From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Srinivas Pandruvada , Zhang Rui , Jonghwan Choi Subject: [PATCH 3.11 12/25] Thermal: x86_pkg_temp: change spin lock Date: Mon, 18 Nov 2013 10:40:41 -0800 Message-Id: <20131118184035.991787661@linuxfoundation.org> In-Reply-To: <20131118184032.248465920@linuxfoundation.org> References: <20131118184032.248465920@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: Srinivas Pandruvada commit 7bed1b3caaedd5918f0820b29f3b7a2ddc812922 upstream. x86_pkg_temp receives thermal notifications via a callback from a therm_throt driver, where thermal interrupts are processed. This callback is pkg_temp_thermal_platform_thermal_notify. Here to avoid multiple interrupts from cores in a package, we disable the source and also set a variable to avoid scheduling delayed work function. This variable is protected via spin_lock_irqsave. On one buggy platform, we still receiving interrupts even if the source is disabled. This can cause deadlock/lockdep warning, when interrupt is generated while under spinlock in work function. Change spin_lock to spin_lock_irqsave and spin_unlock to spin_unlock_irqrestore as the data it is trying to protect can also be modified in a notification call called from interrupt handler. Signed-off-by: Srinivas Pandruvada Signed-off-by: Zhang Rui Cc: Jonghwan Choi Signed-off-by: Greg Kroah-Hartman --- drivers/thermal/x86_pkg_temp_thermal.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) --- a/drivers/thermal/x86_pkg_temp_thermal.c +++ b/drivers/thermal/x86_pkg_temp_thermal.c @@ -316,18 +316,19 @@ static void pkg_temp_thermal_threshold_w int phy_id = topology_physical_package_id(cpu); struct phy_dev_entry *phdev = pkg_temp_thermal_get_phy_entry(cpu); bool notify = false; + unsigned long flags; if (!phdev) return; - spin_lock(&pkg_work_lock); + spin_lock_irqsave(&pkg_work_lock, flags); ++pkg_work_cnt; if (unlikely(phy_id > max_phy_id)) { - spin_unlock(&pkg_work_lock); + spin_unlock_irqrestore(&pkg_work_lock, flags); return; } pkg_work_scheduled[phy_id] = 0; - spin_unlock(&pkg_work_lock); + spin_unlock_irqrestore(&pkg_work_lock, flags); enable_pkg_thres_interrupt(); rdmsrl(MSR_IA32_PACKAGE_THERM_STATUS, msr_val); @@ -397,6 +398,7 @@ static int pkg_temp_thermal_device_add(u int thres_count; u32 eax, ebx, ecx, edx; u8 *temp; + unsigned long flags; cpuid(6, &eax, &ebx, &ecx, &edx); thres_count = ebx & 0x07; @@ -420,19 +422,19 @@ static int pkg_temp_thermal_device_add(u goto err_ret_unlock; } - spin_lock(&pkg_work_lock); + spin_lock_irqsave(&pkg_work_lock, flags); if (topology_physical_package_id(cpu) > max_phy_id) max_phy_id = topology_physical_package_id(cpu); temp = krealloc(pkg_work_scheduled, (max_phy_id+1) * sizeof(u8), GFP_ATOMIC); if (!temp) { - spin_unlock(&pkg_work_lock); + spin_unlock_irqrestore(&pkg_work_lock, flags); err = -ENOMEM; goto err_ret_free; } pkg_work_scheduled = temp; pkg_work_scheduled[topology_physical_package_id(cpu)] = 0; - spin_unlock(&pkg_work_lock); + spin_unlock_irqrestore(&pkg_work_lock, flags); phy_dev_entry->phys_proc_id = topology_physical_package_id(cpu); phy_dev_entry->first_cpu = cpu;