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-rw-r--r--lib/Kconfig.debug11
-rw-r--r--lib/atomic64_test.c124
-rw-r--r--lib/list_debug.c2
-rw-r--r--lib/rhashtable.c3
4 files changed, 97 insertions, 43 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index cdbf7fd69eb9..c98e93c0a084 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -812,6 +812,17 @@ config BOOTPARAM_HUNG_TASK_PANIC_VALUE
default 0 if !BOOTPARAM_HUNG_TASK_PANIC
default 1 if BOOTPARAM_HUNG_TASK_PANIC
+config WQ_WATCHDOG
+ bool "Detect Workqueue Stalls"
+ depends on DEBUG_KERNEL
+ help
+ Say Y here to enable stall detection on workqueues. If a
+ worker pool doesn't make forward progress on a pending work
+ item for over a given amount of time, 30s by default, a
+ warning message is printed along with dump of workqueue
+ state. This can be configured through kernel parameter
+ "workqueue.watchdog_thresh" and its sysfs counterpart.
+
endmenu # "Debug lockups and hangs"
config PANIC_ON_OOPS
diff --git a/lib/atomic64_test.c b/lib/atomic64_test.c
index 83c33a5bcffb..d62de8bf022d 100644
--- a/lib/atomic64_test.c
+++ b/lib/atomic64_test.c
@@ -16,6 +16,10 @@
#include <linux/kernel.h>
#include <linux/atomic.h>
+#ifdef CONFIG_X86
+#include <asm/processor.h> /* for boot_cpu_has below */
+#endif
+
#define TEST(bit, op, c_op, val) \
do { \
atomic##bit##_set(&v, v0); \
@@ -27,6 +31,65 @@ do { \
(unsigned long long)r); \
} while (0)
+/*
+ * Test for a atomic operation family,
+ * @test should be a macro accepting parameters (bit, op, ...)
+ */
+
+#define FAMILY_TEST(test, bit, op, args...) \
+do { \
+ test(bit, op, ##args); \
+ test(bit, op##_acquire, ##args); \
+ test(bit, op##_release, ##args); \
+ test(bit, op##_relaxed, ##args); \
+} while (0)
+
+#define TEST_RETURN(bit, op, c_op, val) \
+do { \
+ atomic##bit##_set(&v, v0); \
+ r = v0; \
+ r c_op val; \
+ BUG_ON(atomic##bit##_##op(val, &v) != r); \
+ BUG_ON(atomic##bit##_read(&v) != r); \
+} while (0)
+
+#define RETURN_FAMILY_TEST(bit, op, c_op, val) \
+do { \
+ FAMILY_TEST(TEST_RETURN, bit, op, c_op, val); \
+} while (0)
+
+#define TEST_ARGS(bit, op, init, ret, expect, args...) \
+do { \
+ atomic##bit##_set(&v, init); \
+ BUG_ON(atomic##bit##_##op(&v, ##args) != ret); \
+ BUG_ON(atomic##bit##_read(&v) != expect); \
+} while (0)
+
+#define XCHG_FAMILY_TEST(bit, init, new) \
+do { \
+ FAMILY_TEST(TEST_ARGS, bit, xchg, init, init, new, new); \
+} while (0)
+
+#define CMPXCHG_FAMILY_TEST(bit, init, new, wrong) \
+do { \
+ FAMILY_TEST(TEST_ARGS, bit, cmpxchg, \
+ init, init, new, init, new); \
+ FAMILY_TEST(TEST_ARGS, bit, cmpxchg, \
+ init, init, init, wrong, new); \
+} while (0)
+
+#define INC_RETURN_FAMILY_TEST(bit, i) \
+do { \
+ FAMILY_TEST(TEST_ARGS, bit, inc_return, \
+ i, (i) + one, (i) + one); \
+} while (0)
+
+#define DEC_RETURN_FAMILY_TEST(bit, i) \
+do { \
+ FAMILY_TEST(TEST_ARGS, bit, dec_return, \
+ i, (i) - one, (i) - one); \
+} while (0)
+
static __init void test_atomic(void)
{
int v0 = 0xaaa31337;
@@ -45,6 +108,18 @@ static __init void test_atomic(void)
TEST(, and, &=, v1);
TEST(, xor, ^=, v1);
TEST(, andnot, &= ~, v1);
+
+ RETURN_FAMILY_TEST(, add_return, +=, onestwos);
+ RETURN_FAMILY_TEST(, add_return, +=, -one);
+ RETURN_FAMILY_TEST(, sub_return, -=, onestwos);
+ RETURN_FAMILY_TEST(, sub_return, -=, -one);
+
+ INC_RETURN_FAMILY_TEST(, v0);
+ DEC_RETURN_FAMILY_TEST(, v0);
+
+ XCHG_FAMILY_TEST(, v0, v1);
+ CMPXCHG_FAMILY_TEST(, v0, v1, onestwos);
+
}
#define INIT(c) do { atomic64_set(&v, c); r = c; } while (0)
@@ -74,25 +149,10 @@ static __init void test_atomic64(void)
TEST(64, xor, ^=, v1);
TEST(64, andnot, &= ~, v1);
- INIT(v0);
- r += onestwos;
- BUG_ON(atomic64_add_return(onestwos, &v) != r);
- BUG_ON(v.counter != r);
-
- INIT(v0);
- r += -one;
- BUG_ON(atomic64_add_return(-one, &v) != r);
- BUG_ON(v.counter != r);
-
- INIT(v0);
- r -= onestwos;
- BUG_ON(atomic64_sub_return(onestwos, &v) != r);
- BUG_ON(v.counter != r);
-
- INIT(v0);
- r -= -one;
- BUG_ON(atomic64_sub_return(-one, &v) != r);
- BUG_ON(v.counter != r);
+ RETURN_FAMILY_TEST(64, add_return, +=, onestwos);
+ RETURN_FAMILY_TEST(64, add_return, +=, -one);
+ RETURN_FAMILY_TEST(64, sub_return, -=, onestwos);
+ RETURN_FAMILY_TEST(64, sub_return, -=, -one);
INIT(v0);
atomic64_inc(&v);
@@ -100,33 +160,15 @@ static __init void test_atomic64(void)
BUG_ON(v.counter != r);
INIT(v0);
- r += one;
- BUG_ON(atomic64_inc_return(&v) != r);
- BUG_ON(v.counter != r);
-
- INIT(v0);
atomic64_dec(&v);
r -= one;
BUG_ON(v.counter != r);
- INIT(v0);
- r -= one;
- BUG_ON(atomic64_dec_return(&v) != r);
- BUG_ON(v.counter != r);
+ INC_RETURN_FAMILY_TEST(64, v0);
+ DEC_RETURN_FAMILY_TEST(64, v0);
- INIT(v0);
- BUG_ON(atomic64_xchg(&v, v1) != v0);
- r = v1;
- BUG_ON(v.counter != r);
-
- INIT(v0);
- BUG_ON(atomic64_cmpxchg(&v, v0, v1) != v0);
- r = v1;
- BUG_ON(v.counter != r);
-
- INIT(v0);
- BUG_ON(atomic64_cmpxchg(&v, v2, v1) != v0);
- BUG_ON(v.counter != r);
+ XCHG_FAMILY_TEST(64, v0, v1);
+ CMPXCHG_FAMILY_TEST(64, v0, v1, v2);
INIT(v0);
BUG_ON(atomic64_add_unless(&v, one, v0));
diff --git a/lib/list_debug.c b/lib/list_debug.c
index c24c2f7e296f..3859bf63561c 100644
--- a/lib/list_debug.c
+++ b/lib/list_debug.c
@@ -37,7 +37,7 @@ void __list_add(struct list_head *new,
next->prev = new;
new->next = next;
new->prev = prev;
- prev->next = new;
+ WRITE_ONCE(prev->next, new);
}
EXPORT_SYMBOL(__list_add);
diff --git a/lib/rhashtable.c b/lib/rhashtable.c
index eb9240c458fa..51282f579760 100644
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -519,7 +519,8 @@ int rhashtable_walk_init(struct rhashtable *ht, struct rhashtable_iter *iter)
return -ENOMEM;
spin_lock(&ht->lock);
- iter->walker->tbl = rht_dereference(ht->tbl, ht);
+ iter->walker->tbl =
+ rcu_dereference_protected(ht->tbl, lockdep_is_held(&ht->lock));
list_add(&iter->walker->list, &iter->walker->tbl->walkers);
spin_unlock(&ht->lock);