From 9ad577087165478c9d9be82b15ed9bf2db5835f5 Mon Sep 17 00:00:00 2001
From: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Date: Thu, 1 Mar 2018 10:15:32 +0200
Subject: [PATCH] intel_th: Use correct method of finding hub
Git-commit: 9ad577087165478c9d9be82b15ed9bf2db5835f5
Patch-mainline: v4.17-rc1
References: FATE#325099

Since commit 8edc514b01e9 ("intel_th: Make SOURCE devices children of the
root device") the hub is not the parent of SOURCE devices any more, so the
new helper function should be used for that instead of always using the
parent. The intel_th_set_output() path, however, still uses the old
logic, leading to the hub driver structure being aliased with something
else, like struct pci_driver or struct acpi_driver, and an incorrect call
to an address inferred from that, potentially resulting in a crash.

Fixes: 8edc514b01e9 ("intel_th: Make SOURCE devices children of the root device")
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/hwtracing/intel_th/core.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/hwtracing/intel_th/core.c
+++ b/drivers/hwtracing/intel_th/core.c
@@ -936,7 +936,7 @@ EXPORT_SYMBOL_GPL(intel_th_trace_disable
 int intel_th_set_output(struct intel_th_device *thdev,
 			unsigned int master)
 {
-	struct intel_th_device *hub = to_intel_th_device(thdev->dev.parent);
+	struct intel_th_device *hub = to_intel_th_hub(thdev);
 	struct intel_th_driver *hubdrv = to_intel_th_driver(hub->dev.driver);
 
 	if (!hubdrv->set_output)