From 17530e71e0166a37f8e20a9b7bcf1d50ae3cff8e Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Mon, 22 May 2017 15:50:23 -0700 Subject: [PATCH] PCI: Protect pci_driver->sriov_configure() usage with device_lock() Every method in struct device_driver or structures derived from it like struct pci_driver MUST provide exclusion vs the driver's ->remove() method, usually by using device_lock(). Protect use of pci_driver->sriov_configure() by holding the device lock while calling it. The PCI core sets the pci_dev->driver pointer in local_pci_probe() before calling ->probe() and only clears it after ->remove(). This means driver's ->sriov_configure() callback will happily race with probe() and remove(), most likely leading to BUGs, since drivers don't expect this. Remove the iov lock completely, since we remove the last user. [bhelgaas: changelog, thanks to Christoph for locking rule] Link: http://lkml.kernel.org/r/20170522225023.14010-1-jakub.kicinski@netronome.com Signed-off-by: Jakub Kicinski Signed-off-by: Bjorn Helgaas Reviewed-by: Christoph Hellwig --- drivers/pci/iov.c | 4 ---- drivers/pci/pci-sysfs.c | 5 ++--- drivers/pci/pci.h | 1 - 3 files changed, 2 insertions(+), 8 deletions(-) diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c index d9dc7363ac77..120485d6f352 100644 --- a/drivers/pci/iov.c +++ b/drivers/pci/iov.c @@ -461,8 +461,6 @@ found: else iov->dev = dev; - mutex_init(&iov->lock); - dev->sriov = iov; dev->is_physfn = 1; rc = compute_max_vf_buses(dev); @@ -491,8 +489,6 @@ static void sriov_release(struct pci_dev *dev) if (dev != dev->sriov->dev) pci_dev_put(dev->sriov->dev); - mutex_destroy(&dev->sriov->lock); - kfree(dev->sriov); dev->sriov = NULL; } diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index 31e99613a12e..7755559558df 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -472,7 +472,6 @@ static ssize_t sriov_numvfs_store(struct device *dev, const char *buf, size_t count) { struct pci_dev *pdev = to_pci_dev(dev); - struct pci_sriov *iov = pdev->sriov; int ret; u16 num_vfs; @@ -483,7 +482,7 @@ static ssize_t sriov_numvfs_store(struct device *dev, if (num_vfs > pci_sriov_get_totalvfs(pdev)) return -ERANGE; - mutex_lock(&iov->dev->sriov->lock); + device_lock(&pdev->dev); if (num_vfs == pdev->sriov->num_VFs) goto exit; @@ -518,7 +517,7 @@ static ssize_t sriov_numvfs_store(struct device *dev, num_vfs, ret); exit: - mutex_unlock(&iov->dev->sriov->lock); + device_unlock(&pdev->dev); if (ret < 0) return ret; diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index f8113e5b9812..93f4044b8f4b 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -272,7 +272,6 @@ struct pci_sriov { u16 driver_max_VFs; /* max num VFs driver supports */ struct pci_dev *dev; /* lowest numbered PF */ struct pci_dev *self; /* this PF */ - struct mutex lock; /* lock for setting sriov_numvfs in sysfs */ resource_size_t barsz[PCI_SRIOV_NUM_BARS]; /* VF BAR size */ bool drivers_autoprobe; /* auto probing of VFs by driver */ }; -- 2.20.1