
 out_free:
         kfree(op_stack);
         kfree(inverts);
-        kfree(prog_stack);
+        if (prog_stack) {
+                for (i = 0; prog_stack[i].pred; i++)
+                        kfree(prog_stack[i].pred);
+                kfree(prog_stack);
+        }
         return ERR_PTR(ret);
 }
 
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 7fca3457c705..ca6b0dff60c5 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -59,7 +59,7 @@
         C(NO_CLOSING_PAREN,     "No closing paren found"),              \
         C(SUBSYS_NOT_FOUND,     "Missing subsystem"),                   \
         C(INVALID_SUBSYS_EVENT, "Invalid subsystem or event name"),     \
-        C(INVALID_REF_KEY,      "Using variable references as keys not supported"), \
+        C(INVALID_REF_KEY,      "Using variable references in keys not supported"), \
         C(VAR_NOT_FOUND,        "Couldn't find variable"),              \
         C(FIELD_NOT_FOUND,      "Couldn't find field"),
 
@@ -1854,6 +1854,9 @@ static u64 hist_field_var_ref(struct hist_field *hist_field,
         struct hist_elt_data *elt_data;
         u64 var_val = 0;
 
+        if (WARN_ON_ONCE(!elt))
+                return var_val;
+
         elt_data = elt->private_data;
         var_val = elt_data->var_ref_vals[hist_field->var_ref_idx];
 
@@ -3582,14 +3585,20 @@ static bool cond_snapshot_update(struct trace_array *tr, void *cond_data)
         struct track_data *track_data = tr->cond_snapshot->cond_data;
         struct hist_elt_data *elt_data, *track_elt_data;
         struct snapshot_context *context = cond_data;
+        struct action_data *action;
         u64 track_val;
 
         if (!track_data)
                 return false;
 
+        action = track_data->action_data;
+
         track_val = get_track_val(track_data->hist_data, context->elt,
                                   track_data->action_data);
 
+        if (!action->track_data.check_val(track_data->track_val, track_val))
+                return false;
+
         track_data->track_val = track_val;
         memcpy(track_data->key, context->key, track_data->key_len);
 
@@ -4503,7 +4512,7 @@ static int create_key_field(struct hist_trigger_data *hist_data,
                         goto out;
                 }
 
-                if (hist_field->flags & HIST_FIELD_FL_VAR_REF) {
+                if (field_has_hist_vars(hist_field, 0)) {
                         hist_err(tr, HIST_ERR_INVALID_REF_KEY, errpos(field_str));
                         destroy_hist_field(hist_field, 0);
                         ret = -EINVAL;
diff --git a/kernel/trace/trace_kdb.c b/kernel/trace/trace_kdb.c
index 6c1ae6b752d1..cca65044c14c 100644
--- a/kernel/trace/trace_kdb.c
+++ b/kernel/trace/trace_kdb.c
@@ -37,12 +37,8 @@ static void ftrace_dump_buf(int skip_entries, long cpu_file)
         if (skip_entries)
                 kdb_printf("(skipping %d entries)\n", skip_entries);
 
-        /* reset all but tr, trace, and overruns */
-        memset(&iter.seq, 0,
-                   sizeof(struct trace_iterator) -
-                   offsetof(struct trace_iterator, seq));
+        trace_iterator_reset(&iter);
         iter.iter_flags |= TRACE_FILE_LAT_FMT;
-        iter.pos = -1;
 
         if (cpu_file == RING_BUFFER_ALL_CPUS) {
                 for_each_tracing_cpu(cpu) {
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>