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authorLinus Torvalds <torvalds@linux-foundation.org>2021-06-28 21:45:29 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2021-06-28 21:45:29 +0300
commita15286c63d113d4296c58867994cd266a28f5d6d (patch)
treeaaebbc86918c0c1943c26115d5bb1dd6c2fc2d9b /lib
parentb89c07dea16137696d0f2d479ef665ef7c1022ab (diff)
parent0e8a89d49d45197770f2e57fb15f1bc9ded96eb0 (diff)
downloadlinux-a15286c63d113d4296c58867994cd266a28f5d6d.tar.xz
Merge tag 'locking-core-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar: - Core locking & atomics: - Convert all architectures to ARCH_ATOMIC: move every architecture to ARCH_ATOMIC, then get rid of ARCH_ATOMIC and all the transitory facilities and #ifdefs. Much reduction in complexity from that series: 63 files changed, 756 insertions(+), 4094 deletions(-) - Self-test enhancements - Futexes: - Add the new FUTEX_LOCK_PI2 ABI, which is a variant that doesn't set FLAGS_CLOCKRT (.e. uses CLOCK_MONOTONIC). [ The temptation to repurpose FUTEX_LOCK_PI's implicit setting of FLAGS_CLOCKRT & invert the flag's meaning to avoid having to introduce a new variant was resisted successfully. ] - Enhance futex self-tests - Lockdep: - Fix dependency path printouts - Optimize trace saving - Broaden & fix wait-context checks - Misc cleanups and fixes. * tag 'locking-core-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits) locking/lockdep: Correct the description error for check_redundant() futex: Provide FUTEX_LOCK_PI2 to support clock selection futex: Prepare futex_lock_pi() for runtime clock selection lockdep/selftest: Remove wait-type RCU_CALLBACK tests lockdep/selftests: Fix selftests vs PROVE_RAW_LOCK_NESTING lockdep: Fix wait-type for empty stack locking/selftests: Add a selftest for check_irq_usage() lockding/lockdep: Avoid to find wrong lock dep path in check_irq_usage() locking/lockdep: Remove the unnecessary trace saving locking/lockdep: Fix the dep path printing for backwards BFS selftests: futex: Add futex compare requeue test selftests: futex: Add futex wait test seqlock: Remove trailing semicolon in macros locking/lockdep: Reduce LOCKDEP dependency list locking/lockdep,doc: Improve readability of the block matrix locking/atomics: atomic-instrumented: simplify ifdeffery locking/atomic: delete !ARCH_ATOMIC remnants locking/atomic: xtensa: move to ARCH_ATOMIC locking/atomic: sparc: move to ARCH_ATOMIC locking/atomic: sh: move to ARCH_ATOMIC ...
Diffstat (limited to 'lib')
-rw-r--r--lib/Kconfig.debug1
-rw-r--r--lib/atomic64.c36
-rw-r--r--lib/locking-selftest.c83
3 files changed, 84 insertions, 36 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 678c13967580..1e1bd6f4a13d 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1372,7 +1372,6 @@ config LOCKDEP
bool
depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
select STACKTRACE
- depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
select KALLSYMS
select KALLSYMS_ALL
diff --git a/lib/atomic64.c b/lib/atomic64.c
index e98c85a99787..3df653994177 100644
--- a/lib/atomic64.c
+++ b/lib/atomic64.c
@@ -42,7 +42,7 @@ static inline raw_spinlock_t *lock_addr(const atomic64_t *v)
return &atomic64_lock[addr & (NR_LOCKS - 1)].lock;
}
-s64 atomic64_read(const atomic64_t *v)
+s64 generic_atomic64_read(const atomic64_t *v)
{
unsigned long flags;
raw_spinlock_t *lock = lock_addr(v);
@@ -53,9 +53,9 @@ s64 atomic64_read(const atomic64_t *v)
raw_spin_unlock_irqrestore(lock, flags);
return val;
}
-EXPORT_SYMBOL(atomic64_read);
+EXPORT_SYMBOL(generic_atomic64_read);
-void atomic64_set(atomic64_t *v, s64 i)
+void generic_atomic64_set(atomic64_t *v, s64 i)
{
unsigned long flags;
raw_spinlock_t *lock = lock_addr(v);
@@ -64,10 +64,10 @@ void atomic64_set(atomic64_t *v, s64 i)
v->counter = i;
raw_spin_unlock_irqrestore(lock, flags);
}
-EXPORT_SYMBOL(atomic64_set);
+EXPORT_SYMBOL(generic_atomic64_set);
#define ATOMIC64_OP(op, c_op) \
-void atomic64_##op(s64 a, atomic64_t *v) \
+void generic_atomic64_##op(s64 a, atomic64_t *v) \
{ \
unsigned long flags; \
raw_spinlock_t *lock = lock_addr(v); \
@@ -76,10 +76,10 @@ void atomic64_##op(s64 a, atomic64_t *v) \
v->counter c_op a; \
raw_spin_unlock_irqrestore(lock, flags); \
} \
-EXPORT_SYMBOL(atomic64_##op);
+EXPORT_SYMBOL(generic_atomic64_##op);
#define ATOMIC64_OP_RETURN(op, c_op) \
-s64 atomic64_##op##_return(s64 a, atomic64_t *v) \
+s64 generic_atomic64_##op##_return(s64 a, atomic64_t *v) \
{ \
unsigned long flags; \
raw_spinlock_t *lock = lock_addr(v); \
@@ -90,10 +90,10 @@ s64 atomic64_##op##_return(s64 a, atomic64_t *v) \
raw_spin_unlock_irqrestore(lock, flags); \
return val; \
} \
-EXPORT_SYMBOL(atomic64_##op##_return);
+EXPORT_SYMBOL(generic_atomic64_##op##_return);
#define ATOMIC64_FETCH_OP(op, c_op) \
-s64 atomic64_fetch_##op(s64 a, atomic64_t *v) \
+s64 generic_atomic64_fetch_##op(s64 a, atomic64_t *v) \
{ \
unsigned long flags; \
raw_spinlock_t *lock = lock_addr(v); \
@@ -105,7 +105,7 @@ s64 atomic64_fetch_##op(s64 a, atomic64_t *v) \
raw_spin_unlock_irqrestore(lock, flags); \
return val; \
} \
-EXPORT_SYMBOL(atomic64_fetch_##op);
+EXPORT_SYMBOL(generic_atomic64_fetch_##op);
#define ATOMIC64_OPS(op, c_op) \
ATOMIC64_OP(op, c_op) \
@@ -130,7 +130,7 @@ ATOMIC64_OPS(xor, ^=)
#undef ATOMIC64_OP_RETURN
#undef ATOMIC64_OP
-s64 atomic64_dec_if_positive(atomic64_t *v)
+s64 generic_atomic64_dec_if_positive(atomic64_t *v)
{
unsigned long flags;
raw_spinlock_t *lock = lock_addr(v);
@@ -143,9 +143,9 @@ s64 atomic64_dec_if_positive(atomic64_t *v)
raw_spin_unlock_irqrestore(lock, flags);
return val;
}
-EXPORT_SYMBOL(atomic64_dec_if_positive);
+EXPORT_SYMBOL(generic_atomic64_dec_if_positive);
-s64 atomic64_cmpxchg(atomic64_t *v, s64 o, s64 n)
+s64 generic_atomic64_cmpxchg(atomic64_t *v, s64 o, s64 n)
{
unsigned long flags;
raw_spinlock_t *lock = lock_addr(v);
@@ -158,9 +158,9 @@ s64 atomic64_cmpxchg(atomic64_t *v, s64 o, s64 n)
raw_spin_unlock_irqrestore(lock, flags);
return val;
}
-EXPORT_SYMBOL(atomic64_cmpxchg);
+EXPORT_SYMBOL(generic_atomic64_cmpxchg);
-s64 atomic64_xchg(atomic64_t *v, s64 new)
+s64 generic_atomic64_xchg(atomic64_t *v, s64 new)
{
unsigned long flags;
raw_spinlock_t *lock = lock_addr(v);
@@ -172,9 +172,9 @@ s64 atomic64_xchg(atomic64_t *v, s64 new)
raw_spin_unlock_irqrestore(lock, flags);
return val;
}
-EXPORT_SYMBOL(atomic64_xchg);
+EXPORT_SYMBOL(generic_atomic64_xchg);
-s64 atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u)
+s64 generic_atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u)
{
unsigned long flags;
raw_spinlock_t *lock = lock_addr(v);
@@ -188,4 +188,4 @@ s64 atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u)
return val;
}
-EXPORT_SYMBOL(atomic64_fetch_add_unless);
+EXPORT_SYMBOL(generic_atomic64_fetch_add_unless);
diff --git a/lib/locking-selftest.c b/lib/locking-selftest.c
index 2d85abac1744..161108e5d2fe 100644
--- a/lib/locking-selftest.c
+++ b/lib/locking-selftest.c
@@ -53,6 +53,7 @@ __setup("debug_locks_verbose=", setup_debug_locks_verbose);
#define LOCKTYPE_WW 0x10
#define LOCKTYPE_RTMUTEX 0x20
#define LOCKTYPE_LL 0x40
+#define LOCKTYPE_SPECIAL 0x80
static struct ww_acquire_ctx t, t2;
static struct ww_mutex o, o2, o3;
@@ -194,6 +195,7 @@ static void init_shared_classes(void)
#define HARDIRQ_ENTER() \
local_irq_disable(); \
__irq_enter(); \
+ lockdep_hardirq_threaded(); \
WARN_ON(!in_irq());
#define HARDIRQ_EXIT() \
@@ -2492,16 +2494,6 @@ static void rcu_sched_exit(int *_)
int rcu_sched_guard_##name __guard(rcu_sched_exit); \
rcu_read_lock_sched();
-static void rcu_callback_exit(int *_)
-{
- rcu_lock_release(&rcu_callback_map);
-}
-
-#define RCU_CALLBACK_CONTEXT(name, ...) \
- int rcu_callback_guard_##name __guard(rcu_callback_exit); \
- rcu_lock_acquire(&rcu_callback_map);
-
-
static void raw_spinlock_exit(raw_spinlock_t **lock)
{
raw_spin_unlock(*lock);
@@ -2558,8 +2550,6 @@ static void __maybe_unused inner##_in_##outer(void) \
* ---------------+-------+----------+------+-------
* RCU_BH | o | o | o | x
* ---------------+-------+----------+------+-------
- * RCU_CALLBACK | o | o | o | x
- * ---------------+-------+----------+------+-------
* RCU_SCHED | o | o | x | x
* ---------------+-------+----------+------+-------
* RAW_SPIN | o | o | x | x
@@ -2576,7 +2566,6 @@ GENERATE_2_CONTEXT_TESTCASE(NOTTHREADED_HARDIRQ, , inner, inner_lock) \
GENERATE_2_CONTEXT_TESTCASE(SOFTIRQ, , inner, inner_lock) \
GENERATE_2_CONTEXT_TESTCASE(RCU, , inner, inner_lock) \
GENERATE_2_CONTEXT_TESTCASE(RCU_BH, , inner, inner_lock) \
-GENERATE_2_CONTEXT_TESTCASE(RCU_CALLBACK, , inner, inner_lock) \
GENERATE_2_CONTEXT_TESTCASE(RCU_SCHED, , inner, inner_lock) \
GENERATE_2_CONTEXT_TESTCASE(RAW_SPINLOCK, raw_lock_A, inner, inner_lock) \
GENERATE_2_CONTEXT_TESTCASE(SPINLOCK, lock_A, inner, inner_lock) \
@@ -2638,10 +2627,6 @@ static void wait_context_tests(void)
DO_CONTEXT_TESTCASE_OUTER_LIMITED_PREEMPTIBLE(RCU_BH);
pr_cont("\n");
- print_testname("in RCU callback context");
- DO_CONTEXT_TESTCASE_OUTER_LIMITED_PREEMPTIBLE(RCU_CALLBACK);
- pr_cont("\n");
-
print_testname("in RCU-sched context");
DO_CONTEXT_TESTCASE_OUTER_NOT_PREEMPTIBLE(RCU_SCHED);
pr_cont("\n");
@@ -2744,6 +2729,66 @@ static void local_lock_tests(void)
pr_cont("\n");
}
+static void hardirq_deadlock_softirq_not_deadlock(void)
+{
+ /* mutex_A is hardirq-unsafe and softirq-unsafe */
+ /* mutex_A -> lock_C */
+ mutex_lock(&mutex_A);
+ HARDIRQ_DISABLE();
+ spin_lock(&lock_C);
+ spin_unlock(&lock_C);
+ HARDIRQ_ENABLE();
+ mutex_unlock(&mutex_A);
+
+ /* lock_A is hardirq-safe */
+ HARDIRQ_ENTER();
+ spin_lock(&lock_A);
+ spin_unlock(&lock_A);
+ HARDIRQ_EXIT();
+
+ /* lock_A -> lock_B */
+ HARDIRQ_DISABLE();
+ spin_lock(&lock_A);
+ spin_lock(&lock_B);
+ spin_unlock(&lock_B);
+ spin_unlock(&lock_A);
+ HARDIRQ_ENABLE();
+
+ /* lock_B -> lock_C */
+ HARDIRQ_DISABLE();
+ spin_lock(&lock_B);
+ spin_lock(&lock_C);
+ spin_unlock(&lock_C);
+ spin_unlock(&lock_B);
+ HARDIRQ_ENABLE();
+
+ /* lock_D is softirq-safe */
+ SOFTIRQ_ENTER();
+ spin_lock(&lock_D);
+ spin_unlock(&lock_D);
+ SOFTIRQ_EXIT();
+
+ /* And lock_D is hardirq-unsafe */
+ SOFTIRQ_DISABLE();
+ spin_lock(&lock_D);
+ spin_unlock(&lock_D);
+ SOFTIRQ_ENABLE();
+
+ /*
+ * mutex_A -> lock_C -> lock_D is softirq-unsafe -> softirq-safe, not
+ * deadlock.
+ *
+ * lock_A -> lock_B -> lock_C -> lock_D is hardirq-safe ->
+ * hardirq-unsafe, deadlock.
+ */
+ HARDIRQ_DISABLE();
+ spin_lock(&lock_C);
+ spin_lock(&lock_D);
+ spin_unlock(&lock_D);
+ spin_unlock(&lock_C);
+ HARDIRQ_ENABLE();
+}
+
void locking_selftest(void)
{
/*
@@ -2872,6 +2917,10 @@ void locking_selftest(void)
local_lock_tests();
+ print_testname("hardirq_unsafe_softirq_safe");
+ dotest(hardirq_deadlock_softirq_not_deadlock, FAILURE, LOCKTYPE_SPECIAL);
+ pr_cont("\n");
+
if (unexpected_testcase_failures) {
printk("-----------------------------------------------------------------\n");
debug_locks = 0;