| Message ID | 20210511101208.16401-1-michael.zaidman@gmail.com |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | [v4] HID: ft260: improve error handling of ft260_hid_feature_report_get() | expand |
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@redhat.com> > Signed-off-by: Michael Zaidman <michael.zaidman@gmail.com> > --- > 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 > hid_err(hdev, "failed to retrieve system status\n"); > - if (ret >= 0) > - return -EIO; > + return ret; > } > return 0; > } > @@ -776,8 +778,8 @@ static int ft260_byte_show(struct hid_device *hdev, int id, u8 *cfg, int len, > int ret; > > ret = ft260_hid_feature_report_get(hdev, id, cfg, len); > - if (ret != len && ret >= 0) > - return -EIO; > + if (ret < 0) > + return ret; > > return scnprintf(buf, PAGE_SIZE, "%hi\n", *field); > } > @@ -788,8 +790,8 @@ static int ft260_word_show(struct hid_device *hdev, int id, u8 *cfg, int len, > int ret; > > ret = ft260_hid_feature_report_get(hdev, id, cfg, len); > - if (ret != len && ret >= 0) > - return -EIO; > + if (ret < 0) > + return ret; > > return scnprintf(buf, PAGE_SIZE, "%hi\n", le16_to_cpu(*field)); > } > @@ -940,10 +942,8 @@ static int ft260_probe(struct hid_device *hdev, const struct hid_device_id *id) > > ret = ft260_hid_feature_report_get(hdev, FT260_CHIP_VERSION, > (u8 *)&version, sizeof(version)); > - if (ret != sizeof(version)) { > + if (ret < 0) { > hid_err(hdev, "failed to retrieve chip version\n"); > - if (ret >= 0) > - ret = -EIO; > goto err_hid_close; > } >
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@redhat.com> > > Signed-off-by: Michael Zaidman <michael.zaidman@gmail.com> > > --- > > 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. Michael
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@redhat.com> >>> Signed-off-by: Michael Zaidman <michael.zaidman@gmail.com> >>> --- >>> 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 >
On Tue, 11 May 2021, 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@redhat.com> > Signed-off-by: Michael Zaidman <michael.zaidman@gmail.com> Who should be the author of the git commit? Thanks,
On 5/13/21 4:09 AM, Jiri Kosina wrote: > On Tue, 11 May 2021, 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@redhat.com> >> Signed-off-by: Michael Zaidman <michael.zaidman@gmail.com> > Who should be the author of the git commit? Go with the latest patch's author, Micheal. Tom > > Thanks, >
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) { hid_err(hdev, "failed to retrieve system status\n"); - if (ret >= 0) - return -EIO; + return ret; } return 0; } @@ -776,8 +778,8 @@ static int ft260_byte_show(struct hid_device *hdev, int id, u8 *cfg, int len, int ret; ret = ft260_hid_feature_report_get(hdev, id, cfg, len); - if (ret != len && ret >= 0) - return -EIO; + if (ret < 0) + return ret; return scnprintf(buf, PAGE_SIZE, "%hi\n", *field); } @@ -788,8 +790,8 @@ static int ft260_word_show(struct hid_device *hdev, int id, u8 *cfg, int len, int ret; ret = ft260_hid_feature_report_get(hdev, id, cfg, len); - if (ret != len && ret >= 0) - return -EIO; + if (ret < 0) + return ret; return scnprintf(buf, PAGE_SIZE, "%hi\n", le16_to_cpu(*field)); } @@ -940,10 +942,8 @@ static int ft260_probe(struct hid_device *hdev, const struct hid_device_id *id) ret = ft260_hid_feature_report_get(hdev, FT260_CHIP_VERSION, (u8 *)&version, sizeof(version)); - if (ret != sizeof(version)) { + if (ret < 0) { hid_err(hdev, "failed to retrieve chip version\n"); - if (ret >= 0) - ret = -EIO; goto err_hid_close; }
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@redhat.com> Signed-off-by: Michael Zaidman <michael.zaidman@gmail.com> --- drivers/hid/hid-ft260.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-)