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coresight: etm3x: Fix cntr_val_show() to match cntr_val_store() behavior

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The cntr_val_show() function was intended to print the values of all
counters using a loop. However, due to a buffer overwrite issue with
sprintf(), it effectively only displayed the value of the last counter.

The companion function, cntr_val_store(), allows users to modify a
specific counter selected by 'cntr_idx'. To maintain consistency
between read and write operations and to align with the ETM4x driver
behavior, modify cntr_val_show() to report only the value of the
currently selected counter.

This change removes the loop and the "counter %d:" prefix, printing
only the hexadecimal value. It also adopts sysfs_emit() for standard
sysfs output formatting.

Fixes: a939fc5a71 ("coresight-etm: add CoreSight ETM/PTM driver")
Cc: stable@vger.kernel.org
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Reviewed-by: James Clark <james.clark@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20251202082613.3265761-1-visitorckw@gmail.com
This commit is contained in:
Kuan-Wei Chiu 2025-12-02 08:26:13 +00:00 committed by Suzuki K Poulose
parent 8cdeaa50ea
commit 41fb4e9255
1 changed files with 4 additions and 11 deletions
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15
drivers/hwtracing/coresight/coresight-etm3x-sysfs.c
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@ -717,26 +717,19 @@ static DEVICE_ATTR_RW(cntr_rld_event);
static ssize_t cntr_val_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
int i, ret = 0;
u32 val;
struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent);
struct etm_config *config = &drvdata->config;
if (!coresight_get_mode(drvdata->csdev)) {
spin_lock(&drvdata->spinlock);
for (i = 0; i < drvdata->nr_cntr; i++)
ret += sprintf(buf, "counter %d: %x\n",
i, config->cntr_val[i]);
val = config->cntr_val[config->cntr_idx];
spin_unlock(&drvdata->spinlock);
return ret;
} else {
val = etm_readl(drvdata, ETMCNTVRn(config->cntr_idx));
}
for (i = 0; i < drvdata->nr_cntr; i++) {
val = etm_readl(drvdata, ETMCNTVRn(i));
ret += sprintf(buf, "counter %d: %x\n", i, val);
}
return ret;
return sysfs_emit(buf, "%#x\n", val);
}
static ssize_t cntr_val_store(struct device *dev,