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    Subject[patch 02/28] pm_qos: clean up racy global "name" variable
    "name" is a poor name for a file-global variable.  It was used in three
    different functions, with no mutual exclusion. But it's just a tiny,
    temporary string; let's just move it onto the stack in the functions that
    need it. Also use snprintf() just in case.

    Signed-off-by: Jonathan Corbet <corbet@lwn.net>
    Cc: Mark Gross <mgross@linux.intel.com>
    Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com>
    Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

    diff --git a/kernel/pm_qos_params.c b/kernel/pm_qos_params.c
    index d96b83e..3db49b9 100644
    --- a/kernel/pm_qos_params.c
    +++ b/kernel/pm_qos_params.c
    @@ -343,18 +343,18 @@ int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier)
    }
    EXPORT_SYMBOL_GPL(pm_qos_remove_notifier);

    -#define PID_NAME_LEN sizeof("process_1234567890")
    -static char name[PID_NAME_LEN];
    +#define PID_NAME_LEN 32

    static int pm_qos_power_open(struct inode *inode, struct file *filp)
    {
    int ret;
    long pm_qos_class;
    + char name[PID_NAME_LEN];

    pm_qos_class = find_pm_qos_object_by_minor(iminor(inode));
    if (pm_qos_class >= 0) {
    filp->private_data = (void *)pm_qos_class;
    - sprintf(name, "process_%d", current->pid);
    + snprintf(name, PID_NAME_LEN, "process_%d", current->pid);
    ret = pm_qos_add_requirement(pm_qos_class, name,
    PM_QOS_DEFAULT_VALUE);
    if (ret >= 0)
    @@ -366,9 +366,10 @@ static int pm_qos_power_open(struct inode *inode, struct file *filp)
    static int pm_qos_power_release(struct inode *inode, struct file *filp)
    {
    int pm_qos_class;
    + char name[PID_NAME_LEN];

    pm_qos_class = (long)filp->private_data;
    - sprintf(name, "process_%d", current->pid);
    + snprintf(name, PID_NAME_LEN, "process_%d", current->pid);
    pm_qos_remove_requirement(pm_qos_class, name);

    return 0;
    @@ -379,13 +380,14 @@ static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf,
    {
    s32 value;
    int pm_qos_class;
    + char name[PID_NAME_LEN];

    pm_qos_class = (long)filp->private_data;
    if (count != sizeof(s32))
    return -EINVAL;
    if (copy_from_user(&value, buf, sizeof(s32)))
    return -EFAULT;
    - sprintf(name, "process_%d", current->pid);
    + snprintf(name, PID_NAME_LEN, "process_%d", current->pid);
    pm_qos_update_requirement(pm_qos_class, name, value);

    return sizeof(s32);



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