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lockdep/selftest: Introduce recursion3 

Add a test case shows that USED_IN_*_READ and ENABLE_*_READ can cause
deadlock too.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200807074238.1632519-20-boqun.feng@gmail.com
This commit is contained in:
Boqun Feng 2020-08-07 15:42:38 +08:00 committed by Peter Zijlstra
parent ad56450db8
commit 96a16f45ae
1 changed files with 55 additions and 0 deletions
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55
lib/locking-selftest.c
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@ -1249,6 +1249,60 @@ GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion2_soft_rlock)
#include "locking-selftest-wlock.h"
GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion2_soft_wlock)
#undef E1
#undef E2
#undef E3
/*
* read-lock / write-lock recursion that is unsafe.
*
* A is a ENABLED_*_READ lock
* B is a USED_IN_*_READ lock
*
* read_lock(A);
* write_lock(B);
* <interrupt>
* read_lock(B);
* write_lock(A); // if this one is read_lock(), no deadlock
*/
#define E1() \
\
IRQ_DISABLE(); \
WL(B); \
LOCK(A); \
UNLOCK(A); \
WU(B); \
IRQ_ENABLE();
#define E2() \
\
RL(A); \
RU(A); \
#define E3() \
\
IRQ_ENTER(); \
RL(B); \
RU(B); \
IRQ_EXIT();
/*
* Generate 24 testcases:
*/
#include "locking-selftest-hardirq.h"
#include "locking-selftest-rlock.h"
GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion3_hard_rlock)
#include "locking-selftest-wlock.h"
GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion3_hard_wlock)
#include "locking-selftest-softirq.h"
#include "locking-selftest-rlock.h"
GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion3_soft_rlock)
#include "locking-selftest-wlock.h"
GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion3_soft_wlock)
#ifdef CONFIG_DEBUG_LOCK_ALLOC
# define I_SPINLOCK(x) lockdep_reset_lock(&lock_##x.dep_map)
# define I_RWLOCK(x) lockdep_reset_lock(&rwlock_##x.dep_map)
@ -2413,6 +2467,7 @@ void locking_selftest(void)
DO_TESTCASE_6x2x2RW("irq read-recursion", irq_read_recursion);
DO_TESTCASE_6x2x2RW("irq read-recursion #2", irq_read_recursion2);
DO_TESTCASE_6x2x2RW("irq read-recursion #3", irq_read_recursion3);
ww_tests();