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Commit 14ff0836 authored by Shashank Mittal's avatar Shashank Mittal
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soc: qcom: jtagv8-etm: fix race condition during probe 



There can be a race condition when one core tries to read its etm data
while coming online, while other core is still writing etm data for same
cpu in jtag_mm_etm_probe.

Protect etm data with hotplug lock to avoid this race condition.

CRs-Fixed: 948917

Change-Id: Ie10a0f09520bf9388860ae2095b3af02c048d7ae
Signed-off-by: default avatarShashank Mittal <mittals@codeaurora.org>
parent 9f7af2ec

drivers/soc/qcom/jtagv8-etm.c

+9 −4
Original line number Diff line number Diff line
@@ -1556,7 +1556,6 @@ static int jtag_mm_etm_probe(struct platform_device *pdev, uint32_t cpu) 
	if (!etmdata)

		return -ENOMEM;



	etm[cpu] = etmdata;



	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "etm-base");

	if (!res)
@@ -1585,12 +1584,18 @@ static int jtag_mm_etm_probe(struct platform_device *pdev, uint32_t cpu) 
	if (cnt++ == 0)

		register_hotcpu_notifier(&jtag_mm_etm_notifier);



	get_online_cpus();



	if (!smp_call_function_single(cpu, etm_init_arch_data, etmdata,

				      1))

		etmdata->init = true;



	if (etmdata->init) {

	etm[cpu] = etmdata;



	put_online_cpus();



	mutex_lock(&etmdata->mutex);

	if (etmdata->init && !etmdata->enable) {

		if (etm_arch_supported(etmdata->arch)) {

			if (scm_get_feat_version(TZ_DBG_ETM_FEAT_ID) <

			    TZ_DBG_ETM_VER)
@@ -1600,8 +1605,8 @@ static int jtag_mm_etm_probe(struct platform_device *pdev, uint32_t cpu) 
		} else

			pr_info("etm arch %u not supported\n", etmdata->arch);

		etmdata->enable = true;

		mutex_unlock(&etmdata->mutex);

	}

	mutex_unlock(&etmdata->mutex);

	return 0;

}