Revision 8700aff089843399f95bc7701ae87b642b35a716 authored by Edward Cree on 20 December 2019, 16:26:40 UTC, committed by David S. Miller on 21 December 2019, 05:56:48 UTC
It was possible for channel allocation logic to get confused between what it had and what it wanted, and end up trying to use the same channel for both PTP and regular TX. This led to a kernel panic: BUG: unable to handle page fault for address: 0000000000047635 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] SMP PTI CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 5.4.0-rc3-ehc14+ #900 Hardware name: Dell Inc. PowerEdge R710/0M233H, BIOS 6.4.0 07/23/2013 RIP: 0010:native_queued_spin_lock_slowpath+0x188/0x1e0 Code: f3 90 48 8b 32 48 85 f6 74 f6 eb e8 c1 ee 12 83 e0 03 83 ee 01 48 c1 e0 05 48 63 f6 48 05 c0 98 02 00 48 03 04 f5 a0 c6 ed 81 <48> 89 10 8b 42 08 85 c0 75 09 f3 90 8b 42 08 85 c0 74 f7 48 8b 32 RSP: 0018:ffffc90000003d28 EFLAGS: 00010006 RAX: 0000000000047635 RBX: 0000000000000246 RCX: 0000000000040000 RDX: ffff888627a298c0 RSI: 0000000000003ffe RDI: ffff88861f6b8dd4 RBP: ffff8886225c6e00 R08: 0000000000040000 R09: 0000000000000000 R10: 0000000616f080c6 R11: 00000000000000c0 R12: ffff88861f6b8dd4 R13: ffffc90000003dc8 R14: ffff88861942bf00 R15: ffff8886150f2000 FS: 0000000000000000(0000) GS:ffff888627a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000047635 CR3: 000000000200a000 CR4: 00000000000006f0 Call Trace: <IRQ> _raw_spin_lock_irqsave+0x22/0x30 skb_queue_tail+0x1b/0x50 sock_queue_err_skb+0x9d/0xf0 __skb_complete_tx_timestamp+0x9d/0xc0 efx_dequeue_buffer+0x126/0x180 [sfc] efx_xmit_done+0x73/0x1c0 [sfc] efx_ef10_ev_process+0x56a/0xfe0 [sfc] ? tick_sched_do_timer+0x60/0x60 ? timerqueue_add+0x5d/0x70 ? enqueue_hrtimer+0x39/0x90 efx_poll+0x111/0x380 [sfc] ? rcu_accelerate_cbs+0x50/0x160 net_rx_action+0x14a/0x400 __do_softirq+0xdd/0x2d0 irq_exit+0xa0/0xb0 do_IRQ+0x53/0xe0 common_interrupt+0xf/0xf </IRQ> In the long run we intend to rewrite the channel allocation code, but for 'net' fix this by allocating extra_channels, and giving them TX queues, even if we do not in fact need them (e.g. on NICs without MAC TX timestamping), and thereby using simpler logic to assign the channels once they're allocated. Fixes: 3990a8fffbda ("sfc: allocate channels for XDP tx queues") Signed-off-by: Edward Cree <ecree@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent 258a980
bsg.c
// SPDX-License-Identifier: GPL-2.0
/*
* bsg.c - block layer implementation of the sg v4 interface
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/file.h>
#include <linux/blkdev.h>
#include <linux/cdev.h>
#include <linux/jiffies.h>
#include <linux/percpu.h>
#include <linux/idr.h>
#include <linux/bsg.h>
#include <linux/slab.h>
#include <scsi/scsi.h>
#include <scsi/scsi_ioctl.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_driver.h>
#include <scsi/sg.h>
#define BSG_DESCRIPTION "Block layer SCSI generic (bsg) driver"
#define BSG_VERSION "0.4"
#define bsg_dbg(bd, fmt, ...) \
pr_debug("%s: " fmt, (bd)->name, ##__VA_ARGS__)
struct bsg_device {
struct request_queue *queue;
spinlock_t lock;
struct hlist_node dev_list;
refcount_t ref_count;
char name[20];
int max_queue;
};
#define BSG_DEFAULT_CMDS 64
#define BSG_MAX_DEVS 32768
static DEFINE_MUTEX(bsg_mutex);
static DEFINE_IDR(bsg_minor_idr);
#define BSG_LIST_ARRAY_SIZE 8
static struct hlist_head bsg_device_list[BSG_LIST_ARRAY_SIZE];
static struct class *bsg_class;
static int bsg_major;
static inline struct hlist_head *bsg_dev_idx_hash(int index)
{
return &bsg_device_list[index & (BSG_LIST_ARRAY_SIZE - 1)];
}
#define uptr64(val) ((void __user *)(uintptr_t)(val))
static int bsg_scsi_check_proto(struct sg_io_v4 *hdr)
{
if (hdr->protocol != BSG_PROTOCOL_SCSI ||
hdr->subprotocol != BSG_SUB_PROTOCOL_SCSI_CMD)
return -EINVAL;
return 0;
}
static int bsg_scsi_fill_hdr(struct request *rq, struct sg_io_v4 *hdr,
fmode_t mode)
{
struct scsi_request *sreq = scsi_req(rq);
if (hdr->dout_xfer_len && hdr->din_xfer_len) {
pr_warn_once("BIDI support in bsg has been removed.\n");
return -EOPNOTSUPP;
}
sreq->cmd_len = hdr->request_len;
if (sreq->cmd_len > BLK_MAX_CDB) {
sreq->cmd = kzalloc(sreq->cmd_len, GFP_KERNEL);
if (!sreq->cmd)
return -ENOMEM;
}
if (copy_from_user(sreq->cmd, uptr64(hdr->request), sreq->cmd_len))
return -EFAULT;
if (blk_verify_command(sreq->cmd, mode))
return -EPERM;
return 0;
}
static int bsg_scsi_complete_rq(struct request *rq, struct sg_io_v4 *hdr)
{
struct scsi_request *sreq = scsi_req(rq);
int ret = 0;
/*
* fill in all the output members
*/
hdr->device_status = sreq->result & 0xff;
hdr->transport_status = host_byte(sreq->result);
hdr->driver_status = driver_byte(sreq->result);
hdr->info = 0;
if (hdr->device_status || hdr->transport_status || hdr->driver_status)
hdr->info |= SG_INFO_CHECK;
hdr->response_len = 0;
if (sreq->sense_len && hdr->response) {
int len = min_t(unsigned int, hdr->max_response_len,
sreq->sense_len);
if (copy_to_user(uptr64(hdr->response), sreq->sense, len))
ret = -EFAULT;
else
hdr->response_len = len;
}
if (rq_data_dir(rq) == READ)
hdr->din_resid = sreq->resid_len;
else
hdr->dout_resid = sreq->resid_len;
return ret;
}
static void bsg_scsi_free_rq(struct request *rq)
{
scsi_req_free_cmd(scsi_req(rq));
}
static const struct bsg_ops bsg_scsi_ops = {
.check_proto = bsg_scsi_check_proto,
.fill_hdr = bsg_scsi_fill_hdr,
.complete_rq = bsg_scsi_complete_rq,
.free_rq = bsg_scsi_free_rq,
};
static int bsg_sg_io(struct request_queue *q, fmode_t mode, void __user *uarg)
{
struct request *rq;
struct bio *bio;
struct sg_io_v4 hdr;
int ret;
if (copy_from_user(&hdr, uarg, sizeof(hdr)))
return -EFAULT;
if (!q->bsg_dev.class_dev)
return -ENXIO;
if (hdr.guard != 'Q')
return -EINVAL;
ret = q->bsg_dev.ops->check_proto(&hdr);
if (ret)
return ret;
rq = blk_get_request(q, hdr.dout_xfer_len ?
REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, 0);
if (IS_ERR(rq))
return PTR_ERR(rq);
ret = q->bsg_dev.ops->fill_hdr(rq, &hdr, mode);
if (ret)
return ret;
rq->timeout = msecs_to_jiffies(hdr.timeout);
if (!rq->timeout)
rq->timeout = q->sg_timeout;
if (!rq->timeout)
rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
if (rq->timeout < BLK_MIN_SG_TIMEOUT)
rq->timeout = BLK_MIN_SG_TIMEOUT;
if (hdr.dout_xfer_len) {
ret = blk_rq_map_user(q, rq, NULL, uptr64(hdr.dout_xferp),
hdr.dout_xfer_len, GFP_KERNEL);
} else if (hdr.din_xfer_len) {
ret = blk_rq_map_user(q, rq, NULL, uptr64(hdr.din_xferp),
hdr.din_xfer_len, GFP_KERNEL);
}
if (ret)
goto out_free_rq;
bio = rq->bio;
blk_execute_rq(q, NULL, rq, !(hdr.flags & BSG_FLAG_Q_AT_TAIL));
ret = rq->q->bsg_dev.ops->complete_rq(rq, &hdr);
blk_rq_unmap_user(bio);
out_free_rq:
rq->q->bsg_dev.ops->free_rq(rq);
blk_put_request(rq);
if (!ret && copy_to_user(uarg, &hdr, sizeof(hdr)))
return -EFAULT;
return ret;
}
static struct bsg_device *bsg_alloc_device(void)
{
struct bsg_device *bd;
bd = kzalloc(sizeof(struct bsg_device), GFP_KERNEL);
if (unlikely(!bd))
return NULL;
spin_lock_init(&bd->lock);
bd->max_queue = BSG_DEFAULT_CMDS;
INIT_HLIST_NODE(&bd->dev_list);
return bd;
}
static int bsg_put_device(struct bsg_device *bd)
{
struct request_queue *q = bd->queue;
mutex_lock(&bsg_mutex);
if (!refcount_dec_and_test(&bd->ref_count)) {
mutex_unlock(&bsg_mutex);
return 0;
}
hlist_del(&bd->dev_list);
mutex_unlock(&bsg_mutex);
bsg_dbg(bd, "tearing down\n");
/*
* close can always block
*/
kfree(bd);
blk_put_queue(q);
return 0;
}
static struct bsg_device *bsg_add_device(struct inode *inode,
struct request_queue *rq,
struct file *file)
{
struct bsg_device *bd;
unsigned char buf[32];
lockdep_assert_held(&bsg_mutex);
if (!blk_get_queue(rq))
return ERR_PTR(-ENXIO);
bd = bsg_alloc_device();
if (!bd) {
blk_put_queue(rq);
return ERR_PTR(-ENOMEM);
}
bd->queue = rq;
refcount_set(&bd->ref_count, 1);
hlist_add_head(&bd->dev_list, bsg_dev_idx_hash(iminor(inode)));
strncpy(bd->name, dev_name(rq->bsg_dev.class_dev), sizeof(bd->name) - 1);
bsg_dbg(bd, "bound to <%s>, max queue %d\n",
format_dev_t(buf, inode->i_rdev), bd->max_queue);
return bd;
}
static struct bsg_device *__bsg_get_device(int minor, struct request_queue *q)
{
struct bsg_device *bd;
lockdep_assert_held(&bsg_mutex);
hlist_for_each_entry(bd, bsg_dev_idx_hash(minor), dev_list) {
if (bd->queue == q) {
refcount_inc(&bd->ref_count);
goto found;
}
}
bd = NULL;
found:
return bd;
}
static struct bsg_device *bsg_get_device(struct inode *inode, struct file *file)
{
struct bsg_device *bd;
struct bsg_class_device *bcd;
/*
* find the class device
*/
mutex_lock(&bsg_mutex);
bcd = idr_find(&bsg_minor_idr, iminor(inode));
if (!bcd) {
bd = ERR_PTR(-ENODEV);
goto out_unlock;
}
bd = __bsg_get_device(iminor(inode), bcd->queue);
if (!bd)
bd = bsg_add_device(inode, bcd->queue, file);
out_unlock:
mutex_unlock(&bsg_mutex);
return bd;
}
static int bsg_open(struct inode *inode, struct file *file)
{
struct bsg_device *bd;
bd = bsg_get_device(inode, file);
if (IS_ERR(bd))
return PTR_ERR(bd);
file->private_data = bd;
return 0;
}
static int bsg_release(struct inode *inode, struct file *file)
{
struct bsg_device *bd = file->private_data;
file->private_data = NULL;
return bsg_put_device(bd);
}
static int bsg_get_command_q(struct bsg_device *bd, int __user *uarg)
{
return put_user(bd->max_queue, uarg);
}
static int bsg_set_command_q(struct bsg_device *bd, int __user *uarg)
{
int queue;
if (get_user(queue, uarg))
return -EFAULT;
if (queue < 1)
return -EINVAL;
spin_lock_irq(&bd->lock);
bd->max_queue = queue;
spin_unlock_irq(&bd->lock);
return 0;
}
static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
struct bsg_device *bd = file->private_data;
void __user *uarg = (void __user *) arg;
switch (cmd) {
/*
* Our own ioctls
*/
case SG_GET_COMMAND_Q:
return bsg_get_command_q(bd, uarg);
case SG_SET_COMMAND_Q:
return bsg_set_command_q(bd, uarg);
/*
* SCSI/sg ioctls
*/
case SG_GET_VERSION_NUM:
case SCSI_IOCTL_GET_IDLUN:
case SCSI_IOCTL_GET_BUS_NUMBER:
case SG_SET_TIMEOUT:
case SG_GET_TIMEOUT:
case SG_GET_RESERVED_SIZE:
case SG_SET_RESERVED_SIZE:
case SG_EMULATED_HOST:
case SCSI_IOCTL_SEND_COMMAND:
return scsi_cmd_ioctl(bd->queue, NULL, file->f_mode, cmd, uarg);
case SG_IO:
return bsg_sg_io(bd->queue, file->f_mode, uarg);
default:
return -ENOTTY;
}
}
static const struct file_operations bsg_fops = {
.open = bsg_open,
.release = bsg_release,
.unlocked_ioctl = bsg_ioctl,
.owner = THIS_MODULE,
.llseek = default_llseek,
};
void bsg_unregister_queue(struct request_queue *q)
{
struct bsg_class_device *bcd = &q->bsg_dev;
if (!bcd->class_dev)
return;
mutex_lock(&bsg_mutex);
idr_remove(&bsg_minor_idr, bcd->minor);
if (q->kobj.sd)
sysfs_remove_link(&q->kobj, "bsg");
device_unregister(bcd->class_dev);
bcd->class_dev = NULL;
mutex_unlock(&bsg_mutex);
}
EXPORT_SYMBOL_GPL(bsg_unregister_queue);
int bsg_register_queue(struct request_queue *q, struct device *parent,
const char *name, const struct bsg_ops *ops)
{
struct bsg_class_device *bcd;
dev_t dev;
int ret;
struct device *class_dev = NULL;
/*
* we need a proper transport to send commands, not a stacked device
*/
if (!queue_is_mq(q))
return 0;
bcd = &q->bsg_dev;
memset(bcd, 0, sizeof(*bcd));
mutex_lock(&bsg_mutex);
ret = idr_alloc(&bsg_minor_idr, bcd, 0, BSG_MAX_DEVS, GFP_KERNEL);
if (ret < 0) {
if (ret == -ENOSPC) {
printk(KERN_ERR "bsg: too many bsg devices\n");
ret = -EINVAL;
}
goto unlock;
}
bcd->minor = ret;
bcd->queue = q;
bcd->ops = ops;
dev = MKDEV(bsg_major, bcd->minor);
class_dev = device_create(bsg_class, parent, dev, NULL, "%s", name);
if (IS_ERR(class_dev)) {
ret = PTR_ERR(class_dev);
goto idr_remove;
}
bcd->class_dev = class_dev;
if (q->kobj.sd) {
ret = sysfs_create_link(&q->kobj, &bcd->class_dev->kobj, "bsg");
if (ret)
goto unregister_class_dev;
}
mutex_unlock(&bsg_mutex);
return 0;
unregister_class_dev:
device_unregister(class_dev);
idr_remove:
idr_remove(&bsg_minor_idr, bcd->minor);
unlock:
mutex_unlock(&bsg_mutex);
return ret;
}
int bsg_scsi_register_queue(struct request_queue *q, struct device *parent)
{
if (!blk_queue_scsi_passthrough(q)) {
WARN_ONCE(true, "Attempt to register a non-SCSI queue\n");
return -EINVAL;
}
return bsg_register_queue(q, parent, dev_name(parent), &bsg_scsi_ops);
}
EXPORT_SYMBOL_GPL(bsg_scsi_register_queue);
static struct cdev bsg_cdev;
static char *bsg_devnode(struct device *dev, umode_t *mode)
{
return kasprintf(GFP_KERNEL, "bsg/%s", dev_name(dev));
}
static int __init bsg_init(void)
{
int ret, i;
dev_t devid;
for (i = 0; i < BSG_LIST_ARRAY_SIZE; i++)
INIT_HLIST_HEAD(&bsg_device_list[i]);
bsg_class = class_create(THIS_MODULE, "bsg");
if (IS_ERR(bsg_class))
return PTR_ERR(bsg_class);
bsg_class->devnode = bsg_devnode;
ret = alloc_chrdev_region(&devid, 0, BSG_MAX_DEVS, "bsg");
if (ret)
goto destroy_bsg_class;
bsg_major = MAJOR(devid);
cdev_init(&bsg_cdev, &bsg_fops);
ret = cdev_add(&bsg_cdev, MKDEV(bsg_major, 0), BSG_MAX_DEVS);
if (ret)
goto unregister_chrdev;
printk(KERN_INFO BSG_DESCRIPTION " version " BSG_VERSION
" loaded (major %d)\n", bsg_major);
return 0;
unregister_chrdev:
unregister_chrdev_region(MKDEV(bsg_major, 0), BSG_MAX_DEVS);
destroy_bsg_class:
class_destroy(bsg_class);
return ret;
}
MODULE_AUTHOR("Jens Axboe");
MODULE_DESCRIPTION(BSG_DESCRIPTION);
MODULE_LICENSE("GPL");
device_initcall(bsg_init);
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