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authorLinus Torvalds <torvalds@linux-foundation.org>2017-07-15 11:47:27 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-07-15 11:47:27 -0700
commit93ff81859733d9697a5a0cc4707e52fb17056abb (patch)
tree9bca6d06cf5dbd0feee592abecdc6e14f9a5dc92
parentMerge branch 'work.uaccess-unaligned' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs (diff)
parentdrm_dp_aux_dev: switch to read_iter/write_iter (diff)
downloadlinux-dev-93ff81859733d9697a5a0cc4707e52fb17056abb.tar.xz
linux-dev-93ff81859733d9697a5a0cc4707e52fb17056abb.zip
Merge branch 'work.__copy_to_user' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more __copy_.._user elimination from Al Viro. * 'work.__copy_to_user' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: drm_dp_aux_dev: switch to read_iter/write_iter
-rw-r--r--drivers/gpu/drm/drm_dp_aux_dev.c109
1 files changed, 46 insertions, 63 deletions
diff --git a/drivers/gpu/drm/drm_dp_aux_dev.c b/drivers/gpu/drm/drm_dp_aux_dev.c
index ec1ed94b2390..d34e5096887a 100644
--- a/drivers/gpu/drm/drm_dp_aux_dev.c
+++ b/drivers/gpu/drm/drm_dp_aux_dev.c
@@ -32,6 +32,7 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/uaccess.h>
+#include <linux/uio.h>
#include <drm/drm_dp_helper.h>
#include <drm/drm_crtc.h>
#include <drm/drmP.h>
@@ -140,101 +141,83 @@ static loff_t auxdev_llseek(struct file *file, loff_t offset, int whence)
return fixed_size_llseek(file, offset, whence, AUX_MAX_OFFSET);
}
-static ssize_t auxdev_read(struct file *file, char __user *buf, size_t count,
- loff_t *offset)
+static ssize_t auxdev_read_iter(struct kiocb *iocb, struct iov_iter *to)
{
- size_t bytes_pending, num_bytes_processed = 0;
- struct drm_dp_aux_dev *aux_dev = file->private_data;
+ struct drm_dp_aux_dev *aux_dev = iocb->ki_filp->private_data;
+ loff_t pos = iocb->ki_pos;
ssize_t res = 0;
if (!atomic_inc_not_zero(&aux_dev->usecount))
return -ENODEV;
- bytes_pending = min((loff_t)count, AUX_MAX_OFFSET - (*offset));
-
- if (!access_ok(VERIFY_WRITE, buf, bytes_pending)) {
- res = -EFAULT;
- goto out;
- }
+ iov_iter_truncate(to, AUX_MAX_OFFSET - pos);
- while (bytes_pending > 0) {
- uint8_t localbuf[DP_AUX_MAX_PAYLOAD_BYTES];
- ssize_t todo = min_t(size_t, bytes_pending, sizeof(localbuf));
+ while (iov_iter_count(to)) {
+ uint8_t buf[DP_AUX_MAX_PAYLOAD_BYTES];
+ ssize_t todo = min(iov_iter_count(to), sizeof(buf));
if (signal_pending(current)) {
- res = num_bytes_processed ?
- num_bytes_processed : -ERESTARTSYS;
- goto out;
+ res = -ERESTARTSYS;
+ break;
}
- res = drm_dp_dpcd_read(aux_dev->aux, *offset, localbuf, todo);
- if (res <= 0) {
- res = num_bytes_processed ? num_bytes_processed : res;
- goto out;
- }
- if (__copy_to_user(buf + num_bytes_processed, localbuf, res)) {
- res = num_bytes_processed ?
- num_bytes_processed : -EFAULT;
- goto out;
+ res = drm_dp_dpcd_read(aux_dev->aux, pos, buf, todo);
+ if (res <= 0)
+ break;
+
+ if (copy_to_iter(buf, res, to) != res) {
+ res = -EFAULT;
+ break;
}
- bytes_pending -= res;
- *offset += res;
- num_bytes_processed += res;
- res = num_bytes_processed;
+
+ pos += res;
}
-out:
+ if (pos != iocb->ki_pos)
+ res = pos - iocb->ki_pos;
+ iocb->ki_pos = pos;
+
atomic_dec(&aux_dev->usecount);
wake_up_atomic_t(&aux_dev->usecount);
return res;
}
-static ssize_t auxdev_write(struct file *file, const char __user *buf,
- size_t count, loff_t *offset)
+static ssize_t auxdev_write_iter(struct kiocb *iocb, struct iov_iter *from)
{
- size_t bytes_pending, num_bytes_processed = 0;
- struct drm_dp_aux_dev *aux_dev = file->private_data;
+ struct drm_dp_aux_dev *aux_dev = iocb->ki_filp->private_data;
+ loff_t pos = iocb->ki_pos;
ssize_t res = 0;
if (!atomic_inc_not_zero(&aux_dev->usecount))
return -ENODEV;
- bytes_pending = min((loff_t)count, AUX_MAX_OFFSET - *offset);
-
- if (!access_ok(VERIFY_READ, buf, bytes_pending)) {
- res = -EFAULT;
- goto out;
- }
+ iov_iter_truncate(from, AUX_MAX_OFFSET - pos);
- while (bytes_pending > 0) {
- uint8_t localbuf[DP_AUX_MAX_PAYLOAD_BYTES];
- ssize_t todo = min_t(size_t, bytes_pending, sizeof(localbuf));
+ while (iov_iter_count(from)) {
+ uint8_t buf[DP_AUX_MAX_PAYLOAD_BYTES];
+ ssize_t todo = min(iov_iter_count(from), sizeof(buf));
if (signal_pending(current)) {
- res = num_bytes_processed ?
- num_bytes_processed : -ERESTARTSYS;
- goto out;
+ res = -ERESTARTSYS;
+ break;
}
- if (__copy_from_user(localbuf,
- buf + num_bytes_processed, todo)) {
- res = num_bytes_processed ?
- num_bytes_processed : -EFAULT;
- goto out;
+ if (!copy_from_iter_full(buf, todo, from)) {
+ res = -EFAULT;
+ break;
}
- res = drm_dp_dpcd_write(aux_dev->aux, *offset, localbuf, todo);
- if (res <= 0) {
- res = num_bytes_processed ? num_bytes_processed : res;
- goto out;
- }
- bytes_pending -= res;
- *offset += res;
- num_bytes_processed += res;
- res = num_bytes_processed;
+ res = drm_dp_dpcd_write(aux_dev->aux, pos, buf, todo);
+ if (res <= 0)
+ break;
+
+ pos += res;
}
-out:
+ if (pos != iocb->ki_pos)
+ res = pos - iocb->ki_pos;
+ iocb->ki_pos = pos;
+
atomic_dec(&aux_dev->usecount);
wake_up_atomic_t(&aux_dev->usecount);
return res;
@@ -251,8 +234,8 @@ static int auxdev_release(struct inode *inode, struct file *file)
static const struct file_operations auxdev_fops = {
.owner = THIS_MODULE,
.llseek = auxdev_llseek,
- .read = auxdev_read,
- .write = auxdev_write,
+ .read_iter = auxdev_read_iter,
+ .write_iter = auxdev_write_iter,
.open = auxdev_open,
.release = auxdev_release,
};