[PATCH 5.5 087/119] xhci: Do not open code __print_symbolic() in xhci trace events

From: Greg Kroah-Hartman
Date: Tue Mar 24 2020 - 09:27:45 EST


From: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>

commit 045706bff837ee89c13f1ace173db71922c1c40b upstream.

libtraceevent (used by perf and trace-cmd) failed to parse the
xhci_urb_dequeue trace event. This is because the user space trace
event format parsing is not a full C compiler. It can handle some basic
logic, but is not meant to be able to handle everything C can do.

In cases where a trace event field needs to be converted from a number
to a string, there's the __print_symbolic() macro that should be used:

See samples/trace_events/trace-events-sample.h

Some xhci trace events open coded the __print_symbolic() causing the
user spaces tools to fail to parse it. This has to be replaced with
__print_symbolic() instead.

CC: stable@xxxxxxxxxxxxxxx
Reported-by: Tzvetomir Stoyanov <tstoyanov@xxxxxxxxxx>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=206531
Fixes: 5abdc2e6e12ff ("usb: host: xhci: add urb_enqueue/dequeue/giveback tracers")
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20200306150858.21904-2-mathias.nyman@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/usb/host/xhci-trace.h | 23 ++++++-----------------
1 file changed, 6 insertions(+), 17 deletions(-)

--- a/drivers/usb/host/xhci-trace.h
+++ b/drivers/usb/host/xhci-trace.h
@@ -289,23 +289,12 @@ DECLARE_EVENT_CLASS(xhci_log_urb,
),
TP_printk("ep%d%s-%s: urb %p pipe %u slot %d length %d/%d sgs %d/%d stream %d flags %08x",
__entry->epnum, __entry->dir_in ? "in" : "out",
- ({ char *s;
- switch (__entry->type) {
- case USB_ENDPOINT_XFER_INT:
- s = "intr";
- break;
- case USB_ENDPOINT_XFER_CONTROL:
- s = "control";
- break;
- case USB_ENDPOINT_XFER_BULK:
- s = "bulk";
- break;
- case USB_ENDPOINT_XFER_ISOC:
- s = "isoc";
- break;
- default:
- s = "UNKNOWN";
- } s; }), __entry->urb, __entry->pipe, __entry->slot_id,
+ __print_symbolic(__entry->type,
+ { USB_ENDPOINT_XFER_INT, "intr" },
+ { USB_ENDPOINT_XFER_CONTROL, "control" },
+ { USB_ENDPOINT_XFER_BULK, "bulk" },
+ { USB_ENDPOINT_XFER_ISOC, "isoc" }),
+ __entry->urb, __entry->pipe, __entry->slot_id,
__entry->actual, __entry->length, __entry->num_mapped_sgs,
__entry->num_sgs, __entry->stream, __entry->flags
)