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Date:   Thu, 27 Aug 2020 07:54:15 -0000
From:   "tip-bot2 for Boqun Feng" <tip-bot2@linutronix.de>
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Subject: [tip: locking/core] lockdep/selftest: Add more recursive read related
 test cases
Cc:     Boqun Feng <boqun.feng@gmail.com>,
        "Peter Zijlstra (Intel)" <peterz@infradead.org>,
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The following commit has been merged into the locking/core branch of tip:

Commit-ID:     8ef7ca75120a39167def40f41daefee013c4b5af
Gitweb:        https://git.kernel.org/tip/8ef7ca75120a39167def40f41daefee013c4b5af
Author:        Boqun Feng <boqun.feng@gmail.com>
AuthorDate:    Fri, 07 Aug 2020 15:42:35 +08:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Wed, 26 Aug 2020 12:42:07 +02:00

lockdep/selftest: Add more recursive read related test cases

Add those four test cases:

1.	X --(ER)--> Y --(ER)--> Z --(ER)--> X is deadlock.

2.	X --(EN)--> Y --(SR)--> Z --(ER)--> X is deadlock.

3.	X --(EN)--> Y --(SR)--> Z --(SN)--> X is not deadlock.

4.	X --(ER)--> Y --(SR)--> Z --(EN)--> X is not deadlock.

Those self testcases are valuable for the development of supporting
recursive read related deadlock detection.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200807074238.1632519-17-boqun.feng@gmail.com
---
 lib/locking-selftest.c | 161 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 161 insertions(+)

diff --git a/lib/locking-selftest.c b/lib/locking-selftest.c
index f65a658..76c314a 100644
--- a/lib/locking-selftest.c
+++ b/lib/locking-selftest.c
@@ -1035,6 +1035,133 @@ GENERATE_PERMUTATIONS_3_EVENTS(irq_inversion_soft_wlock)
 #undef E3
 
 /*
+ * write-read / write-read / write-read deadlock even if read is recursive
+ */
+
+#define E1()				\
+					\
+	WL(X1);				\
+	RL(Y1);				\
+	RU(Y1);				\
+	WU(X1);
+
+#define E2()				\
+					\
+	WL(Y1);				\
+	RL(Z1);				\
+	RU(Z1);				\
+	WU(Y1);
+
+#define E3()				\
+					\
+	WL(Z1);				\
+	RL(X1);				\
+	RU(X1);				\
+	WU(Z1);
+
+#include "locking-selftest-rlock.h"
+GENERATE_PERMUTATIONS_3_EVENTS(W1R2_W2R3_W3R1)
+
+#undef E1
+#undef E2
+#undef E3
+
+/*
+ * write-write / read-read / write-read deadlock even if read is recursive
+ */
+
+#define E1()				\
+					\
+	WL(X1);				\
+	WL(Y1);				\
+	WU(Y1);				\
+	WU(X1);
+
+#define E2()				\
+					\
+	RL(Y1);				\
+	RL(Z1);				\
+	RU(Z1);				\
+	RU(Y1);
+
+#define E3()				\
+					\
+	WL(Z1);				\
+	RL(X1);				\
+	RU(X1);				\
+	WU(Z1);
+
+#include "locking-selftest-rlock.h"
+GENERATE_PERMUTATIONS_3_EVENTS(W1W2_R2R3_W3R1)
+
+#undef E1
+#undef E2
+#undef E3
+
+/*
+ * write-write / read-read / read-write is not deadlock when read is recursive
+ */
+
+#define E1()				\
+					\
+	WL(X1);				\
+	WL(Y1);				\
+	WU(Y1);				\
+	WU(X1);
+
+#define E2()				\
+					\
+	RL(Y1);				\
+	RL(Z1);				\
+	RU(Z1);				\
+	RU(Y1);
+
+#define E3()				\
+					\
+	RL(Z1);				\
+	WL(X1);				\
+	WU(X1);				\
+	RU(Z1);
+
+#include "locking-selftest-rlock.h"
+GENERATE_PERMUTATIONS_3_EVENTS(W1R2_R2R3_W3W1)
+
+#undef E1
+#undef E2
+#undef E3
+
+/*
+ * write-read / read-read / write-write is not deadlock when read is recursive
+ */
+
+#define E1()				\
+					\
+	WL(X1);				\
+	RL(Y1);				\
+	RU(Y1);				\
+	WU(X1);
+
+#define E2()				\
+					\
+	RL(Y1);				\
+	RL(Z1);				\
+	RU(Z1);				\
+	RU(Y1);
+
+#define E3()				\
+					\
+	WL(Z1);				\
+	WL(X1);				\
+	WU(X1);				\
+	WU(Z1);
+
+#include "locking-selftest-rlock.h"
+GENERATE_PERMUTATIONS_3_EVENTS(W1W2_R2R3_R3W1)
+
+#undef E1
+#undef E2
+#undef E3
+/*
  * read-lock / write-lock recursion that is actually safe.
  */
 
@@ -1259,6 +1386,19 @@ static inline void print_testname(const char *testname)
 	dotest(name##_##nr, FAILURE, LOCKTYPE_RWLOCK);		\
 	pr_cont("\n");
 
+#define DO_TESTCASE_1RR(desc, name, nr)				\
+	print_testname(desc"/"#nr);				\
+	pr_cont("             |");				\
+	dotest(name##_##nr, SUCCESS, LOCKTYPE_RWLOCK);		\
+	pr_cont("\n");
+
+#define DO_TESTCASE_1RRB(desc, name, nr)			\
+	print_testname(desc"/"#nr);				\
+	pr_cont("             |");				\
+	dotest(name##_##nr, FAILURE, LOCKTYPE_RWLOCK);		\
+	pr_cont("\n");
+
+
 #define DO_TESTCASE_3(desc, name, nr)				\
 	print_testname(desc"/"#nr);				\
 	dotest(name##_spin_##nr, FAILURE, LOCKTYPE_SPIN);	\
@@ -1368,6 +1508,22 @@ static inline void print_testname(const char *testname)
 	DO_TESTCASE_2IB(desc, name, 312);			\
 	DO_TESTCASE_2IB(desc, name, 321);
 
+#define DO_TESTCASE_6x1RR(desc, name)				\
+	DO_TESTCASE_1RR(desc, name, 123);			\
+	DO_TESTCASE_1RR(desc, name, 132);			\
+	DO_TESTCASE_1RR(desc, name, 213);			\
+	DO_TESTCASE_1RR(desc, name, 231);			\
+	DO_TESTCASE_1RR(desc, name, 312);			\
+	DO_TESTCASE_1RR(desc, name, 321);
+
+#define DO_TESTCASE_6x1RRB(desc, name)				\
+	DO_TESTCASE_1RRB(desc, name, 123);			\
+	DO_TESTCASE_1RRB(desc, name, 132);			\
+	DO_TESTCASE_1RRB(desc, name, 213);			\
+	DO_TESTCASE_1RRB(desc, name, 231);			\
+	DO_TESTCASE_1RRB(desc, name, 312);			\
+	DO_TESTCASE_1RRB(desc, name, 321);
+
 #define DO_TESTCASE_6x6(desc, name)				\
 	DO_TESTCASE_6I(desc, name, 123);			\
 	DO_TESTCASE_6I(desc, name, 132);			\
@@ -2144,6 +2300,11 @@ void locking_selftest(void)
 	pr_cont("             |");
 	dotest(rlock_chaincache_ABBA1, FAILURE, LOCKTYPE_RWLOCK);
 
+	DO_TESTCASE_6x1RRB("rlock W1R2/W2R3/W3R1", W1R2_W2R3_W3R1);
+	DO_TESTCASE_6x1RRB("rlock W1W2/R2R3/W3R1", W1W2_R2R3_W3R1);
+	DO_TESTCASE_6x1RR("rlock W1W2/R2R3/R3W1", W1W2_R2R3_R3W1);
+	DO_TESTCASE_6x1RR("rlock W1R2/R2R3/W3W1", W1R2_R2R3_W3W1);
+
 	printk("  --------------------------------------------------------------------------\n");
 
 	/*