From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757880AbcHCPLB (ORCPT ); Wed, 3 Aug 2016 11:11:01 -0400 Received: from aserp1050.oracle.com ([141.146.126.70]:37782 "EHLO aserp1050.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755340AbcHCPKJ (ORCPT ); Wed, 3 Aug 2016 11:10:09 -0400 From: Vegard Nossum To: Akinobu Mita , Peter Zijlstra , Ingo Molnar Cc: linux-kernel@vger.kernel.org, Vegard Nossum Subject: [PATCH 07/10] fault injection: down_trylock() fault injection Date: Wed, 3 Aug 2016 17:05:52 +0200 Message-Id: <1470236755-29844-7-git-send-email-vegard.nossum@oracle.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1470236755-29844-1-git-send-email-vegard.nossum@oracle.com> References: <1470236755-29844-1-git-send-email-vegard.nossum@oracle.com> X-Source-IP: aserp1040.oracle.com [141.146.126.69] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Cc: Peter Zijlstra Cc: Ingo Molnar Signed-off-by: Vegard Nossum --- kernel/locking/semaphore.c | 26 ++++++++++++++++++++++++++ lib/Kconfig.debug | 6 ++++++ 2 files changed, 32 insertions(+) diff --git a/kernel/locking/semaphore.c b/kernel/locking/semaphore.c index b8120ab..367bae3 100644 --- a/kernel/locking/semaphore.c +++ b/kernel/locking/semaphore.c @@ -25,6 +25,7 @@ * semaphore. If it's zero, there may be tasks waiting on the wait_list. */ +#include #include #include #include @@ -114,6 +115,28 @@ int down_killable(struct semaphore *sem) } EXPORT_SYMBOL(down_killable); +#ifdef CONFIG_FAIL_SEMAPHORE +DECLARE_FAULT_ATTR(fail_semaphore); + +static int __init fail_semaphore_debugfs(void) +{ + struct dentry *dir = fault_create_debugfs_attr("fail_semaphore", + NULL, &fail_semaphore); + return PTR_ERR_OR_ZERO(dir); +} +late_initcall(fail_semaphore_debugfs); + +static inline bool should_fail_semaphore(struct semaphore *sem) +{ + return should_fail(&fail_semaphore, 1); +} +#else +static inline bool should_fail_semaphore(struct semaphore *sem) +{ + return false; +} +#endif + /** * down_trylock - try to acquire the semaphore, without waiting * @sem: the semaphore to be acquired @@ -132,6 +155,9 @@ int down_trylock(struct semaphore *sem) unsigned long flags; int count; + if (should_fail_semaphore(sem)) + return 1; + raw_spin_lock_irqsave(&sem->lock, flags); count = sem->count - 1; if (likely(count >= 0)) diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 4d7110c..5473759 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1669,6 +1669,12 @@ config FAIL_RT_MUTEX help Provide fault-injection capability for rt_mutex_trylock(). +config FAIL_SEMAPHORE + bool "Fault-injection capability for semaphores" + depends on FAULT_INJECTION + help + Provide fault-injection capability for down_trylock(). + config FAULT_INJECTION_DEBUG_FS bool "Debugfs entries for fault-injection capabilities" depends on FAULT_INJECTION && SYSFS && DEBUG_FS -- 1.9.1