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

From: Dan Carpenter
Date: Wed Jul 13 2016 - 06:36:31 EST


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

Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

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(&perf->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, &perf->buf[perf->bufpos], n);
- if (ret)
+ if (copy_to_user(buf, &perf->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(&rd->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;