On 7/20/22 16:47, Steven Rostedt wrote: > On Tue, 19 Jul 2022 19:27:06 +0200 > Daniel Bristot de Oliveira <bristot@xxxxxxxxxx> wrote: > >> +/* >> + * Interface to read the enable/disable status of a monitor. >> + */ >> +static ssize_t monitor_desc_read_data(struct file *filp, char __user *user_buf, size_t count, >> + loff_t *ppos) >> +{ >> + struct rv_monitor_def *mdef = filp->private_data; >> + char buff[256]; >> + >> + memset(buff, 0, sizeof(buff)); >> + >> + mutex_lock(&rv_interface_lock); >> + snprintf(buff, sizeof(buff), "%s\n", mdef->monitor->description); >> + mutex_unlock(&rv_interface_lock); > > What exactly is the mutex protecting here? I placed it around all access on read/write in the interface, but indeed, it is not needed here (static data). It is in a file inside the monitor's directory... so the directory is there, and the module is there as well. -- Daniel