rpmsg: char: Migrate to iter versions of read and write
authorBjorn Andersson <bjorn.andersson@linaro.org>
Tue, 7 Aug 2018 07:14:24 +0000 (00:14 -0700)
committerSuman Anna <s-anna@ti.com>
Mon, 10 Dec 2018 22:26:13 +0000 (16:26 -0600)
[ Upstream commit ccf45b18ce89f598c69a0c945ced1635013fc0b1 ]

In order to be able to use the aio interface for writing to a rpmsg_char
the write_iter function must be implemented, so migrate to iter version
for read and write functions.

Regular read and write uses the iter methods if present and is as such
unaffected.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
[s-anna@ti.com: cherry-pick commit 'ccf45b18ce89' from v4.20]
Signed-off-by: Suman Anna <s-anna@ti.com>
drivers/rpmsg/rpmsg_char.c

index a76b963a7e50f31e919c9e476de8d2161fad390f..eea5ebbb5119a85eb12b1ca550ea93b75ed88c8f 100644 (file)
@@ -167,9 +167,9 @@ static int rpmsg_eptdev_release(struct inode *inode, struct file *filp)
        return 0;
 }
 
-static ssize_t rpmsg_eptdev_read(struct file *filp, char __user *buf,
-                                size_t len, loff_t *f_pos)
+static ssize_t rpmsg_eptdev_read_iter(struct kiocb *iocb, struct iov_iter *to)
 {
+       struct file *filp = iocb->ki_filp;
        struct rpmsg_eptdev *eptdev = filp->private_data;
        unsigned long flags;
        struct sk_buff *skb;
@@ -205,8 +205,8 @@ static ssize_t rpmsg_eptdev_read(struct file *filp, char __user *buf,
        if (!skb)
                return -EFAULT;
 
-       use = min_t(size_t, len, skb->len);
-       if (copy_to_user(buf, skb->data, use))
+       use = min_t(size_t, iov_iter_count(to), skb->len);
+       if (copy_to_iter(skb->data, use, to) != use)
                use = -EFAULT;
 
        kfree_skb(skb);
@@ -214,16 +214,21 @@ static ssize_t rpmsg_eptdev_read(struct file *filp, char __user *buf,
        return use;
 }
 
-static ssize_t rpmsg_eptdev_write(struct file *filp, const char __user *buf,
-                                 size_t len, loff_t *f_pos)
+static ssize_t rpmsg_eptdev_write_iter(struct kiocb *iocb,
+                                      struct iov_iter *from)
 {
+       struct file *filp = iocb->ki_filp;
        struct rpmsg_eptdev *eptdev = filp->private_data;
+       size_t len = iov_iter_count(from);
        void *kbuf;
        int ret;
 
-       kbuf = memdup_user(buf, len);
-       if (IS_ERR(kbuf))
-               return PTR_ERR(kbuf);
+       kbuf = kzalloc(len, GFP_KERNEL);
+       if (!kbuf)
+               return -ENOMEM;
+
+       if (!copy_from_iter_full(kbuf, len, from))
+               return -EFAULT;
 
        if (mutex_lock_interruptible(&eptdev->ept_lock)) {
                ret = -ERESTARTSYS;
@@ -281,8 +286,8 @@ static const struct file_operations rpmsg_eptdev_fops = {
        .owner = THIS_MODULE,
        .open = rpmsg_eptdev_open,
        .release = rpmsg_eptdev_release,
-       .read = rpmsg_eptdev_read,
-       .write = rpmsg_eptdev_write,
+       .read_iter = rpmsg_eptdev_read_iter,
+       .write_iter = rpmsg_eptdev_write_iter,
        .poll = rpmsg_eptdev_poll,
        .unlocked_ioctl = rpmsg_eptdev_ioctl,
        .compat_ioctl = rpmsg_eptdev_ioctl,