ARM: imx: Check return value of devm_kasprintf in imx_mmdc_perf_init

devm_kasprintf() returns a pointer to dynamically allocated memory
which can be NULL upon failure. Ensure the allocation was successful
by checking the pointer validity.

Release the id allocated in 'mmdc_pmu_init' when 'devm_kasprintf'
return NULL

Suggested-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Fixes: e76bdfd ("ARM: imx: Added perf functionality to mmdc driver")
Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

Author: KunWuChan

arch/arm/mach-imx/mmdc.c

@@ -501,6 +501,10 @@ static int imx_mmdc_perf_init(struct platform_device *pdev, void __iomem *mmdc_b
 
 	name = devm_kasprintf(&pdev->dev,
 				GFP_KERNEL, "mmdc%d", ret);
+	if (!name) {
+		ret = -ENOMEM;
+		goto pmu_release_id;
+	}
 
 	pmu_mmdc->mmdc_ipg_clk = mmdc_ipg_clk;
 	pmu_mmdc->devtype_data = (struct fsl_mmdc_devtype_data *)of_id->data;
@@ -523,9 +527,10 @@ static int imx_mmdc_perf_init(struct platform_device *pdev, void __iomem *mmdc_b
 
 pmu_register_err:
 	pr_warn("MMDC Perf PMU failed (%d), disabled\n", ret);
-	ida_simple_remove(&mmdc_ida, pmu_mmdc->id);
 	cpuhp_state_remove_instance_nocalls(cpuhp_mmdc_state, &pmu_mmdc->node);
 	hrtimer_cancel(&pmu_mmdc->hrtimer);
+pmu_release_id:
+	ida_simple_remove(&mmdc_ida, pmu_mmdc->id);
 pmu_free:
 	kfree(pmu_mmdc);
 	return ret;