[patch] drm/msm: return -EFAULT instead of bytes remaining

[Dan Carpenter]

copy_to/from_user returns the number of bytes remaining to be copied but
we want to return -EFAULT.

Signed-off-by: Dan Carpenter 

diff --git a/drivers/gpu/drm/msm/msm_perf.c b/drivers/gpu/drm/msm/msm_perf.c
index 830857c..17fe4e5 100644
--- a/drivers/gpu/drm/msm/msm_perf.c
+++ b/drivers/gpu/drm/msm/msm_perf.c
@@ -132,7 +132,7 @@ static ssize_t perf_read(struct file *file, char __user 
*buf,
size_t sz, loff_t *ppos)
 {
struct msm_perf_state *perf = file->private_data;
-   int n = 0, ret;
+   int n = 0, ret = 0;

mutex_lock(>read_lock);

@@ -143,9 +143,10 @@ static ssize_t perf_read(struct file *file, char __user 
*buf,
}

n = min((int)sz, perf->buftot - perf->bufpos);
-   ret = copy_to_user(buf, >buf[perf->bufpos], n);
-   if (ret)
+   if (copy_to_user(buf, >buf[perf->bufpos], n)) {
+   ret = -EFAULT;
goto out;
+   }

perf->bufpos += n;
*ppos += n;
diff --git a/drivers/gpu/drm/msm/msm_rd.c b/drivers/gpu/drm/msm/msm_rd.c
index 24254e0..3a5fdfc 100644
--- a/drivers/gpu/drm/msm/msm_rd.c
+++ b/drivers/gpu/drm/msm/msm_rd.c
@@ -149,9 +149,10 @@ static ssize_t rd_read(struct file *file, char __user *buf,
goto out;

n = min_t(int, sz, circ_count_to_end(>fifo));
-   ret = copy_to_user(buf, fptr, n);
-   if (ret)
+   if (copy_to_user(buf, fptr, n)) {
+   ret = -EFAULT;
goto out;
+   }

fifo->tail = (fifo->tail + n) & (BUF_SZ - 1);
*ppos += n;

[patch] drm/msm: return -EFAULT instead of bytes remaining

[Rob Clark]

On Wed, Jul 13, 2016 at 6:35 AM, Dan Carpenter  
wrote:
> copy_to/from_user returns the number of bytes remaining to be copied but
> we want to return -EFAULT.
>
> Signed-off-by: Dan Carpenter 

thanks, I've added to msm-next

BR,
-R

>
> diff --git a/drivers/gpu/drm/msm/msm_perf.c b/drivers/gpu/drm/msm/msm_perf.c
> index 830857c..17fe4e5 100644
> --- a/drivers/gpu/drm/msm/msm_perf.c
> +++ b/drivers/gpu/drm/msm/msm_perf.c
> @@ -132,7 +132,7 @@ static ssize_t perf_read(struct file *file, char __user 
> *buf,
> size_t sz, loff_t *ppos)
>  {
> struct msm_perf_state *perf = file->private_data;
> -   int n = 0, ret;
> +   int n = 0, ret = 0;
>
> mutex_lock(>read_lock);
>
> @@ -143,9 +143,10 @@ static ssize_t perf_read(struct file *file, char __user 
> *buf,
> }
>
> n = min((int)sz, perf->buftot - perf->bufpos);
> -   ret = copy_to_user(buf, >buf[perf->bufpos], n);
> -   if (ret)
> +   if (copy_to_user(buf, >buf[perf->bufpos], n)) {
> +   ret = -EFAULT;
> goto out;
> +   }
>
> perf->bufpos += n;
> *ppos += n;
> diff --git a/drivers/gpu/drm/msm/msm_rd.c b/drivers/gpu/drm/msm/msm_rd.c
> index 24254e0..3a5fdfc 100644
> --- a/drivers/gpu/drm/msm/msm_rd.c
> +++ b/drivers/gpu/drm/msm/msm_rd.c
> @@ -149,9 +149,10 @@ static ssize_t rd_read(struct file *file, char __user 
> *buf,
> goto out;
>
> n = min_t(int, sz, circ_count_to_end(>fifo));
> -   ret = copy_to_user(buf, fptr, n);
> -   if (ret)
> +   if (copy_to_user(buf, fptr, n)) {
> +   ret = -EFAULT;
> goto out;
> +   }
>
> fifo->tail = (fifo->tail + n) & (BUF_SZ - 1);
> *ppos += n;