lkml.org 
[lkml]   [2016]   [Oct]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 05/10] fault injection: mutex_trylock() fault injection
Date
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
---
kernel/locking/mutex.c | 32 ++++++++++++++++++++++++++++++++
lib/Kconfig.debug | 6 ++++++
2 files changed, 38 insertions(+)

diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
index a70b90d..0651ca6 100644
--- a/kernel/locking/mutex.c
+++ b/kernel/locking/mutex.c
@@ -17,6 +17,7 @@
*
* Also see Documentation/locking/mutex-design.txt.
*/
+#include <linux/fault-inject.h>
#include <linux/mutex.h>
#include <linux/ww_mutex.h>
#include <linux/sched.h>
@@ -887,6 +888,34 @@ static inline int __mutex_trylock_slowpath(atomic_t *lock_count)
return prev == 1;
}

+#ifdef CONFIG_FAIL_MUTEX
+DECLARE_FAULT_ATTR(fail_mutex);
+
+static int __init setup_fail_mutex(char *str)
+{
+ return setup_fault_attr(&fail_mutex, str);
+}
+__setup("fail_mutex=", setup_fail_mutex);
+
+static int __init fail_mutex_debugfs(void)
+{
+ struct dentry *dir = fault_create_debugfs_attr("fail_mutex",
+ NULL, &fail_mutex);
+ return PTR_ERR_OR_ZERO(dir);
+}
+late_initcall(fail_mutex_debugfs);
+
+static inline bool should_fail_mutex(struct mutex *lock)
+{
+ return should_fail(&fail_mutex, 1);
+}
+#else
+static inline bool should_fail_mutex(struct mutex *lock)
+{
+ return false;
+}
+#endif
+
/**
* mutex_trylock - try to acquire the mutex, without waiting
* @lock: the mutex to be acquired
@@ -905,6 +934,9 @@ int __sched mutex_trylock(struct mutex *lock)
{
int ret;

+ if (should_fail_mutex(lock))
+ return 0;
+
ret = __mutex_fastpath_trylock(&lock->count, __mutex_trylock_slowpath);
if (ret)
mutex_set_owner(lock);
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 861fc1d..7e9a9b2e 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1657,6 +1657,12 @@ config FAIL_FUTEX
help
Provide fault-injection capability for futexes.

+config FAIL_MUTEX
+ bool "Fault-injection capability for mutexes"
+ depends on FAULT_INJECTION
+ help
+ Provide fault-injection capability for mutex_trylock().
+
config FAULT_INJECTION_DEBUG_FS
bool "Debugfs entries for fault-injection capabilities"
depends on FAULT_INJECTION && SYSFS && DEBUG_FS
--
2.10.0.479.g221bd91
\
 
 \ /
  Last update: 2016-10-16 17:59    [W:0.104 / U:15.020 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site