linux-kernel - [PATCH 12/16] rcutorture: Add reader

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20241112145159.23032-13-frederic@kernel.org>
Date: Tue, 12 Nov 2024 15:51:55 +0100
From: Frederic Weisbecker <frederic@...nel.org>
To: LKML <linux-kernel@...r.kernel.org>
Cc: "Paul E. McKenney" <paulmck@...nel.org>,
	Boqun Feng <boqun.feng@...il.com>,
	Joel Fernandes <joel@...lfernandes.org>,
	Josh Triplett <josh@...htriplett.org>,
	Lai Jiangshan <jiangshanlai@...il.com>,
	Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
	Neeraj Upadhyay <neeraj.upadhyay@....com>,
	Steven Rostedt <rostedt@...dmis.org>,
	Uladzislau Rezki <urezki@...il.com>,
	Zqiang <qiang.zhang1211@...il.com>,
	rcu <rcu@...r.kernel.org>,
	Alexei Starovoitov <ast@...nel.org>,
	Andrii Nakryiko <andrii@...nel.org>,
	Peter Zijlstra <peterz@...radead.org>,
	Kent Overstreet <kent.overstreet@...ux.dev>,
	bpf@...r.kernel.org,
	Neeraj Upadhyay <Neeraj.Upadhyay@....com>,
	Frederic Weisbecker <frederic@...nel.org>
Subject: [PATCH 12/16] rcutorture: Add reader_flavor parameter for SRCU readers

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

This commit adds an rcutorture.reader_flavor parameter whose bits
correspond to reader flavors.  For example, SRCU's readers are 0x1 for
normal and 0x2 for NMI-safe.

Signed-off-by: Paul E. McKenney <paulmck@...nel.org>
Cc: Alexei Starovoitov <ast@...nel.org>
Cc: Andrii Nakryiko <andrii@...nel.org>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Kent Overstreet <kent.overstreet@...ux.dev>
Cc: <bpf@...r.kernel.org>
Reviewed-by: Neeraj Upadhyay <Neeraj.Upadhyay@....com>
Signed-off-by: Frederic Weisbecker <frederic@...nel.org>
---
 .../admin-guide/kernel-parameters.txt         |  8 +++++
 kernel/rcu/rcutorture.c                       | 30 ++++++++++++++-----
 2 files changed, 30 insertions(+), 8 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 1518343bbe22..52922727006f 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -5426,6 +5426,14 @@
 			The delay, in seconds, between successive
 			read-then-exit testing episodes.
 
+	rcutorture.reader_flavor= [KNL]
+			A bit mask indicating which readers to use.
+			If there is more than one bit set, the readers
+			are entered from low-order bit up, and are
+			exited in the opposite order.  For SRCU, the
+			0x1 bit is normal readers and the 0x2 bit is
+			for NMI-safe readers.
+
 	rcutorture.shuffle_interval= [KNL]
 			Set task-shuffle interval (s).  Shuffling tasks
 			allows some CPUs to go into dyntick-idle mode
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index f96ab98f8182..405decec3367 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -111,6 +111,7 @@ torture_param(int, nocbs_nthreads, 0, "Number of NOCB toggle threads, 0 to disab
 torture_param(int, nocbs_toggle, 1000, "Time between toggling nocb state (ms)");
 torture_param(int, read_exit_delay, 13, "Delay between read-then-exit episodes (s)");
 torture_param(int, read_exit_burst, 16, "# of read-then-exit bursts per episode, zero to disable");
+torture_param(int, reader_flavor, 0x1, "Reader flavors to use, one per bit.");
 torture_param(int, shuffle_interval, 3, "Number of seconds between shuffles");
 torture_param(int, shutdown_secs, 0, "Shutdown time (s), <= zero to disable.");
 torture_param(int, stall_cpu, 0, "Stall duration (s), zero to disable.");
@@ -644,10 +645,20 @@ static void srcu_get_gp_data(int *flags, unsigned long *gp_seq)
 
 static int srcu_torture_read_lock(void)
 {
-	if (cur_ops == &srcud_ops)
-		return srcu_read_lock_nmisafe(srcu_ctlp);
-	else
-		return srcu_read_lock(srcu_ctlp);
+	int idx;
+	int ret = 0;
+
+	if ((reader_flavor & 0x1) || !(reader_flavor & 0x7)) {
+		idx = srcu_read_lock(srcu_ctlp);
+		WARN_ON_ONCE(idx & ~0x1);
+		ret += idx;
+	}
+	if (reader_flavor & 0x2) {
+		idx = srcu_read_lock_nmisafe(srcu_ctlp);
+		WARN_ON_ONCE(idx & ~0x1);
+		ret += idx << 1;
+	}
+	return ret;
 }
 
 static void
@@ -671,10 +682,11 @@ srcu_read_delay(struct torture_random_state *rrsp, struct rt_read_seg *rtrsp)
 
 static void srcu_torture_read_unlock(int idx)
 {
-	if (cur_ops == &srcud_ops)
-		srcu_read_unlock_nmisafe(srcu_ctlp, idx);
-	else
-		srcu_read_unlock(srcu_ctlp, idx);
+	WARN_ON_ONCE((reader_flavor && (idx & ~reader_flavor)) || (!reader_flavor && (idx & ~0x1)));
+	if (reader_flavor & 0x2)
+		srcu_read_unlock_nmisafe(srcu_ctlp, (idx & 0x2) >> 1);
+	if ((reader_flavor & 0x1) || !(reader_flavor & 0x7))
+		srcu_read_unlock(srcu_ctlp, idx & 0x1);
 }
 
 static int torture_srcu_read_lock_held(void)
@@ -2389,6 +2401,7 @@ rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag)
 		 "n_barrier_cbs=%d "
 		 "onoff_interval=%d onoff_holdoff=%d "
 		 "read_exit_delay=%d read_exit_burst=%d "
+		 "reader_flavor=%x "
 		 "nocbs_nthreads=%d nocbs_toggle=%d "
 		 "test_nmis=%d\n",
 		 torture_type, tag, nrealreaders, nfakewriters,
@@ -2401,6 +2414,7 @@ rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag)
 		 n_barrier_cbs,
 		 onoff_interval, onoff_holdoff,
 		 read_exit_delay, read_exit_burst,
+		 reader_flavor,
 		 nocbs_nthreads, nocbs_toggle,
 		 test_nmis);
 }
-- 
2.46.0