[PATCH 2/2] ASoC: SOF: sof-client-probes: cleanup tokenize_input()

Dan Carpenter
2022-07-06T07:26:16Z

The tokenize_input() function is cleaner if it uses strndup_user()
instead of simple_write_to_buffer(). The way it's written now, if
*ppos is non-zero then it returns -EIO but normally we would return
0 in that case. It's easier to handle that in the callers.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
sound/soc/sof/sof-client-probes.c | 27 +++++++++++++--------------
1 file changed, 13 insertions(+), 14 deletions(-)

diff --git a/sound/soc/sof/sof-client-probes.c b/sound/soc/sof/sof-client-probes.c
index 679bc7d371fc..6c922b683f67 100644
--- a/sound/soc/sof/sof-client-probes.c
+++ b/sound/soc/sof/sof-client-probes.c
@@ -461,24 +461,17 @@ static int strsplit_u32(char *buf, const char *delim, u32 **tkns, size_t *num_tk
}

static int tokenize_input(const char __user *from, size_t count,
- loff_t *ppos, u32 **tkns, size_t *num_tkns)
+ u32 **tkns, size_t *num_tkns)
{
char *buf;
int ret;

- buf = kmalloc(count + 1, GFP_KERNEL);
- if (!buf)
- return -ENOMEM;
-
- ret = simple_write_to_buffer(buf, count, ppos, from, count);
- if (ret != count) {
- ret = ret >= 0 ? -EIO : ret;
- goto exit;
- }
+ buf = strndup_user(from, count + 1);
+ if (IS_ERR(buf))
+ return PTR_ERR(buf);

- buf[count] = '\0';
ret = strsplit_u32(buf, ",", tkns, num_tkns);
-exit:
+
kfree(buf);
return ret;
}
@@ -552,12 +545,15 @@ sof_probes_dfs_points_write(struct file *file, const char __user *from,
u32 *tkns;
int ret, err;

+ if (*ppos)
+ return 0;
+
if (priv->extractor_stream_tag == SOF_PROBES_INVALID_NODE_ID) {
dev_warn(dev, "no extractor stream running\n");
return -ENOENT;
}

- ret = tokenize_input(from, count, ppos, &tkns, &num_tkns);
+ ret = tokenize_input(from, count, &tkns, &num_tkns);
if (ret < 0)
return ret;
bytes = sizeof(*tkns) * num_tkns;
@@ -607,12 +603,15 @@ sof_probes_dfs_points_remove_write(struct file *file, const char __user *from,
u32 *tkns;
int ret, err;

+ if (*ppos)
+ return 0;
+
if (priv->extractor_stream_tag == SOF_PROBES_INVALID_NODE_ID) {
dev_warn(dev, "no extractor stream running\n");
return -ENOENT;
}

- ret = tokenize_input(from, count, ppos, &tkns, &num_tkns);
+ ret = tokenize_input(from, count, &tkns, &num_tkns);
if (ret < 0)
return ret;
if (!num_tkns) {
--
2.35.1