From 14a6043379e2132c11b815972c0e2201e68d7467 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Google)" Date: Sun, 3 Jul 2022 09:14:49 -0400 Subject: [PATCH] USB: gadget: udc: tracing: Do not open code __string() with __dynamic_array() 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 Cc: Greg Kroah-Hartman Cc: linux-usb@vger.kernel.org Signed-off-by: Steven Rostedt (Google) Link: https://lore.kernel.org/r/20220703091449.317f94b1@rorschach.local.home Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/udc/trace.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/usb/gadget/udc/trace.h b/drivers/usb/gadget/udc/trace.h index 98584f6..abdbcb1 100644 --- a/drivers/usb/gadget/udc/trace.h +++ b/drivers/usb/gadget/udc/trace.h @@ -140,7 +140,7 @@ DECLARE_EVENT_CLASS(udc_log_ep, TP_PROTO(struct usb_ep *ep, int ret), TP_ARGS(ep, ret), TP_STRUCT__entry( - __dynamic_array(char, name, UDC_TRACE_STR_MAX) + __string(name, ep->name) __field(unsigned, maxpacket) __field(unsigned, maxpacket_limit) __field(unsigned, max_streams) @@ -152,7 +152,7 @@ DECLARE_EVENT_CLASS(udc_log_ep, __field(int, ret) ), TP_fast_assign( - snprintf(__get_str(name), UDC_TRACE_STR_MAX, "%s", ep->name); + __assign_str(name, ep->name); __entry->maxpacket = ep->maxpacket; __entry->maxpacket_limit = ep->maxpacket_limit; __entry->max_streams = ep->max_streams; @@ -214,7 +214,7 @@ DECLARE_EVENT_CLASS(udc_log_req, TP_PROTO(struct usb_ep *ep, struct usb_request *req, int ret), TP_ARGS(ep, req, ret), TP_STRUCT__entry( - __dynamic_array(char, name, UDC_TRACE_STR_MAX) + __string(name, ep->name) __field(unsigned, length) __field(unsigned, actual) __field(unsigned, num_sgs) @@ -228,7 +228,7 @@ DECLARE_EVENT_CLASS(udc_log_req, __field(struct usb_request *, req) ), TP_fast_assign( - snprintf(__get_str(name), UDC_TRACE_STR_MAX, "%s", ep->name); + __assign_str(name, ep->name); __entry->length = req->length; __entry->actual = req->actual; __entry->num_sgs = req->num_sgs; -- 2.7.4