Commit 8f4c4963 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

perf/core: Simplify the perf_pmu_register() error path 



The error path of perf_pmu_register() is of course very similar to a
subset of perf_pmu_unregister(). Extract this common part in
perf_pmu_free() and simplify things.

[ mingo: Forward ported it ]

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Acked-by: default avatarRavi Bangoria <ravi.bangoria@amd.com>
Link: https://lore.kernel.org/r/20241104135518.090915501@infradead.org
parent c70ca298

kernel/events/core.c

+30 −37
Original line number Diff line number Diff line
@@ -11675,11 +11675,6 @@ static int perf_event_idx_default(struct perf_event *event) 
	return 0;

}



static void free_pmu_context(struct pmu *pmu)

{

	free_percpu(pmu->cpu_pmu_context);

}



/*

 * Let userspace know that this PMU supports address range filtering:

 */
@@ -11885,6 +11880,7 @@ static int pmu_dev_alloc(struct pmu *pmu) 


free_dev:

	put_device(pmu->dev);

	pmu->dev = NULL;

	goto out;

}
@@ -11906,25 +11902,38 @@ static bool idr_cmpxchg(struct idr *idr, unsigned long id, void *old, void *new) 
	return true;

}



static void perf_pmu_free(struct pmu *pmu)

{

	free_percpu(pmu->pmu_disable_count);

	if (pmu_bus_running && pmu->dev && pmu->dev != PMU_NULL_DEV) {

		if (pmu->nr_addr_filters)

			device_remove_file(pmu->dev, &dev_attr_nr_addr_filters);

		device_del(pmu->dev);

		put_device(pmu->dev);

	}

	free_percpu(pmu->cpu_pmu_context);

}



int perf_pmu_register(struct pmu *pmu, const char *name, int type)

{

	int cpu, ret, max = PERF_TYPE_MAX;



	pmu->type = -1;



	mutex_lock(&pmus_lock);

	ret = -ENOMEM;

	pmu->pmu_disable_count = alloc_percpu(int);

	if (!pmu->pmu_disable_count)

		goto unlock;



	pmu->type = -1;

	if (WARN_ONCE(!name, "Can not register anonymous pmu.\n")) {

		ret = -EINVAL;

		goto free_pdc;

		goto free;

	}



	if (WARN_ONCE(pmu->scope >= PERF_PMU_MAX_SCOPE, "Can not register a pmu with an invalid scope.\n")) {

		ret = -EINVAL;

		goto free_pdc;

		goto free;

	}



	pmu->name = name;
@@ -11934,24 +11943,23 @@ int perf_pmu_register(struct pmu *pmu, const char *name, int type) 


	ret = idr_alloc(&pmu_idr, NULL, max, 0, GFP_KERNEL);

	if (ret < 0)

		goto free_pdc;

		goto free;



	WARN_ON(type >= 0 && ret != type);



	type = ret;

	pmu->type = type;

	pmu->type = ret;

	atomic_set(&pmu->exclusive_cnt, 0);



	if (pmu_bus_running && !pmu->dev) {

		ret = pmu_dev_alloc(pmu);

		if (ret)

			goto free_idr;

			goto free;

	}



	ret = -ENOMEM;

	pmu->cpu_pmu_context = alloc_percpu(struct perf_cpu_pmu_context);

	if (!pmu->cpu_pmu_context)

		goto free_dev;

		goto free;



	for_each_possible_cpu(cpu) {

		struct perf_cpu_pmu_context *cpc;
@@ -11992,8 +12000,10 @@ int perf_pmu_register(struct pmu *pmu, const char *name, int type) 
	/*

	 * Now that the PMU is complete, make it visible to perf_try_init_event().

	 */

	if (!idr_cmpxchg(&pmu_idr, pmu->type, NULL, pmu))

		goto free_context;

	if (!idr_cmpxchg(&pmu_idr, pmu->type, NULL, pmu)) {

		ret = -EINVAL;

		goto free;

	}

	list_add_rcu(&pmu->entry, &pmus);



	ret = 0;
@@ -12002,20 +12012,10 @@ int perf_pmu_register(struct pmu *pmu, const char *name, int type) 


	return ret;



free_context:

	free_percpu(pmu->cpu_pmu_context);



free_dev:

	if (pmu->dev && pmu->dev != PMU_NULL_DEV) {

		device_del(pmu->dev);

		put_device(pmu->dev);

	}



free_idr:

free:

	if (pmu->type >= 0)

		idr_remove(&pmu_idr, pmu->type);



free_pdc:

	free_percpu(pmu->pmu_disable_count);

	perf_pmu_free(pmu);

	goto unlock;

}

EXPORT_SYMBOL_GPL(perf_pmu_register);
@@ -12034,14 +12034,7 @@ void perf_pmu_unregister(struct pmu *pmu) 
	synchronize_srcu(&pmus_srcu);

	synchronize_rcu();



	free_percpu(pmu->pmu_disable_count);

	if (pmu_bus_running && pmu->dev && pmu->dev != PMU_NULL_DEV) {

		if (pmu->nr_addr_filters)

			device_remove_file(pmu->dev, &dev_attr_nr_addr_filters);

		device_del(pmu->dev);

		put_device(pmu->dev);

	}

	free_pmu_context(pmu);

	perf_pmu_free(pmu);

}

EXPORT_SYMBOL_GPL(perf_pmu_unregister);