diff options
author | Jens Axboe <axboe@kernel.dk> | 2019-11-07 12:27:19 -0700 |
---|---|---|
committer | Jens Axboe <axboe@kernel.dk> | 2019-11-07 12:27:19 -0700 |
commit | 912c0a85911a6364ac127b6e1de8c2c7782db1bc (patch) | |
tree | f9092380a9688cf422c337802e8c51657851297c /drivers/usb/misc/usblcd.c | |
parent | e876df1fe0ad1b191284ee6ed2db7960bd322d00 (diff) | |
parent | b0814361a25cba73a224548843ed92d8ea78715a (diff) |
Merge branch 'for-linus' into for-5.5/block
Pull on for-linus to resolve what otherwise would have been a conflict
with the cgroups rstat patchset from Tejun.
* for-linus: (942 commits)
blkcg: make blkcg_print_stat() print stats only for online blkgs
nvme: change nvme_passthru_cmd64 to explicitly mark rsvd
nvme-multipath: fix crash in nvme_mpath_clear_ctrl_paths
nvme-rdma: fix a segmentation fault during module unload
iocost: don't nest spin_lock_irq in ioc_weight_write()
io_uring: ensure we clear io_kiocb->result before each issue
um-ubd: Entrust re-queue to the upper layers
nvme-multipath: remove unused groups_only mode in ana log
nvme-multipath: fix possible io hang after ctrl reconnect
io_uring: don't touch ctx in setup after ring fd install
io_uring: Fix leaked shadow_req
Linux 5.4-rc5
riscv: cleanup do_trap_break
nbd: verify socket is supported during setup
ata: libahci_platform: Fix regulator_get_optional() misuse
nbd: handle racing with error'ed out commands
nbd: protect cmd->status with cmd->lock
io_uring: fix bad inflight accounting for SETUP_IOPOLL|SETUP_SQTHREAD
io_uring: used cached copies of sq->dropped and cq->overflow
ARM: dts: stm32: relax qspi pins slew-rate for stm32mp157
...
Diffstat (limited to 'drivers/usb/misc/usblcd.c')
-rw-r--r-- | drivers/usb/misc/usblcd.c | 60 |
1 files changed, 33 insertions, 27 deletions
diff --git a/drivers/usb/misc/usblcd.c b/drivers/usb/misc/usblcd.c index 9ba4a4e68d91..61e9e987fe4a 100644 --- a/drivers/usb/misc/usblcd.c +++ b/drivers/usb/misc/usblcd.c @@ -18,6 +18,7 @@ #include <linux/slab.h> #include <linux/errno.h> #include <linux/mutex.h> +#include <linux/rwsem.h> #include <linux/uaccess.h> #include <linux/usb.h> @@ -29,16 +30,12 @@ #define IOCTL_GET_DRV_VERSION 2 -static DEFINE_MUTEX(lcd_mutex); static const struct usb_device_id id_table[] = { { .idVendor = 0x10D2, .match_flags = USB_DEVICE_ID_MATCH_VENDOR, }, { }, }; MODULE_DEVICE_TABLE(usb, id_table); -static DEFINE_MUTEX(open_disc_mutex); - - struct usb_lcd { struct usb_device *udev; /* init: probe_lcd */ struct usb_interface *interface; /* the interface for @@ -57,6 +54,8 @@ struct usb_lcd { using up all RAM */ struct usb_anchor submitted; /* URBs to wait for before suspend */ + struct rw_semaphore io_rwsem; + unsigned long disconnected:1; }; #define to_lcd_dev(d) container_of(d, struct usb_lcd, kref) @@ -81,40 +80,29 @@ static int lcd_open(struct inode *inode, struct file *file) struct usb_interface *interface; int subminor, r; - mutex_lock(&lcd_mutex); subminor = iminor(inode); interface = usb_find_interface(&lcd_driver, subminor); if (!interface) { - mutex_unlock(&lcd_mutex); - printk(KERN_ERR "USBLCD: %s - error, can't find device for minor %d\n", + pr_err("USBLCD: %s - error, can't find device for minor %d\n", __func__, subminor); return -ENODEV; } - mutex_lock(&open_disc_mutex); dev = usb_get_intfdata(interface); - if (!dev) { - mutex_unlock(&open_disc_mutex); - mutex_unlock(&lcd_mutex); - return -ENODEV; - } /* increment our usage count for the device */ kref_get(&dev->kref); - mutex_unlock(&open_disc_mutex); /* grab a power reference */ r = usb_autopm_get_interface(interface); if (r < 0) { kref_put(&dev->kref, lcd_delete); - mutex_unlock(&lcd_mutex); return r; } /* save our object in the file's private structure */ file->private_data = dev; - mutex_unlock(&lcd_mutex); return 0; } @@ -142,6 +130,13 @@ static ssize_t lcd_read(struct file *file, char __user * buffer, dev = file->private_data; + down_read(&dev->io_rwsem); + + if (dev->disconnected) { + retval = -ENODEV; + goto out_up_io; + } + /* do a blocking bulk read to get data from the device */ retval = usb_bulk_msg(dev->udev, usb_rcvbulkpipe(dev->udev, @@ -158,6 +153,9 @@ static ssize_t lcd_read(struct file *file, char __user * buffer, retval = bytes_read; } +out_up_io: + up_read(&dev->io_rwsem); + return retval; } @@ -173,14 +171,12 @@ static long lcd_ioctl(struct file *file, unsigned int cmd, unsigned long arg) switch (cmd) { case IOCTL_GET_HARD_VERSION: - mutex_lock(&lcd_mutex); bcdDevice = le16_to_cpu((dev->udev)->descriptor.bcdDevice); sprintf(buf, "%1d%1d.%1d%1d", (bcdDevice & 0xF000)>>12, (bcdDevice & 0xF00)>>8, (bcdDevice & 0xF0)>>4, (bcdDevice & 0xF)); - mutex_unlock(&lcd_mutex); if (copy_to_user((void __user *)arg, buf, strlen(buf)) != 0) return -EFAULT; break; @@ -237,11 +233,18 @@ static ssize_t lcd_write(struct file *file, const char __user * user_buffer, if (r < 0) return -EINTR; + down_read(&dev->io_rwsem); + + if (dev->disconnected) { + retval = -ENODEV; + goto err_up_io; + } + /* create a urb, and a buffer for it, and copy the data to the urb */ urb = usb_alloc_urb(0, GFP_KERNEL); if (!urb) { retval = -ENOMEM; - goto err_no_buf; + goto err_up_io; } buf = usb_alloc_coherent(dev->udev, count, GFP_KERNEL, @@ -278,6 +281,7 @@ static ssize_t lcd_write(struct file *file, const char __user * user_buffer, the USB core will eventually free it entirely */ usb_free_urb(urb); + up_read(&dev->io_rwsem); exit: return count; error_unanchor: @@ -285,7 +289,8 @@ error_unanchor: error: usb_free_coherent(dev->udev, count, buf, urb->transfer_dma); usb_free_urb(urb); -err_no_buf: +err_up_io: + up_read(&dev->io_rwsem); up(&dev->limit_sem); return retval; } @@ -325,6 +330,7 @@ static int lcd_probe(struct usb_interface *interface, kref_init(&dev->kref); sema_init(&dev->limit_sem, USB_LCD_CONCURRENT_WRITES); + init_rwsem(&dev->io_rwsem); init_usb_anchor(&dev->submitted); dev->udev = usb_get_dev(interface_to_usbdev(interface)); @@ -365,7 +371,6 @@ static int lcd_probe(struct usb_interface *interface, /* something prevented us from registering this driver */ dev_err(&interface->dev, "Not able to get a minor for this device.\n"); - usb_set_intfdata(interface, NULL); goto error; } @@ -411,17 +416,18 @@ static int lcd_resume(struct usb_interface *intf) static void lcd_disconnect(struct usb_interface *interface) { - struct usb_lcd *dev; + struct usb_lcd *dev = usb_get_intfdata(interface); int minor = interface->minor; - mutex_lock(&open_disc_mutex); - dev = usb_get_intfdata(interface); - usb_set_intfdata(interface, NULL); - mutex_unlock(&open_disc_mutex); - /* give back our minor */ usb_deregister_dev(interface, &lcd_class); + down_write(&dev->io_rwsem); + dev->disconnected = 1; + up_write(&dev->io_rwsem); + + usb_kill_anchored_urbs(&dev->submitted); + /* decrement our usage count */ kref_put(&dev->kref, lcd_delete); |