Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762340AbZD1Pxt (ORCPT ); Tue, 28 Apr 2009 11:53:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761597AbZD1Pxh (ORCPT ); Tue, 28 Apr 2009 11:53:37 -0400 Received: from hera.kernel.org ([140.211.167.34]:41261 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761199AbZD1Pxf (ORCPT ); Tue, 28 Apr 2009 11:53:35 -0400 Message-ID: <49F7260F.8030405@kernel.org> Date: Tue, 28 Apr 2009 08:51:43 -0700 From: Yinghai Lu User-Agent: Thunderbird 2.0.0.19 (X11/20081227) MIME-Version: 1.0 To: Greg KH CC: Kay Sievers , Ingo Molnar , Linus Torvalds , Jesse Barnes , Andrew Morton , "H. Peter Anvin" , Thomas Gleixner , "linux-kernel@vger.kernel.org" , linux-pci@vger.kernel.org Subject: Re: [RFC PATCH] use dev_set_name(,NULL) to prevent leaking References: <20090418192314.GA22107@suse.de> <1240086446.2411.9.camel@poy> <20090418203718.GD30144@elte.hu> <49EA4EB9.2030307@kernel.org> <49F6B1E6.7050008@kernel.org> <49F6B350.9080703@kernel.org> <49F71EF6.3050102@kernel.org> <49F72205.7030306@kernel.org> <20090428153906.GA8896@suse.de> In-Reply-To: <20090428153906.GA8896@suse.de> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3372 Lines: 94 Greg KH wrote: > On Tue, Apr 28, 2009 at 08:34:29AM -0700, Yinghai Lu wrote: >> Yinghai Lu wrote: >>> Kay Sievers wrote: >>>> On Tue, Apr 28, 2009 at 09:42, Yinghai Lu wrote: >>>>> those about 1/3 dev_set_name() etc. >>>> put_device()? >>>> >>>> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blob;f=drivers/base/core.c;h=4aa527b8a91381289eb175b33f46e3e418d10374;hb=HEAD#l848 >>>> >>> ok, normal release path seems right, put_device will free the name. >>> >>> how about other fail path, that there is not put_device involved? >>> >> >> looks like need to follow this pattern >> >> static int >> sa1111_init_one_child(struct sa1111 *sachip, struct resource *parent, >> struct sa1111_dev_info *info) >> { >> struct sa1111_dev *dev; >> int ret; >> >> dev = kzalloc(sizeof(struct sa1111_dev), GFP_KERNEL); >> if (!dev) { >> ret = -ENOMEM; >> goto out; >> } >> >> dev_set_name(&dev->dev, "%4.4lx", info->offset); >> dev->devid = info->devid; >> dev->dev.parent = sachip->dev; >> dev->dev.bus = &sa1111_bus_type; >> dev->dev.release = sa1111_dev_release; >> dev->dev.coherent_dma_mask = sachip->dev->coherent_dma_mask; >> dev->res.start = sachip->phys + info->offset; >> dev->res.end = dev->res.start + 511; >> dev->res.name = dev_name(&dev->dev); >> dev->res.flags = IORESOURCE_MEM; >> dev->mapbase = sachip->base + info->offset; >> dev->skpcr_mask = info->skpcr_mask; >> memmove(dev->irq, info->irq, sizeof(dev->irq)); >> >> ret = request_resource(parent, &dev->res); >> if (ret) { >> printk("SA1111: failed to allocate resource for %s\n", >> dev->res.name); >> dev_set_name(&dev->dev, NULL); ============> clear the name >> kfree(dev); >> goto out; >> } >> >> >> ret = device_register(&dev->dev); >> if (ret) { >> release_resource(&dev->res); >> put_device(&dev->dev); ==================> put the device... >> kfree(dev); >> goto out; >> } > > You can just do a "put_device()" in both places, and it should be fine. > before device_register==>device_initialize is called, kobj->ref is still 0. will get warn from if (!kobj->state_initialized) WARN(1, KERN_WARNING "kobject: '%s' (%p): is not " "initialized, yet kobject_put() is being " "called.\n", kobject_name(kobj), kobj); also wonder int kref_put(struct kref *kref, void (*release)(struct kref *kref)) { WARN_ON(release == NULL); WARN_ON(release == (void (*)(struct kref *))kfree); if (atomic_dec_and_test(&kref->refcount)) { release(kref); return 1; } return 0; } what will be return from atomic_dec_and_test YH -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/