Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Don't destroy user event fields when removal fails

   User event fields are destroyed before the event is removed from
   visibility. But that can fail leaving the still visible event with no
   fields. Move the destroying of the fields to after the event is
   successfully removed from visibility.

 - Initialize function graph state is fork before calling
   copy_exec_state()

   For non-CLONE_VM forks, copy_exec_state() allocates a new
   task_exec_state. If that allocation fails, ftrace_graph_exit_task()
   will free the tasks ret_stack pointer. Since that pointer is still
   using the parent's ret_stack, it mistakenly frees the parent's
   pointer too.

   Call ftrace_graph_init() on the task first which will NULL out the
   new tasks's ret_stack and if the copy fails, it will not free
   anything.

 - Remove FGRAPH_MAX_INDEX

   The macro FGRAPH_MAX_INDEX was added but never used. Remove it.

 - Save ent_size in function graph printing of nested functions

   The function graph tracer needs to look at the next event to see if
   the next event is the return of the current function entry. If it is,
   it prints a single line:

	ktime_get();

   Otherwise it prints it like a nested function:

	tick_nohz_irq_exit() {
	    ktime_get();
	    kcpustat_irq_exit();
	}

   In order to look at the next event, it must save the current event so
   that it has the information to print from it. It saves the event in
   the iterator descriptor called "ent". What it doesn't save is the
   ent_size of the event which is now used to know if the function graph
   arguments are to be printed. The peek doesn't save the size so the
   size used happens to be that of the size of the last event that was
   seen.

   Save the entry event size in the iterator descriptor so that the
   correct size is used.

 - Fix several errors with freeing data in the histogram code

   The histogram code had a lot of leaked or or incorrect accounting
   when failures happen. Correct them.

 - Fix histogram regression of .percent and .graph modifiers

   Up until 6.3 histogram values could have "percent" or "graph"
   modifiers that changed how they were printed. But a change that added
   restricting histograms values from being strings, stack traces and
   other modifiers inadvertently prevented them from using the percent
   and graph modifiers, which were legal use cases for values.

   Put back the percent and graph modifiers.

 - Fix various typos in the comments

 - Set the trace_clock before initializing a histogram with clock
   argument

   The histogram API allows the user to specific which trace clock to
   use via a "clock=" string. The histogram is set up first before the
   clock is checked. If the passed in clock is not valid, it exits
   without fully fixing up the histogram leaving it on the list and a
   use-after-free can trigger.

   Update the clock argument first and if it fails then exit gracefully
   before the histogram trigger is placed on any lists.

 - Restore :mod: trailer after parsing in ftrace_set_clr_event

   The function ftrace_set_clr_event() modifies the parse string and
   needs to put it back to what was passed in. It searches for ":mod:"
   via a strsep() but fails to put back the first ':' in the string.

   Add back the ':' in the passed in string.

 - Take trace_array reference when opening a tracer options file

   The options files are dynamically created and some tracers add their
   own options. When a tracer adds their own list of options, the
   trace_array holding them has an array to hold the list of options for
   each tracer. This array increases in size via a krealloc(), and the
   new entry gets a newly allocated array to hold the options of the new
   tracer being added.

   The element in each entry of the tracer's option array holds a
   pointer back to the trace_array, a pointer to the tracer it is
   associated to, a pointer to the flags of the option.

   The issue is that these arrays are freed when the trace_array is
   freed when its instance it represents is removed from the instances
   directory. There's a race that an open of one of these options files
   can happen when the instance is being removed.

   Add a new helper function to be called by the open function of the
   options file to iterate all existing trace_arrays under a lock and
   find the one that has the given option element in one of it's tracer
   arrays. If found, then update the associated trace_array's reference
   counter to keep it from being freed. If not found, have the open call
   return -ENODEV.

 - Disable interrupts when acquiring the lock in rb_wake_up_waiters()

   The function rb_wake_up_waiters() assumes it will be called in
   interrupt context and does not disable irqs when taking
   cpu_buffer->reader_lock, which can be called in hard interrupt
   context. The issue is in PREEMPT_RT, this function is called in
   thread context leaving this lock open to a deadlock.

   Take the lock with interrupts disabled.

 - Use rcu_assign_pointer() for tmp_ops filter hash

   The tmp_ops used in update_ftrace_direct_mod() assigns its
   filter_hash field directly, but that field is annotated as __rcu and
   sparse complains. Assign it with rcu_assign_pointer()

 - Fix use-after-free in enable_trigger_private_data_free()

   The trace_event_call is accessed through the event_trigger_data's
   trace_event_file pointer to put the trace_event_call on freeing. The
   issue is that the trace_event_file data may have been freed already
   causing a use-after-free. Add a field to the event_trigger_data that
   points directly to the trace_event_call so that it can decrement its
   reference directly without needing to go through the
   trace_event_file.

 - Fix accounting of buffer data remote headers

   trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount
   the number of pages is needed for the asked for size as it doesn't
   take into account the meta data on each page. Add a helper function
   to do the calculation properly and use that in these functions.

 - Catch nr_page_va overflow in ring_buffer_desc sizing

   The number of pages per remote ring buffer is capped by
   ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to
   overflow that field would silently allocate a descriptor smaller than
   what was asked for.

 - Do not resize the subbuf order if any per_cpu buffer is disabled

   The mmapping of ring buffers disables resizing the subbuffers, but it
   is done per-cpu whereas the subbuf size change is done for all the
   per_cpu buffers under the buffer->mutex. It could change the size of
   some while the mapping is happening on others. Have the resize of the
   subbuf order check all the per_cpu buffers under the lock to see if
   any of them is disabled before starting and causing an inconsistency
   between buffers that are being mapped.

* tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits)
  ring-buffer: Check resize_disabled before publishing the new subbuf order
  tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing
  tracing/remotes: Account for ring buffer page header in size calculation
  tracing: Don't dereference trace_event_file in deferred trigger free
  ftrace: Use rcu_assign_pointer() for tmp_ops filter hash
  ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters()
  tracing: Take trace_array reference when opening a tracer options file
  tracing: Fix ring_buffer_read_page_size() kernel-doc
  tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event()
  tracing: Fix memory corruption from a "STACKTRACE" histogram key
  tracing: Fix memory corruption from the histogram stacktrace modifier
  tracing: Undo the registration when enabling the histogram trigger fails
  tracing: Take the reference before publishing the named histogram trigger
  tracing: Set the trace clock before registering the histogram trigger
  tracing: Fix typo "preceeded" in comment
  tracing: Fix typo "availabe" in comment
  tracing: Let histogram values keep the percent and graph modifiers
  tracing: Keep the entry count when the histogram stats allocation fails
  tracing: Free histogram the field rejected for a bad modifier
  tracing: Free histogram the var ref when its initialization fails
  ...

15 files changed, 1156 insertions, 0 deletions

diff --git a/tools/memory-model/scripts/README b/tools/memory-model/scripts/README
new file mode 100644
index 000000000..fb39bd0fd
--- /dev/null
+++ b/tools/memory-model/scripts/README
@@ -0,0 +1,110 @@
+			============
+			LKMM SCRIPTS
+			============
+
+
+These scripts are run from the tools/memory-model directory.
+
+checkalllitmus.sh
+
+	Run all litmus tests in the litmus-tests directory, checking
+	the results against the expected results recorded in the
+	"Result:" comment lines.
+
+checkghlitmus.sh
+
+	Run all litmus tests in the https://github.com/paulmckrcu/litmus
+	archive that are C-language and that have "Result:" comment lines
+	documenting expected results, comparing the actual results to
+	those expected.
+
+checklitmushist.sh
+
+	Run all litmus tests having .litmus.out files from previous
+	initlitmushist.sh or newlitmushist.sh runs, comparing the
+	herd7 output to that of the original runs.
+
+checklitmus.sh
+
+	Check a single litmus test against its "Result:" expected result.
+	Not intended to for manual use.
+
+checktheselitmus.sh
+
+	Check the specified list of litmus tests against their "Result:"
+	expected results.  This takes optional parseargs.sh arguments,
+	followed by "--" followed by pathnames starting from the current
+	directory.
+
+cmplitmushist.sh
+
+	Compare output from two different runs of the same litmus tests,
+	with the absolute pathnames of the tests to run provided one
+	name per line on standard input.  Not normally run manually,
+	provided instead for use by other scripts.
+
+initlitmushist.sh
+
+	Run all litmus tests having no more than the specified number
+	of processes given a specified timeout, recording the results
+	in .litmus.out files.
+
+judgelitmus.sh
+
+	Given a .litmus file and its herd7 output, check the output file
+	against the .litmus file's "Result:" comment to judge whether
+	the test ran correctly.  Not normally run manually, provided
+	instead for use by other scripts.
+
+newlitmushist.sh
+
+	For all new or updated litmus tests having no more than the
+	specified number of processes given a specified timeout, run
+	and record the results in .litmus.out files.
+
+parseargs.sh
+
+	Parse command-line arguments.  Not normally run manually,
+	provided instead for use by other scripts.
+
+runlitmushist.sh
+
+	Run the litmus tests whose absolute pathnames are provided one
+	name per line on standard input.  Not normally run manually,
+	provided instead for use by other scripts.
+
+README
+
+	This file
+
+Testing a change to LKMM might go as follows:
+
+	# Populate expected results without that change, and
+	# runs for about an hour on an 8-CPU x86 system:
+	scripts/initlitmushist.sh --timeout 10m --procs 10
+	# Incorporate the change:
+	git am -s -3 /path/to/patch # Or whatever it takes.
+
+	# Test the new version of LKMM as follows...
+
+	# Runs in seconds, good smoke test:
+	scripts/checkalllitmus.sh
+
+	# Compares results to those produced by initlitmushist.sh,
+	# and runs for about an hour on an 8-CPU x86 system:
+	scripts/checklitmushist.sh --timeout 10m --procs 10
+
+	# Checks results against Result tags, runs in minutes:
+	scripts/checkghlitmus.sh --timeout 10m --procs 10
+
+The checkghlitmus.sh should not report errors in cases where the
+checklitmushist.sh script did not also report a change.  However,
+this check is nevertheless valuable because it can find errors in the
+original version of LKMM.  Note however, that given the above procedure,
+an error in the original LKMM version that is fixed by the patch will
+be reported both as a mismatch by checklitmushist.sh and as an error
+by checkghlitmus.sh.  One exception to this rule of thumb is when the
+test fails completely on the original version of LKMM and passes on the
+new version.  In this case, checklitmushist.sh will report a mismatch
+and checkghlitmus.sh will report success.  This happens when the change
+to LKMM introduces a new primitive for which litmus tests already existed.
diff --git a/tools/memory-model/scripts/checkalllitmus.sh b/tools/memory-model/scripts/checkalllitmus.sh
new file mode 100755
index 000000000..2d3ee850a
--- /dev/null
+++ b/tools/memory-model/scripts/checkalllitmus.sh
@@ -0,0 +1,65 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Run herd7 tests on all .litmus files in the litmus-tests directory
+# and check each file's result against a "Result:" comment within that
+# litmus test.  If the verification result does not match that specified
+# in the litmus test, this script prints an error message prefixed with
+# "^^^".  It also outputs verification results to a file whose name is
+# that of the specified litmus test, but with ".out" appended.
+#
+# If the --hw argument is specified, this script translates the .litmus
+# C-language file to the specified type of assembly and verifies that.
+# But in this case, litmus tests using complex synchronization (such as
+# locking, RCU, and SRCU) are cheerfully ignored.
+#
+# Usage:
+#	checkalllitmus.sh
+#
+# Run this in the directory containing the memory model.
+#
+# This script makes no attempt to run the litmus tests concurrently.
+#
+# Copyright IBM Corporation, 2018
+#
+# Author: Paul E. McKenney <paulmck@linux.ibm.com>
+
+. scripts/parseargs.sh
+
+litmusdir=litmus-tests
+if test -d "$litmusdir" -a -r "$litmusdir" -a -x "$litmusdir"
+then
+	:
+else
+	echo ' --- ' error: $litmusdir is not an accessible directory
+	exit 255
+fi
+
+# Create any new directories that have appeared in the litmus-tests
+# directory since the last run.
+if test "$LKMM_DESTDIR" != "."
+then
+	find $litmusdir -type d -print |
+	( cd "$LKMM_DESTDIR"; sed -e 's/^/mkdir -p /' | sh )
+fi
+
+# Run the script on all the litmus tests in the specified directory
+ret=0
+for i in $litmusdir/*.litmus
+do
+	if test -n "$LKMM_HW_MAP_FILE" && ! scripts/simpletest.sh $i
+	then
+		continue
+	fi
+	if ! scripts/checklitmus.sh $i
+	then
+		ret=1
+	fi
+done
+if test "$ret" -ne 0
+then
+	echo " ^^^ VERIFICATION MISMATCHES" 1>&2
+else
+	echo All litmus tests verified as was expected. 1>&2
+fi
+exit $ret
diff --git a/tools/memory-model/scripts/checkghlitmus.sh b/tools/memory-model/scripts/checkghlitmus.sh
new file mode 100755
index 000000000..d3dfb3212
--- /dev/null
+++ b/tools/memory-model/scripts/checkghlitmus.sh
@@ -0,0 +1,66 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Runs the C-language litmus tests having a maximum number of processes
+# to run, defaults to 6.
+#
+# sh checkghlitmus.sh
+#
+# Run from the Linux kernel tools/memory-model directory.  See the
+# parseargs.sh scripts for arguments.
+
+. scripts/parseargs.sh
+. scripts/hwfnseg.sh
+
+T=/tmp/checkghlitmus.sh.$$
+trap 'rm -rf $T' 0
+mkdir $T
+
+# Clone the repository if it is not already present.
+if test -d litmus
+then
+	:
+else
+	git clone https://github.com/paulmckrcu/litmus
+	( cd litmus; git checkout origin/master )
+fi
+
+# Create any new directories that have appeared in the github litmus
+# repo since the last run.
+if test "$LKMM_DESTDIR" != "."
+then
+	find litmus -type d -print |
+	( cd "$LKMM_DESTDIR"; sed -e 's/^/mkdir -p /' | sh )
+fi
+
+# Create a list of the specified litmus tests previously run.
+( cd $LKMM_DESTDIR; find litmus -name "*.litmus${hwfnseg}.out" -print ) |
+	sed -e "s/${hwfnseg}"'\.out$//' |
+	xargs -r grep -E -l '^ \* Result: (Never|Sometimes|Always|DEADLOCK)' |
+	xargs -r grep -L "^P${LKMM_PROCS}"> $T/list-C-already
+
+# Create a list of C-language litmus tests with "Result:" commands and
+# no more than the specified number of processes.
+find litmus -name '*.litmus' -print | mselect7 -arch C > $T/list-C
+xargs < $T/list-C -r grep -E -l '^ \* Result: (Never|Sometimes|Always|DEADLOCK)' > $T/list-C-result
+xargs < $T/list-C-result -r grep -L "^P${LKMM_PROCS}" > $T/list-C-result-short
+
+# Form list of tests without corresponding .out files
+sort $T/list-C-already $T/list-C-result-short | uniq -u > $T/list-C-needed
+
+# Run any needed tests.
+if scripts/runlitmushist.sh < $T/list-C-needed > $T/run.stdout 2> $T/run.stderr
+then
+	errs=
+else
+	errs=1
+fi
+
+sed < $T/list-C-result-short -e 's,^,scripts/judgelitmus.sh ,' |
+	sh > $T/judge.stdout 2> $T/judge.stderr
+
+if test -n "$errs"
+then
+	cat $T/run.stderr 1>&2
+fi
+grep '!!!' $T/judge.stdout
diff --git a/tools/memory-model/scripts/checklitmus.sh b/tools/memory-model/scripts/checklitmus.sh
new file mode 100755
index 000000000..4c1d0cf0d
--- /dev/null
+++ b/tools/memory-model/scripts/checklitmus.sh
@@ -0,0 +1,19 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Invokes runlitmus.sh and judgelitmus.sh on its arguments to run the
+# specified litmus test and pass judgment on the results.
+#
+# Usage:
+#	checklitmus.sh file.litmus
+#
+# Run this in the directory containing the memory model, specifying the
+# pathname of the litmus test to check.  The caller is expected to have
+# properly set up the LKMM environment variables.
+#
+# Copyright IBM Corporation, 2018
+#
+# Author: Paul E. McKenney <paulmck@linux.ibm.com>
+
+scripts/runlitmus.sh $1
+scripts/judgelitmus.sh $1
diff --git a/tools/memory-model/scripts/checklitmushist.sh b/tools/memory-model/scripts/checklitmushist.sh
new file mode 100755
index 000000000..406ecfc0a
--- /dev/null
+++ b/tools/memory-model/scripts/checklitmushist.sh
@@ -0,0 +1,60 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Reruns the C-language litmus tests previously run that match the
+# specified criteria, and compares the result to that of the previous
+# runs from initlitmushist.sh and/or newlitmushist.sh.
+#
+# sh checklitmushist.sh
+#
+# Run from the Linux kernel tools/memory-model directory.
+# See scripts/parseargs.sh for list of arguments.
+#
+# Copyright IBM Corporation, 2018
+#
+# Author: Paul E. McKenney <paulmck@linux.ibm.com>
+
+. scripts/parseargs.sh
+
+T=/tmp/checklitmushist.sh.$$
+trap 'rm -rf $T' 0
+mkdir $T
+
+if test -d litmus
+then
+	:
+else
+	echo Run scripts/initlitmushist.sh first, need litmus repo.
+	exit 1
+fi
+
+# Create the results directory and populate it with subdirectories.
+# The initial output is created here to avoid clobbering the output
+# generated earlier.
+mkdir $T/results
+find litmus -type d -print | ( cd $T/results; sed -e 's/^/mkdir -p /' | sh )
+
+# Create the list of litmus tests already run, then remove those that
+# are excluded by this run's --procs argument.
+( cd $LKMM_DESTDIR; find litmus -name '*.litmus.out' -print ) |
+	sed -e 's/\.out$//' |
+	xargs -r grep -L "^P${LKMM_PROCS}"> $T/list-C-already
+xargs < $T/list-C-already -r grep -L "^P${LKMM_PROCS}" > $T/list-C-short
+
+# Redirect output, run tests, then restore destination directory.
+destdir="$LKMM_DESTDIR"
+LKMM_DESTDIR=$T/results; export LKMM_DESTDIR
+scripts/runlitmushist.sh < $T/list-C-short > $T/runlitmushist.sh.out 2>&1
+LKMM_DESTDIR="$destdir"; export LKMM_DESTDIR
+
+# Move the newly generated .litmus.out files to .litmus.out.new files
+# in the destination directory.
+cdir=`pwd`
+ddir=`awk -v c="$cdir" -v d="$LKMM_DESTDIR" \
+	'END { if (d ~ /^\//) print d; else print c "/" d; }' < /dev/null`
+( cd $T/results; find litmus -type f -name '*.litmus.out' -print |
+  sed -e 's,^.*$,cp & '"$ddir"'/&.new,' | sh )
+
+sed < $T/list-C-short -e 's,^,'"$LKMM_DESTDIR/"',' |
+	sh scripts/cmplitmushist.sh
+exit $?
diff --git a/tools/memory-model/scripts/checktheselitmus.sh b/tools/memory-model/scripts/checktheselitmus.sh
new file mode 100755
index 000000000..10eeb5ece
--- /dev/null
+++ b/tools/memory-model/scripts/checktheselitmus.sh
@@ -0,0 +1,43 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Invokes checklitmus.sh on its arguments to run the specified litmus
+# test and pass judgment on the results.
+#
+# Usage:
+#	checktheselitmus.sh -- [ file1.litmus [ file2.litmus ... ] ]
+#
+# Run this in the directory containing the memory model, specifying the
+# pathname of the litmus test to check.  The usual parseargs.sh arguments
+# can be specified prior to the "--".
+#
+# This script is intended for use with pathnames that start from the
+# tools/memory-model directory.  If some of the pathnames instead start at
+# the root directory, they all must do so and the "--destdir /" parseargs.sh
+# argument must be specified prior to the "--".  Alternatively, some other
+# "--destdir" argument can be supplied as long as the needed subdirectories
+# are populated.
+#
+# Copyright IBM Corporation, 2018
+#
+# Author: Paul E. McKenney <paulmck@linux.ibm.com>
+
+. scripts/parseargs.sh
+
+ret=0
+for i in "$@"
+do
+	if scripts/checklitmus.sh $i
+	then
+		:
+	else
+		ret=1
+	fi
+done
+if test "$ret" -ne 0
+then
+	echo " ^^^ VERIFICATION MISMATCHES" 1>&2
+else
+	echo All litmus tests verified as was expected. 1>&2
+fi
+exit $ret
diff --git a/tools/memory-model/scripts/cmplitmushist.sh b/tools/memory-model/scripts/cmplitmushist.sh
new file mode 100755
index 000000000..ca1ac8b64
--- /dev/null
+++ b/tools/memory-model/scripts/cmplitmushist.sh
@@ -0,0 +1,132 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Compares .out and .out.new files for each name on standard input,
+# one full pathname per line.  Outputs comparison results followed by
+# a summary.
+#
+# sh cmplitmushist.sh
+
+T=/tmp/cmplitmushist.sh.$$
+trap 'rm -rf $T' 0
+mkdir $T
+
+# comparetest oldpath newpath
+badmacnam=0
+timedout=0
+perfect=0
+obsline=0
+noobsline=0
+obsresult=0
+badcompare=0
+comparetest () {
+	if grep -q ': Unknown macro ' $1 || grep -q ': Unknown macro ' $2
+	then
+		if grep -q ': Unknown macro ' $1
+		then
+			badname=`grep ': Unknown macro ' $1 |
+				sed -e 's/^.*: Unknown macro //' |
+				sed -e 's/ (User error).*$//'`
+			echo 'Current LKMM version does not know "'$badname'"' $1
+		fi
+		if grep -q ': Unknown macro ' $2
+		then
+			badname=`grep ': Unknown macro ' $2 |
+				sed -e 's/^.*: Unknown macro //' |
+				sed -e 's/ (User error).*$//'`
+			echo 'Current LKMM version does not know "'$badname'"' $2
+		fi
+		badmacnam=`expr "$badmacnam" + 1`
+		return 0
+	elif grep -q '^Command exited with non-zero status 124' $1 ||
+	     grep -q '^Command exited with non-zero status 124' $2
+	then
+		if grep -q '^Command exited with non-zero status 124' $1 &&
+		   grep -q '^Command exited with non-zero status 124' $2
+		then
+			echo Both runs timed out: $2
+		elif grep -q '^Command exited with non-zero status 124' $1
+		then
+			echo Old run timed out: $2
+		elif grep -q '^Command exited with non-zero status 124' $2
+		then
+			echo New run timed out: $2
+		fi
+		timedout=`expr "$timedout" + 1`
+		return 0
+	fi
+	grep -v 'maxresident)k\|minor)pagefaults\|^Time' $1 > $T/oldout
+	grep -v 'maxresident)k\|minor)pagefaults\|^Time' $2 > $T/newout
+	if cmp -s $T/oldout $T/newout && grep -q '^Observation' $1
+	then
+		echo Exact output match: $2
+		perfect=`expr "$perfect" + 1`
+		return 0
+	fi
+
+	grep '^Observation' $1 > $T/oldout
+	grep '^Observation' $2 > $T/newout
+	if test -s $T/oldout -o -s $T/newout
+	then
+		if cmp -s $T/oldout $T/newout
+		then
+			echo Matching Observation result and counts: $2
+			obsline=`expr "$obsline" + 1`
+			return 0
+		fi
+	else
+		echo Missing Observation line "(e.g., syntax error)": $2
+		noobsline=`expr "$noobsline" + 1`
+		return 0
+	fi
+
+	grep '^Observation' $1 | awk '{ print $3 }' > $T/oldout
+	grep '^Observation' $2 | awk '{ print $3 }' > $T/newout
+	if cmp -s $T/oldout $T/newout
+	then
+		echo Matching Observation Always/Sometimes/Never result: $2
+		obsresult=`expr "$obsresult" + 1`
+		return 0
+	fi
+	echo ' !!!' Result changed: $2
+	badcompare=`expr "$badcompare" + 1`
+	return 1
+}
+
+sed -e 's/^.*$/comparetest &.out &.out.new/' > $T/cmpscript
+. $T/cmpscript > $T/cmpscript.out
+cat $T/cmpscript.out
+
+echo ' ---' Summary: 1>&2
+grep '!!!' $T/cmpscript.out 1>&2
+if test "$perfect" -ne 0
+then
+	echo Exact output matches: $perfect 1>&2
+fi
+if test "$obsline" -ne 0
+then
+	echo Matching Observation result and counts: $obsline 1>&2
+fi
+if test "$noobsline" -ne 0
+then
+	echo Missing Observation line "(e.g., syntax error)": $noobsline 1>&2
+fi
+if test "$obsresult" -ne 0
+then
+	echo Matching Observation Always/Sometimes/Never result: $obsresult 1>&2
+fi
+if test "$timedout" -ne 0
+then
+	echo "!!!" Timed out: $timedout 1>&2
+fi
+if test "$badmacnam" -ne 0
+then
+	echo "!!!" Unknown primitive: $badmacnam 1>&2
+fi
+if test "$badcompare" -ne 0
+then
+	echo "!!!" Result changed: $badcompare 1>&2
+	exit 1
+fi
+
+exit 0
diff --git a/tools/memory-model/scripts/hwfnseg.sh b/tools/memory-model/scripts/hwfnseg.sh
new file mode 100755
index 000000000..580c32811
--- /dev/null
+++ b/tools/memory-model/scripts/hwfnseg.sh
@@ -0,0 +1,20 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Generate the hardware extension to the litmus-test filename, or the
+# empty string if this is an LKMM run.  The extension is placed in
+# the shell variable hwfnseg.
+#
+# Usage:
+#	. hwfnseg.sh
+#
+# Copyright IBM Corporation, 2019
+#
+# Author: Paul E. McKenney <paulmck@linux.ibm.com>
+
+if test -z "$LKMM_HW_MAP_FILE"
+then
+	hwfnseg=
+else
+	hwfnseg=".$LKMM_HW_MAP_FILE"
+fi
diff --git a/tools/memory-model/scripts/initlitmushist.sh b/tools/memory-model/scripts/initlitmushist.sh
new file mode 100755
index 000000000..31ea78295
--- /dev/null
+++ b/tools/memory-model/scripts/initlitmushist.sh
@@ -0,0 +1,68 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Runs the C-language litmus tests matching the specified criteria.
+# Generates the output for each .litmus file into a corresponding
+# .litmus.out file, and does not judge the result.
+#
+# sh initlitmushist.sh
+#
+# Run from the Linux kernel tools/memory-model directory.
+# See scripts/parseargs.sh for list of arguments.
+#
+# This script can consume significant wallclock time and CPU, especially as
+# the value of --procs rises.  On a four-core (eight hardware threads)
+# 2.5GHz x86 with a one-minute per-run timeout:
+#
+# --procs wallclock CPU		timeouts	tests
+#	1 0m11.241s 0m1.086s           0	   19
+#	2 1m12.598s 2m8.459s           2	  393
+#	3 1m30.007s 6m2.479s           4	 2291
+#	4 3m26.042s 18m5.139s	       9	 3217
+#	5 4m26.661s 23m54.128s	      13	 3784
+#	6 4m41.900s 26m4.721s         13	 4352
+#	7 5m51.463s 35m50.868s        13	 4626
+#	8 10m5.235s 68m43.672s        34	 5117
+#	9 15m57.80s 105m58.101s       69	 5156
+#      10 16m14.13s 103m35.009s       69         5165
+#      20 27m48.55s 198m3.286s       156         5269
+#
+# Increasing the timeout on the 20-process run to five minutes increases
+# the runtime to about 90 minutes with the CPU time rising to about
+# 10 hours.  On the other hand, it decreases the number of timeouts to 101.
+#
+# Note that there are historical tests for which herd7 will fail
+# completely, for example, litmus/manual/atomic/C-unlock-wait-00.litmus
+# contains a call to spin_unlock_wait(), which no longer exists in either
+# the kernel or LKMM.
+
+. scripts/parseargs.sh
+
+T=/tmp/initlitmushist.sh.$$
+trap 'rm -rf $T' 0
+mkdir $T
+
+if test -d litmus
+then
+	:
+else
+	git clone https://github.com/paulmckrcu/litmus
+	( cd litmus; git checkout origin/master )
+fi
+
+# Create any new directories that have appeared in the github litmus
+# repo since the last run.
+if test "$LKMM_DESTDIR" != "."
+then
+	find litmus -type d -print |
+	( cd "$LKMM_DESTDIR"; sed -e 's/^/mkdir -p /' | sh )
+fi
+
+# Create a list of the C-language litmus tests with no more than the
+# specified number of processes (per the --procs argument).
+find litmus -name '*.litmus' -print | mselect7 -arch C > $T/list-C
+xargs < $T/list-C -r grep -L "^P${LKMM_PROCS}" > $T/list-C-short
+
+scripts/runlitmushist.sh < $T/list-C-short
+
+exit 0
diff --git a/tools/memory-model/scripts/judgelitmus.sh b/tools/memory-model/scripts/judgelitmus.sh
new file mode 100755
index 000000000..1ec5d89fc
--- /dev/null
+++ b/tools/memory-model/scripts/judgelitmus.sh
@@ -0,0 +1,156 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Given a .litmus test and the corresponding litmus output file, check
+# the .litmus.out file against the "Result:" comment to judge whether the
+# test ran correctly.  If the --hw argument is omitted, check against the
+# LKMM output, which is assumed to be in file.litmus.out. If either a
+# "DATARACE" marker in the "Result:" comment or a "Flag data-race" marker
+# in the LKMM output is present, the other must also be as well, at least
+# for litmus tests having a "Result:" comment. In this case, a failure of
+# the Always/Sometimes/Never portion of the "Result:" prediction will be
+# noted, but forgiven.
+#
+# If the --hw argument is provided, this is assumed to be a hardware
+# test, and the output is assumed to be in file.litmus.HW.out, where
+# "HW" is the --hw argument. In addition, non-Sometimes verification
+# results will be noted, but forgiven.  Furthermore, if there is no
+# "Result:" comment but there is an LKMM .litmus.out file, the observation
+# in that file will be used to judge the assembly-language verification.
+#
+# Usage:
+#	judgelitmus.sh file.litmus
+#
+# Run this in the directory containing the memory model, specifying the
+# pathname of the litmus test to check.
+#
+# Copyright IBM Corporation, 2018
+#
+# Author: Paul E. McKenney <paulmck@linux.ibm.com>
+
+litmus=$1
+
+if test -f "$litmus" -a -r "$litmus"
+then
+	:
+else
+	echo ' --- ' error: \"$litmus\" is not a readable file
+	exit 255
+fi
+if test -z "$LKMM_HW_MAP_FILE"
+then
+	litmusout=$litmus.out
+	lkmmout=
+else
+	litmusout="`echo $litmus |
+		sed -e 's/\.litmus$/.litmus.'${LKMM_HW_MAP_FILE}'/'`.out"
+	lkmmout=$litmus.out
+fi
+if test -f "$LKMM_DESTDIR/$litmusout" -a -r "$LKMM_DESTDIR/$litmusout"
+then
+	:
+else
+	echo ' --- ' error: \"$LKMM_DESTDIR/$litmusout is not a readable file
+	exit 255
+fi
+if grep -q '^Flag data-race$' "$LKMM_DESTDIR/$litmusout"
+then
+	datarace_modeled=1
+fi
+if grep -q '^[( ]\* Result: ' $litmus
+then
+	outcome=`grep -m 1 '^[( ]\* Result: ' $litmus | awk '{ print $3 }'`
+	if grep -m1 '^[( ]\* Result: .* DATARACE' $litmus
+	then
+		datarace_predicted=1
+	fi
+	if test -n "$datarace_predicted" -a -z "$datarace_modeled" -a -z "$LKMM_HW_MAP_FILE"
+	then
+		echo '!!! Predicted data race not modeled' $litmus
+		exit 252
+	elif test -z "$datarace_predicted" -a -n "$datarace_modeled"
+	then
+		# Note that hardware models currently don't model data races
+		echo '!!! Unexpected data race modeled' $litmus
+		exit 253
+	fi
+elif test -n "$LKMM_HW_MAP_FILE" && grep -q '^Observation' $LKMM_DESTDIR/$lkmmout > /dev/null 2>&1
+then
+	outcome=`grep -m 1 '^Observation ' $LKMM_DESTDIR/$lkmmout | awk '{ print $3 }'`
+else
+	outcome=specified
+fi
+
+grep '^Observation' $LKMM_DESTDIR/$litmusout
+if grep -q '^Observation' $LKMM_DESTDIR/$litmusout
+then
+	:
+elif grep ': Unknown macro ' $LKMM_DESTDIR/$litmusout
+then
+	badname=`grep ': Unknown macro ' $LKMM_DESTDIR/$litmusout |
+		sed -e 's/^.*: Unknown macro //' |
+		sed -e 's/ (User error).*$//'`
+	badmsg=' !!! Current LKMM version does not know "'$badname'"'" $litmus"
+	echo $badmsg
+	if ! grep -q '!!!' $LKMM_DESTDIR/$litmusout
+	then
+		echo ' !!! '$badmsg >> $LKMM_DESTDIR/$litmusout 2>&1
+	fi
+	exit 254
+elif grep '^Command exited with non-zero status 124' $LKMM_DESTDIR/$litmusout
+then
+	echo ' !!! Timeout' $litmus
+	if ! grep -q '!!!' $LKMM_DESTDIR/$litmusout
+	then
+		echo ' !!! Timeout' >> $LKMM_DESTDIR/$litmusout 2>&1
+	fi
+	exit 124
+else
+	echo ' !!! Verification error' $litmus
+	if ! grep -q '!!!' $LKMM_DESTDIR/$litmusout
+	then
+		echo ' !!! Verification error' >> $LKMM_DESTDIR/$litmusout 2>&1
+	fi
+	exit 255
+fi
+if test "$outcome" = DEADLOCK
+then
+	if grep '^Observation' $LKMM_DESTDIR/$litmusout | grep -q 'Never 0 0$'
+	then
+		ret=0
+	else
+		echo " !!! Unexpected non-$outcome verification" $litmus
+		if ! grep -q '!!!' $LKMM_DESTDIR/$litmusout
+		then
+			echo " !!! Unexpected non-$outcome verification" >> $LKMM_DESTDIR/$litmusout 2>&1
+		fi
+		ret=1
+	fi
+elif grep '^Observation' $LKMM_DESTDIR/$litmusout | grep -q 'Never 0 0$'
+then
+	echo " !!! Unexpected non-$outcome deadlock" $litmus
+	if ! grep -q '!!!' $LKMM_DESTDIR/$litmusout
+	then
+		echo " !!! Unexpected non-$outcome deadlock" $litmus >> $LKMM_DESTDIR/$litmusout 2>&1
+	fi
+	ret=1
+elif grep '^Observation' $LKMM_DESTDIR/$litmusout | grep -q $outcome || test "$outcome" = Maybe
+then
+	ret=0
+else
+	if test \( -n "$LKMM_HW_MAP_FILE" -a "$outcome" = Sometimes \) -o -n "$datarace_modeled"
+	then
+		flag="--- Forgiven"
+		ret=0
+	else
+		flag="!!! Unexpected"
+		ret=1
+	fi
+	echo " $flag non-$outcome verification" $litmus
+	if ! grep -qe "$flag" $LKMM_DESTDIR/$litmusout
+	then
+		echo " $flag non-$outcome verification" >> $LKMM_DESTDIR/$litmusout 2>&1
+	fi
+fi
+tail -2 $LKMM_DESTDIR/$litmusout | head -1
+exit $ret
diff --git a/tools/memory-model/scripts/newlitmushist.sh b/tools/memory-model/scripts/newlitmushist.sh
new file mode 100755
index 000000000..25235e204
--- /dev/null
+++ b/tools/memory-model/scripts/newlitmushist.sh
@@ -0,0 +1,61 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Runs the C-language litmus tests matching the specified criteria
+# that do not already have a corresponding .litmus.out file, and does
+# not judge the result.
+#
+# sh newlitmushist.sh
+#
+# Run from the Linux kernel tools/memory-model directory.
+# See scripts/parseargs.sh for list of arguments.
+#
+# Copyright IBM Corporation, 2018
+#
+# Author: Paul E. McKenney <paulmck@linux.ibm.com>
+
+. scripts/parseargs.sh
+
+T=/tmp/newlitmushist.sh.$$
+trap 'rm -rf $T' 0
+mkdir $T
+
+if test -d litmus
+then
+	:
+else
+	echo Run scripts/initlitmushist.sh first, need litmus repo.
+	exit 1
+fi
+
+# Create any new directories that have appeared in the github litmus
+# repo since the last run.
+if test "$LKMM_DESTDIR" != "."
+then
+	find litmus -type d -print |
+	( cd "$LKMM_DESTDIR"; sed -e 's/^/mkdir -p /' | sh )
+fi
+
+# Create a list of the C-language litmus tests previously run.
+( cd $LKMM_DESTDIR; find litmus -name '*.litmus.out' -print ) |
+	sed -e 's/\.out$//' |
+	xargs -r grep -L "^P${LKMM_PROCS}"> $T/list-C-already
+
+# Form full list of litmus tests with no more than the specified
+# number of processes (per the --procs argument).
+find litmus -name '*.litmus' -print | mselect7 -arch C > $T/list-C-all
+xargs < $T/list-C-all -r grep -L "^P${LKMM_PROCS}" > $T/list-C-short
+
+# Form list of new tests.  Note: This does not handle litmus-test deletion!
+sort $T/list-C-already $T/list-C-short | uniq -u > $T/list-C-new
+
+# Form list of litmus tests that have changed since the last run.
+sed < $T/list-C-short -e 's,^.*$,if test & -nt '"$LKMM_DESTDIR"'/&.out; then echo &; fi,' > $T/list-C-script
+sh $T/list-C-script > $T/list-C-newer
+
+# Merge the list of new and of updated litmus tests: These must be (re)run.
+sort -u $T/list-C-new $T/list-C-newer > $T/list-C-needed
+
+scripts/runlitmushist.sh < $T/list-C-needed
+
+exit 0
diff --git a/tools/memory-model/scripts/parseargs.sh b/tools/memory-model/scripts/parseargs.sh
new file mode 100755
index 000000000..08ded5909
--- /dev/null
+++ b/tools/memory-model/scripts/parseargs.sh
@@ -0,0 +1,147 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Parse arguments common to the various scripts.
+#
+# . scripts/parseargs.sh
+#
+# Include into other Linux kernel tools/memory-model scripts.
+#
+# Copyright IBM Corporation, 2018
+#
+# Author: Paul E. McKenney <paulmck@linux.ibm.com>
+
+T=/tmp/parseargs.sh.$$
+mkdir $T
+
+# Initialize one parameter: initparam name default
+initparam () {
+	echo if test -z '"$'$1'"' > $T/s
+	echo then >> $T/s
+	echo	$1='"'$2'"' >> $T/s
+	echo	export $1 >> $T/s
+	echo fi >> $T/s
+	echo $1_DEF='$'$1  >> $T/s
+	. $T/s
+}
+
+initparam LKMM_DESTDIR "."
+initparam LKMM_HERD_OPTIONS "-conf linux-kernel.cfg"
+initparam LKMM_HW_MAP_FILE ""
+initparam LKMM_JOBS `getconf _NPROCESSORS_ONLN`
+initparam LKMM_PROCS "3"
+initparam LKMM_TIMEOUT "1m"
+
+scriptname=$0
+
+usagehelp () {
+	echo "Usage $scriptname [ arguments ]"
+	echo "      --destdir path (place for .litmus.out, default by .litmus)"
+	echo "      --herdopts -conf linux-kernel.cfg ..."
+	echo "      --hw AArch64"
+	echo "      --jobs N (number of jobs, default one per CPU)"
+	echo "      --procs N (litmus tests with at most this many processes)"
+	echo "      --timeout N (herd7 timeout (e.g., 10s, 1m, 2hr, 1d, '')"
+	echo "Defaults: --destdir '$LKMM_DESTDIR_DEF' --herdopts '$LKMM_HERD_OPTIONS_DEF' --hw '$LKMM_HW_MAP_FILE' --jobs '$LKMM_JOBS_DEF' --procs '$LKMM_PROCS_DEF' --timeout '$LKMM_TIMEOUT_DEF'"
+	exit 1
+}
+
+usage () {
+	usagehelp 1>&2
+}
+
+# checkarg --argname argtype $# arg mustmatch cannotmatch
+checkarg () {
+	if test $3 -le 1
+	then
+		echo $1 needs argument $2 matching \"$5\"
+		usage
+	fi
+	if echo "$4" | grep -q -e "$5"
+	then
+		:
+	else
+		echo $1 $2 \"$4\" must match \"$5\"
+		usage
+	fi
+	if echo "$4" | grep -q -e "$6"
+	then
+		echo $1 $2 \"$4\" must not match \"$6\"
+		usage
+	fi
+}
+
+while test $# -gt 0
+do
+	case "$1" in
+	--destdir)
+		checkarg --destdir "(path to directory)" "$#" "$2" '.\+' '^--'
+		LKMM_DESTDIR="$2"
+		mkdir $LKMM_DESTDIR > /dev/null 2>&1
+		if ! test -e "$LKMM_DESTDIR"
+		then
+			echo "Cannot create directory --destdir '$LKMM_DESTDIR'"
+			usage
+		fi
+		if test -d "$LKMM_DESTDIR" -a -x "$LKMM_DESTDIR"
+		then
+			:
+		else
+			echo "Directory --destdir '$LKMM_DESTDIR' insufficient permissions to create files"
+			usage
+		fi
+		shift
+		;;
+	--herdopts|--herdopt)
+		checkarg --destdir "(herd7 options)" "$#" "$2" '.*' '^--'
+		LKMM_HERD_OPTIONS="$2"
+		shift
+		;;
+	--hw)
+		checkarg --hw "(.map file architecture name)" "$#" "$2" '^[A-Za-z0-9_-]\+' '^--'
+		LKMM_HW_MAP_FILE="$2"
+		shift
+		;;
+	-j[1-9]*)
+		njobs="`echo $1 | sed -e 's/^-j//'`"
+		trailchars="`echo $njobs | sed -e 's/[0-9]\+\(.*\)$/\1/'`"
+		if test -n "$trailchars"
+		then
+			echo $1 trailing characters "'$trailchars'"
+			usagehelp
+		fi
+		LKMM_JOBS="`echo $njobs | sed -e 's/^\([0-9]\+\).*$/\1/'`"
+		;;
+	--jobs|--job|-j)
+		checkarg --jobs "(number)" "$#" "$2" '^[1-9][0-9]*$' '^--'
+		LKMM_JOBS="$2"
+		shift
+		;;
+	--procs|--proc)
+		checkarg --procs "(number)" "$#" "$2" '^[0-9]\+$' '^--'
+		LKMM_PROCS="$2"
+		shift
+		;;
+	--timeout)
+		checkarg --timeout "(timeout spec)" "$#" "$2" '^\([0-9]\+[smhd]\?\|\)$' '^--'
+		LKMM_TIMEOUT="$2"
+		shift
+		;;
+	--)
+		shift
+		break
+		;;
+	*)
+		echo Unknown argument $1
+		usage
+		;;
+	esac
+	shift
+done
+if test -z "$LKMM_TIMEOUT"
+then
+	LKMM_TIMEOUT_CMD=""; export LKMM_TIMEOUT_CMD
+else
+	LKMM_TIMEOUT_CMD="timeout $LKMM_TIMEOUT"; export LKMM_TIMEOUT_CMD
+fi
+rm -rf $T
diff --git a/tools/memory-model/scripts/runlitmus.sh b/tools/memory-model/scripts/runlitmus.sh
new file mode 100755
index 000000000..94608d4b6
--- /dev/null
+++ b/tools/memory-model/scripts/runlitmus.sh
@@ -0,0 +1,80 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Without the -hw argument, runs a herd7 test and outputs verification
+# results to a file whose name is that of the specified litmus test,
+# but with ".out" appended.
+#
+# If the --hw argument is specified, this script translates the .litmus
+# C-language file to the specified type of assembly and verifies that.
+# But in this case, litmus tests using complex synchronization (such as
+# locking, RCU, and SRCU) are cheerfully ignored.
+#
+# Either way, return the status of the herd7 command.
+#
+# Usage:
+#	runlitmus.sh file.litmus
+#
+# Run this in the directory containing the memory model, specifying the
+# pathname of the litmus test to check.  The caller is expected to have
+# properly set up the LKMM environment variables.
+#
+# Copyright IBM Corporation, 2019
+#
+# Author: Paul E. McKenney <paulmck@linux.ibm.com>
+
+litmus=$1
+if test -f "$litmus" -a -r "$litmus"
+then
+	:
+else
+	echo ' !!! ' error: \"$litmus\" is not a readable file
+	exit 255
+fi
+
+if test -z "$LKMM_HW_MAP_FILE" -o ! -e $LKMM_DESTDIR/$litmus.out
+then
+	# LKMM run
+	herdoptions=${LKMM_HERD_OPTIONS--conf linux-kernel.cfg}
+	echo Herd options: $herdoptions > $LKMM_DESTDIR/$litmus.out
+	/usr/bin/time $LKMM_TIMEOUT_CMD herd7 $herdoptions $litmus >> $LKMM_DESTDIR/$litmus.out 2>&1
+	ret=$?
+	if test -z "$LKMM_HW_MAP_FILE"
+	then
+		exit $ret
+	fi
+	echo " --- " Automatically generated LKMM output for '"'--hw $LKMM_HW_MAP_FILE'"' run
+fi
+
+# Hardware run
+
+T=/tmp/checklitmushw.sh.$$
+trap 'rm -rf $T' 0 2
+mkdir $T
+
+# Generate filenames
+mapfile="Linux2${LKMM_HW_MAP_FILE}.map"
+themefile="$T/${LKMM_HW_MAP_FILE}.theme"
+herdoptions="-model $LKMM_HW_CAT_FILE"
+hwlitmus=`echo $litmus | sed -e 's/\.litmus$/.litmus.'${LKMM_HW_MAP_FILE}'/'`
+hwlitmusfile=`echo $hwlitmus | sed -e 's,^.*/,,'`
+
+# Don't run on litmus tests with complex synchronization
+if ! scripts/simpletest.sh $litmus
+then
+	echo ' --- ' error: \"$litmus\" contains locking, RCU, or SRCU
+	exit 254
+fi
+
+# Generate the assembly code and run herd7 on it.
+gen_theme7 -n 10 -map $mapfile -call Linux.call > $themefile
+jingle7 -v -theme $themefile $litmus > $LKMM_DESTDIR/$hwlitmus 2> $T/$hwlitmusfile.jingle7.out
+if grep -q "Generated 0 tests" $T/$hwlitmusfile.jingle7.out
+then
+	echo ' !!! ' jingle7 failed, errors in $hwlitmus.err
+	cp $T/$hwlitmusfile.jingle7.out $LKMM_DESTDIR/$hwlitmus.err
+	exit 253
+fi
+/usr/bin/time $LKMM_TIMEOUT_CMD herd7 -unroll 0 $LKMM_DESTDIR/$hwlitmus > $LKMM_DESTDIR/$hwlitmus.out 2>&1
+
+exit $?
diff --git a/tools/memory-model/scripts/runlitmushist.sh b/tools/memory-model/scripts/runlitmushist.sh
new file mode 100755
index 000000000..c6c2bdc67
--- /dev/null
+++ b/tools/memory-model/scripts/runlitmushist.sh
@@ -0,0 +1,94 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Runs the C-language litmus tests specified on standard input, using up
+# to the specified number of CPUs (defaulting to all of them) and placing
+# the results in the specified directory (defaulting to the same place
+# the litmus test came from).
+#
+# sh runlitmushist.sh
+#
+# Run from the Linux kernel tools/memory-model directory.
+# This script uses environment variables produced by parseargs.sh.
+#
+# Copyright IBM Corporation, 2018
+#
+# Author: Paul E. McKenney <paulmck@linux.ibm.com>
+
+. scripts/hwfnseg.sh
+
+T=/tmp/runlitmushist.sh.$$
+trap 'rm -rf $T' 0
+mkdir $T
+
+if test -d litmus
+then
+	:
+else
+	echo Directory \"litmus\" missing, aborting run.
+	exit 1
+fi
+
+# Prefixes for per-CPU scripts
+for ((i=0;i<$LKMM_JOBS;i++))
+do
+	echo T=$T >> $T/$i.sh
+	cat << '___EOF___' >> $T/$i.sh
+	runtest () {
+		if scripts/runlitmus.sh $1
+		then
+			if ! grep -q '^Observation ' $LKMM_DESTDIR/$1$2.out
+			then
+				echo ' !!! Herd failed, no Observation:' $1
+			fi
+		else
+			exitcode=$?
+			if test "$exitcode" -eq 124
+			then
+				exitmsg="timed out"
+			elif test "$exitcode" -eq 253
+			then
+				exitmsg=
+			else
+				exitmsg="failed, exit code $exitcode"
+			fi
+			if test -n "$exitmsg"
+			then
+				echo ' !!! Herd' ${exitmsg}: $1
+			fi
+		fi
+	}
+___EOF___
+done
+
+awk -v q="'" -v b='\\' '
+{
+	print "echo `grep " q "^P[0-9]" b "+(" q " " $0 " | tail -1 | sed -e " q "s/^P" b "([0-9]" b "+" b ")(.*$/" b "1/" q "` " $0
+}' | sh | sort -k1n |
+awk -v dq='"' -v hwfnseg="$hwfnseg" -v ncpu="$LKMM_JOBS" -v t="$T" '
+{
+	print "if test -z " dq hwfnseg dq " || scripts/simpletest.sh " dq $2 dq
+	print "then"
+	print "\techo runtest " dq $2 dq " " hwfnseg " >> " t "/" NR % ncpu ".sh";
+	print "fi"
+}
+
+END {
+	for (i = 0; i < ncpu; i++) {
+		print "sh " t "/" i ".sh > " t "/" i ".sh.out 2>&1 &";
+		close(t "/" i ".sh");
+	}
+	print "wait";
+}' | sh
+cat $T/*.sh.out
+if grep -q '!!!' $T/*.sh.out
+then
+	echo ' ---' Summary: 1>&2
+	grep '!!!' $T/*.sh.out 1>&2
+	nfail="`grep '!!!' $T/*.sh.out | wc -l`"
+	echo 'Number of failed herd7 runs (e.g., timeout): ' $nfail 1>&2
+	exit 1
+else
+	echo All runs completed successfully. 1>&2
+	exit 0
+fi
diff --git a/tools/memory-model/scripts/simpletest.sh b/tools/memory-model/scripts/simpletest.sh
new file mode 100755
index 000000000..7edc5d361
--- /dev/null
+++ b/tools/memory-model/scripts/simpletest.sh
@@ -0,0 +1,35 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Give zero status if this is a simple test and non-zero otherwise.
+# Simple tests do not contain locking, RCU, or SRCU.
+#
+# Usage:
+#	simpletest.sh file.litmus
+#
+# Copyright IBM Corporation, 2019
+#
+# Author: Paul E. McKenney <paulmck@linux.ibm.com>
+
+
+litmus=$1
+
+if test -f "$litmus" -a -r "$litmus"
+then
+	:
+else
+	echo ' --- ' error: \"$litmus\" is not a readable file
+	exit 255
+fi
+exclude="^[[:space:]]*\("
+exclude="${exclude}spin_lock(\|spin_unlock(\|spin_trylock(\|spin_is_locked("
+exclude="${exclude}\|rcu_read_lock(\|rcu_read_unlock("
+exclude="${exclude}\|synchronize_rcu(\|synchronize_rcu_expedited("
+exclude="${exclude}\|srcu_read_lock(\|srcu_read_unlock("
+exclude="${exclude}\|synchronize_srcu(\|synchronize_srcu_expedited("
+exclude="${exclude}\)"
+if grep -q $exclude $litmus
+then
+	exit 255
+fi
+exit 0