x86/mce: Fix return value of mce_chrdev_read() when erst is disabled

[platform/adaptation/renesas_rcar/renesas_kernel.git] / arch / x86 / kernel / cpu / mcheck / mce.c

diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 29ba329..87c56ba 100644 (file)
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -1541,6 +1541,12 @@ static int __mce_read_apei(char __user **ubuf, size_t usize)
        /* Error or no more MCE record */
        if (rc <= 0) {
                mce_apei_read_done = 1;
+               /*
+                * When ERST is disabled, mce_chrdev_read() should return
+                * "no record" instead of "no device."
+                */
+               if (rc == -ENODEV)
+                       return 0;
                return rc;
        }
        rc = -EFAULT;
@@ -1859,7 +1865,7 @@ static struct bus_type mce_subsys = {
        .dev_name       = "machinecheck",
 };
 
-DEFINE_PER_CPU(struct device, mce_device);
+DEFINE_PER_CPU(struct device *, mce_device);
 
 __cpuinitdata
 void (*threshold_cpu_callback)(unsigned long action, unsigned int cpu);
@@ -2001,19 +2007,27 @@ static struct device_attribute *mce_device_attrs[] = {
 
 static cpumask_var_t mce_device_initialized;
 
+static void mce_device_release(struct device *dev)
+{
+       kfree(dev);
+}
+
 /* Per cpu device init. All of the cpus still share the same ctrl bank: */
 static __cpuinit int mce_device_create(unsigned int cpu)
 {
-       struct device *dev = &per_cpu(mce_device, cpu);
+       struct device *dev;
        int err;
        int i, j;
 
        if (!mce_available(&boot_cpu_data))
                return -EIO;
 
-       memset(dev, 0, sizeof(struct device));
+       dev = kzalloc(sizeof *dev, GFP_KERNEL);
+       if (!dev)
+               return -ENOMEM;
        dev->id  = cpu;
        dev->bus = &mce_subsys;
+       dev->release = &mce_device_release;
 
        err = device_register(dev);
        if (err)
@@ -2030,6 +2044,7 @@ static __cpuinit int mce_device_create(unsigned int cpu)
                        goto error2;
        }
        cpumask_set_cpu(cpu, mce_device_initialized);
+       per_cpu(mce_device, cpu) = dev;
 
        return 0;
 error2:
@@ -2046,7 +2061,7 @@ error:
 
 static __cpuinit void mce_device_remove(unsigned int cpu)
 {
-       struct device *dev = &per_cpu(mce_device, cpu);
+       struct device *dev = per_cpu(mce_device, cpu);
        int i;
 
        if (!cpumask_test_cpu(cpu, mce_device_initialized))
@@ -2060,6 +2075,7 @@ static __cpuinit void mce_device_remove(unsigned int cpu)
 
        device_unregister(dev);
        cpumask_clear_cpu(cpu, mce_device_initialized);
+       per_cpu(mce_device, cpu) = NULL;
 }
 
 /* Make sure there are no machine checks on offlined CPUs. */