On Wed, Jul 11, 2018 at 01:17:38PM +0000, Wei Yongjun wrote: > platform_get_resource() may fail and return NULL, so we should > better check it's return value to avoid a NULL pointer dereference > a bit later in the code. > > This is detected by Coccinelle semantic patch. > > @@ > expression pdev, res, n, t, e, e1, e2; > @@ > > res = platform_get_resource(pdev, t, n); > + if (!res) > + return -EINVAL; > ... when != res == NULL > e = devm_ioremap(e1, res->start, e2); Instead of adding unnecessary check here, I would go with replacing it with devm_ioremap_resource as it's designed to deal with that (patch inline) Regards, Sudeep -->8 >From a6de466984e657dad24dcbe87e5dde2d21cb8d35 Mon Sep 17 00:00:00 2001 From: Sudeep Holla <sudeep.holla@xxxxxxx> Date: Wed, 11 Jul 2018 16:17:39 +0100 Subject: [PATCH] misc: vexpress/syscfg: Use devm_ioremap_resource() to map memory Instead of checking the return value of platform_get_resource(), we can use devm_ioremap_resource() which has the NULL pointer check and the memory region requesting. devm_ioremap_resource is designed to replace calls to devm_request_mem_region followed by devm_ioremap, so let's use the same. Cc: Liviu Dudau <liviu.dudau@xxxxxxx> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx> --- drivers/misc/vexpress-syscfg.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/drivers/misc/vexpress-syscfg.c b/drivers/misc/vexpress-syscfg.c index 80a6f199077c..6c3591cdf855 100644 --- a/drivers/misc/vexpress-syscfg.c +++ b/drivers/misc/vexpress-syscfg.c @@ -258,13 +258,9 @@ static int vexpress_syscfg_probe(struct platform_device *pdev) INIT_LIST_HEAD(&syscfg->funcs); res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - if (!devm_request_mem_region(&pdev->dev, res->start, - resource_size(res), pdev->name)) - return -EBUSY; - - syscfg->base = devm_ioremap(&pdev->dev, res->start, resource_size(res)); - if (!syscfg->base) - return -EFAULT; + syscfg->base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(syscfg->base)) + return PTR_ERR(syscfg->base); /* Must use dev.parent (MFD), as that's where DT phandle points at... */ bridge = vexpress_config_bridge_register(pdev->dev.parent, -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
