[PATCH tip/core/rcu 0/18] Torture-test updates for v5.8

[PATCH tip/core/rcu 0/18] Torture-test updates for v5.8

[Paul E. McKenney]

Hello!

This series contains a variety of torture-test updates:

1.	Add KCSAN stubs.

2.	Make kvm-recheck-rcu.sh handle truncated lines.

3.	Mark data-race potential for rcu_barrier() test statistics.

4.	locktorture.c: Fix if-statement empty body warnings, courtesy
	of Randy Dunlap.

5.	Default enable RCU list lockdep debugging with PROVE_RCU,
	courtesy of Madhuparna Bhowmik.

6.	Add flag to produce non-busy-wait task stalls.

7.	Right-size TREE10 CPU consumption.

8.	Allow rcutorture to starve grace-period kthread.

9.	Add --kcsan argument to top-level kvm.sh script.

10.	Make --kcsan argument also create a summary.

11.	Make rcu_fwds and rcu_fwd_emergency_stop static, courtesy of
	Jason Yan.

12.	Eliminate duplicate #CHECK# from ConfigFragment.

13.	Abstract application of additional Kconfig options.

14.	Allow --kconfig options to override --kcsan defaults.

15.	Allow scenario-specific Kconfig options to override CFcommon.

16.	Save a few lines by using config_override_param initially.

17.	Add a --kasan argument.

18.	Convert ULONG_CMP_LT() to time_before().

							Thanx, Paul

------------------------------------------------------------------------

 Documentation/admin-guide/kernel-parameters.txt           |   12 +
 include/linux/torture.h                                   |    2 
 kernel/rcu/Kconfig.debug                                  |   11 -
 kernel/rcu/rcu.h                                          |    2 
 kernel/rcu/rcutorture.c                                   |   63 +++++++--
 kernel/rcu/tree.c                                         |   27 ++++
 tools/testing/selftests/rcutorture/bin/kcsan-collapse.sh  |   22 +++
 tools/testing/selftests/rcutorture/bin/kvm-recheck-rcu.sh |   16 ++
 tools/testing/selftests/rcutorture/bin/kvm-recheck.sh     |    9 +
 tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh  |   90 +++++++-------
 tools/testing/selftests/rcutorture/bin/kvm.sh             |   17 ++
 tools/testing/selftests/rcutorture/configs/rcu/TREE10     |    2 
 12 files changed, 198 insertions(+), 75 deletions(-)

[PATCH tip/core/rcu 01/18] rcutorture: Add KCSAN stubs

[paulmck]

From: "Paul E. McKenney" <paulmck@kernel.org>

This commit adds stubs for KCSAN's data_race(), ASSERT_EXCLUSIVE_WRITER(),
and ASSERT_EXCLUSIVE_ACCESS() macros to allow code using these macros to
move ahead.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 kernel/rcu/rcutorture.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 5453bd5..7e2ea0c5 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -51,6 +51,18 @@
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.ibm.com> and Josh Triplett <josh@joshtriplett.org>");
 
+#ifndef data_race
+#define data_race(expr)							\
+	({								\
+		expr;							\
+	})
+#endif
+#ifndef ASSERT_EXCLUSIVE_WRITER
+#define ASSERT_EXCLUSIVE_WRITER(var) do { } while (0)
+#endif
+#ifndef ASSERT_EXCLUSIVE_ACCESS
+#define ASSERT_EXCLUSIVE_ACCESS(var) do { } while (0)
+#endif
 
 /* Bits for ->extendables field, extendables param, and related definitions. */
 #define RCUTORTURE_RDR_SHIFT	 8	/* Put SRCU index in upper bits. */
-- 
2.9.5

[PATCH tip/core/rcu 02/18] rcutorture: Make kvm-recheck-rcu.sh handle truncated lines

[paulmck]

From: "Paul E. McKenney" <paulmck@kernel.org>

System hangs or killed rcutorture guest OSes can result in truncated
"Reader Pipe:" lines, which can in turn result in false-positive
reader-batch near-miss warnings.  This commit therefore adjusts the
reader-batch checks to account for possible line truncation.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 .../testing/selftests/rcutorture/bin/kvm-recheck-rcu.sh  | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/rcutorture/bin/kvm-recheck-rcu.sh b/tools/testing/selftests/rcutorture/bin/kvm-recheck-rcu.sh
index 9d9a416..1706cd4 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-recheck-rcu.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-recheck-rcu.sh
@@ -41,7 +41,21 @@ else
 		title="$title ($ngpsps/s)"
 	fi
 	echo $title $stopstate $fwdprog
-	nclosecalls=`grep --binary-files=text 'torture: Reader Batch' $i/console.log | tail -1 | awk '{for (i=NF-8;i<=NF;i++) sum+=$i; } END {print sum}'`
+	nclosecalls=`grep --binary-files=text 'torture: Reader Batch' $i/console.log | tail -1 | \
+		awk -v sum=0 '
+		{
+			for (i = 0; i <= NF; i++) {
+				sum += $i;
+				if ($i ~ /Batch:/) {
+					sum = 0;
+					i = i + 2;
+				}
+			}
+		}
+
+		END {
+			print sum
+		}'`
 	if test -z "$nclosecalls"
 	then
 		exit 0
-- 
2.9.5

[PATCH tip/core/rcu 03/18] rcutorture: Mark data-race potential for rcu_barrier() test statistics

[paulmck]

From: "Paul E. McKenney" <paulmck@kernel.org>

The n_barrier_successes, n_barrier_attempts, and
n_rcu_torture_barrier_error variables are updated (without access
markings) by the main rcu_barrier() test kthread, and accessed (also
without access markings) by the rcu_torture_stats() kthread.  This of
course can result in KCSAN complaints.

Because the accesses are in diagnostic prints, this commit uses
data_race() to excuse the diagnostic prints from the data race.  If this
were to ever cause bogus statistics prints (for example, due to store
tearing), any misleading information would be disambiguated by the
presence or absence of an rcutorture splat.

This data race was reported by KCSAN.  Not appropriate for backporting
due to failure being unlikely and due to the mild consequences of the
failure, namely a confusing rcutorture console message.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
---
 kernel/rcu/rcutorture.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 7e2ea0c5..d0345d1 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -1456,9 +1456,9 @@ rcu_torture_stats_print(void)
 		atomic_long_read(&n_rcu_torture_timers));
 	torture_onoff_stats();
 	pr_cont("barrier: %ld/%ld:%ld\n",
-		n_barrier_successes,
-		n_barrier_attempts,
-		n_rcu_torture_barrier_error);
+		data_race(n_barrier_successes),
+		data_race(n_barrier_attempts),
+		data_race(n_rcu_torture_barrier_error));
 
 	pr_alert("%s%s ", torture_type, TORTURE_FLAG);
 	if (atomic_read(&n_rcu_torture_mberror) ||
-- 
2.9.5

[PATCH tip/core/rcu 04/18] locktorture.c: Fix if-statement empty body warnings

[paulmck]

From: Randy Dunlap <rdunlap@infradead.org>

When using -Wextra, gcc complains about torture_preempt_schedule()
when its definition is empty (i.e., when CONFIG_PREEMPTION is not
set/enabled).  Fix these warnings by adding an empty do-while block
for that macro when CONFIG_PREEMPTION is not set.
Fixes these build warnings:

../kernel/locking/locktorture.c:119:29: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body]
../kernel/locking/locktorture.c:166:29: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body]
../kernel/locking/locktorture.c:337:29: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body]
../kernel/locking/locktorture.c:490:29: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body]
../kernel/locking/locktorture.c:528:29: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body]
../kernel/locking/locktorture.c:553:29: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body]

I have verified that there is no object code change (with gcc 7.5.0).

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: "Paul E. McKenney" <paulmck@kernel.org>
---
 include/linux/torture.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/torture.h b/include/linux/torture.h
index 6241f59..629b66e 100644
--- a/include/linux/torture.h
+++ b/include/linux/torture.h
@@ -89,7 +89,7 @@ void _torture_stop_kthread(char *m, struct task_struct **tp);
 #ifdef CONFIG_PREEMPTION
 #define torture_preempt_schedule() preempt_schedule()
 #else
-#define torture_preempt_schedule()
+#define torture_preempt_schedule()	do { } while (0)
 #endif
 
 #endif /* __LINUX_TORTURE_H */
-- 
2.9.5

[PATCH tip/core/rcu 05/18] Default enable RCU list lockdep debugging with PROVE_RCU

[paulmck]

From: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>

This patch default enables CONFIG_PROVE_RCU_LIST option with
CONFIG_PROVE_RCU for RCU list lockdep debugging.

With this change, RCU list lockdep debugging will be default
enabled in CONFIG_PROVE_RCU=y kernels.

Most of the RCU users (in core kernel/, drivers/, and net/
subsystem) have already been modified to include lockdep
expressions hence RCU list debugging can be enabled by
default.

However, there are still chances of enountering
false-positive lockdep splats because not everything is converted,
in case RCU list primitives are used in non-RCU read-side critical
section but under the protection of a lock. It would be okay to
have a few false-positives, as long as bugs are identified, since this
patch only affects debugging kernels.

Co-developed-by: Amol Grover <frextrite@gmail.com>
Signed-off-by: Amol Grover <frextrite@gmail.com>
Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Acked-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 kernel/rcu/Kconfig.debug | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/kernel/rcu/Kconfig.debug b/kernel/rcu/Kconfig.debug
index 4aa02ee..ec4bb6c 100644
--- a/kernel/rcu/Kconfig.debug
+++ b/kernel/rcu/Kconfig.debug
@@ -9,15 +9,10 @@ config PROVE_RCU
 	def_bool PROVE_LOCKING
 
 config PROVE_RCU_LIST
-	bool "RCU list lockdep debugging"
-	depends on PROVE_RCU && RCU_EXPERT
-	default n
+	def_bool PROVE_RCU
 	help
-	  Enable RCU lockdep checking for list usages. By default it is
-	  turned off since there are several list RCU users that still
-	  need to be converted to pass a lockdep expression. To prevent
-	  false-positive splats, we keep it default disabled but once all
-	  users are converted, we can remove this config option.
+	  Enable RCU lockdep checking for list usages. It is default
+	  enabled with CONFIG_PROVE_RCU.
 
 config TORTURE_TEST
 	tristate
-- 
2.9.5

[PATCH tip/core/rcu 06/18] rcutorture: Add flag to produce non-busy-wait task stalls

[paulmck]

From: "Paul E. McKenney" <paulmck@kernel.org>

This commit aids testing of RCU task stall warning messages by adding
an rcutorture.stall_cpu_block module parameter that results in the
induced stall sleeping within the RCU read-side critical section.
Spinning with interrupts disabled is still available via the
rcutorture.stall_cpu_irqsoff module parameter, and specifying neither
of these two module parameters will spin with preemption disabled.

Note that sleeping (as opposed to preemption) results in additional
complaints from RCU at context-switch time, so yet more testing.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 Documentation/admin-guide/kernel-parameters.txt |  5 +++++
 kernel/rcu/rcutorture.c                         | 17 +++++++++++------
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index f2a93c8..ad12b39 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -4210,6 +4210,11 @@
 			Duration of CPU stall (s) to test RCU CPU stall
 			warnings, zero to disable.
 
+	rcutorture.stall_cpu_block= [KNL]
+			Sleep while stalling if set.  This will result
+			in warnings from preemptible RCU in addition
+			to any other stall-related activity.
+
 	rcutorture.stall_cpu_holdoff= [KNL]
 			Time to wait (s) after boot before inducing stall.
 
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index d0345d1..60dc368 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -114,6 +114,7 @@ torture_param(int, stall_cpu, 0, "Stall duration (s), zero to disable.");
 torture_param(int, stall_cpu_holdoff, 10,
 	     "Time to wait before starting stall (s).");
 torture_param(int, stall_cpu_irqsoff, 0, "Disable interrupts while stalling.");
+torture_param(int, stall_cpu_block, 0, "Sleep while stalling.");
 torture_param(int, stat_interval, 60,
 	     "Number of seconds between stats printk()s");
 torture_param(int, stutter, 5, "Number of seconds to run/halt test");
@@ -1548,6 +1549,7 @@ rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag)
 		 "test_boost=%d/%d test_boost_interval=%d "
 		 "test_boost_duration=%d shutdown_secs=%d "
 		 "stall_cpu=%d stall_cpu_holdoff=%d stall_cpu_irqsoff=%d "
+		 "stall_cpu_block=%d "
 		 "n_barrier_cbs=%d "
 		 "onoff_interval=%d onoff_holdoff=%d\n",
 		 torture_type, tag, nrealreaders, nfakewriters,
@@ -1556,6 +1558,7 @@ rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag)
 		 test_boost, cur_ops->can_boost,
 		 test_boost_interval, test_boost_duration, shutdown_secs,
 		 stall_cpu, stall_cpu_holdoff, stall_cpu_irqsoff,
+		 stall_cpu_block,
 		 n_barrier_cbs,
 		 onoff_interval, onoff_holdoff);
 }
@@ -1611,6 +1614,7 @@ static int rcutorture_booster_init(unsigned int cpu)
  */
 static int rcu_torture_stall(void *args)
 {
+	int idx;
 	unsigned long stop_at;
 
 	VERBOSE_TOROUT_STRING("rcu_torture_stall task started");
@@ -1622,21 +1626,22 @@ static int rcu_torture_stall(void *args)
 	if (!kthread_should_stop()) {
 		stop_at = ktime_get_seconds() + stall_cpu;
 		/* RCU CPU stall is expected behavior in following code. */
-		rcu_read_lock();
+		idx = cur_ops->readlock();
 		if (stall_cpu_irqsoff)
 			local_irq_disable();
-		else
+		else if (!stall_cpu_block)
 			preempt_disable();
 		pr_alert("rcu_torture_stall start on CPU %d.\n",
-			 smp_processor_id());
+			 raw_smp_processor_id());
 		while (ULONG_CMP_LT((unsigned long)ktime_get_seconds(),
 				    stop_at))
-			continue;  /* Induce RCU CPU stall warning. */
+			if (stall_cpu_block)
+				schedule_timeout_uninterruptible(HZ);
 		if (stall_cpu_irqsoff)
 			local_irq_enable();
-		else
+		else if (!stall_cpu_block)
 			preempt_enable();
-		rcu_read_unlock();
+		cur_ops->readunlock(idx);
 		pr_alert("rcu_torture_stall end.\n");
 	}
 	torture_shutdown_absorb("rcu_torture_stall");
-- 
2.9.5

[PATCH tip/core/rcu 07/18] rcutorture: Right-size TREE10 CPU consumption

[paulmck]

From: "Paul E. McKenney" <paulmck@kernel.org>

The number of CPUs is tuned to allow "4*CFLIST TREE10" on a large system,
up from "3*CFLIST TREE10" previously.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 tools/testing/selftests/rcutorture/configs/rcu/TREE10 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE10 b/tools/testing/selftests/rcutorture/configs/rcu/TREE10
index 2debe78..7311f84 100644
--- a/tools/testing/selftests/rcutorture/configs/rcu/TREE10
+++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE10
@@ -1,5 +1,5 @@
 CONFIG_SMP=y
-CONFIG_NR_CPUS=100
+CONFIG_NR_CPUS=56
 CONFIG_PREEMPT_NONE=y
 CONFIG_PREEMPT_VOLUNTARY=n
 CONFIG_PREEMPT=n
-- 
2.9.5

[PATCH tip/core/rcu 08/18] rcu: Allow rcutorture to starve grace-period kthread

[paulmck]

From: "Paul E. McKenney" <paulmck@kernel.org>

This commit provides an rcutorture.stall_gp_kthread module parameter
to allow rcutorture to starve the grace-period kthread.  This allows
testing the code that detects such starvation.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 Documentation/admin-guide/kernel-parameters.txt |  7 +++++++
 kernel/rcu/rcu.h                                |  2 ++
 kernel/rcu/rcutorture.c                         | 18 ++++++++++++++---
 kernel/rcu/tree.c                               | 27 +++++++++++++++++++++++++
 4 files changed, 51 insertions(+), 3 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index ad12b39..be94358a 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -4221,6 +4221,13 @@
 	rcutorture.stall_cpu_irqsoff= [KNL]
 			Disable interrupts while stalling if set.
 
+	rcutorture.stall_gp_kthread= [KNL]
+			Duration (s) of forced sleep within RCU
+			grace-period kthread to test RCU CPU stall
+			warnings, zero to disable.  If both stall_cpu
+			and stall_gp_kthread are specified, the
+			kthread is starved first, then the CPU.
+
 	rcutorture.stat_interval= [KNL]
 			Time (s) between statistics printk()s.
 
diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h
index 00ddc92..cdbc5f9 100644
--- a/kernel/rcu/rcu.h
+++ b/kernel/rcu/rcu.h
@@ -454,6 +454,7 @@ void do_trace_rcu_torture_read(const char *rcutorturename,
 			       unsigned long secs,
 			       unsigned long c_old,
 			       unsigned long c);
+void rcu_gp_set_torture_wait(int duration);
 #else
 static inline void rcutorture_get_gp_data(enum rcutorture_type test_type,
 					  int *flags, unsigned long *gp_seq)
@@ -471,6 +472,7 @@ void do_trace_rcu_torture_read(const char *rcutorturename,
 #define do_trace_rcu_torture_read(rcutorturename, rhp, secs, c_old, c) \
 	do { } while (0)
 #endif
+static inline void rcu_gp_set_torture_wait(int duration) { }
 #endif
 
 #if IS_ENABLED(CONFIG_RCU_TORTURE_TEST) || IS_MODULE(CONFIG_RCU_TORTURE_TEST)
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 60dc368..3d47dca 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -115,6 +115,8 @@ torture_param(int, stall_cpu_holdoff, 10,
 	     "Time to wait before starting stall (s).");
 torture_param(int, stall_cpu_irqsoff, 0, "Disable interrupts while stalling.");
 torture_param(int, stall_cpu_block, 0, "Sleep while stalling.");
+torture_param(int, stall_gp_kthread, 0,
+	      "Grace-period kthread stall duration (s).");
 torture_param(int, stat_interval, 60,
 	     "Number of seconds between stats printk()s");
 torture_param(int, stutter, 5, "Number of seconds to run/halt test");
@@ -1623,7 +1625,17 @@ static int rcu_torture_stall(void *args)
 		schedule_timeout_interruptible(stall_cpu_holdoff * HZ);
 		VERBOSE_TOROUT_STRING("rcu_torture_stall end holdoff");
 	}
-	if (!kthread_should_stop()) {
+	if (!kthread_should_stop() && stall_gp_kthread > 0) {
+		VERBOSE_TOROUT_STRING("rcu_torture_stall begin GP stall");
+		rcu_gp_set_torture_wait(stall_gp_kthread * HZ);
+		for (idx = 0; idx < stall_gp_kthread + 2; idx++) {
+			if (kthread_should_stop())
+				break;
+			schedule_timeout_uninterruptible(HZ);
+		}
+	}
+	if (!kthread_should_stop() && stall_cpu > 0) {
+		VERBOSE_TOROUT_STRING("rcu_torture_stall begin CPU stall");
 		stop_at = ktime_get_seconds() + stall_cpu;
 		/* RCU CPU stall is expected behavior in following code. */
 		idx = cur_ops->readlock();
@@ -1642,8 +1654,8 @@ static int rcu_torture_stall(void *args)
 		else if (!stall_cpu_block)
 			preempt_enable();
 		cur_ops->readunlock(idx);
-		pr_alert("rcu_torture_stall end.\n");
 	}
+	pr_alert("rcu_torture_stall end.\n");
 	torture_shutdown_absorb("rcu_torture_stall");
 	while (!kthread_should_stop())
 		schedule_timeout_interruptible(10 * HZ);
@@ -1653,7 +1665,7 @@ static int rcu_torture_stall(void *args)
 /* Spawn CPU-stall kthread, if stall_cpu specified. */
 static int __init rcu_torture_stall_init(void)
 {
-	if (stall_cpu <= 0)
+	if (stall_cpu <= 0 && stall_gp_kthread <= 0)
 		return 0;
 	return torture_create_kthread(rcu_torture_stall, NULL, stall_task);
 }
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index f13130a..c5e0e66 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1486,6 +1486,31 @@ static void rcu_gp_slow(int delay)
 		schedule_timeout_uninterruptible(delay);
 }
 
+static unsigned long sleep_duration;
+
+/* Allow rcutorture to stall the grace-period kthread. */
+void rcu_gp_set_torture_wait(int duration)
+{
+	if (IS_ENABLED(CONFIG_RCU_TORTURE_TEST) && duration > 0)
+		WRITE_ONCE(sleep_duration, duration);
+}
+EXPORT_SYMBOL_GPL(rcu_gp_set_torture_wait);
+
+/* Actually implement the aforementioned wait. */
+static void rcu_gp_torture_wait(void)
+{
+	unsigned long duration;
+
+	if (!IS_ENABLED(CONFIG_RCU_TORTURE_TEST))
+		return;
+	duration = xchg(&sleep_duration, 0UL);
+	if (duration > 0) {
+		pr_alert("%s: Waiting %lu jiffies\n", __func__, duration);
+		schedule_timeout_uninterruptible(duration);
+		pr_alert("%s: Wait complete\n", __func__);
+	}
+}
+
 /*
  * Initialize a new grace period.  Return false if no grace period required.
  */
@@ -1686,6 +1711,7 @@ static void rcu_gp_fqs_loop(void)
 		rcu_state.gp_state = RCU_GP_WAIT_FQS;
 		ret = swait_event_idle_timeout_exclusive(
 				rcu_state.gp_wq, rcu_gp_fqs_check_wake(&gf), j);
+		rcu_gp_torture_wait();
 		rcu_state.gp_state = RCU_GP_DOING_FQS;
 		/* Locking provides needed memory barriers. */
 		/* If grace period done, leave loop. */
@@ -1834,6 +1860,7 @@ static int __noreturn rcu_gp_kthread(void *unused)
 			swait_event_idle_exclusive(rcu_state.gp_wq,
 					 READ_ONCE(rcu_state.gp_flags) &
 					 RCU_GP_FLAG_INIT);
+			rcu_gp_torture_wait();
 			rcu_state.gp_state = RCU_GP_DONE_GPS;
 			/* Locking provides needed memory barrier. */
 			if (rcu_gp_init())
-- 
2.9.5

[PATCH tip/core/rcu 09/18] torture: Add --kcsan argument to top-level kvm.sh script

[paulmck]

From: "Paul E. McKenney" <paulmck@kernel.org>

Although the existing --kconfig argument can be used to run KCSAN for
an rcutorture test, it is not as straightforward as one might like:

	--kconfig "CONFIG_DEBUG_INFO=y CONFIG_KCSAN=y \
		   CONFIG_KCSAN_ASSUME_PLAIN_WRITES_ATOMIC=n \
		   CONFIG_KCSAN_REPORT_VALUE_CHANGE_ONLY=n \
		   CONFIG_KCSAN_REPORT_ONCE_IN_MS=100000 \
		   CONFIG_KCSAN_VERBOSE=y CONFIG_KCSAN_INTERRUPT_WATCHER=y"

This commit therefore adds a "--kcsan" argument that emulates the above
--kconfig command.  Note that if you specify a Kconfig option using
-kconfig that conflicts with one that --kcsan adds, you get whatever
the script and the build system decide to give you.

Cc: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 tools/testing/selftests/rcutorture/bin/kvm.sh | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/tools/testing/selftests/rcutorture/bin/kvm.sh b/tools/testing/selftests/rcutorture/bin/kvm.sh
index 2315e2e..34b368d 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm.sh
@@ -31,6 +31,7 @@ TORTURE_DEFCONFIG=defconfig
 TORTURE_BOOT_IMAGE=""
 TORTURE_INITRD="$KVM/initrd"; export TORTURE_INITRD
 TORTURE_KCONFIG_ARG=""
+TORTURE_KCONFIG_KCSAN_ARG=""
 TORTURE_KMAKE_ARG=""
 TORTURE_QEMU_MEM=512
 TORTURE_SHUTDOWN_GRACE=180
@@ -133,6 +134,9 @@ do
 		TORTURE_KCONFIG_ARG="$2"
 		shift
 		;;
+	--kcsan)
+		TORTURE_KCONFIG_KCSAN_ARG="CONFIG_DEBUG_INFO=y CONFIG_KCSAN=y CONFIG_KCSAN_ASSUME_PLAIN_WRITES_ATOMIC=n CONFIG_KCSAN_REPORT_VALUE_CHANGE_ONLY=n CONFIG_KCSAN_REPORT_ONCE_IN_MS=100000 CONFIG_KCSAN_VERBOSE=y CONFIG_KCSAN_INTERRUPT_WATCHER=y"; export TORTURE_KCONFIG_KCSAN_ARG
+		;;
 	--kmake-arg)
 		checkarg --kmake-arg "(kernel make arguments)" $# "$2" '.*' '^error$'
 		TORTURE_KMAKE_ARG="$2"
@@ -201,6 +205,9 @@ else
 	exit 1
 fi
 
+TORTURE_KCONFIG_ARG="${TORTURE_KCONFIG_ARG} ${TORTURE_KCONFIG_KCSAN_ARG}"
+TORTURE_KCONFIG_ARG="`echo ${TORTURE_KCONFIG_ARG} | sed -e 's/^ *//' -e 's/ *$//'`"
+
 CONFIGFRAG=${KVM}/configs/${TORTURE_SUITE}; export CONFIGFRAG
 
 defaultconfigs="`tr '\012' ' ' < $CONFIGFRAG/CFLIST`"
@@ -310,6 +317,7 @@ TORTURE_BUILDONLY="$TORTURE_BUILDONLY"; export TORTURE_BUILDONLY
 TORTURE_DEFCONFIG="$TORTURE_DEFCONFIG"; export TORTURE_DEFCONFIG
 TORTURE_INITRD="$TORTURE_INITRD"; export TORTURE_INITRD
 TORTURE_KCONFIG_ARG="$TORTURE_KCONFIG_ARG"; export TORTURE_KCONFIG_ARG
+TORTURE_KCONFIG_KCSAN_ARG="$TORTURE_KCONFIG_KCSAN_ARG"; export TORTURE_KCONFIG_KCSAN_ARG
 TORTURE_KMAKE_ARG="$TORTURE_KMAKE_ARG"; export TORTURE_KMAKE_ARG
 TORTURE_QEMU_CMD="$TORTURE_QEMU_CMD"; export TORTURE_QEMU_CMD
 TORTURE_QEMU_INTERACTIVE="$TORTURE_QEMU_INTERACTIVE"; export TORTURE_QEMU_INTERACTIVE
-- 
2.9.5

[PATCH tip/core/rcu 10/18] torture: Make --kcsan argument also create a summary

[paulmck]

From: "Paul E. McKenney" <paulmck@kernel.org>

The KCSAN tool emits a great many warnings for current kernels, for
example, a one-hour run of the full set of rcutorture scenarios results
in no fewer than 3252 such warnings, many of which are duplicates
or are otherwise closely related.  This commit therefore introduces
a kcsan-collapse.sh script that maps these warnings down to a set of
function pairs (22 of them given the 3252 individual warnings), placing
the resulting list in decreasing order of frequency of occurrence into
a kcsan.sum file.  If any KCSAN warnings were produced, the pathname of
this file is emitted at the end of the summary of the rcutorture runs.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 .../selftests/rcutorture/bin/kcsan-collapse.sh     | 22 ++++++++++++++++++++++
 .../selftests/rcutorture/bin/kvm-recheck.sh        |  9 +++++++++
 tools/testing/selftests/rcutorture/bin/kvm.sh      |  1 +
 3 files changed, 32 insertions(+)
 create mode 100755 tools/testing/selftests/rcutorture/bin/kcsan-collapse.sh

diff --git a/tools/testing/selftests/rcutorture/bin/kcsan-collapse.sh b/tools/testing/selftests/rcutorture/bin/kcsan-collapse.sh
new file mode 100755
index 0000000..e5cc6b2
--- /dev/null
+++ b/tools/testing/selftests/rcutorture/bin/kcsan-collapse.sh
@@ -0,0 +1,22 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0+
+#
+# If this was a KCSAN run, collapse the reports in the various console.log
+# files onto pairs of functions.
+#
+# Usage: kcsan-collapse.sh resultsdir
+#
+# Copyright (C) 2020 Facebook, Inc.
+#
+# Authors: Paul E. McKenney <paulmck@kernel.org>
+
+if test -z "$TORTURE_KCONFIG_KCSAN_ARG"
+then
+	exit 0
+fi
+cat $1/*/console.log |
+	grep "BUG: KCSAN: " |
+	sed -e 's/^\[[^]]*] //' |
+	sort |
+	uniq -c |
+	sort -k1nr > $1/kcsan.sum
diff --git a/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh b/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh
index 0326f4a..736f047 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-recheck.sh
@@ -70,6 +70,15 @@ do
 			fi
 		fi
 	done
+	if test -f "$rd/kcsan.sum"
+	then
+		if test -s "$rd/kcsan.sum"
+		then
+			echo KCSAN summary in $rd/kcsan.sum
+		else
+			echo Clean KCSAN run in $rd
+		fi
+	fi
 done
 EDITOR=echo kvm-find-errors.sh "${@: -1}" > $T 2>&1
 ret=$?
diff --git a/tools/testing/selftests/rcutorture/bin/kvm.sh b/tools/testing/selftests/rcutorture/bin/kvm.sh
index 34b368d..75ae8e3 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm.sh
@@ -472,6 +472,7 @@ echo
 echo
 echo " --- `date` Test summary:"
 echo Results directory: $resdir/$ds
+kcsan-collapse.sh $resdir/$ds
 kvm-recheck.sh $resdir/$ds
 ___EOF___
 
-- 
2.9.5

[PATCH tip/core/rcu 11/18] rcutorture: Make rcu_fwds and rcu_fwd_emergency_stop static

[paulmck]

From: Jason Yan <yanaijie@huawei.com>

This commit fixes the following sparse warning:

kernel/rcu/rcutorture.c:1695:16: warning: symbol 'rcu_fwds' was not declared. Should it be static?
kernel/rcu/rcutorture.c:1696:6: warning: symbol 'rcu_fwd_emergency_stop' was not declared. Should it be static?

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 kernel/rcu/rcutorture.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 3d47dca..c7b7594b 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -1721,8 +1721,8 @@ struct rcu_fwd {
 	unsigned long rcu_launder_gp_seq_start;
 };
 
-struct rcu_fwd *rcu_fwds;
-bool rcu_fwd_emergency_stop;
+static struct rcu_fwd *rcu_fwds;
+static bool rcu_fwd_emergency_stop;
 
 static void rcu_torture_fwd_cb_hist(struct rcu_fwd *rfp)
 {
-- 
2.9.5

[PATCH tip/core/rcu 12/18] torture: Eliminate duplicate #CHECK# from ConfigFragment

[paulmck]

From: "Paul E. McKenney" <paulmck@kernel.org>

The #CHECK# directives that can be present in CFcommon and in the
rcutorture scenario Kconfig files are both copied to ConfigFragment
and grepped out of the two directive files and added to ConfigFragment.
This commit therefore removes the redundant "grep" commands and takes
advantage of the consequent opportunity to simplify redirection.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

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 e035230..74da059 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
@@ -44,19 +44,17 @@ then
 fi
 echo ' ---' `date`: Starting build
 echo ' ---' Kconfig fragment at: $config_template >> $resdir/log
-touch $resdir/ConfigFragment.input $resdir/ConfigFragment
+touch $resdir/ConfigFragment.input
 if test -r "$config_dir/CFcommon"
 then
 	echo " --- $config_dir/CFcommon" >> $resdir/ConfigFragment.input
 	cat < $config_dir/CFcommon >> $resdir/ConfigFragment.input
 	config_override.sh $config_dir/CFcommon $config_template > $T/Kc1
-	grep '#CHECK#' $config_dir/CFcommon >> $resdir/ConfigFragment
 else
 	cp $config_template $T/Kc1
 fi
 echo " --- $config_template" >> $resdir/ConfigFragment.input
 cat $config_template >> $resdir/ConfigFragment.input
-grep '#CHECK#' $config_template >> $resdir/ConfigFragment
 if test -n "$TORTURE_KCONFIG_ARG"
 then
 	echo $TORTURE_KCONFIG_ARG | tr -s " " "\012" > $T/cmdline
@@ -67,7 +65,7 @@ then
 else
 	cp $T/Kc1 $T/Kc2
 fi
-cat $T/Kc2 >> $resdir/ConfigFragment
+cat $T/Kc2 > $resdir/ConfigFragment
 
 base_resdir=`echo $resdir | sed -e 's/\.[0-9]\+$//'`
 if test "$base_resdir" != "$resdir" -a -f $base_resdir/bzImage -a -f $base_resdir/vmlinux
-- 
2.9.5

[PATCH tip/core/rcu 13/18] torture: Abstract application of additional Kconfig options

[paulmck]

From: "Paul E. McKenney" <paulmck@kernel.org>

This commit introduces a config_override_param() bash function that
folds in an additional set of Kconfig options.  This is initially applied
to fold in the --kconfig kvm.sh parameter, but later commits will also
apply it to the Kconfig options added by the --kcsan kvm.sh parameter.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 .../selftests/rcutorture/bin/kvm-test-1-run.sh     | 31 ++++++++++++++--------
 1 file changed, 20 insertions(+), 11 deletions(-)

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 74da059..1801b06 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
@@ -45,6 +45,24 @@ fi
 echo ' ---' `date`: Starting build
 echo ' ---' Kconfig fragment at: $config_template >> $resdir/log
 touch $resdir/ConfigFragment.input
+
+# Combine additional Kconfig options into an existing set such that newer
+# options win.  The first argument is the Kconfig source ID, the second
+# the source file within $T, the third the destination file within $T,
+# and the fourth and final the list of additional Kconfig options.
+config_override_param () {
+	if test -n "$4"
+	then
+		echo $4 | sed -e 's/^ *//' -e 's/ *$//' | tr -s " " "\012" > $T/Kconfig_args
+		echo " --- $1" >> $resdir/ConfigFragment.input
+		cat $T/Kconfig_args >> $resdir/ConfigFragment.input
+		config_override.sh $T/$2 $T/Kconfig_args > $T/$3
+		# Note that "#CHECK#" is not permitted on commandline.
+	else
+		cp $T/$2 $T/$3
+	fi
+}
+
 if test -r "$config_dir/CFcommon"
 then
 	echo " --- $config_dir/CFcommon" >> $resdir/ConfigFragment.input
@@ -55,17 +73,8 @@ else
 fi
 echo " --- $config_template" >> $resdir/ConfigFragment.input
 cat $config_template >> $resdir/ConfigFragment.input
-if test -n "$TORTURE_KCONFIG_ARG"
-then
-	echo $TORTURE_KCONFIG_ARG | tr -s " " "\012" > $T/cmdline
-	echo " --- --kconfig argument" >> $resdir/ConfigFragment.input
-	cat $T/cmdline >> $resdir/ConfigFragment.input
-	config_override.sh $T/Kc1 $T/cmdline > $T/Kc2
-	# Note that "#CHECK#" is not permitted on commandline.
-else
-	cp $T/Kc1 $T/Kc2
-fi
-cat $T/Kc2 > $resdir/ConfigFragment
+config_override_param "--kconfig argument" Kc1 Kc2 "$TORTURE_KCONFIG_ARG"
+cp $T/Kc2 $resdir/ConfigFragment
 
 base_resdir=`echo $resdir | sed -e 's/\.[0-9]\+$//'`
 if test "$base_resdir" != "$resdir" -a -f $base_resdir/bzImage -a -f $base_resdir/vmlinux
-- 
2.9.5

[PATCH tip/core/rcu 14/18] torture: Allow --kconfig options to override --kcsan defaults

[paulmck]

From: "Paul E. McKenney" <paulmck@kernel.org>

Currently, attempting to override a --kcsan default with a --kconfig
option might or might not work.  However, it would be good to allow the
user to adjust the --kcsan defaults, for example, to specify a different
time for CONFIG_KCSAN_REPORT_ONCE_IN_MS.  This commit therefore uses the
new config_override_param() bash function to apply the --kcsan defaults
and then apply the --kconfig options, which allows this overriding
to occur.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh | 7 ++++---
 tools/testing/selftests/rcutorture/bin/kvm.sh            | 3 ---
 2 files changed, 4 insertions(+), 6 deletions(-)

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 1801b06..b7296f1 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
@@ -73,8 +73,9 @@ else
 fi
 echo " --- $config_template" >> $resdir/ConfigFragment.input
 cat $config_template >> $resdir/ConfigFragment.input
-config_override_param "--kconfig argument" Kc1 Kc2 "$TORTURE_KCONFIG_ARG"
-cp $T/Kc2 $resdir/ConfigFragment
+config_override_param "--kcsan options" Kc1 Kc2 "$TORTURE_KCONFIG_KCSAN_ARG"
+config_override_param "--kconfig argument" Kc2 Kc3 "$TORTURE_KCONFIG_ARG"
+cp $T/Kc3 $resdir/ConfigFragment
 
 base_resdir=`echo $resdir | sed -e 's/\.[0-9]\+$//'`
 if test "$base_resdir" != "$resdir" -a -f $base_resdir/bzImage -a -f $base_resdir/vmlinux
@@ -87,7 +88,7 @@ then
 	ln -s $base_resdir/.config $resdir  # for kvm-recheck.sh
 	# Arch-independent indicator
 	touch $resdir/builtkernel
-elif kvm-build.sh $T/Kc2 $resdir
+elif kvm-build.sh $T/Kc3 $resdir
 then
 	# Had to build a kernel for this test.
 	QEMU="`identify_qemu vmlinux`"
diff --git a/tools/testing/selftests/rcutorture/bin/kvm.sh b/tools/testing/selftests/rcutorture/bin/kvm.sh
index 75ae8e3..e001fc4 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm.sh
@@ -205,9 +205,6 @@ else
 	exit 1
 fi
 
-TORTURE_KCONFIG_ARG="${TORTURE_KCONFIG_ARG} ${TORTURE_KCONFIG_KCSAN_ARG}"
-TORTURE_KCONFIG_ARG="`echo ${TORTURE_KCONFIG_ARG} | sed -e 's/^ *//' -e 's/ *$//'`"
-
 CONFIGFRAG=${KVM}/configs/${TORTURE_SUITE}; export CONFIGFRAG
 
 defaultconfigs="`tr '\012' ' ' < $CONFIGFRAG/CFLIST`"
-- 
2.9.5

[PATCH tip/core/rcu 15/18] torture: Allow scenario-specific Kconfig options to override CFcommon

[paulmck]

From: "Paul E. McKenney" <paulmck@kernel.org>

This commit applies config_override_param() to allow scenario-specific
Kconfig options to override those in CFcommon.  This in turn will allow
additional Kconfig options to be placed in CFcommon, for example, an
option common to all but a few scenario can be placed in CFcommon and
then overridden in those few scenarios.  Plus this change saves one
whole line of code.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

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 b7296f1..c7534fd 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
@@ -67,12 +67,11 @@ if test -r "$config_dir/CFcommon"
 then
 	echo " --- $config_dir/CFcommon" >> $resdir/ConfigFragment.input
 	cat < $config_dir/CFcommon >> $resdir/ConfigFragment.input
-	config_override.sh $config_dir/CFcommon $config_template > $T/Kc1
+	cp $config_dir/CFcommon $T/Kc0
 else
-	cp $config_template $T/Kc1
+	echo > $T/Kc0
 fi
-echo " --- $config_template" >> $resdir/ConfigFragment.input
-cat $config_template >> $resdir/ConfigFragment.input
+config_override_param "$config_template" Kc0 Kc1 "`cat $config_template 2> /dev/null`"
 config_override_param "--kcsan options" Kc1 Kc2 "$TORTURE_KCONFIG_KCSAN_ARG"
 config_override_param "--kconfig argument" Kc2 Kc3 "$TORTURE_KCONFIG_ARG"
 cp $T/Kc3 $resdir/ConfigFragment
-- 
2.9.5

[PATCH tip/core/rcu 16/18] torture: Save a few lines by using config_override_param initially

[paulmck]

From: "Paul E. McKenney" <paulmck@kernel.org>

This commit saves a few lines of code by also using the bash
config_override_param() to set the initial list of Kconfig options from
the CFcommon file.  While in the area, it makes this function capable of
update-in-place on the file containing the cumulative Kconfig options,
thus avoiding annoying changes when adding another source of options.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 .../selftests/rcutorture/bin/kvm-test-1-run.sh     | 38 +++++++++-------------
 1 file changed, 16 insertions(+), 22 deletions(-)

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 c7534fd..52f8966 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
@@ -46,35 +46,29 @@ echo ' ---' `date`: Starting build
 echo ' ---' Kconfig fragment at: $config_template >> $resdir/log
 touch $resdir/ConfigFragment.input
 
-# Combine additional Kconfig options into an existing set such that newer
-# options win.  The first argument is the Kconfig source ID, the second
-# the source file within $T, the third the destination file within $T,
-# and the fourth and final the list of additional Kconfig options.
+# Combine additional Kconfig options into an existing set such that
+# newer options win.  The first argument is the Kconfig source ID, the
+# second the to-be-updated file within $T, and the third and final the
+# list of additional Kconfig options.  Note that a $2.tmp file is
+# created when doing the update.
 config_override_param () {
-	if test -n "$4"
+	if test -n "$3"
 	then
-		echo $4 | sed -e 's/^ *//' -e 's/ *$//' | tr -s " " "\012" > $T/Kconfig_args
+		echo $3 | sed -e 's/^ *//' -e 's/ *$//' | tr -s " " "\012" > $T/Kconfig_args
 		echo " --- $1" >> $resdir/ConfigFragment.input
 		cat $T/Kconfig_args >> $resdir/ConfigFragment.input
-		config_override.sh $T/$2 $T/Kconfig_args > $T/$3
+		config_override.sh $T/$2 $T/Kconfig_args > $T/$2.tmp
+		mv $T/$2.tmp $T/$2
 		# Note that "#CHECK#" is not permitted on commandline.
-	else
-		cp $T/$2 $T/$3
 	fi
 }
 
-if test -r "$config_dir/CFcommon"
-then
-	echo " --- $config_dir/CFcommon" >> $resdir/ConfigFragment.input
-	cat < $config_dir/CFcommon >> $resdir/ConfigFragment.input
-	cp $config_dir/CFcommon $T/Kc0
-else
-	echo > $T/Kc0
-fi
-config_override_param "$config_template" Kc0 Kc1 "`cat $config_template 2> /dev/null`"
-config_override_param "--kcsan options" Kc1 Kc2 "$TORTURE_KCONFIG_KCSAN_ARG"
-config_override_param "--kconfig argument" Kc2 Kc3 "$TORTURE_KCONFIG_ARG"
-cp $T/Kc3 $resdir/ConfigFragment
+echo > $T/KcList
+config_override_param "$config_dir/CFcommon" KcList "`cat $config_dir/CFcommon 2> /dev/null`"
+config_override_param "$config_template" KcList "`cat $config_template 2> /dev/null`"
+config_override_param "--kcsan options" KcList "$TORTURE_KCONFIG_KCSAN_ARG"
+config_override_param "--kconfig argument" KcList "$TORTURE_KCONFIG_ARG"
+cp $T/KcList $resdir/ConfigFragment
 
 base_resdir=`echo $resdir | sed -e 's/\.[0-9]\+$//'`
 if test "$base_resdir" != "$resdir" -a -f $base_resdir/bzImage -a -f $base_resdir/vmlinux
@@ -87,7 +81,7 @@ then
 	ln -s $base_resdir/.config $resdir  # for kvm-recheck.sh
 	# Arch-independent indicator
 	touch $resdir/builtkernel
-elif kvm-build.sh $T/Kc3 $resdir
+elif kvm-build.sh $T/KcList $resdir
 then
 	# Had to build a kernel for this test.
 	QEMU="`identify_qemu vmlinux`"
-- 
2.9.5

[PATCH tip/core/rcu 17/18] torture: Add a --kasan argument

[paulmck]

From: "Paul E. McKenney" <paulmck@kernel.org>

Make it a bit easier to apply KASAN to rcutorture runs with a new --kasan
argument, again leveraging the config_override_param() bash function.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh | 1 +
 tools/testing/selftests/rcutorture/bin/kvm.sh            | 5 +++++
 2 files changed, 6 insertions(+)

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 52f8966..6ff611c 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh
@@ -66,6 +66,7 @@ config_override_param () {
 echo > $T/KcList
 config_override_param "$config_dir/CFcommon" KcList "`cat $config_dir/CFcommon 2> /dev/null`"
 config_override_param "$config_template" KcList "`cat $config_template 2> /dev/null`"
+config_override_param "--kasan options" KcList "$TORTURE_KCONFIG_KASAN_ARG"
 config_override_param "--kcsan options" KcList "$TORTURE_KCONFIG_KCSAN_ARG"
 config_override_param "--kconfig argument" KcList "$TORTURE_KCONFIG_ARG"
 cp $T/KcList $resdir/ConfigFragment
diff --git a/tools/testing/selftests/rcutorture/bin/kvm.sh b/tools/testing/selftests/rcutorture/bin/kvm.sh
index e001fc4..c279cf9 100755
--- a/tools/testing/selftests/rcutorture/bin/kvm.sh
+++ b/tools/testing/selftests/rcutorture/bin/kvm.sh
@@ -31,6 +31,7 @@ TORTURE_DEFCONFIG=defconfig
 TORTURE_BOOT_IMAGE=""
 TORTURE_INITRD="$KVM/initrd"; export TORTURE_INITRD
 TORTURE_KCONFIG_ARG=""
+TORTURE_KCONFIG_KASAN_ARG=""
 TORTURE_KCONFIG_KCSAN_ARG=""
 TORTURE_KMAKE_ARG=""
 TORTURE_QEMU_MEM=512
@@ -134,6 +135,9 @@ do
 		TORTURE_KCONFIG_ARG="$2"
 		shift
 		;;
+	--kasan)
+		TORTURE_KCONFIG_KASAN_ARG="CONFIG_DEBUG_INFO=y CONFIG_KASAN=y"; export TORTURE_KCONFIG_KASAN_ARG
+		;;
 	--kcsan)
 		TORTURE_KCONFIG_KCSAN_ARG="CONFIG_DEBUG_INFO=y CONFIG_KCSAN=y CONFIG_KCSAN_ASSUME_PLAIN_WRITES_ATOMIC=n CONFIG_KCSAN_REPORT_VALUE_CHANGE_ONLY=n CONFIG_KCSAN_REPORT_ONCE_IN_MS=100000 CONFIG_KCSAN_VERBOSE=y CONFIG_KCSAN_INTERRUPT_WATCHER=y"; export TORTURE_KCONFIG_KCSAN_ARG
 		;;
@@ -314,6 +318,7 @@ TORTURE_BUILDONLY="$TORTURE_BUILDONLY"; export TORTURE_BUILDONLY
 TORTURE_DEFCONFIG="$TORTURE_DEFCONFIG"; export TORTURE_DEFCONFIG
 TORTURE_INITRD="$TORTURE_INITRD"; export TORTURE_INITRD
 TORTURE_KCONFIG_ARG="$TORTURE_KCONFIG_ARG"; export TORTURE_KCONFIG_ARG
+TORTURE_KCONFIG_KASAN_ARG="$TORTURE_KCONFIG_KASAN_ARG"; export TORTURE_KCONFIG_KASAN_ARG
 TORTURE_KCONFIG_KCSAN_ARG="$TORTURE_KCONFIG_KCSAN_ARG"; export TORTURE_KCONFIG_KCSAN_ARG
 TORTURE_KMAKE_ARG="$TORTURE_KMAKE_ARG"; export TORTURE_KMAKE_ARG
 TORTURE_QEMU_CMD="$TORTURE_QEMU_CMD"; export TORTURE_QEMU_CMD
-- 
2.9.5

[PATCH tip/core/rcu 18/18] rcutorture: Convert ULONG_CMP_LT() to time_before()

[paulmck]

From: "Paul E. McKenney" <paulmck@kernel.org>

This commit converts three ULONG_CMP_LT() invocations in rcutorture to
time_before() to reflect the fact that they are comparing timestamps to
the jiffies counter.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 kernel/rcu/rcutorture.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index c7b7594b..fc96147 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -848,7 +848,7 @@ static int rcu_torture_boost(void *arg)
 
 		/* Wait for the next test interval. */
 		oldstarttime = boost_starttime;
-		while (ULONG_CMP_LT(jiffies, oldstarttime)) {
+		while (time_before(jiffies, oldstarttime)) {
 			schedule_timeout_interruptible(oldstarttime - jiffies);
 			stutter_wait("rcu_torture_boost");
 			if (torture_must_stop())
@@ -858,7 +858,7 @@ static int rcu_torture_boost(void *arg)
 		/* Do one boost-test interval. */
 		endtime = oldstarttime + test_boost_duration * HZ;
 		call_rcu_time = jiffies;
-		while (ULONG_CMP_LT(jiffies, endtime)) {
+		while (time_before(jiffies, endtime)) {
 			/* If we don't have a callback in flight, post one. */
 			if (!smp_load_acquire(&rbi.inflight)) {
 				/* RCU core before ->inflight = 1. */
@@ -929,7 +929,7 @@ rcu_torture_fqs(void *arg)
 	VERBOSE_TOROUT_STRING("rcu_torture_fqs task started");
 	do {
 		fqs_resume_time = jiffies + fqs_stutter * HZ;
-		while (ULONG_CMP_LT(jiffies, fqs_resume_time) &&
+		while (time_before(jiffies, fqs_resume_time) &&
 		       !kthread_should_stop()) {
 			schedule_timeout_interruptible(1);
 		}
-- 
2.9.5