diff options
| -rw-r--r-- | drivers/usb/gadget/inode.c | 38 |
1 files changed, 29 insertions, 9 deletions
diff --git a/drivers/usb/gadget/inode.c b/drivers/usb/gadget/inode.c index dda0dc4a5567..32bcbeba119e 100644 --- a/drivers/usb/gadget/inode.c +++ b/drivers/usb/gadget/inode.c @@ -24,6 +24,7 @@ #include <linux/sched.h> #include <linux/slab.h> #include <linux/poll.h> +#include <linux/mmu_context.h> #include <linux/device.h> #include <linux/moduleparam.h> @@ -513,6 +514,9 @@ static long ep_ioctl(struct file *fd, unsigned code, unsigned long value) struct kiocb_priv { struct usb_request *req; struct ep_data *epdata; + struct kiocb *iocb; + struct mm_struct *mm; + struct work_struct work; void *buf; const struct iovec *iv; unsigned long nr_segs; @@ -540,15 +544,12 @@ static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e) return value; } -static ssize_t ep_aio_read_retry(struct kiocb *iocb) +static ssize_t ep_copy_to_user(struct kiocb_priv *priv) { - struct kiocb_priv *priv = iocb->private; ssize_t len, total; void *to_copy; int i; - /* we "retry" to get the right mm context for this: */ - /* copy stuff into user buffers */ total = priv->actual; len = 0; @@ -568,9 +569,26 @@ static ssize_t ep_aio_read_retry(struct kiocb *iocb) if (total == 0) break; } + + return len; +} + +static void ep_user_copy_worker(struct work_struct *work) +{ + struct kiocb_priv *priv = container_of(work, struct kiocb_priv, work); + struct mm_struct *mm = priv->mm; + struct kiocb *iocb = priv->iocb; + size_t ret; + + use_mm(mm); + ret = ep_copy_to_user(priv); + unuse_mm(mm); + + /* completing the iocb can drop the ctx and mm, don't touch mm after */ + aio_complete(iocb, ret, ret); + kfree(priv->buf); kfree(priv); - return len; } static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req) @@ -596,14 +614,14 @@ static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req) aio_complete(iocb, req->actual ? req->actual : req->status, req->status); } else { - /* retry() won't report both; so we hide some faults */ + /* ep_copy_to_user() won't report both; we hide some faults */ if (unlikely(0 != req->status)) DBG(epdata->dev, "%s fault %d len %d\n", ep->name, req->status, req->actual); priv->buf = req->buf; priv->actual = req->actual; - kick_iocb(iocb); + schedule_work(&priv->work); } spin_unlock(&epdata->dev->lock); @@ -633,8 +651,10 @@ fail: return value; } iocb->private = priv; + priv->iocb = iocb; priv->iv = iv; priv->nr_segs = nr_segs; + INIT_WORK(&priv->work, ep_user_copy_worker); value = get_ready_ep(iocb->ki_filp->f_flags, epdata); if (unlikely(value < 0)) { @@ -646,6 +666,7 @@ fail: get_ep(epdata); priv->epdata = epdata; priv->actual = 0; + priv->mm = current->mm; /* mm teardown waits for iocbs in exit_aio() */ /* each kiocb is coupled to one usb_request, but we can't * allocate or submit those if the host disconnected. @@ -674,7 +695,7 @@ fail: kfree(priv); put_ep(epdata); } else - value = (iv ? -EIOCBRETRY : -EIOCBQUEUED); + value = -EIOCBQUEUED; return value; } @@ -692,7 +713,6 @@ ep_aio_read(struct kiocb *iocb, const struct iovec *iov, if (unlikely(!buf)) return -ENOMEM; - iocb->ki_retry = ep_aio_read_retry; return ep_aio_rwtail(iocb, buf, iocb->ki_left, epdata, iov, nr_segs); } |