From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from g6t0187.atlanta.hp.com (g6t0187.atlanta.hp.com [15.193.32.64]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "smtp.hp.com", Issuer "VeriSign Class 3 Secure Server CA - G3" (not verified)) by ozlabs.org (Postfix) with ESMTPS id BC97D2C0202 for ; Sun, 18 Aug 2013 05:55:08 +1000 (EST) From: Toshi Kani To: mingo@redhat.com, hpa@linux.intel.com, tglx@linutronix.de, gregkh@linuxfoundation.org, benh@kernel.crashing.org Subject: [PATCH 2/4] hotplug, x86: Add hotplug lock to missing places Date: Sat, 17 Aug 2013 13:46:57 -0600 Message-Id: <1376768819-28975-3-git-send-email-toshi.kani@hp.com> In-Reply-To: <1376768819-28975-1-git-send-email-toshi.kani@hp.com> References: <1376768819-28975-1-git-send-email-toshi.kani@hp.com> Cc: fenghua.yu@intel.com, Toshi Kani , x86@kernel.org, linux-kernel@vger.kernel.org, rjw@sisk.pl, isimatu.yasuaki@jp.fujitsu.com, srivatsa.bhat@linux.vnet.ibm.com, bp@suse.de, linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , lock_device_hotplug() serializes CPU & Memory online/offline and hotplug operations. However, this lock is not held in the debug interfaces below that initiate CPU online/offline operations. - _debug_hotplug_cpu(), cpu0 hotplug test interface enabled by CONFIG_DEBUG_HOTPLUG_CPU0. - cpu_probe_store() and cpu_release_store(), cpu hotplug test interface enabled by CONFIG_ARCH_CPU_PROBE_RELEASE. This patch changes the above interfaces to hold lock_device_hotplug(). Signed-off-by: Toshi Kani --- arch/x86/kernel/topology.c | 2 ++ drivers/base/cpu.c | 16 ++++++++++++++-- 2 files changed, 16 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/topology.c b/arch/x86/kernel/topology.c index 5823bbd..a3f35eb 100644 --- a/arch/x86/kernel/topology.c +++ b/arch/x86/kernel/topology.c @@ -65,6 +65,7 @@ int __ref _debug_hotplug_cpu(int cpu, int action) if (!cpu_is_hotpluggable(cpu)) return -EINVAL; + lock_device_hotplug(); cpu_hotplug_driver_lock(); switch (action) { @@ -91,6 +92,7 @@ int __ref _debug_hotplug_cpu(int cpu, int action) } cpu_hotplug_driver_unlock(); + unlock_device_hotplug(); return ret; } diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index 4c358bc..4cc6928 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -88,7 +88,13 @@ static ssize_t cpu_probe_store(struct device *dev, const char *buf, size_t count) { - return arch_cpu_probe(buf, count); + ssize_t ret; + + lock_device_hotplug(); + ret = arch_cpu_probe(buf, count); + unlock_device_hotplug(); + + return ret; } static ssize_t cpu_release_store(struct device *dev, @@ -96,7 +102,13 @@ static ssize_t cpu_release_store(struct device *dev, const char *buf, size_t count) { - return arch_cpu_release(buf, count); + ssize_t ret; + + lock_device_hotplug(); + ret = arch_cpu_release(buf, count); + unlock_device_hotplug(); + + return ret; } static DEVICE_ATTR(probe, S_IWUSR, NULL, cpu_probe_store);