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From: Alexander Shishkin <alexander.shishkin@linux.intel.com>
To: Greg KH <greg@kroah.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>,
	Chunyan Zhang <zhang.chunyan@linaro.org>,
	laurent.fert@intel.com, yann.fouassier@intel.com,
	linux-kernel@vger.kernel.org,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>
Subject: [QUEUED v20160408 16/18] intel_th: Hold output driver module reference while capture is active
Date: Fri,  8 Apr 2016 17:56:39 +0300	[thread overview]
Message-ID: <1460127401-30801-17-git-send-email-alexander.shishkin@linux.intel.com> (raw)
In-Reply-To: <1460127401-30801-1-git-send-email-alexander.shishkin@linux.intel.com>

Right now it's possible to unload the output subdevice's driver while
the capture to this output is active. Prevent this by holding the
output driver's module reference.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
---
 drivers/hwtracing/intel_th/core.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/hwtracing/intel_th/core.c b/drivers/hwtracing/intel_th/core.c
index 20339470c2..1be543e8e4 100644
--- a/drivers/hwtracing/intel_th/core.c
+++ b/drivers/hwtracing/intel_th/core.c
@@ -189,6 +189,9 @@ static int intel_th_output_activate(struct intel_th_device *thdev)
 	if (!thdrv)
 		return -ENODEV;
 
+	if (!try_module_get(thdrv->driver.owner))
+		return -ENODEV;
+
 	if (thdrv->activate)
 		return thdrv->activate(thdev);
 
@@ -209,6 +212,8 @@ static void intel_th_output_deactivate(struct intel_th_device *thdev)
 		thdrv->deactivate(thdev);
 	else
 		intel_th_trace_disable(thdev);
+
+	module_put(thdrv->driver.owner);
 }
 
 static ssize_t active_show(struct device *dev, struct device_attribute *attr,
-- 
2.8.0.rc3

  parent reply	other threads:[~2016-04-08 14:58 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-04-08 14:56 [QUEUED v20160408 00/18] stm class/intel_th: Patches in my queue Alexander Shishkin
2016-04-08 14:56 ` [QUEUED v20160408 01/18] MAINTAINERS: Add a git tree for the stm class Alexander Shishkin
2016-04-08 14:56 ` [QUEUED v20160408 02/18] stm class: Fix integer boundary checks for master range Alexander Shishkin
2016-04-08 14:56 ` [QUEUED v20160408 03/18] stm class: dummy_stm: Make nr_dummies parameter read-only Alexander Shishkin
2016-04-08 14:56 ` [QUEUED v20160408 04/18] stm class: stm_heartbeat: Make nr_devs " Alexander Shishkin
2016-04-08 14:56 ` [QUEUED v20160408 05/18] stm class: Remove a pointless line Alexander Shishkin
2016-04-08 14:56 ` [QUEUED v20160408 06/18] stm class: Do not leak the chrdev in error path Alexander Shishkin
2016-04-08 14:56 ` [QUEUED v20160408 07/18] stm class: Fix stm device initialization order Alexander Shishkin
2016-04-08 14:56 ` [QUEUED v20160408 08/18] stm class: Remove unnecessary pointer increment Alexander Shishkin
2016-04-08 14:56 ` [QUEUED v20160408 09/18] intel_th: pti: Do remove sysfs group on device removal Alexander Shishkin
2016-04-08 14:56 ` [QUEUED v20160408 10/18] intel_th: msu: Handle kstrndup() failure Alexander Shishkin
2016-04-08 14:56 ` [QUEUED v20160408 11/18] intel_th: Allow subdevice drivers to bring in own attribute groups Alexander Shishkin
2016-04-08 14:56 ` [QUEUED v20160408 12/18] intel_th: msu: Create sysfs attributes using core driver's facility Alexander Shishkin
2016-04-08 14:56 ` [QUEUED v20160408 13/18] intel_th: pti: " Alexander Shishkin
2016-04-08 14:56 ` [QUEUED v20160408 14/18] intel_th: Fix activating a subdevice without a driver Alexander Shishkin
2016-04-08 14:56 ` [QUEUED v20160408 15/18] intel_th: msu: Serialize enabling/disabling Alexander Shishkin
2016-04-08 14:56 ` Alexander Shishkin [this message]
2016-04-08 14:56 ` [QUEUED v20160408 17/18] intel_th: msu: Set fops::owner to prevent module from unloading Alexander Shishkin
2016-04-08 14:56 ` [QUEUED v20160408 18/18] intel_th: msu: Release resources on removal Alexander Shishkin

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