xhci: fix even more unsafe memory usage in xhci tracing

Removes static char buffer usage in the following decode functions:
	xhci_decode_ctrl_ctx()
	xhci_decode_slot_context()
	xhci_decode_usbsts()
	xhci_decode_doorbell()
	xhci_decode_ep_context()

Caller must provide a buffer to use.
In tracing use __get_str() as recommended to pass buffer.

Minor changes are needed in other xhci code as these functions are also
used elsewhere

Cc: <stable@vger.kernel.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210820123503.2605901-3-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 11 insertions, 7 deletions

diff --git a/drivers/usb/host/xhci-trace.h b/drivers/usb/host/xhci-trace.h
index 5e1c50cb7016..a5da02077297 100644
--- a/drivers/usb/host/xhci-trace.h
+++ b/drivers/usb/host/xhci-trace.h
@@ -322,6 +322,7 @@ DECLARE_EVENT_CLASS(xhci_log_ep_ctx,
 		__field(u32, info2)
 		__field(u64, deq)
 		__field(u32, tx_info)
+		__dynamic_array(char, str, XHCI_MSG_MAX)
 	),
 	TP_fast_assign(
 		__entry->info = le32_to_cpu(ctx->ep_info);
@@ -329,8 +330,8 @@ DECLARE_EVENT_CLASS(xhci_log_ep_ctx,
 		__entry->deq = le64_to_cpu(ctx->deq);
 		__entry->tx_info = le32_to_cpu(ctx->tx_info);
 	),
-	TP_printk("%s", xhci_decode_ep_context(__entry->info,
-		__entry->info2, __entry->deq, __entry->tx_info)
+	TP_printk("%s", xhci_decode_ep_context(__get_str(str),
+		__entry->info, __entry->info2, __entry->deq, __entry->tx_info)
 	)
 );
 
@@ -367,6 +368,7 @@ DECLARE_EVENT_CLASS(xhci_log_slot_ctx,
 		__field(u32, info2)
 		__field(u32, tt_info)
 		__field(u32, state)
+		__dynamic_array(char, str, XHCI_MSG_MAX)
 	),
 	TP_fast_assign(
 		__entry->info = le32_to_cpu(ctx->dev_info);
@@ -374,9 +376,9 @@ DECLARE_EVENT_CLASS(xhci_log_slot_ctx,
 		__entry->tt_info = le64_to_cpu(ctx->tt_info);
 		__entry->state = le32_to_cpu(ctx->dev_state);
 	),
-	TP_printk("%s", xhci_decode_slot_context(__entry->info,
-			__entry->info2, __entry->tt_info,
-			__entry->state)
+	TP_printk("%s", xhci_decode_slot_context(__get_str(str),
+			__entry->info, __entry->info2,
+			__entry->tt_info, __entry->state)
 	)
 );
 
@@ -431,12 +433,13 @@ DECLARE_EVENT_CLASS(xhci_log_ctrl_ctx,
 	TP_STRUCT__entry(
 		__field(u32, drop)
 		__field(u32, add)
+		__dynamic_array(char, str, XHCI_MSG_MAX)
 	),
 	TP_fast_assign(
 		__entry->drop = le32_to_cpu(ctrl_ctx->drop_flags);
 		__entry->add = le32_to_cpu(ctrl_ctx->add_flags);
 	),
-	TP_printk("%s", xhci_decode_ctrl_ctx(__entry->drop, __entry->add)
+	TP_printk("%s", xhci_decode_ctrl_ctx(__get_str(str), __entry->drop, __entry->add)
 	)
 );
 
@@ -555,13 +558,14 @@ DECLARE_EVENT_CLASS(xhci_log_doorbell,
 	TP_STRUCT__entry(
 		__field(u32, slot)
 		__field(u32, doorbell)
+		__dynamic_array(char, str, XHCI_MSG_MAX)
 	),
 	TP_fast_assign(
 		__entry->slot = slot;
 		__entry->doorbell = doorbell;
 	),
 	TP_printk("Ring doorbell for %s",
-		xhci_decode_doorbell(__entry->slot, __entry->doorbell)
+		  xhci_decode_doorbell(__get_str(str), __entry->slot, __entry->doorbell)
 	)
 );