From 0c8482ac92db5ac15792caf23b7f7df9e4f48ae1 Mon Sep 17 00:00:00 2001 From: Fam Zheng Date: Mon, 14 Apr 2014 10:16:09 +0800 Subject: [PATCH] [SCSI] virtio-scsi: Skip setting affinity on uninitialized vq virtscsi_init calls virtscsi_remove_vqs on err, even before initializing the vqs. The latter calls virtscsi_set_affinity, so let's check the pointer there before setting affinity on it. This fixes a panic when setting device's num_queues=2 on RHEL 6.5: qemu-system-x86_64 ... \ -device virtio-scsi-pci,id=scsi0,addr=0x13,...,num_queues=2 \ -drive file=/stor/vm/dummy.raw,id=drive-scsi-disk,... \ -device scsi-hd,drive=drive-scsi-disk,... [ 0.354734] scsi0 : Virtio SCSI HBA [ 0.379504] BUG: unable to handle kernel NULL pointer dereference at 0000000000000020 [ 0.380141] IP: [] __virtscsi_set_affinity+0x4f/0x120 [ 0.380141] PGD 0 [ 0.380141] Oops: 0000 [#1] SMP [ 0.380141] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.14.0+ #5 [ 0.380141] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2007 [ 0.380141] task: ffff88003c9f0000 ti: ffff88003c9f8000 task.ti: ffff88003c9f8000 [ 0.380141] RIP: 0010:[] [] __virtscsi_set_affinity+0x4f/0x120 [ 0.380141] RSP: 0000:ffff88003c9f9c08 EFLAGS: 00010256 [ 0.380141] RAX: 0000000000000000 RBX: ffff88003c3a9d40 RCX: 0000000000001070 [ 0.380141] RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000 [ 0.380141] RBP: ffff88003c9f9c28 R08: 00000000000136c0 R09: ffff88003c801c00 [ 0.380141] R10: ffffffff81475229 R11: 0000000000000008 R12: 0000000000000000 [ 0.380141] R13: ffffffff81cc7ca8 R14: ffff88003cac3d40 R15: ffff88003cac37a0 [ 0.380141] FS: 0000000000000000(0000) GS:ffff88003e400000(0000) knlGS:0000000000000000 [ 0.380141] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 0.380141] CR2: 0000000000000020 CR3: 0000000001c0e000 CR4: 00000000000006f0 [ 0.380141] Stack: [ 0.380141] ffff88003c3a9d40 0000000000000000 ffff88003cac3d80 ffff88003cac3d40 [ 0.380141] ffff88003c9f9c48 ffffffff814742e8 ffff88003c26d000 ffff88003c26d000 [ 0.380141] ffff88003c9f9c68 ffffffff81474321 ffff88003c26d000 ffff88003c3a9d40 [ 0.380141] Call Trace: [ 0.380141] [] virtscsi_set_affinity+0x28/0x40 [ 0.380141] [] virtscsi_remove_vqs+0x21/0x50 [ 0.380141] [] virtscsi_init+0x91/0x240 [ 0.380141] [] ? vp_get+0x50/0x70 [ 0.380141] [] virtscsi_probe+0xf4/0x280 [ 0.380141] [] virtio_dev_probe+0xe5/0x140 [ 0.380141] [] driver_probe_device+0x89/0x230 [ 0.380141] [] __driver_attach+0x9b/0xa0 [ 0.380141] [] ? driver_probe_device+0x230/0x230 [ 0.380141] [] ? driver_probe_device+0x230/0x230 [ 0.380141] [] bus_for_each_dev+0x8c/0xb0 [ 0.380141] [] driver_attach+0x19/0x20 [ 0.380141] [] bus_add_driver+0x198/0x220 [ 0.380141] [] driver_register+0x5f/0xf0 [ 0.380141] [] ? spi_transport_init+0x79/0x79 [ 0.380141] [] register_virtio_driver+0x1b/0x30 [ 0.380141] [] init+0x88/0xd6 [ 0.380141] [] ? scsi_init_procfs+0x5b/0x5b [ 0.380141] [] do_one_initcall+0x7f/0x10a [ 0.380141] [] kernel_init_freeable+0x14a/0x1de [ 0.380141] [] ? kernel_init_freeable+0x1de/0x1de [ 0.380141] [] ? rest_init+0x80/0x80 [ 0.380141] [] kernel_init+0x9/0xf0 [ 0.380141] [] ret_from_fork+0x7c/0xb0 [ 0.380141] [] ? rest_init+0x80/0x80 [ 0.380141] RIP [] __virtscsi_set_affinity+0x4f/0x120 [ 0.380141] RSP [ 0.380141] CR2: 0000000000000020 [ 0.380141] ---[ end trace 8074b70c3d5e1d73 ]--- [ 0.475018] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000009 [ 0.475018] [ 0.475068] Kernel Offset: 0x0 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffff9fffffff) [ 0.475068] ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000009 [jejb: checkpatch fixes] Signed-off-by: Fam Zheng Acked-by: Paolo Bonzini Cc: stable@vger.kernel.org Signed-off-by: James Bottomley --- drivers/scsi/virtio_scsi.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c index 16bfd50cd3fe..db3b494e5926 100644 --- a/drivers/scsi/virtio_scsi.c +++ b/drivers/scsi/virtio_scsi.c @@ -750,8 +750,12 @@ static void __virtscsi_set_affinity(struct virtio_scsi *vscsi, bool affinity) vscsi->affinity_hint_set = true; } else { - for (i = 0; i < vscsi->num_queues; i++) + for (i = 0; i < vscsi->num_queues; i++) { + if (!vscsi->req_vqs[i].vq) + continue; + virtqueue_set_affinity(vscsi->req_vqs[i].vq, -1); + } vscsi->affinity_hint_set = false; } -- 2.20.1