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-rw-r--r--drivers/hwtracing/coresight/coresight-tmc-etr.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index e0d83ee01b77..fc0a946053dd 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -1307,6 +1307,19 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev)
raw_spin_lock_irqsave(&drvdata->spinlock, flags);
/*
+ * Since the sysfs buffer allocation and the hardware enablement is not
+ * in the same critical region, it's possible to race with the perf.
+ */
+ if (coresight_get_mode(csdev) == CS_MODE_PERF) {
+ drvdata->sysfs_buf = NULL;
+ raw_spin_unlock_irqrestore(&drvdata->spinlock, flags);
+
+ /* Free allocated memory out side of the spinlock */
+ tmc_etr_free_sysfs_buf(sysfs_buf);
+ return -EBUSY;
+ }
+
+ /*
* In sysFS mode we can have multiple writers per sink. Since this
* sink is already enabled no memory is needed and the HW need not be
* touched, even if the buffer size has changed.