From: Jason Gunthorpe jgg@nvidia.com
[ Upstream commit 61e90817482871b614133c0f20feb1aba2faec86 ]
vfio_pci_probe() is quite complicated, with optional VF and VGA sub components. Move these into clear init/uninit functions and have a linear flow in probe/remove.
This fixes a few little buglets: - vfio_pci_remove() is in the wrong order, vga_client_register() removes a notifier and is after kfree(vdev), but the notifier refers to vdev, so it can use after free in a race. - vga_client_register() can fail but was ignored
Organize things so destruction order is the reverse of creation order.
Fixes: ecaa1f6a0154 ("vfio-pci: Add VGA arbiter client") Reviewed-by: Christoph Hellwig hch@lst.de Reviewed-by: Kevin Tian kevin.tian@intel.com Reviewed-by: Max Gurtovoy mgurtovoy@nvidia.com Reviewed-by: Cornelia Huck cohuck@redhat.com Reviewed-by: Eric Auger eric.auger@redhat.com Signed-off-by: Jason Gunthorpe jgg@nvidia.com Message-Id: 7-v3-225de1400dfc+4e074-vfio1_jgg@nvidia.com Signed-off-by: Alex Williamson alex.williamson@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/vfio/pci/vfio_pci.c | 116 +++++++++++++++++++++++------------- 1 file changed, 74 insertions(+), 42 deletions(-)
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index 5023e23db3bc..b73144a6804a 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -1924,6 +1924,68 @@ static int vfio_pci_bus_notifier(struct notifier_block *nb, return 0; }
+static int vfio_pci_vf_init(struct vfio_pci_device *vdev) +{ + struct pci_dev *pdev = vdev->pdev; + int ret; + + if (!pdev->is_physfn) + return 0; + + vdev->vf_token = kzalloc(sizeof(*vdev->vf_token), GFP_KERNEL); + if (!vdev->vf_token) + return -ENOMEM; + + mutex_init(&vdev->vf_token->lock); + uuid_gen(&vdev->vf_token->uuid); + + vdev->nb.notifier_call = vfio_pci_bus_notifier; + ret = bus_register_notifier(&pci_bus_type, &vdev->nb); + if (ret) { + kfree(vdev->vf_token); + return ret; + } + return 0; +} + +static void vfio_pci_vf_uninit(struct vfio_pci_device *vdev) +{ + if (!vdev->vf_token) + return; + + bus_unregister_notifier(&pci_bus_type, &vdev->nb); + WARN_ON(vdev->vf_token->users); + mutex_destroy(&vdev->vf_token->lock); + kfree(vdev->vf_token); +} + +static int vfio_pci_vga_init(struct vfio_pci_device *vdev) +{ + struct pci_dev *pdev = vdev->pdev; + int ret; + + if (!vfio_pci_is_vga(pdev)) + return 0; + + ret = vga_client_register(pdev, vdev, NULL, vfio_pci_set_vga_decode); + if (ret) + return ret; + vga_set_legacy_decoding(pdev, vfio_pci_set_vga_decode(vdev, false)); + return 0; +} + +static void vfio_pci_vga_uninit(struct vfio_pci_device *vdev) +{ + struct pci_dev *pdev = vdev->pdev; + + if (!vfio_pci_is_vga(pdev)) + return; + vga_client_register(pdev, NULL, NULL, NULL); + vga_set_legacy_decoding(pdev, VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM | + VGA_RSRC_LEGACY_IO | + VGA_RSRC_LEGACY_MEM); +} + static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) { struct vfio_pci_device *vdev; @@ -1977,28 +2039,12 @@ static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) ret = vfio_pci_reflck_attach(vdev); if (ret) goto out_del_group_dev; - - if (pdev->is_physfn) { - vdev->vf_token = kzalloc(sizeof(*vdev->vf_token), GFP_KERNEL); - if (!vdev->vf_token) { - ret = -ENOMEM; - goto out_reflck; - } - - mutex_init(&vdev->vf_token->lock); - uuid_gen(&vdev->vf_token->uuid); - - vdev->nb.notifier_call = vfio_pci_bus_notifier; - ret = bus_register_notifier(&pci_bus_type, &vdev->nb); - if (ret) - goto out_vf_token; - } - - if (vfio_pci_is_vga(pdev)) { - vga_client_register(pdev, vdev, NULL, vfio_pci_set_vga_decode); - vga_set_legacy_decoding(pdev, - vfio_pci_set_vga_decode(vdev, false)); - } + ret = vfio_pci_vf_init(vdev); + if (ret) + goto out_reflck; + ret = vfio_pci_vga_init(vdev); + if (ret) + goto out_vf;
vfio_pci_probe_power_state(vdev);
@@ -2018,8 +2064,8 @@ static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
return ret;
-out_vf_token: - kfree(vdev->vf_token); +out_vf: + vfio_pci_vf_uninit(vdev); out_reflck: vfio_pci_reflck_put(vdev->reflck); out_del_group_dev: @@ -2041,33 +2087,19 @@ static void vfio_pci_remove(struct pci_dev *pdev) if (!vdev) return;
- if (vdev->vf_token) { - WARN_ON(vdev->vf_token->users); - mutex_destroy(&vdev->vf_token->lock); - kfree(vdev->vf_token); - } - - if (vdev->nb.notifier_call) - bus_unregister_notifier(&pci_bus_type, &vdev->nb); - + vfio_pci_vf_uninit(vdev); vfio_pci_reflck_put(vdev->reflck); + vfio_pci_vga_uninit(vdev);
vfio_iommu_group_put(pdev->dev.iommu_group, &pdev->dev); - kfree(vdev->region); - mutex_destroy(&vdev->ioeventfds_lock);
if (!disable_idle_d3) vfio_pci_set_power_state(vdev, PCI_D0);
+ mutex_destroy(&vdev->ioeventfds_lock); + kfree(vdev->region); kfree(vdev->pm_save); kfree(vdev); - - if (vfio_pci_is_vga(pdev)) { - vga_client_register(pdev, NULL, NULL, NULL); - vga_set_legacy_decoding(pdev, - VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM | - VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM); - } }
static pci_ers_result_t vfio_pci_aer_err_detected(struct pci_dev *pdev,