On 5/11/21 7:34 AM, Michael Zaidman wrote:
On Tue, May 11, 2021 at 06:10:36AM -0700, Tom Rix wrote:
Generally change is fine.
a nit below.
On 5/11/21 3:12 AM, Michael Zaidman wrote:
Fixes: 6a82582d9fa4 ("HID: ft260: add usb hid to i2c host bridge driver")
The ft260_hid_feature_report_get() checks if the return size matches
the requested size. But the function can also fail with at least -ENOMEM.
Add the < 0 checks.
In ft260_hid_feature_report_get(), do not do the memcpy to the caller's
buffer if there is an error.
---
v4 Fixed commit message
---
v3 Simplify and optimize the changes
---
v2: add unlikely()'s for error conditions
---
Signed-off-by: Tom Rix <trix@xxxxxxxxxx>
Signed-off-by: Michael Zaidman <michael.zaidman@xxxxxxxxx>
---
drivers/hid/hid-ft260.c | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)
diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c
index 047aa85a7c83..7f4cb823129e 100644
--- a/drivers/hid/hid-ft260.c
+++ b/drivers/hid/hid-ft260.c
@@ -249,7 +249,10 @@ static int ft260_hid_feature_report_get(struct hid_device *hdev,
ret = hid_hw_raw_request(hdev, report_id, buf, len, HID_FEATURE_REPORT,
HID_REQ_GET_REPORT);
- memcpy(data, buf, len);
+ if (likely(ret == len))
+ memcpy(data, buf, len);
+ else if (ret >= 0)
+ ret = -EIO;
kfree(buf);
return ret;
}
@@ -298,7 +301,7 @@ static int ft260_xfer_status(struct ft260_device *dev)
ret = ft260_hid_feature_report_get(hdev, FT260_I2C_STATUS,
(u8 *)&report, sizeof(report));
- if (ret < 0) {
+ if (unlikely(ret < 0)) {
hid_err(hdev, "failed to retrieve status: %d\n", ret);
return ret;
}
@@ -720,10 +723,9 @@ static int ft260_get_system_config(struct hid_device *hdev,
ret = ft260_hid_feature_report_get(hdev, FT260_SYSTEM_SETTINGS,
(u8 *)cfg, len);
- if (ret != len) {
+ if (ret < 0) {
nit: should be consistent and use unlikely(ret < 0) for this and other
similar checks.
Tom
I preserved the likely/unlikely hints in the critical path where the
performance matters. And for the sake of consistency, I removed them from
the rest of the places that are called rarely and are not performance-critical
to be aligned to the other "if" statements in the code.
This is fine.
Thanks,
Tom
Michael
