From 45423cff1db66cf0993e8a9bd0ac93e740149e49 Mon Sep 17 00:00:00 2001 From: =?utf8?q?=C3=8D=C3=B1igo=20Huguet?= Date: Mon, 21 Jun 2021 17:32:35 +0200 Subject: [PATCH] sfc: avoid double pci_remove of VFs MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit If pci_remove was called for a PF with VFs, the removal of the VFs was called twice from efx_ef10_sriov_fini: one directly with pci_driver->remove and another implicit by calling pci_disable_sriov, which also perform the VFs remove. This was leading to crashing the kernel on the second attempt. Given that pci_disable_sriov already calls to pci remove function, get rid of the direct call to pci_driver->remove from the driver. 2 different ways to trigger the bug: - Create one or more VFs, then attach the PF to a virtual machine (at least with qemu/KVM) - Create one or more VFs, then remove the PF with: echo 1 > /sys/bus/pci/devices/PF_PCI_ID/remove Removing sfc module does not trigger the error, at least for me, because it removes the VF first, and then the PF. Example of a log with the error: list_del corruption, ffff967fd20a8ad0->next is LIST_POISON1 (dead000000000100) ------------[ cut here ]------------ kernel BUG at lib/list_debug.c:47! [...trimmed...] RIP: 0010:__list_del_entry_valid.cold.1+0x12/0x4c [...trimmed...] Call Trace: efx_dissociate+0x1f/0x140 [sfc] efx_pci_remove+0x27/0x150 [sfc] pci_device_remove+0x3b/0xc0 device_release_driver_internal+0x103/0x1f0 pci_stop_bus_device+0x69/0x90 pci_stop_and_remove_bus_device+0xe/0x20 pci_iov_remove_virtfn+0xba/0x120 sriov_disable+0x2f/0xe0 efx_ef10_pci_sriov_disable+0x52/0x80 [sfc] ? pcie_aer_is_native+0x12/0x40 efx_ef10_sriov_fini+0x72/0x110 [sfc] efx_pci_remove+0x62/0x150 [sfc] pci_device_remove+0x3b/0xc0 device_release_driver_internal+0x103/0x1f0 unbind_store+0xf6/0x130 kernfs_fop_write+0x116/0x190 vfs_write+0xa5/0x1a0 ksys_write+0x4f/0xb0 do_syscall_64+0x5b/0x1a0 entry_SYSCALL_64_after_hwframe+0x65/0xca Signed-off-by: Íñigo Huguet Signed-off-by: David S. Miller --- drivers/net/ethernet/sfc/ef10_sriov.c | 10 +--------- 1 file changed, 1 insertion(+), 9 deletions(-) diff --git a/drivers/net/ethernet/sfc/ef10_sriov.c b/drivers/net/ethernet/sfc/ef10_sriov.c index 21fa6c0..a5d28b0 100644 --- a/drivers/net/ethernet/sfc/ef10_sriov.c +++ b/drivers/net/ethernet/sfc/ef10_sriov.c @@ -439,7 +439,6 @@ int efx_ef10_sriov_init(struct efx_nic *efx) void efx_ef10_sriov_fini(struct efx_nic *efx) { struct efx_ef10_nic_data *nic_data = efx->nic_data; - unsigned int i; int rc; if (!nic_data->vf) { @@ -449,14 +448,7 @@ void efx_ef10_sriov_fini(struct efx_nic *efx) return; } - /* Remove any VFs in the host */ - for (i = 0; i < efx->vf_count; ++i) { - struct efx_nic *vf_efx = nic_data->vf[i].efx; - - if (vf_efx) - vf_efx->pci_dev->driver->remove(vf_efx->pci_dev); - } - + /* Disable SRIOV and remove any VFs in the host */ rc = efx_ef10_pci_sriov_disable(efx, true); if (rc) netif_dbg(efx, drv, efx->net_dev, -- 2.7.4