[PATCH HID v3 2/9] HID: core: save one kmemdup during .probe()

From: Benjamin Tissoires
Date: Tue Oct 01 2024 - 10:31:36 EST


Turns out the first kmemdup is only required for the .report_fixup()
driver callback. There is no need to do two kmemdup() in a row in case
.report_fixup() is not present.

Reviewed-by: Peter Hutterer <peter.hutterer@xxxxxxxxx>
Signed-off-by: Benjamin Tissoires <bentiss@xxxxxxxxxx>

---

no changes in v3

new in v2
---
drivers/hid/hid-core.c | 18 +++++++++++-------
1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index d6bf933623e8..6053e7cdc0c1 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -1214,7 +1214,7 @@ int hid_open_report(struct hid_device *device)
struct hid_item item;
unsigned int size;
const __u8 *start;
- __u8 *buf;
+ __u8 *buf = NULL;
const __u8 *end;
const __u8 *next;
int ret;
@@ -1235,14 +1235,18 @@ int hid_open_report(struct hid_device *device)
return -ENODEV;
size = device->bpf_rsize;

- buf = kmemdup(start, size, GFP_KERNEL);
- if (buf == NULL)
- return -ENOMEM;
+ if (device->driver->report_fixup) {
+ /*
+ * device->driver->report_fixup() needs to work
+ * on a copy of our report descriptor so it can
+ * change it.
+ */
+ buf = kmemdup(start, size, GFP_KERNEL);
+ if (buf == NULL)
+ return -ENOMEM;

- if (device->driver->report_fixup)
start = device->driver->report_fixup(device, buf, &size);
- else
- start = buf;
+ }

start = kmemdup(start, size, GFP_KERNEL);
kfree(buf);

--
2.46.0