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authorLinus Torvalds <torvalds@linux-foundation.org>2015-09-03 22:46:07 (GMT)
committerLinus Torvalds <torvalds@linux-foundation.org>2015-09-03 22:46:07 (GMT)
commitca520cab25e0e8da717c596ccaa2c2b3650cfa09 (patch)
tree883eb497642d98635817f9cf954ac98e043fb573 /lib
parent4c12ab7e5e2e892fa94df500f96001837918a281 (diff)
parentd420acd816c07c7be31bd19d09cbcb16e5572fa6 (diff)
Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking and atomic updates from Ingo Molnar: "Main changes in this cycle are: - Extend atomic primitives with coherent logic op primitives (atomic_{or,and,xor}()) and deprecate the old partial APIs (atomic_{set,clear}_mask()) The old ops were incoherent with incompatible signatures across architectures and with incomplete support. Now every architecture supports the primitives consistently (by Peter Zijlstra) - Generic support for 'relaxed atomics': - _acquire/release/relaxed() flavours of xchg(), cmpxchg() and {add,sub}_return() - atomic_read_acquire() - atomic_set_release() This came out of porting qwrlock code to arm64 (by Will Deacon) - Clean up the fragile static_key APIs that were causing repeat bugs, by introducing a new one: DEFINE_STATIC_KEY_TRUE(name); DEFINE_STATIC_KEY_FALSE(name); which define a key of different types with an initial true/false value. Then allow: static_branch_likely() static_branch_unlikely() to take a key of either type and emit the right instruction for the case. To be able to know the 'type' of the static key we encode it in the jump entry (by Peter Zijlstra) - Static key self-tests (by Jason Baron) - qrwlock optimizations (by Waiman Long) - small futex enhancements (by Davidlohr Bueso) - ... and misc other changes" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (63 commits) jump_label/x86: Work around asm build bug on older/backported GCCs locking, ARM, atomics: Define our SMP atomics in terms of _relaxed() operations locking, include/llist: Use linux/atomic.h instead of asm/cmpxchg.h locking/qrwlock: Make use of _{acquire|release|relaxed}() atomics locking/qrwlock: Implement queue_write_unlock() using smp_store_release() locking/lockref: Remove homebrew cmpxchg64_relaxed() macro definition locking, asm-generic: Add _{relaxed|acquire|release}() variants for 'atomic_long_t' locking, asm-generic: Rework atomic-long.h to avoid bulk code duplication locking/atomics: Add _{acquire|release|relaxed}() variants of some atomic operations locking, compiler.h: Cast away attributes in the WRITE_ONCE() magic locking/static_keys: Make verify_keys() static jump label, locking/static_keys: Update docs locking/static_keys: Provide a selftest jump_label: Provide a self-test s390/uaccess, locking/static_keys: employ static_branch_likely() x86, tsc, locking/static_keys: Employ static_branch_likely() locking/static_keys: Add selftest locking/static_keys: Add a new static_key interface locking/static_keys: Rework update logic locking/static_keys: Add static_key_{en,dis}able() helpers ...
Diffstat (limited to 'lib')
-rw-r--r--lib/Kconfig.debug22
-rw-r--r--lib/Makefile2
-rw-r--r--lib/atomic64.c3
-rw-r--r--lib/atomic64_test.c68
-rw-r--r--lib/lockref.c8
-rw-r--r--lib/test_static_key_base.c68
-rw-r--r--lib/test_static_keys.c225
7 files changed, 361 insertions, 35 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 3e0b662..ab76b99 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -916,12 +916,6 @@ config DEBUG_RT_MUTEXES
This allows rt mutex semantics violations and rt mutex related
deadlocks (lockups) to be detected and reported automatically.
-config RT_MUTEX_TESTER
- bool "Built-in scriptable tester for rt-mutexes"
- depends on DEBUG_KERNEL && RT_MUTEXES && BROKEN
- help
- This option enables a rt-mutex tester.
-
config DEBUG_SPINLOCK
bool "Spinlock and rw-lock debugging: basic checks"
depends on DEBUG_KERNEL
@@ -1528,6 +1522,13 @@ config FAIL_MMC_REQUEST
and to test how the mmc host driver handles retries from
the block device.
+config FAIL_FUTEX
+ bool "Fault-injection capability for futexes"
+ select DEBUG_FS
+ depends on FAULT_INJECTION && FUTEX
+ help
+ Provide fault-injection capability for futexes.
+
config FAULT_INJECTION_DEBUG_FS
bool "Debugfs entries for fault-injection capabilities"
depends on FAULT_INJECTION && SYSFS && DEBUG_FS
@@ -1826,6 +1827,15 @@ config MEMTEST
memtest=17, mean do 17 test patterns.
If you are unsure how to answer this question, answer N.
+config TEST_STATIC_KEYS
+ tristate "Test static keys"
+ default n
+ depends on m
+ help
+ Test the static key interfaces.
+
+ If unsure, say N.
+
source "samples/Kconfig"
source "lib/Kconfig.kgdb"
diff --git a/lib/Makefile b/lib/Makefile
index f261006..f01c558 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -39,6 +39,8 @@ obj-$(CONFIG_TEST_KSTRTOX) += test-kstrtox.o
obj-$(CONFIG_TEST_LKM) += test_module.o
obj-$(CONFIG_TEST_RHASHTABLE) += test_rhashtable.o
obj-$(CONFIG_TEST_USER_COPY) += test_user_copy.o
+obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_keys.o
+obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_key_base.o
ifeq ($(CONFIG_DEBUG_KOBJECT),y)
CFLAGS_kobject.o += -DDEBUG
diff --git a/lib/atomic64.c b/lib/atomic64.c
index 1298c05e..2886eba 100644
--- a/lib/atomic64.c
+++ b/lib/atomic64.c
@@ -102,6 +102,9 @@ EXPORT_SYMBOL(atomic64_##op##_return);
ATOMIC64_OPS(add, +=)
ATOMIC64_OPS(sub, -=)
+ATOMIC64_OP(and, &=)
+ATOMIC64_OP(or, |=)
+ATOMIC64_OP(xor, ^=)
#undef ATOMIC64_OPS
#undef ATOMIC64_OP_RETURN
diff --git a/lib/atomic64_test.c b/lib/atomic64_test.c
index 0211d30..83c33a5b 100644
--- a/lib/atomic64_test.c
+++ b/lib/atomic64_test.c
@@ -16,8 +16,39 @@
#include <linux/kernel.h>
#include <linux/atomic.h>
+#define TEST(bit, op, c_op, val) \
+do { \
+ atomic##bit##_set(&v, v0); \
+ r = v0; \
+ atomic##bit##_##op(val, &v); \
+ r c_op val; \
+ WARN(atomic##bit##_read(&v) != r, "%Lx != %Lx\n", \
+ (unsigned long long)atomic##bit##_read(&v), \
+ (unsigned long long)r); \
+} while (0)
+
+static __init void test_atomic(void)
+{
+ int v0 = 0xaaa31337;
+ int v1 = 0xdeadbeef;
+ int onestwos = 0x11112222;
+ int one = 1;
+
+ atomic_t v;
+ int r;
+
+ TEST(, add, +=, onestwos);
+ TEST(, add, +=, -one);
+ TEST(, sub, -=, onestwos);
+ TEST(, sub, -=, -one);
+ TEST(, or, |=, v1);
+ TEST(, and, &=, v1);
+ TEST(, xor, ^=, v1);
+ TEST(, andnot, &= ~, v1);
+}
+
#define INIT(c) do { atomic64_set(&v, c); r = c; } while (0)
-static __init int test_atomic64(void)
+static __init void test_atomic64(void)
{
long long v0 = 0xaaa31337c001d00dLL;
long long v1 = 0xdeadbeefdeafcafeLL;
@@ -34,15 +65,14 @@ static __init int test_atomic64(void)
BUG_ON(v.counter != r);
BUG_ON(atomic64_read(&v) != r);
- INIT(v0);
- atomic64_add(onestwos, &v);
- r += onestwos;
- BUG_ON(v.counter != r);
-
- INIT(v0);
- atomic64_add(-one, &v);
- r += -one;
- BUG_ON(v.counter != r);
+ TEST(64, add, +=, onestwos);
+ TEST(64, add, +=, -one);
+ TEST(64, sub, -=, onestwos);
+ TEST(64, sub, -=, -one);
+ TEST(64, or, |=, v1);
+ TEST(64, and, &=, v1);
+ TEST(64, xor, ^=, v1);
+ TEST(64, andnot, &= ~, v1);
INIT(v0);
r += onestwos;
@@ -55,16 +85,6 @@ static __init int test_atomic64(void)
BUG_ON(v.counter != r);
INIT(v0);
- atomic64_sub(onestwos, &v);
- r -= onestwos;
- BUG_ON(v.counter != r);
-
- INIT(v0);
- atomic64_sub(-one, &v);
- r -= -one;
- BUG_ON(v.counter != r);
-
- INIT(v0);
r -= onestwos;
BUG_ON(atomic64_sub_return(onestwos, &v) != r);
BUG_ON(v.counter != r);
@@ -147,6 +167,12 @@ static __init int test_atomic64(void)
BUG_ON(!atomic64_inc_not_zero(&v));
r += one;
BUG_ON(v.counter != r);
+}
+
+static __init int test_atomics(void)
+{
+ test_atomic();
+ test_atomic64();
#ifdef CONFIG_X86
pr_info("passed for %s platform %s CX8 and %s SSE\n",
@@ -166,4 +192,4 @@ static __init int test_atomic64(void)
return 0;
}
-core_initcall(test_atomic64);
+core_initcall(test_atomics);
diff --git a/lib/lockref.c b/lib/lockref.c
index 494994b..5a92189 100644
--- a/lib/lockref.c
+++ b/lib/lockref.c
@@ -4,14 +4,6 @@
#if USE_CMPXCHG_LOCKREF
/*
- * Allow weakly-ordered memory architectures to provide barrier-less
- * cmpxchg semantics for lockref updates.
- */
-#ifndef cmpxchg64_relaxed
-# define cmpxchg64_relaxed cmpxchg64
-#endif
-
-/*
* Note that the "cmpxchg()" reloads the "old" value for the
* failure case.
*/
diff --git a/lib/test_static_key_base.c b/lib/test_static_key_base.c
new file mode 100644
index 0000000..729447a
--- /dev/null
+++ b/lib/test_static_key_base.c
@@ -0,0 +1,68 @@
+/*
+ * Kernel module for testing static keys.
+ *
+ * Copyright 2015 Akamai Technologies Inc. All Rights Reserved
+ *
+ * Authors:
+ * Jason Baron <jbaron@akamai.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/jump_label.h>
+
+/* old keys */
+struct static_key base_old_true_key = STATIC_KEY_INIT_TRUE;
+EXPORT_SYMBOL_GPL(base_old_true_key);
+struct static_key base_inv_old_true_key = STATIC_KEY_INIT_TRUE;
+EXPORT_SYMBOL_GPL(base_inv_old_true_key);
+struct static_key base_old_false_key = STATIC_KEY_INIT_FALSE;
+EXPORT_SYMBOL_GPL(base_old_false_key);
+struct static_key base_inv_old_false_key = STATIC_KEY_INIT_FALSE;
+EXPORT_SYMBOL_GPL(base_inv_old_false_key);
+
+/* new keys */
+DEFINE_STATIC_KEY_TRUE(base_true_key);
+EXPORT_SYMBOL_GPL(base_true_key);
+DEFINE_STATIC_KEY_TRUE(base_inv_true_key);
+EXPORT_SYMBOL_GPL(base_inv_true_key);
+DEFINE_STATIC_KEY_FALSE(base_false_key);
+EXPORT_SYMBOL_GPL(base_false_key);
+DEFINE_STATIC_KEY_FALSE(base_inv_false_key);
+EXPORT_SYMBOL_GPL(base_inv_false_key);
+
+static void invert_key(struct static_key *key)
+{
+ if (static_key_enabled(key))
+ static_key_disable(key);
+ else
+ static_key_enable(key);
+}
+
+static int __init test_static_key_base_init(void)
+{
+ invert_key(&base_inv_old_true_key);
+ invert_key(&base_inv_old_false_key);
+ invert_key(&base_inv_true_key.key);
+ invert_key(&base_inv_false_key.key);
+
+ return 0;
+}
+
+static void __exit test_static_key_base_exit(void)
+{
+}
+
+module_init(test_static_key_base_init);
+module_exit(test_static_key_base_exit);
+
+MODULE_AUTHOR("Jason Baron <jbaron@akamai.com>");
+MODULE_LICENSE("GPL");
diff --git a/lib/test_static_keys.c b/lib/test_static_keys.c
new file mode 100644
index 0000000..c61b299
--- /dev/null
+++ b/lib/test_static_keys.c
@@ -0,0 +1,225 @@
+/*
+ * Kernel module for testing static keys.
+ *
+ * Copyright 2015 Akamai Technologies Inc. All Rights Reserved
+ *
+ * Authors:
+ * Jason Baron <jbaron@akamai.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/jump_label.h>
+
+/* old keys */
+struct static_key old_true_key = STATIC_KEY_INIT_TRUE;
+struct static_key old_false_key = STATIC_KEY_INIT_FALSE;
+
+/* new api */
+DEFINE_STATIC_KEY_TRUE(true_key);
+DEFINE_STATIC_KEY_FALSE(false_key);
+
+/* external */
+extern struct static_key base_old_true_key;
+extern struct static_key base_inv_old_true_key;
+extern struct static_key base_old_false_key;
+extern struct static_key base_inv_old_false_key;
+
+/* new api */
+extern struct static_key_true base_true_key;
+extern struct static_key_true base_inv_true_key;
+extern struct static_key_false base_false_key;
+extern struct static_key_false base_inv_false_key;
+
+
+struct test_key {
+ bool init_state;
+ struct static_key *key;
+ bool (*test_key)(void);
+};
+
+#define test_key_func(key, branch) \
+ ({bool func(void) { return branch(key); } func; })
+
+static void invert_key(struct static_key *key)
+{
+ if (static_key_enabled(key))
+ static_key_disable(key);
+ else
+ static_key_enable(key);
+}
+
+static void invert_keys(struct test_key *keys, int size)
+{
+ struct static_key *previous = NULL;
+ int i;
+
+ for (i = 0; i < size; i++) {
+ if (previous != keys[i].key) {
+ invert_key(keys[i].key);
+ previous = keys[i].key;
+ }
+ }
+}
+
+static int verify_keys(struct test_key *keys, int size, bool invert)
+{
+ int i;
+ bool ret, init;
+
+ for (i = 0; i < size; i++) {
+ ret = static_key_enabled(keys[i].key);
+ init = keys[i].init_state;
+ if (ret != (invert ? !init : init))
+ return -EINVAL;
+ ret = keys[i].test_key();
+ if (static_key_enabled(keys[i].key)) {
+ if (!ret)
+ return -EINVAL;
+ } else {
+ if (ret)
+ return -EINVAL;
+ }
+ }
+ return 0;
+}
+
+static int __init test_static_key_init(void)
+{
+ int ret;
+ int size;
+
+ struct test_key static_key_tests[] = {
+ /* internal keys - old keys */
+ {
+ .init_state = true,
+ .key = &old_true_key,
+ .test_key = test_key_func(&old_true_key, static_key_true),
+ },
+ {
+ .init_state = false,
+ .key = &old_false_key,
+ .test_key = test_key_func(&old_false_key, static_key_false),
+ },
+ /* internal keys - new keys */
+ {
+ .init_state = true,
+ .key = &true_key.key,
+ .test_key = test_key_func(&true_key, static_branch_likely),
+ },
+ {
+ .init_state = true,
+ .key = &true_key.key,
+ .test_key = test_key_func(&true_key, static_branch_unlikely),
+ },
+ {
+ .init_state = false,
+ .key = &false_key.key,
+ .test_key = test_key_func(&false_key, static_branch_likely),
+ },
+ {
+ .init_state = false,
+ .key = &false_key.key,
+ .test_key = test_key_func(&false_key, static_branch_unlikely),
+ },
+ /* external keys - old keys */
+ {
+ .init_state = true,
+ .key = &base_old_true_key,
+ .test_key = test_key_func(&base_old_true_key, static_key_true),
+ },
+ {
+ .init_state = false,
+ .key = &base_inv_old_true_key,
+ .test_key = test_key_func(&base_inv_old_true_key, static_key_true),
+ },
+ {
+ .init_state = false,
+ .key = &base_old_false_key,
+ .test_key = test_key_func(&base_old_false_key, static_key_false),
+ },
+ {
+ .init_state = true,
+ .key = &base_inv_old_false_key,
+ .test_key = test_key_func(&base_inv_old_false_key, static_key_false),
+ },
+ /* external keys - new keys */
+ {
+ .init_state = true,
+ .key = &base_true_key.key,
+ .test_key = test_key_func(&base_true_key, static_branch_likely),
+ },
+ {
+ .init_state = true,
+ .key = &base_true_key.key,
+ .test_key = test_key_func(&base_true_key, static_branch_unlikely),
+ },
+ {
+ .init_state = false,
+ .key = &base_inv_true_key.key,
+ .test_key = test_key_func(&base_inv_true_key, static_branch_likely),
+ },
+ {
+ .init_state = false,
+ .key = &base_inv_true_key.key,
+ .test_key = test_key_func(&base_inv_true_key, static_branch_unlikely),
+ },
+ {
+ .init_state = false,
+ .key = &base_false_key.key,
+ .test_key = test_key_func(&base_false_key, static_branch_likely),
+ },
+ {
+ .init_state = false,
+ .key = &base_false_key.key,
+ .test_key = test_key_func(&base_false_key, static_branch_unlikely),
+ },
+ {
+ .init_state = true,
+ .key = &base_inv_false_key.key,
+ .test_key = test_key_func(&base_inv_false_key, static_branch_likely),
+ },
+ {
+ .init_state = true,
+ .key = &base_inv_false_key.key,
+ .test_key = test_key_func(&base_inv_false_key, static_branch_unlikely),
+ },
+ };
+
+ size = ARRAY_SIZE(static_key_tests);
+
+ ret = verify_keys(static_key_tests, size, false);
+ if (ret)
+ goto out;
+
+ invert_keys(static_key_tests, size);
+ ret = verify_keys(static_key_tests, size, true);
+ if (ret)
+ goto out;
+
+ invert_keys(static_key_tests, size);
+ ret = verify_keys(static_key_tests, size, false);
+ if (ret)
+ goto out;
+ return 0;
+out:
+ return ret;
+}
+
+static void __exit test_static_key_exit(void)
+{
+}
+
+module_init(test_static_key_init);
+module_exit(test_static_key_exit);
+
+MODULE_AUTHOR("Jason Baron <jbaron@akamai.com>");
+MODULE_LICENSE("GPL");

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