From 3fe931b31a4078395c1967f0495dcc9e5ec6b5e3 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Mon, 17 Dec 2018 10:02:42 +0300 Subject: [PATCH 1/2] thermal: int340x_thermal: Fix a NULL vs IS_ERR() check The intel_soc_dts_iosf_init() function doesn't return NULL, it returns error pointers. Fixes: 4d0dd6c1576b ("Thermal/int340x/processor_thermal: Enable auxiliary DTS for Braswell") Signed-off-by: Dan Carpenter Signed-off-by: Zhang Rui --- .../thermal/intel/int340x_thermal/processor_thermal_device.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/thermal/intel/int340x_thermal/processor_thermal_device.c b/drivers/thermal/intel/int340x_thermal/processor_thermal_device.c index 284cf2c5a8fd..8e0f665cf06f 100644 --- a/drivers/thermal/intel/int340x_thermal/processor_thermal_device.c +++ b/drivers/thermal/intel/int340x_thermal/processor_thermal_device.c @@ -423,7 +423,7 @@ static int proc_thermal_pci_probe(struct pci_dev *pdev, proc_priv->soc_dts = intel_soc_dts_iosf_init( INTEL_SOC_DTS_INTERRUPT_MSI, 2, 0); - if (proc_priv->soc_dts && pdev->irq) { + if (!IS_ERR(proc_priv->soc_dts) && pdev->irq) { ret = pci_enable_msi(pdev); if (!ret) { ret = request_threaded_irq(pdev->irq, NULL, From 129699bb8c7572106b5bbb2407c2daee4727ccad Mon Sep 17 00:00:00 2001 From: Aaron Hill Date: Mon, 24 Dec 2018 14:23:36 -0500 Subject: [PATCH 2/2] drivers: thermal: int340x_thermal: Fix sysfs race condition Changes since V1: * Use dev_info instead of printk * Use dev_warn instead of BUG_ON Previously, sysfs_create_group was called before all initialization had fully run - specifically, before pci_set_drvdata was called. Since the sysctl group is visible to userspace as soon as sysfs_create_group returns, a small window of time existed during which a process could read from an uninitialized/partially-initialized device. This commit moves the creation of the sysctl group to after all initialized is completed. This ensures that it's impossible for userspace to read from a sysctl file before initialization has fully completed. To catch any future regressions, I've added a check to ensure that proc_thermal_emum_mode is never PROC_THERMAL_NONE when a process tries to read from a sysctl file. Previously, the aforementioned race condition could result in the 'else' branch running while PROC_THERMAL_NONE was set, leading to a null pointer deference. Signed-off-by: Aaron Hill Signed-off-by: Zhang Rui --- .../processor_thermal_device.c | 28 ++++++++++--------- 1 file changed, 15 insertions(+), 13 deletions(-) diff --git a/drivers/thermal/intel/int340x_thermal/processor_thermal_device.c b/drivers/thermal/intel/int340x_thermal/processor_thermal_device.c index 8e0f665cf06f..8e1cf4d789be 100644 --- a/drivers/thermal/intel/int340x_thermal/processor_thermal_device.c +++ b/drivers/thermal/intel/int340x_thermal/processor_thermal_device.c @@ -84,7 +84,12 @@ static ssize_t power_limit_##index##_##suffix##_show(struct device *dev, \ struct pci_dev *pci_dev; \ struct platform_device *pdev; \ struct proc_thermal_device *proc_dev; \ -\ + \ + if (proc_thermal_emum_mode == PROC_THERMAL_NONE) { \ + dev_warn(dev, "Attempted to get power limit before device was initialized!\n"); \ + return 0; \ + } \ + \ if (proc_thermal_emum_mode == PROC_THERMAL_PLATFORM_DEV) { \ pdev = to_platform_device(dev); \ proc_dev = platform_get_drvdata(pdev); \ @@ -298,11 +303,6 @@ static int proc_thermal_add(struct device *dev, *priv = proc_priv; ret = proc_thermal_read_ppcc(proc_priv); - if (!ret) { - ret = sysfs_create_group(&dev->kobj, - &power_limit_attribute_group); - - } if (ret) return ret; @@ -316,8 +316,7 @@ static int proc_thermal_add(struct device *dev, proc_priv->int340x_zone = int340x_thermal_zone_add(adev, ops); if (IS_ERR(proc_priv->int340x_zone)) { - ret = PTR_ERR(proc_priv->int340x_zone); - goto remove_group; + return PTR_ERR(proc_priv->int340x_zone); } else ret = 0; @@ -331,9 +330,6 @@ static int proc_thermal_add(struct device *dev, remove_zone: int340x_thermal_zone_remove(proc_priv->int340x_zone); -remove_group: - sysfs_remove_group(&proc_priv->dev->kobj, - &power_limit_attribute_group); return ret; } @@ -364,7 +360,10 @@ static int int3401_add(struct platform_device *pdev) platform_set_drvdata(pdev, proc_priv); proc_thermal_emum_mode = PROC_THERMAL_PLATFORM_DEV; - return 0; + dev_info(&pdev->dev, "Creating sysfs group for PROC_THERMAL_PLATFORM_DEV\n"); + + return sysfs_create_group(&pdev->dev.kobj, + &power_limit_attribute_group); } static int int3401_remove(struct platform_device *pdev) @@ -441,7 +440,10 @@ static int proc_thermal_pci_probe(struct pci_dev *pdev, dev_err(&pdev->dev, "No auxiliary DTSs enabled\n"); } - return 0; + dev_info(&pdev->dev, "Creating sysfs group for PROC_THERMAL_PCI\n"); + + return sysfs_create_group(&pdev->dev.kobj, + &power_limit_attribute_group); } static void proc_thermal_pci_remove(struct pci_dev *pdev)