From e0e2147c1a6a722f6b2e359c5132a825ecb8a420 Mon Sep 17 00:00:00 2001
From: "Joel Fernandes (Google)" <joel@joelfernandes.org>
Date: Tue, 26 Mar 2019 15:24:10 -0400
Subject: rcutorture: Select from only online CPUs

The rcutorture jitter.sh script selects a random CPU but does not check
if it is offline or online. This leads to taskset errors many times. On
my machine, hyper threading is disabled so half the cores are offline
causing taskset errors a lot of times. Let us fix this by checking from
only the online CPUs on the system.

Cc: rcu@vger.kernel.org
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
 tools/testing/selftests/rcutorture/bin/jitter.sh | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

(limited to 'tools/testing')

diff --git a/tools/testing/selftests/rcutorture/bin/jitter.sh b/tools/testing/selftests/rcutorture/bin/jitter.sh
index 435b60933985..81c6e6ab5d83 100755
--- a/tools/testing/selftests/rcutorture/bin/jitter.sh
+++ b/tools/testing/selftests/rcutorture/bin/jitter.sh
@@ -34,10 +34,11 @@ do
 		exit 0;
 	fi
 
-	# Set affinity to randomly selected CPU
-	cpus=`ls /sys/devices/system/cpu/*/online |
+	# Set affinity to randomly selected online CPU
+	cpus=`grep 1 /sys/devices/system/cpu/*/online |
 		sed -e 's,/[^/]*$,,' -e 's/^[^0-9]*//' |
 		grep -v '^0*$'`
+
 	cpumask=`awk -v cpus="$cpus" -v me=$me -v n=$n 'BEGIN {
 		srand(n + me + systime());
 		ncpus = split(cpus, ca);
-- 
cgit v1.2.3


From dd064c35991435efc4da2a6c551601f6e80f2611 Mon Sep 17 00:00:00 2001
From: "Joel Fernandes (Google)" <joel@joelfernandes.org>
Date: Tue, 26 Mar 2019 15:24:11 -0400
Subject: rcutorture: Add cpu0 to the set of CPUs to add jitter

jitter.sh currently does not add CPU0 to the list of CPUs for adding of
jitter. Let us add it to this list even when it is not hot-pluggable.

Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
 tools/testing/selftests/rcutorture/bin/jitter.sh | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

(limited to 'tools/testing')

diff --git a/tools/testing/selftests/rcutorture/bin/jitter.sh b/tools/testing/selftests/rcutorture/bin/jitter.sh
index 81c6e6ab5d83..dc49a3ba6111 100755
--- a/tools/testing/selftests/rcutorture/bin/jitter.sh
+++ b/tools/testing/selftests/rcutorture/bin/jitter.sh
@@ -36,8 +36,12 @@ do
 
 	# Set affinity to randomly selected online CPU
 	cpus=`grep 1 /sys/devices/system/cpu/*/online |
-		sed -e 's,/[^/]*$,,' -e 's/^[^0-9]*//' |
-		grep -v '^0*$'`
+		sed -e 's,/[^/]*$,,' -e 's/^[^0-9]*//'`
+
+	# Do not leave out poor old cpu0 which may not be hot-pluggable
+	if [ ! -f "/sys/devices/system/cpu/cpu0/online" ]; then
+		cpus="0 $cpus"
+	fi
 
 	cpumask=`awk -v cpus="$cpus" -v me=$me -v n=$n 'BEGIN {
 		srand(n + me + systime());
-- 
cgit v1.2.3


From 63b29eaed6f57c27639b2954ac1f202409840abf Mon Sep 17 00:00:00 2001
From: "Paul E. McKenney" <paulmck@linux.ibm.com>
Date: Thu, 11 Apr 2019 13:31:57 -0700
Subject: torture: Make kvm-find-errors.sh and kvm-recheck.sh provide exit
 status

This commit causes both kvm-find-errors.sh and kvm-recheck.sh to provide
an exit status based on whether or not errors were located.  In the
case of kvm-recheck.sh, this will be the error status of the last run.
This change allows these commands to be used in scripting and Makefiles
to automatically report failed rcutorture runs.

Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
 tools/testing/selftests/rcutorture/bin/kvm-find-errors.sh | 3 +++
 tools/testing/selftests/rcutorture/bin/kvm-recheck.sh     | 3 +++
 2 files changed, 6 insertions(+)

(limited to 'tools/testing')

diff --git a/tools/testing/selftests/rcutorture/bin/kvm-find-errors.sh b/tools/testing/selftests/rcutorture/bin/kvm-find-errors.sh
index 8426fe1f15ee..1871d00bccd7 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-find-errors.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-find-errors.sh
@@ -11,6 +11,7 @@
 #
 # The "directory" above should end with the date/time directory, for example,
 # "tools/testing/selftests/rcutorture/res/2018.02.25-14:27:27".
+# Returns error status reflecting the success (or not) of the specified run.
 #
 # Copyright (C) IBM Corporation, 2018
 #
@@ -56,6 +57,8 @@ done
 if test -n "$files"
 then
 	$editor $files
+	exit 1
 else
 	echo No errors in console logs.
+	exit 0
 fi
diff --git a/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh b/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh
index 2adde6aaafdb..2297ddc2d4c5 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh
@@ -7,6 +7,8 @@
 #
 # Usage: kvm-recheck.sh resdir ...
 #
+# Returns status reflecting the success or not of the last run specified.
+#
 # Copyright (C) IBM Corporation, 2011
 #
 # Authors: Paul E. McKenney <paulmck@linux.ibm.com>
@@ -58,3 +60,4 @@ do
 		fi
 	done
 done
+EDITOR=echo kvm-find-errors.sh "${@: -1}" > /dev/null 2>&1
-- 
cgit v1.2.3


From 2456a8562b296453b4cdce8b6928e3f91e39fefc Mon Sep 17 00:00:00 2001
From: "Paul E. McKenney" <paulmck@linux.ibm.com>
Date: Thu, 11 Apr 2019 14:51:13 -0700
Subject: rcutorture: Provide rudimentary Makefile

This commit provides a rudimentary Makefile that runs a 10-minute
rcutorture test on scenario TREE01.  This must be run on a system capable
of spawning virtual machines and with everything installed to permit
building Linux kernels.

Reported-by: Shuah Khan <shuah@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
 tools/testing/selftests/rcutorture/Makefile | 3 +++
 1 file changed, 3 insertions(+)
 create mode 100644 tools/testing/selftests/rcutorture/Makefile

(limited to 'tools/testing')

diff --git a/tools/testing/selftests/rcutorture/Makefile b/tools/testing/selftests/rcutorture/Makefile
new file mode 100644
index 000000000000..5202dc666206
--- /dev/null
+++ b/tools/testing/selftests/rcutorture/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0+
+all:
+	( cd ../../../..; tools/testing/selftests/rcutorture/bin/kvm.sh --duration 10 --configs TREE01 )
-- 
cgit v1.2.3


From 52b23be7ee023d7f1b67e7a20443ef352c7b5d2d Mon Sep 17 00:00:00 2001
From: "Paul E. McKenney" <paulmck@linux.ibm.com>
Date: Sat, 13 Apr 2019 15:41:49 -0700
Subject: rcutorture: Exempt TREE01 from forward-progress testing

Because TREE01 can end up running more vCPUs that physical CPUs,
hammering these shortchanged CPUs with tight loops containing call_rcu()
invocations seems a bit like overkill.  This commit therefore exempts
TREE01 from rcutorture's forward-progress testing.

Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
 tools/testing/selftests/rcutorture/configs/rcu/TREE01.boot | 1 +
 1 file changed, 1 insertion(+)

(limited to 'tools/testing')

diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE01.boot b/tools/testing/selftests/rcutorture/configs/rcu/TREE01.boot
index ea47da95374b..d6da9a61d44a 100644
--- a/tools/testing/selftests/rcutorture/configs/rcu/TREE01.boot
+++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE01.boot
@@ -3,3 +3,4 @@ rcutree.gp_preinit_delay=3
 rcutree.gp_init_delay=3
 rcutree.gp_cleanup_delay=3
 rcu_nocbs=0
+rcutorture.fwd_progress=0
-- 
cgit v1.2.3


From c682db558e6eec10a711b0a6bcb8c35fd15f6a39 Mon Sep 17 00:00:00 2001
From: "Paul E. McKenney" <paulmck@linux.ibm.com>
Date: Fri, 19 Apr 2019 07:38:27 -0700
Subject: rcutorture: Add trivial RCU implementation

I have been showing off a trivial RCU implementation for non-preemptive
environments for some time now:

	#define rcu_read_lock()
	#define rcu_read_unlock()
	#define rcu_dereference(p) READ_ONCE(p)
	#define rcu_assign_pointer(p, v) smp_store_release(&(p), (v))
	void synchronize_rcu(void)
	{
	int cpu;
		for_each_online_cpu(cpu)
			sched_setaffinity(current->pid, cpumask_of(cpu));
	}

Trivial or not, as the old saying goes, "if it ain't tested, it don't
work!".  This commit therefore adds a "trivial" flavor to rcutorture
and a corresponding TRIVIAL test scenario.  This variant does not handle
CPU hotplug, which is unconditionally enabled on x86 for post-v5.1-rc3
kernels, which is why the TRIVIAL.boot says "rcutorture.onoff_interval=0".
This commit actually does handle CONFIG_PREEMPT=y kernels, but only
because it turns back the Linux-kernel clock in order to provide these
alternative definitions (or the moral equivalent thereof):

	#define rcu_read_lock() preempt_disable()
	#define rcu_read_unlock() preempt_enable()

In CONFIG_PREEMPT=n kernels without debugging, these are equivalent to
empty macros give or take a compiler barrier.  However, the have been
successfully tested with actual empty macros as well.

Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
[ paulmck: Fix symbol issue reported by kbuild test robot <lkp@intel.com>. ]
[ paulmck: Work around sched_setaffinity() issue noted by Andrea Parri. ]
[ paulmck: Add rcutorture.shuffle_interval=0 to TRIVIAL.boot to fix
  interaction with shuffler task noted by Peter Zijlstra. ]
Tested-by: Andrea Parri <andrea.parri@amarulasolutions.com>
---
 kernel/rcu/rcu.h                                   |  5 +++
 kernel/rcu/rcutorture.c                            | 45 +++++++++++++++++++++-
 kernel/rcu/update.c                                | 13 +++++++
 .../selftests/rcutorture/configs/rcu/TRIVIAL       | 14 +++++++
 .../selftests/rcutorture/configs/rcu/TRIVIAL.boot  |  3 ++
 5 files changed, 79 insertions(+), 1 deletion(-)
 create mode 100644 tools/testing/selftests/rcutorture/configs/rcu/TRIVIAL
 create mode 100644 tools/testing/selftests/rcutorture/configs/rcu/TRIVIAL.boot

(limited to 'tools/testing')

diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h
index 390aab20115e..5290b01de534 100644
--- a/kernel/rcu/rcu.h
+++ b/kernel/rcu/rcu.h
@@ -446,6 +446,7 @@ void rcu_request_urgent_qs_task(struct task_struct *t);
 enum rcutorture_type {
 	RCU_FLAVOR,
 	RCU_TASKS_FLAVOR,
+	RCU_TRIVIAL_FLAVOR,
 	SRCU_FLAVOR,
 	INVALID_RCU_FLAVOR
 };
@@ -479,6 +480,10 @@ void do_trace_rcu_torture_read(const char *rcutorturename,
 #endif
 #endif
 
+#if IS_ENABLED(CONFIG_RCU_TORTURE_TEST) || IS_MODULE(CONFIG_RCU_TORTURE_TEST)
+long rcutorture_sched_setaffinity(pid_t pid, const struct cpumask *in_mask);
+#endif
+
 #ifdef CONFIG_TINY_SRCU
 
 static inline void srcutorture_get_gp_data(enum rcutorture_type test_type,
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index a3f5488a319a..6b803fb2f7ca 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -672,6 +672,47 @@ static struct rcu_torture_ops tasks_ops = {
 	.name		= "tasks"
 };
 
+/*
+ * Definitions for trivial CONFIG_PREEMPT=n-only torture testing.
+ * This implementation does not necessarily work well with CPU hotplug.
+ */
+
+static void synchronize_rcu_trivial(void)
+{
+	int cpu;
+
+	for_each_online_cpu(cpu) {
+		rcutorture_sched_setaffinity(current->pid, cpumask_of(cpu));
+		WARN_ON_ONCE(raw_smp_processor_id() != cpu);
+	}
+}
+
+static int rcu_torture_read_lock_trivial(void) __acquires(RCU)
+{
+	preempt_disable();
+	return 0;
+}
+
+static void rcu_torture_read_unlock_trivial(int idx) __releases(RCU)
+{
+	preempt_enable();
+}
+
+static struct rcu_torture_ops trivial_ops = {
+	.ttype		= RCU_TRIVIAL_FLAVOR,
+	.init		= rcu_sync_torture_init,
+	.readlock	= rcu_torture_read_lock_trivial,
+	.read_delay	= rcu_read_delay,  /* just reuse rcu's version. */
+	.readunlock	= rcu_torture_read_unlock_trivial,
+	.get_gp_seq	= rcu_no_completed,
+	.sync		= synchronize_rcu_trivial,
+	.exp_sync	= synchronize_rcu_trivial,
+	.fqs		= NULL,
+	.stats		= NULL,
+	.irq_capable	= 1,
+	.name		= "trivial"
+};
+
 static unsigned long rcutorture_seq_diff(unsigned long new, unsigned long old)
 {
 	if (!cur_ops->gp_diff)
@@ -1789,6 +1830,8 @@ static void rcu_torture_fwd_prog_cr(void)
 
 	if (READ_ONCE(rcu_fwd_emergency_stop))
 		return; /* Get out of the way quickly, no GP wait! */
+	if (!cur_ops->call)
+		return; /* Can't do call_rcu() fwd prog without ->call. */
 
 	/* Loop continuously posting RCU callbacks. */
 	WRITE_ONCE(rcu_fwd_cb_nodelay, true);
@@ -2265,7 +2308,7 @@ rcu_torture_init(void)
 	int firsterr = 0;
 	static struct rcu_torture_ops *torture_ops[] = {
 		&rcu_ops, &rcu_busted_ops, &srcu_ops, &srcud_ops,
-		&busted_srcud_ops, &tasks_ops,
+		&busted_srcud_ops, &tasks_ops, &trivial_ops,
 	};
 
 	if (!torture_init_begin(torture_type, verbose))
diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c
index c3bf44ba42e5..61df2bf08563 100644
--- a/kernel/rcu/update.c
+++ b/kernel/rcu/update.c
@@ -423,6 +423,19 @@ EXPORT_SYMBOL_GPL(do_trace_rcu_torture_read);
 	do { } while (0)
 #endif
 
+#if IS_ENABLED(CONFIG_RCU_TORTURE_TEST) || IS_MODULE(CONFIG_RCU_TORTURE_TEST)
+/* Get rcutorture access to sched_setaffinity(). */
+long rcutorture_sched_setaffinity(pid_t pid, const struct cpumask *in_mask)
+{
+	int ret;
+
+	ret = sched_setaffinity(pid, in_mask);
+	WARN_ONCE(ret, "%s: sched_setaffinity() returned %d\n", __func__, ret);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(rcutorture_sched_setaffinity);
+#endif
+
 #ifdef CONFIG_RCU_STALL_COMMON
 int rcu_cpu_stall_suppress __read_mostly; /* 1 = suppress stall warnings. */
 EXPORT_SYMBOL_GPL(rcu_cpu_stall_suppress);
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TRIVIAL b/tools/testing/selftests/rcutorture/configs/rcu/TRIVIAL
new file mode 100644
index 000000000000..4d8eb5bfb6f6
--- /dev/null
+++ b/tools/testing/selftests/rcutorture/configs/rcu/TRIVIAL
@@ -0,0 +1,14 @@
+CONFIG_SMP=y
+CONFIG_NR_CPUS=8
+CONFIG_PREEMPT_NONE=y
+CONFIG_PREEMPT_VOLUNTARY=n
+CONFIG_PREEMPT=n
+CONFIG_HZ_PERIODIC=n
+CONFIG_NO_HZ_IDLE=y
+CONFIG_NO_HZ_FULL=n
+CONFIG_HOTPLUG_CPU=n
+CONFIG_SUSPEND=n
+CONFIG_HIBERNATION=n
+CONFIG_DEBUG_LOCK_ALLOC=n
+CONFIG_DEBUG_OBJECTS_RCU_HEAD=n
+CONFIG_RCU_EXPERT=y
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TRIVIAL.boot b/tools/testing/selftests/rcutorture/configs/rcu/TRIVIAL.boot
new file mode 100644
index 000000000000..7017f5f5a55f
--- /dev/null
+++ b/tools/testing/selftests/rcutorture/configs/rcu/TRIVIAL.boot
@@ -0,0 +1,3 @@
+rcutorture.torture_type=trivial
+rcutorture.onoff_interval=0
+rcutorture.shuffle_interval=0
-- 
cgit v1.2.3


From a6fda6dab93c2c06ef4b8cb4b9258df6674d2438 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Wed, 24 Apr 2019 09:34:46 +0200
Subject: rcutorture: Tweak kvm options

In one of my rcutorture tests the TSC clocksource got marked unstable
due to a large difference in the TSC value. I'm not sure if the guest
run for a long time with disabled interrupts or if the host was very
busy and didn't schedule the guest for some time.

I took a look on the qemu/KVM options and decided to update the options:

- Use kvm{32|64} as CPU. We could probably use `host' (like ARM does)
  for maximum available features but since we don't run any userland I'm
  not sure if it makes any difference.

- Drop the "noapic" option. There is no history why the APIC was disabled,
  I see no reason for it.  Once old qemu versions fade away, we can add
  "x2apic=on,tsc-deadline=on,hypervisor=on,tsc_adjust=on".

- Additional config options. It ensures that the kernel knowns that it
  runs as a kvm guest and can use virt devices like the kvm-clock as
  clocksource. The kvm-clock was the main motivation here.

- I didn't add a random HW device. It would make the random device ready
  earlier (not it doesn't complete the initialisation at all) but I
  doubt that there is any need for this.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
[ paulmck: The world is not quite ready for CONFIG_PARAVIRT_SPINLOCKS=y
  and x2apic, so they are omitted for the time being. ]
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
 tools/testing/selftests/rcutorture/bin/functions.sh     | 13 ++++++++++++-
 tools/testing/selftests/rcutorture/configs/rcu/CFcommon |  3 +++
 2 files changed, 15 insertions(+), 1 deletion(-)

(limited to 'tools/testing')

diff --git a/tools/testing/selftests/rcutorture/bin/functions.sh b/tools/testing/selftests/rcutorture/bin/functions.sh
index 6bcb8b5b2ff2..c3a49fb4d6f6 100644
--- a/tools/testing/selftests/rcutorture/bin/functions.sh
+++ b/tools/testing/selftests/rcutorture/bin/functions.sh
@@ -172,7 +172,7 @@ identify_qemu_append () {
 	local console=ttyS0
 	case "$1" in
 	qemu-system-x86_64|qemu-system-i386)
-		echo noapic selinux=0 initcall_debug debug
+		echo selinux=0 initcall_debug debug
 		;;
 	qemu-system-aarch64)
 		console=ttyAMA0
@@ -191,8 +191,19 @@ identify_qemu_append () {
 # Output arguments for qemu arguments based on the TORTURE_QEMU_MAC
 # and TORTURE_QEMU_INTERACTIVE environment variables.
 identify_qemu_args () {
+	local KVM_CPU=""
+	case "$1" in
+	qemu-system-x86_64)
+		KVM_CPU=kvm64
+		;;
+	qemu-system-i386)
+		KVM_CPU=kvm32
+		;;
+	esac
 	case "$1" in
 	qemu-system-x86_64|qemu-system-i386)
+		echo -machine q35,accel=kvm
+		echo -cpu ${KVM_CPU}
 		;;
 	qemu-system-aarch64)
 		echo -machine virt,gic-version=host -cpu host
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/CFcommon b/tools/testing/selftests/rcutorture/configs/rcu/CFcommon
index d2d2a86139db..e19a444a0684 100644
--- a/tools/testing/selftests/rcutorture/configs/rcu/CFcommon
+++ b/tools/testing/selftests/rcutorture/configs/rcu/CFcommon
@@ -1,2 +1,5 @@
 CONFIG_RCU_TORTURE_TEST=y
 CONFIG_PRINTK_TIME=y
+CONFIG_HYPERVISOR_GUEST=y
+CONFIG_PARAVIRT=y
+CONFIG_KVM_GUEST=y
-- 
cgit v1.2.3


From 7dedfd4335f7b795d12191d03626212ff71e52aa Mon Sep 17 00:00:00 2001
From: "Paul E. McKenney" <paulmck@linux.ibm.com>
Date: Wed, 24 Apr 2019 04:39:10 -0700
Subject: torture: Capture qemu output

Currently qemu output appears on standard output, but is inaccessible
later on.  This commit therefore captures this output and causes
kvm-recheck.sh to output this output if QEMU gave a non-zero non-137
exit code.  (And exit code of 137 indicates that QEMU was killed, in
which case we want to know about the hang rather than the fact that
QEMU was killed.)

Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
 tools/testing/selftests/rcutorture/bin/kvm-recheck.sh    | 10 +++++++++-
 tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh |  2 +-
 2 files changed, 10 insertions(+), 2 deletions(-)

(limited to 'tools/testing')

diff --git a/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh b/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh
index 2297ddc2d4c5..e5edd5198725 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh
@@ -30,8 +30,16 @@ do
 		TORTURE_SUITE="`cat $i/../TORTURE_SUITE`"
 		rm -f $i/console.log.*.diags
 		kvm-recheck-${TORTURE_SUITE}.sh $i
-		if test -f "$i/console.log"
+		if test -f "$i/qemu-retval" && test "`cat $i/qemu-retval`" -ne 0 && test "`cat $i/qemu-retval`" -ne 137
 		then
+			echo QEMU error, output:
+			cat $i/qemu-output
+		elif test -f "$i/console.log"
+		then
+			if test -f "$i/qemu-retval" && test "`cat $i/qemu-retval`" -eq 137
+			then
+				echo QEMU killed
+			fi
 			configcheck.sh $i/.config $i/ConfigFragment
 			if test -r $i/Make.oldconfig.err
 			then
diff --git a/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh b/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
index 0eb1ec16d78a..003511494fd9 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
@@ -165,7 +165,7 @@ then
 fi
 echo "NOTE: $QEMU either did not run or was interactive" > $resdir/console.log
 echo $QEMU $qemu_args -m $TORTURE_QEMU_MEM -kernel $KERNEL -append \"$qemu_append $boot_args\" > $resdir/qemu-cmd
-( $QEMU $qemu_args -m $TORTURE_QEMU_MEM -kernel $KERNEL -append "$qemu_append $boot_args"& echo $! > $resdir/qemu_pid; wait `cat  $resdir/qemu_pid`; echo $? > $resdir/qemu-retval ) &
+( $QEMU $qemu_args -m $TORTURE_QEMU_MEM -kernel $KERNEL -append "$qemu_append $boot_args" > $resdir/qemu-output 2>&1 & echo $! > $resdir/qemu_pid; wait `cat  $resdir/qemu_pid`; echo $? > $resdir/qemu-retval ) &
 commandcompleted=0
 sleep 10 # Give qemu's pid a chance to reach the file
 if test -s "$resdir/qemu_pid"
-- 
cgit v1.2.3


From cd6cb7c8a509b1e785fa67e2eb6bd5003198ac39 Mon Sep 17 00:00:00 2001
From: "Paul E. McKenney" <paulmck@linux.ibm.com>
Date: Wed, 1 May 2019 13:26:11 -0700
Subject: torture: Add function graph-tracing cheat sheet

Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
 tools/testing/selftests/rcutorture/bin/kvm.sh | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'tools/testing')

diff --git a/tools/testing/selftests/rcutorture/bin/kvm.sh b/tools/testing/selftests/rcutorture/bin/kvm.sh
index 8f1e337b9b54..3b4868906794 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm.sh
@@ -464,3 +464,5 @@ else
 fi
 
 # Tracing: trace_event=rcu:rcu_grace_period,rcu:rcu_future_grace_period,rcu:rcu_grace_period_init,rcu:rcu_nocb_wake,rcu:rcu_preempt_task,rcu:rcu_unlock_preempted_task,rcu:rcu_quiescent_state_report,rcu:rcu_fqs,rcu:rcu_callback,rcu:rcu_kfree_callback,rcu:rcu_batch_start,rcu:rcu_invoke_callback,rcu:rcu_invoke_kfree_callback,rcu:rcu_batch_end,rcu:rcu_torture_read,rcu:rcu_barrier
+# Function-graph tracing: ftrace=function_graph ftrace_graph_filter=sched_setaffinity,migration_cpu_stop
+# Also --kconfig "CONFIG_FUNCTION_TRACER=y CONFIG_FUNCTION_GRAPH_TRACER=y"
-- 
cgit v1.2.3


From 6dc82595ef0839a45c26075612f304979b6c92c2 Mon Sep 17 00:00:00 2001
From: "Paul E. McKenney" <paulmck@linux.ibm.com>
Date: Fri, 10 May 2019 21:31:52 -0700
Subject: torture: Run kernel build in source directory

For historical reasons, rcutorture places its build products in a
tools/testing/selftests/rcutorture/b1 directory using the O= kbuild
command-line argument.  However, doing this requires that the source
directory be pristine: Not just "make clean" pristine, but instead "make
mrproper" (or, equivalently, "make distclean") pristine.  Therefore,
rcutorture executes a "make mrproper" before each build.  Unfortunately,
"make mrproper" has the side effect of removing pretty much everything,
including tags files and cscope databases, which can be inconvenient
to people whose workflow centers around a single source tree.

This commit therefore makes rcutorture do the build directly in the
source directory, removing the need for "make mrproper".  This works
because all needed build products are moved to their proper place in the
"res" directory immediately after the build completes, so that multiple
rcutorture kernels can still run concurrently.

Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
 .../testing/selftests/rcutorture/bin/configinit.sh | 36 ++++++----------------
 .../testing/selftests/rcutorture/bin/kvm-build.sh  |  9 +++---
 .../selftests/rcutorture/bin/kvm-test-1-run.sh     | 21 +++++--------
 tools/testing/selftests/rcutorture/bin/kvm.sh      |  3 +-
 4 files changed, 22 insertions(+), 47 deletions(-)

(limited to 'tools/testing')

diff --git a/tools/testing/selftests/rcutorture/bin/configinit.sh b/tools/testing/selftests/rcutorture/bin/configinit.sh
index 40359486b3a8..bbeae6f67c36 100755
--- a/tools/testing/selftests/rcutorture/bin/configinit.sh
+++ b/tools/testing/selftests/rcutorture/bin/configinit.sh
@@ -1,7 +1,7 @@
 #!/bin/bash
 # SPDX-License-Identifier: GPL-2.0+
 #
-# Usage: configinit.sh config-spec-file build-output-dir results-dir
+# Usage: configinit.sh config-spec-file results-dir
 #
 # Create a .config file from the spec file.  Run from the kernel source tree.
 # Exits with 0 if all went well, with 1 if all went well but the config
@@ -11,10 +11,6 @@
 # desired settings, for example, "CONFIG_NO_HZ=y".  For best results,
 # this should be a full pathname.
 #
-# The second argument is a optional path to a build output directory,
-# for example, "O=/tmp/foo".  If this argument is omitted, the .config
-# file will be generated directly in the current directory.
-#
 # Copyright (C) IBM Corporation, 2013
 #
 # Authors: Paul E. McKenney <paulmck@linux.ibm.com>
@@ -26,34 +22,20 @@ mkdir $T
 # Capture config spec file.
 
 c=$1
-buildloc=$2
-resdir=$3
-builddir=
-if echo $buildloc | grep -q '^O='
-then
-	builddir=`echo $buildloc | sed -e 's/^O=//'`
-	if test ! -d $builddir
-	then
-		mkdir $builddir
-	fi
-else
-	echo Bad build directory: \"$buildloc\"
-	exit 2
-fi
+resdir=$2
 
 sed -e 's/^\(CONFIG[0-9A-Z_]*\)=.*$/grep -v "^# \1" |/' < $c > $T/u.sh
 sed -e 's/^\(CONFIG[0-9A-Z_]*=\).*$/grep -v \1 |/' < $c >> $T/u.sh
 grep '^grep' < $T/u.sh > $T/upd.sh
 echo "cat - $c" >> $T/upd.sh
-make mrproper
-make $buildloc distclean > $resdir/Make.distclean 2>&1
-make $buildloc $TORTURE_DEFCONFIG > $resdir/Make.defconfig.out 2>&1
-mv $builddir/.config $builddir/.config.sav
-sh $T/upd.sh < $builddir/.config.sav > $builddir/.config
-cp $builddir/.config $builddir/.config.new
-yes '' | make $buildloc oldconfig > $resdir/Make.oldconfig.out 2> $resdir/Make.oldconfig.err
+make clean > $resdir/Make.clean 2>&1
+make $TORTURE_DEFCONFIG > $resdir/Make.defconfig.out 2>&1
+mv .config .config.sav
+sh $T/upd.sh < .config.sav > .config
+cp .config .config.new
+yes '' | make oldconfig > $resdir/Make.oldconfig.out 2> $resdir/Make.oldconfig.err
 
 # verify new config matches specification.
-configcheck.sh $builddir/.config $c
+configcheck.sh .config $c
 
 exit 0
diff --git a/tools/testing/selftests/rcutorture/bin/kvm-build.sh b/tools/testing/selftests/rcutorture/bin/kvm-build.sh
index c27a0bbb9c02..18d6518504ee 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-build.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-build.sh
@@ -3,7 +3,7 @@
 #
 # Build a kvm-ready Linux kernel from the tree in the current directory.
 #
-# Usage: kvm-build.sh config-template build-dir resdir
+# Usage: kvm-build.sh config-template resdir
 #
 # Copyright (C) IBM Corporation, 2011
 #
@@ -15,8 +15,7 @@ then
 	echo "kvm-build.sh :$config_template: Not a readable file"
 	exit 1
 fi
-builddir=${2}
-resdir=${3}
+resdir=${2}
 
 T=${TMPDIR-/tmp}/test-linux.sh.$$
 trap 'rm -rf $T' 0
@@ -29,14 +28,14 @@ CONFIG_VIRTIO_PCI=y
 CONFIG_VIRTIO_CONSOLE=y
 ___EOF___
 
-configinit.sh $T/config O=$builddir $resdir
+configinit.sh $T/config $resdir
 retval=$?
 if test $retval -gt 1
 then
 	exit 2
 fi
 ncpus=`cpus2use.sh`
-make O=$builddir -j$ncpus $TORTURE_KMAKE_ARG > $resdir/Make.out 2>&1
+make -j$ncpus $TORTURE_KMAKE_ARG > $resdir/Make.out 2>&1
 retval=$?
 if test $retval -ne 0 || grep "rcu[^/]*": < $resdir/Make.out | egrep -q "Stop|Error|error:|warning:" || egrep -q "Stop|Error|error:" < $resdir/Make.out
 then
diff --git a/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh b/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
index 003511494fd9..27b7b5693ede 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
@@ -36,11 +36,6 @@ config_template=${1}
 config_dir=`echo $config_template | sed -e 's,/[^/]*$,,'`
 title=`echo $config_template | sed -e 's/^.*\///'`
 builddir=${2}
-if test -z "$builddir" -o ! -d "$builddir" -o ! -w "$builddir"
-then
-	echo "kvm-test-1-run.sh :$builddir: Not a writable directory, cannot build into it"
-	exit 1
-fi
 resdir=${3}
 if test -z "$resdir" -o ! -d "$resdir" -o ! -w "$resdir"
 then
@@ -85,18 +80,18 @@ then
 	ln -s $base_resdir/.config $resdir  # for kvm-recheck.sh
 	# Arch-independent indicator
 	touch $resdir/builtkernel
-elif kvm-build.sh $T/Kc2 $builddir $resdir
+elif kvm-build.sh $T/Kc2 $resdir
 then
 	# Had to build a kernel for this test.
-	QEMU="`identify_qemu $builddir/vmlinux`"
+	QEMU="`identify_qemu vmlinux`"
 	BOOT_IMAGE="`identify_boot_image $QEMU`"
-	cp $builddir/vmlinux $resdir
-	cp $builddir/.config $resdir
-	cp $builddir/Module.symvers $resdir > /dev/null || :
-	cp $builddir/System.map $resdir > /dev/null || :
+	cp vmlinux $resdir
+	cp .config $resdir
+	cp Module.symvers $resdir > /dev/null || :
+	cp System.map $resdir > /dev/null || :
 	if test -n "$BOOT_IMAGE"
 	then
-		cp $builddir/$BOOT_IMAGE $resdir
+		cp $BOOT_IMAGE $resdir
 		KERNEL=$resdir/${BOOT_IMAGE##*/}
 		# Arch-independent indicator
 		touch $resdir/builtkernel
@@ -107,7 +102,7 @@ then
 	parse-build.sh $resdir/Make.out $title
 else
 	# Build failed.
-	cp $builddir/.config $resdir || :
+	cp .config $resdir || :
 	echo Build failed, not running KVM, see $resdir.
 	if test -f $builddir.wait
 	then
diff --git a/tools/testing/selftests/rcutorture/bin/kvm.sh b/tools/testing/selftests/rcutorture/bin/kvm.sh
index 3b4868906794..8c43eb43409b 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm.sh
@@ -342,7 +342,7 @@ function dump(first, pastlast, batchnum)
 	print "needqemurun="
 	jn=1
 	for (j = first; j < pastlast; j++) {
-		builddir=KVM "/b1"
+		builddir=KVM "/b" j - first + 1
 		cpusr[jn] = cpus[j];
 		if (cfrep[cf[j]] == "") {
 			cfr[jn] = cf[j];
@@ -358,7 +358,6 @@ function dump(first, pastlast, batchnum)
 		print "echo ", cfr[jn], cpusr[jn] ovf ": Starting build. `date` | tee -a " rd "log";
 		print "rm -f " builddir ".*";
 		print "touch " builddir ".wait";
-		print "mkdir " builddir " > /dev/null 2>&1 || :";
 		print "mkdir " rd cfr[jn] " || :";
 		print "kvm-test-1-run.sh " CONFIGDIR cf[j], builddir, rd cfr[jn], dur " \"" TORTURE_QEMU_ARG "\" \"" TORTURE_BOOTARGS "\" > " rd cfr[jn]  "/kvm-test-1-run.sh.out 2>&1 &"
 		print "echo ", cfr[jn], cpusr[jn] ovf ": Waiting for build to complete. `date` | tee -a " rd "log";
-- 
cgit v1.2.3


From 7225c0777271bb489ad6fb095aa10985ad138a81 Mon Sep 17 00:00:00 2001
From: "Paul E. McKenney" <paulmck@linux.ibm.com>
Date: Sat, 11 May 2019 17:59:52 -0700
Subject: torture: Make --cpus override idleness calculations

Currently, rcutorture will use relatively few CPUs to build the kernel
on a busy system, which is often as it should be.  However, if the user
has used the --cpus argument to dedicate a specified number of CPUs to
this torture test, it would be good if the kernel build also made use
of them.  This commit therefore changes the cpus2use.sh script to use
--cpus when specified and to do the idleness calculations otherwise.

Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
 tools/testing/selftests/rcutorture/bin/cpus2use.sh | 5 +++++
 tools/testing/selftests/rcutorture/bin/kvm.sh      | 3 +++
 2 files changed, 8 insertions(+)

(limited to 'tools/testing')

diff --git a/tools/testing/selftests/rcutorture/bin/cpus2use.sh b/tools/testing/selftests/rcutorture/bin/cpus2use.sh
index ff7102212703..4e9485590c10 100755
--- a/tools/testing/selftests/rcutorture/bin/cpus2use.sh
+++ b/tools/testing/selftests/rcutorture/bin/cpus2use.sh
@@ -9,6 +9,11 @@
 #
 # Authors: Paul E. McKenney <paulmck@linux.ibm.com>
 
+if test -n "$TORTURE_ALLOTED_CPUS"
+then
+	echo $TORTURE_ALLOTED_CPUS
+	exit 0
+fi
 ncpus=`grep '^processor' /proc/cpuinfo | wc -l`
 idlecpus=`mpstat | tail -1 | \
 	awk -v ncpus=$ncpus '{ print ncpus * ($7 + $NF) / 100 }'`
diff --git a/tools/testing/selftests/rcutorture/bin/kvm.sh b/tools/testing/selftests/rcutorture/bin/kvm.sh
index 8c43eb43409b..ea6289a335f2 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm.sh
@@ -24,6 +24,7 @@ dur=$((30*60))
 dryrun=""
 KVM="`pwd`/tools/testing/selftests/rcutorture"; export KVM
 PATH=${KVM}/bin:$PATH; export PATH
+TORTURE_ALLOTED_CPUS=""
 TORTURE_DEFCONFIG=defconfig
 TORTURE_BOOT_IMAGE=""
 TORTURE_INITRD="$KVM/initrd"; export TORTURE_INITRD
@@ -89,6 +90,7 @@ do
 	--cpus)
 		checkarg --cpus "(number)" "$#" "$2" '^[0-9]*$' '^--'
 		cpus=$2
+		TORTURE_ALLOTED_CPUS="$2"
 		shift
 		;;
 	--datestamp)
@@ -285,6 +287,7 @@ cat << ___EOF___ > $T/script
 CONFIGFRAG="$CONFIGFRAG"; export CONFIGFRAG
 KVM="$KVM"; export KVM
 PATH="$PATH"; export PATH
+TORTURE_ALLOTED_CPUS="$TORTURE_ALLOTED_CPUS"; export TORTURE_ALLOTED_CPUS
 TORTURE_BOOT_IMAGE="$TORTURE_BOOT_IMAGE"; export TORTURE_BOOT_IMAGE
 TORTURE_BUILDONLY="$TORTURE_BUILDONLY"; export TORTURE_BUILDONLY
 TORTURE_DEFCONFIG="$TORTURE_DEFCONFIG"; export TORTURE_DEFCONFIG
-- 
cgit v1.2.3


From b93c765fda30cadae6aafb9d32a30f9391dc0b41 Mon Sep 17 00:00:00 2001
From: "Paul E. McKenney" <paulmck@linux.ibm.com>
Date: Sat, 11 May 2019 20:18:00 -0700
Subject: torture: Add --trust-make to suppress "make clean"

The current rcutorture scripts unconditionally do "make clean", which is
a good way of getting the needed testing done despite any imperfections in
Makefile dependency tracking.  However, this can be a bit irritating when
repeatedly running a single scenario after small changes, for example,
when debugging a problem that affects only a single scenario.  This commit
therefore adds a --trust-make argument that suppresses the "make clean".

Even when using ccache, this speeds up kernel builds by up to almost an
order of magnitude on my laptop.

Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
 tools/testing/selftests/rcutorture/bin/configinit.sh  | 5 ++++-
 tools/testing/selftests/rcutorture/bin/kvm.sh         | 6 ++++++
 tools/testing/selftests/rcutorture/bin/parse-build.sh | 2 +-
 3 files changed, 11 insertions(+), 2 deletions(-)

(limited to 'tools/testing')

diff --git a/tools/testing/selftests/rcutorture/bin/configinit.sh b/tools/testing/selftests/rcutorture/bin/configinit.sh
index bbeae6f67c36..93e80a42249a 100755
--- a/tools/testing/selftests/rcutorture/bin/configinit.sh
+++ b/tools/testing/selftests/rcutorture/bin/configinit.sh
@@ -28,7 +28,10 @@ sed -e 's/^\(CONFIG[0-9A-Z_]*\)=.*$/grep -v "^# \1" |/' < $c > $T/u.sh
 sed -e 's/^\(CONFIG[0-9A-Z_]*=\).*$/grep -v \1 |/' < $c >> $T/u.sh
 grep '^grep' < $T/u.sh > $T/upd.sh
 echo "cat - $c" >> $T/upd.sh
-make clean > $resdir/Make.clean 2>&1
+if test -z "$TORTURE_TRUST_MAKE"
+then
+	make clean > $resdir/Make.clean 2>&1
+fi
 make $TORTURE_DEFCONFIG > $resdir/Make.defconfig.out 2>&1
 mv .config .config.sav
 sh $T/upd.sh < .config.sav > .config
diff --git a/tools/testing/selftests/rcutorture/bin/kvm.sh b/tools/testing/selftests/rcutorture/bin/kvm.sh
index ea6289a335f2..72518580df23 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm.sh
@@ -33,6 +33,7 @@ TORTURE_KMAKE_ARG=""
 TORTURE_QEMU_MEM=512
 TORTURE_SHUTDOWN_GRACE=180
 TORTURE_SUITE=rcu
+TORTURE_TRUST_MAKE=""
 resdir=""
 configs=""
 cpus=0
@@ -63,6 +64,7 @@ usage () {
 	echo "       --qemu-cmd qemu-system-..."
 	echo "       --results absolute-pathname"
 	echo "       --torture rcu"
+	echo "       --trust-make"
 	exit 1
 }
 
@@ -175,6 +177,9 @@ do
 			jitter=0
 		fi
 		;;
+	--trust-make)
+		TORTURE_TRUST_MAKE="y"
+		;;
 	*)
 		echo Unknown argument $1
 		usage
@@ -300,6 +305,7 @@ TORTURE_QEMU_MAC="$TORTURE_QEMU_MAC"; export TORTURE_QEMU_MAC
 TORTURE_QEMU_MEM="$TORTURE_QEMU_MEM"; export TORTURE_QEMU_MEM
 TORTURE_SHUTDOWN_GRACE="$TORTURE_SHUTDOWN_GRACE"; export TORTURE_SHUTDOWN_GRACE
 TORTURE_SUITE="$TORTURE_SUITE"; export TORTURE_SUITE
+TORTURE_TRUST_MAKE="$TORTURE_TRUST_MAKE"; export TORTURE_TRUST_MAKE
 if ! test -e $resdir
 then
 	mkdir -p "$resdir" || :
diff --git a/tools/testing/selftests/rcutorture/bin/parse-build.sh b/tools/testing/selftests/rcutorture/bin/parse-build.sh
index 0701b3bf6ade..09155c15ea65 100755
--- a/tools/testing/selftests/rcutorture/bin/parse-build.sh
+++ b/tools/testing/selftests/rcutorture/bin/parse-build.sh
@@ -21,7 +21,7 @@ mkdir $T
 
 . functions.sh
 
-if grep -q CC < $F
+if grep -q CC < $F || test -n "$TORTURE_TRUST_MAKE"
 then
 	:
 else
-- 
cgit v1.2.3


From 8997e6311ed6cb95be34409bc6b4a11c7a84ac35 Mon Sep 17 00:00:00 2001
From: "Paul E. McKenney" <paulmck@linux.ibm.com>
Date: Wed, 22 May 2019 08:52:18 -0700
Subject: torture: Suppress propagating trace_printk() warning

When trace_printk() is used, a message including "BUG" is printed to
the console, which fools the rcutorture scripting into believing that
the corresponding test scenario failed.  This commit therefore filters
out this particular instance of "BUG", thus avoiding the false-positive
test-failure report.

Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
 tools/testing/selftests/rcutorture/bin/parse-console.sh | 1 +
 1 file changed, 1 insertion(+)

(limited to 'tools/testing')

diff --git a/tools/testing/selftests/rcutorture/bin/parse-console.sh b/tools/testing/selftests/rcutorture/bin/parse-console.sh
index 4508373a922f..4bf62d7b1cbc 100755
--- a/tools/testing/selftests/rcutorture/bin/parse-console.sh
+++ b/tools/testing/selftests/rcutorture/bin/parse-console.sh
@@ -106,6 +106,7 @@ fi | tee -a $file.diags
 
 egrep 'Badness|WARNING:|Warn|BUG|===========|Call Trace:|Oops:|detected stalls on CPUs/tasks:|self-detected stall on CPU|Stall ended before state dump start|\?\?\? Writer stall state|rcu_.*kthread starved for' < $file |
 grep -v 'ODEBUG: ' |
+grep -v 'This means that this is a DEBUG kernel and it is' |
 grep -v 'Warning: unable to open an initial console' > $T.diags
 if test -s $T.diags
 then
-- 
cgit v1.2.3


From 9129b017b54dab09eb69b7269026243156e5188e Mon Sep 17 00:00:00 2001
From: Andrea Parri <andrea.parri@amarulasolutions.com>
Date: Mon, 27 May 2019 10:49:57 +0200
Subject: rcu: Don't return a value from rcu_assign_pointer()

Quoting Paul [1]:

  "Given that a quick (and perhaps error-prone) search of the uses
   of rcu_assign_pointer() in v5.1 didn't find a single use of the
   return value, let's please instead change the documentation and
   implementation to eliminate the return value."

[1] https://lkml.kernel.org/r/20190523135013.GL28207@linux.ibm.com

Signed-off-by: Andrea Parri <andrea.parri@amarulasolutions.com>
Cc: "Paul E. McKenney" <paulmck@linux.ibm.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: rcu@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Sasha Levin <sashal@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
---
 Documentation/RCU/whatisRCU.txt           | 8 ++++----
 include/linux/rcupdate.h                  | 5 ++---
 tools/include/linux/rcu.h                 | 4 ++--
 tools/testing/radix-tree/linux/rcupdate.h | 2 +-
 4 files changed, 9 insertions(+), 10 deletions(-)

(limited to 'tools/testing')

diff --git a/Documentation/RCU/whatisRCU.txt b/Documentation/RCU/whatisRCU.txt
index 981651a8b65d..7e1a8721637a 100644
--- a/Documentation/RCU/whatisRCU.txt
+++ b/Documentation/RCU/whatisRCU.txt
@@ -212,7 +212,7 @@ synchronize_rcu()
 
 rcu_assign_pointer()
 
-	typeof(p) rcu_assign_pointer(p, typeof(p) v);
+	void rcu_assign_pointer(p, typeof(p) v);
 
 	Yes, rcu_assign_pointer() -is- implemented as a macro, though it
 	would be cool to be able to declare a function in this manner.
@@ -220,9 +220,9 @@ rcu_assign_pointer()
 
 	The updater uses this function to assign a new value to an
 	RCU-protected pointer, in order to safely communicate the change
-	in value from the updater to the reader.  This function returns
-	the new value, and also executes any memory-barrier instructions
-	required for a given CPU architecture.
+	in value from the updater to the reader.  This macro does not
+	evaluate to an rvalue, but it does execute any memory-barrier
+	instructions required for a given CPU architecture.
 
 	Perhaps just as important, it serves to document (1) which
 	pointers are protected by RCU and (2) the point at which a
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index a8ed624da555..0c9b92799abc 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -367,7 +367,7 @@ static inline void rcu_preempt_sleep_check(void) { }
  * other macros that it invokes.
  */
 #define rcu_assign_pointer(p, v)					      \
-({									      \
+do {									      \
 	uintptr_t _r_a_p__v = (uintptr_t)(v);				      \
 	rcu_check_sparse(p, __rcu);					      \
 									      \
@@ -375,8 +375,7 @@ static inline void rcu_preempt_sleep_check(void) { }
 		WRITE_ONCE((p), (typeof(p))(_r_a_p__v));		      \
 	else								      \
 		smp_store_release(&p, RCU_INITIALIZER((typeof(p))_r_a_p__v)); \
-	_r_a_p__v;							      \
-})
+} while (0)
 
 /**
  * rcu_swap_protected() - swap an RCU and a regular pointer
diff --git a/tools/include/linux/rcu.h b/tools/include/linux/rcu.h
index 7d02527e5bce..9554d3fa54f3 100644
--- a/tools/include/linux/rcu.h
+++ b/tools/include/linux/rcu.h
@@ -19,7 +19,7 @@ static inline bool rcu_is_watching(void)
 	return false;
 }
 
-#define rcu_assign_pointer(p, v) ((p) = (v))
-#define RCU_INIT_POINTER(p, v) p=(v)
+#define rcu_assign_pointer(p, v)	do { (p) = (v); } while (0)
+#define RCU_INIT_POINTER(p, v)	do { (p) = (v); } while (0)
 
 #endif
diff --git a/tools/testing/radix-tree/linux/rcupdate.h b/tools/testing/radix-tree/linux/rcupdate.h
index fd280b070fdb..fed468fb0c78 100644
--- a/tools/testing/radix-tree/linux/rcupdate.h
+++ b/tools/testing/radix-tree/linux/rcupdate.h
@@ -7,6 +7,6 @@
 #define rcu_dereference_raw(p) rcu_dereference(p)
 #define rcu_dereference_protected(p, cond) rcu_dereference(p)
 #define rcu_dereference_check(p, cond) rcu_dereference(p)
-#define RCU_INIT_POINTER(p, v)	(p) = (v)
+#define RCU_INIT_POINTER(p, v)	do { (p) = (v); } while (0)
 
 #endif
-- 
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