Commit 81f3b9aa authored May 05, 2017 by Mukesh Ojha

coresight-tmc: Adds lock to avoid race condition



There can be a case of race in the call to tmc_etr_bam_disable(). The call
from usb_notifier() to tmc_etr_bam_disable() is within a lock
'drvdata->mem_lock' but the call from tmc_disable is not under any lock
which can lead to race.

This patch adds the missing lock.

CRs-Fixed: 2047196
Change-Id: I3986b498ae8e2b2ddfe8f5b3315fdefab197d11c
Signed-off-by: Mukesh Ojha <mojha@codeaurora.org>

parent 5404e350

drivers/hwtracing/coresight/coresight-tmc.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -1018,6 +1018,7 @@ static void tmc_disable(struct tmc_drvdata *drvdata, enum tmc_mode mode)
		{
		unsigned long flags;

		mutex_lock(&drvdata->mem_lock);
		spin_lock_irqsave(&drvdata->spinlock, flags);
		if (drvdata->reading)
		goto out;
		@@ -1054,7 +1055,7 @@ out:
		}

		pm_runtime_put(drvdata->dev);

		mutex_unlock(&drvdata->mem_lock);
		dev_info(drvdata->dev, "TMC disabled\n");
		}