From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ferruh Yigit Subject: Re: [PATCH V4 7/9] igb_uio: fix uio release issue when hot unplug Date: Tue, 3 Jul 2018 13:12:11 +0100 Message-ID: References: <1498711073-42917-1-git-send-email-jia.guo@intel.com> <1530268248-7328-1-git-send-email-jia.guo@intel.com> <1530268248-7328-8-git-send-email-jia.guo@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: jblunck@infradead.org, shreyansh.jain@nxp.com, dev@dpdk.org, helin.zhang@intel.com To: Jeff Guo , stephen@networkplumber.org, bruce.richardson@intel.com, konstantin.ananyev@intel.com, gaetan.rivet@6wind.com, jingjing.wu@intel.com, thomas@monjalon.net, motih@mellanox.com, matan@mellanox.com, harry.van.haaren@intel.com, qi.z.zhang@intel.com, shaopeng.he@intel.com, bernard.iremonger@intel.com Return-path: Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by dpdk.org (Postfix) with ESMTP id 0C21A1BDD1 for ; Tue, 3 Jul 2018 14:12:16 +0200 (CEST) In-Reply-To: <1530268248-7328-8-git-send-email-jia.guo@intel.com> Content-Language: en-US List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On 6/29/2018 11:30 AM, Jeff Guo wrote: > When hot unplug device, the kernel will release the device resource in the > kernel side, such as the fd sys file will disappear, and the irq will be > released. At this time, if igb uio driver still try to release this > resource, it will cause kernel crash. On the other hand, something like > interrupt disabling do not automatically process in kernel side. If not > handler it, this redundancy and dirty thing will affect the interrupt > resource be used by other device. So the igb_uio driver have to check the > hot plug status, and the corresponding process should be taken in igb uio > driver. > > This patch propose to add structure of rte_udev_state into rte_uio_pci_dev > of igb_uio kernel driver, which will record the state of uio device, such > as probed/opened/released/removed/unplug. When detect the unexpected > removal which cause of hot unplug behavior, it will corresponding disable > interrupt resource, while for the part of releasement which kernel have > already handle, just skip it to avoid double free or null pointer kernel > crash issue. > > Signed-off-by: Jeff Guo > --- > v4->v3: > no change > --- > kernel/linux/igb_uio/igb_uio.c | 50 +++++++++++++++++++++++++++++++++++++----- > 1 file changed, 45 insertions(+), 5 deletions(-) > > diff --git a/kernel/linux/igb_uio/igb_uio.c b/kernel/linux/igb_uio/igb_uio.c > index b3233f1..d301302 100644 > --- a/kernel/linux/igb_uio/igb_uio.c > +++ b/kernel/linux/igb_uio/igb_uio.c > @@ -19,6 +19,15 @@ > > #include "compat.h" > > +/* uio pci device state */ > +enum rte_udev_state { > + RTE_UDEV_PROBED, > + RTE_UDEV_OPENNED, > + RTE_UDEV_RELEASED, > + RTE_UDEV_REMOVED, > + RTE_UDEV_UNPLUG > +}; > + > /** > * A structure describing the private information for a uio device. > */ > @@ -28,6 +37,7 @@ struct rte_uio_pci_dev { > enum rte_intr_mode mode; > struct mutex lock; > int refcnt; > + enum rte_udev_state state; > }; > > static char *intr_mode; > @@ -194,12 +204,20 @@ igbuio_pci_irqhandler(int irq, void *dev_id) > { > struct rte_uio_pci_dev *udev = (struct rte_uio_pci_dev *)dev_id; > struct uio_info *info = &udev->info; > + struct pci_dev *pdev = udev->pdev; > > /* Legacy mode need to mask in hardware */ > if (udev->mode == RTE_INTR_MODE_LEGACY && > !pci_check_and_mask_intx(udev->pdev)) > return IRQ_NONE; > > + /* check the uevent of the kobj */ > + if ((&pdev->dev.kobj)->state_remove_uevent_sent == 1) { > + dev_notice(&pdev->dev, "device:%s, sent remove uevent!\n", > + (&pdev->dev.kobj)->name); > + udev->state = RTE_UDEV_UNPLUG; > + } I guess commit log says kernel can remove device, if so do we need any locking before accessing dev? > + > uio_event_notify(info); > > /* Message signal mode, no share IRQ and automasked */ > @@ -308,7 +326,6 @@ igbuio_pci_disable_interrupts(struct rte_uio_pci_dev *udev) > #endif > } > > - > /** > * This gets called while opening uio device file. > */ > @@ -330,24 +347,33 @@ igbuio_pci_open(struct uio_info *info, struct inode *inode) > > /* enable interrupts */ > err = igbuio_pci_enable_interrupts(udev); > - mutex_unlock(&udev->lock); > if (err) { > dev_err(&dev->dev, "Enable interrupt fails\n"); > + pci_clear_master(dev); > return err; > } > + udev->state = RTE_UDEV_OPENNED; > + mutex_unlock(&udev->lock); > return 0; > } > > +/** > + * This gets called while closing uio device file. > + */ > static int > igbuio_pci_release(struct uio_info *info, struct inode *inode) > { > + > struct rte_uio_pci_dev *udev = info->priv; > struct pci_dev *dev = udev->pdev; > > + if (udev->state == RTE_UDEV_REMOVED) > + return 0; > + > mutex_lock(&udev->lock); > if (--udev->refcnt > 0) { > mutex_unlock(&udev->lock); > - return 0; > + return -1; > } > > /* disable interrupts */ > @@ -355,7 +381,7 @@ igbuio_pci_release(struct uio_info *info, struct inode *inode) > > /* stop the device from further DMA */ > pci_clear_master(dev); > - > + udev->state = RTE_UDEV_RELEASED; > mutex_unlock(&udev->lock); > return 0; > } > @@ -557,6 +583,7 @@ igbuio_pci_probe(struct pci_dev *dev, const struct pci_device_id *id) > (unsigned long long)map_dma_addr, map_addr); > } > > + udev->state = RTE_UDEV_PROBED; > return 0; > > fail_remove_group: > @@ -573,11 +600,24 @@ igbuio_pci_probe(struct pci_dev *dev, const struct pci_device_id *id) > static void > igbuio_pci_remove(struct pci_dev *dev) > { > + > struct rte_uio_pci_dev *udev = pci_get_drvdata(dev); > + int ret; > + > + /* handler hot unplug */ > + if (udev->state == RTE_UDEV_OPENNED || > + udev->state == RTE_UDEV_UNPLUG) { > + dev_notice(&dev->dev, "Unexpected removal!\n"); > + ret = igbuio_pci_release(&udev->info, NULL); > + if (ret) > + return; > + udev->state = RTE_UDEV_REMOVED; > + return; > + } > > mutex_destroy(&udev->lock); > - sysfs_remove_group(&dev->dev.kobj, &dev_attr_grp); > uio_unregister_device(&udev->info); > + sysfs_remove_group(&dev->dev.kobj, &dev_attr_grp); > igbuio_pci_release_iomem(&udev->info); > pci_disable_device(dev); > pci_set_drvdata(dev, NULL); >