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Merge branch 'work.__copy_to_user' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

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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
This commit is contained in:
Linus Torvalds 2017-07-15 11:47:27 -07:00
commit 93ff818597
1 changed files with 46 additions and 63 deletions
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109
drivers/gpu/drm/drm_dp_aux_dev.c
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@ -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));
iov_iter_truncate(to, AUX_MAX_OFFSET - pos);
if (!access_ok(VERIFY_WRITE, buf, bytes_pending)) {
res = -EFAULT;
goto out;
}
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;
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;
}
if (__copy_to_user(buf + num_bytes_processed, localbuf, res)) {
res = num_bytes_processed ?
num_bytes_processed : -EFAULT;
goto out;
}
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);
iov_iter_truncate(from, AUX_MAX_OFFSET - pos);
if (!access_ok(VERIFY_READ, buf, bytes_pending)) {
res = -EFAULT;
goto out;
}
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,
};