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authorLinus Torvalds <torvalds@linux-foundation.org>2017-02-20 13:23:30 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-02-20 13:23:30 -0800
commit42e1b14b6e1455ece2ccbe474c25388d0230a590 (patch)
tree7f62d95f795a2ac5c183248dce39e75340ccfb76 /drivers/misc
parent828cad8ea05d194d8a9452e0793261c2024c23a2 (diff)
parent95cb64c1fe61e70685a95f6260c8e9cd219fe08c (diff)
Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar: "The main changes in this cycle were: - Implement wraparound-safe refcount_t and kref_t types based on generic atomic primitives (Peter Zijlstra) - Improve and fix the ww_mutex code (Nicolai Hähnle) - Add self-tests to the ww_mutex code (Chris Wilson) - Optimize percpu-rwsems with the 'rcuwait' mechanism (Davidlohr Bueso) - Micro-optimize the current-task logic all around the core kernel (Davidlohr Bueso) - Tidy up after recent optimizations: remove stale code and APIs, clean up the code (Waiman Long) - ... plus misc fixes, updates and cleanups" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (50 commits) fork: Fix task_struct alignment locking/spinlock/debug: Remove spinlock lockup detection code lockdep: Fix incorrect condition to print bug msgs for MAX_LOCKDEP_CHAIN_HLOCKS lkdtm: Convert to refcount_t testing kref: Implement 'struct kref' using refcount_t refcount_t: Introduce a special purpose refcount type sched/wake_q: Clarify queue reinit comment sched/wait, rcuwait: Fix typo in comment locking/mutex: Fix lockdep_assert_held() fail locking/rtmutex: Flip unlikely() branch to likely() in __rt_mutex_slowlock() locking/rwsem: Reinit wake_q after use locking/rwsem: Remove unnecessary atomic_long_t casts jump_labels: Move header guard #endif down where it belongs locking/atomic, kref: Implement kref_put_lock() locking/ww_mutex: Turn off __must_check for now locking/atomic, kref: Avoid more abuse locking/atomic, kref: Use kref_get_unless_zero() more locking/atomic, kref: Kill kref_sub() locking/atomic, kref: Add kref_read() locking/atomic, kref: Add KREF_INIT() ...
Diffstat (limited to 'drivers/misc')
-rw-r--r--drivers/misc/genwqe/card_dev.c2
-rw-r--r--drivers/misc/lkdtm.h8
-rw-r--r--drivers/misc/lkdtm_bugs.c87
-rw-r--r--drivers/misc/lkdtm_core.c8
-rw-r--r--drivers/misc/mei/debugfs.c2
5 files changed, 87 insertions, 20 deletions
diff --git a/drivers/misc/genwqe/card_dev.c b/drivers/misc/genwqe/card_dev.c
index 7f1b282d7d96..cb290b8ca0c8 100644
--- a/drivers/misc/genwqe/card_dev.c
+++ b/drivers/misc/genwqe/card_dev.c
@@ -1396,7 +1396,7 @@ int genwqe_device_remove(struct genwqe_dev *cd)
* application which will decrease this reference from
* 1/unused to 0/illegal and not from 2/used 1/empty.
*/
- rc = atomic_read(&cd->cdev_genwqe.kobj.kref.refcount);
+ rc = kref_read(&cd->cdev_genwqe.kobj.kref);
if (rc != 1) {
dev_err(&pci_dev->dev,
"[%s] err: cdev_genwqe...refcount=%d\n", __func__, rc);
diff --git a/drivers/misc/lkdtm.h b/drivers/misc/lkdtm.h
index cfa1039c62e7..67d27be60405 100644
--- a/drivers/misc/lkdtm.h
+++ b/drivers/misc/lkdtm.h
@@ -19,8 +19,12 @@ void lkdtm_SOFTLOCKUP(void);
void lkdtm_HARDLOCKUP(void);
void lkdtm_SPINLOCKUP(void);
void lkdtm_HUNG_TASK(void);
-void lkdtm_ATOMIC_UNDERFLOW(void);
-void lkdtm_ATOMIC_OVERFLOW(void);
+void lkdtm_REFCOUNT_SATURATE_INC(void);
+void lkdtm_REFCOUNT_SATURATE_ADD(void);
+void lkdtm_REFCOUNT_ZERO_DEC(void);
+void lkdtm_REFCOUNT_ZERO_INC(void);
+void lkdtm_REFCOUNT_ZERO_SUB(void);
+void lkdtm_REFCOUNT_ZERO_ADD(void);
void lkdtm_CORRUPT_LIST_ADD(void);
void lkdtm_CORRUPT_LIST_DEL(void);
diff --git a/drivers/misc/lkdtm_bugs.c b/drivers/misc/lkdtm_bugs.c
index 91edd0b55e5c..cba0837aee2e 100644
--- a/drivers/misc/lkdtm_bugs.c
+++ b/drivers/misc/lkdtm_bugs.c
@@ -6,6 +6,7 @@
*/
#include "lkdtm.h"
#include <linux/list.h>
+#include <linux/refcount.h>
#include <linux/sched.h>
struct lkdtm_list {
@@ -129,28 +130,86 @@ void lkdtm_HUNG_TASK(void)
schedule();
}
-void lkdtm_ATOMIC_UNDERFLOW(void)
+void lkdtm_REFCOUNT_SATURATE_INC(void)
{
- atomic_t under = ATOMIC_INIT(INT_MIN);
+ refcount_t over = REFCOUNT_INIT(UINT_MAX - 1);
- pr_info("attempting good atomic increment\n");
- atomic_inc(&under);
- atomic_dec(&under);
+ pr_info("attempting good refcount decrement\n");
+ refcount_dec(&over);
+ refcount_inc(&over);
- pr_info("attempting bad atomic underflow\n");
- atomic_dec(&under);
+ pr_info("attempting bad refcount inc overflow\n");
+ refcount_inc(&over);
+ refcount_inc(&over);
+ if (refcount_read(&over) == UINT_MAX)
+ pr_err("Correctly stayed saturated, but no BUG?!\n");
+ else
+ pr_err("Fail: refcount wrapped\n");
+}
+
+void lkdtm_REFCOUNT_SATURATE_ADD(void)
+{
+ refcount_t over = REFCOUNT_INIT(UINT_MAX - 1);
+
+ pr_info("attempting good refcount decrement\n");
+ refcount_dec(&over);
+ refcount_inc(&over);
+
+ pr_info("attempting bad refcount add overflow\n");
+ refcount_add(2, &over);
+ if (refcount_read(&over) == UINT_MAX)
+ pr_err("Correctly stayed saturated, but no BUG?!\n");
+ else
+ pr_err("Fail: refcount wrapped\n");
+}
+
+void lkdtm_REFCOUNT_ZERO_DEC(void)
+{
+ refcount_t zero = REFCOUNT_INIT(1);
+
+ pr_info("attempting bad refcount decrement to zero\n");
+ refcount_dec(&zero);
+ if (refcount_read(&zero) == 0)
+ pr_err("Stayed at zero, but no BUG?!\n");
+ else
+ pr_err("Fail: refcount went crazy\n");
}
-void lkdtm_ATOMIC_OVERFLOW(void)
+void lkdtm_REFCOUNT_ZERO_SUB(void)
{
- atomic_t over = ATOMIC_INIT(INT_MAX);
+ refcount_t zero = REFCOUNT_INIT(1);
+
+ pr_info("attempting bad refcount subtract past zero\n");
+ if (!refcount_sub_and_test(2, &zero))
+ pr_info("wrap attempt was noticed\n");
+ if (refcount_read(&zero) == 1)
+ pr_err("Correctly stayed above 0, but no BUG?!\n");
+ else
+ pr_err("Fail: refcount wrapped\n");
+}
- pr_info("attempting good atomic decrement\n");
- atomic_dec(&over);
- atomic_inc(&over);
+void lkdtm_REFCOUNT_ZERO_INC(void)
+{
+ refcount_t zero = REFCOUNT_INIT(0);
- pr_info("attempting bad atomic overflow\n");
- atomic_inc(&over);
+ pr_info("attempting bad refcount increment from zero\n");
+ refcount_inc(&zero);
+ if (refcount_read(&zero) == 0)
+ pr_err("Stayed at zero, but no BUG?!\n");
+ else
+ pr_err("Fail: refcount went past zero\n");
+}
+
+void lkdtm_REFCOUNT_ZERO_ADD(void)
+{
+ refcount_t zero = REFCOUNT_INIT(0);
+
+ pr_info("attempting bad refcount addition from zero\n");
+ refcount_add(2, &zero);
+ if (refcount_read(&zero) == 0)
+ pr_err("Stayed at zero, but no BUG?!\n");
+ else
+ pr_err("Fail: refcount went past zero\n");
}
void lkdtm_CORRUPT_LIST_ADD(void)
diff --git a/drivers/misc/lkdtm_core.c b/drivers/misc/lkdtm_core.c
index 7eeb71a75549..16e4cf110930 100644
--- a/drivers/misc/lkdtm_core.c
+++ b/drivers/misc/lkdtm_core.c
@@ -220,8 +220,12 @@ struct crashtype crashtypes[] = {
CRASHTYPE(WRITE_RO),
CRASHTYPE(WRITE_RO_AFTER_INIT),
CRASHTYPE(WRITE_KERN),
- CRASHTYPE(ATOMIC_UNDERFLOW),
- CRASHTYPE(ATOMIC_OVERFLOW),
+ CRASHTYPE(REFCOUNT_SATURATE_INC),
+ CRASHTYPE(REFCOUNT_SATURATE_ADD),
+ CRASHTYPE(REFCOUNT_ZERO_DEC),
+ CRASHTYPE(REFCOUNT_ZERO_INC),
+ CRASHTYPE(REFCOUNT_ZERO_SUB),
+ CRASHTYPE(REFCOUNT_ZERO_ADD),
CRASHTYPE(USERCOPY_HEAP_SIZE_TO),
CRASHTYPE(USERCOPY_HEAP_SIZE_FROM),
CRASHTYPE(USERCOPY_HEAP_FLAG_TO),
diff --git a/drivers/misc/mei/debugfs.c b/drivers/misc/mei/debugfs.c
index c6217a4993ad..a617aa5a3ad8 100644
--- a/drivers/misc/mei/debugfs.c
+++ b/drivers/misc/mei/debugfs.c
@@ -67,7 +67,7 @@ static ssize_t mei_dbgfs_read_meclients(struct file *fp, char __user *ubuf,
me_cl->props.max_number_of_connections,
me_cl->props.max_msg_length,
me_cl->props.single_recv_buf,
- atomic_read(&me_cl->refcnt.refcount));
+ kref_read(&me_cl->refcnt));
mei_me_cl_put(me_cl);
}