• Steven Rostedt (Google)'s avatar
    USB: gadget: udc: tracing: Do not open code __string() with __dynamic_array() · 14a60433
    Steven Rostedt (Google) authored
    The event classes udc_log_ep and udc_log_req both declare:
    
        __dynamic_array(char, name, UDC_TRACE_STR_MAX)
    
    Which will reserve UDC_TRACE_STR_MAX bytes on the ring buffer for the
    event to write in name. It then uses snprintf() to write into that space.
    
    Assuming that the string being copied is nul terminated, it is better to
    just use the __string() helper. That way only the size of the string is
    saved into the ring buffer and not the max size (yes, the entire
    UDC_TRACE_STR_MAX is used in the trace event, and anything not used is
    just junk in the ring buffer). Worse, there's also meta data saved into
    the event that denotes where the string is stored in the event and also
    saves its size, which is always going to be UDC_TRACE_STR_MAX.
    
    Convert both to use the __string() and __assign_str() helpers that are for
    this kind of use case.
    
    Cc: Felipe Balbi <balbi@kernel.org>
    Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    Cc: linux-usb@vger.kernel.org
    Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
    Link: https://lore.kernel.org/r/20220703091449.317f94b1@rorschach.local.homeSigned-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    14a60433
trace.h 8.12 KB