[PATCH bpf-next v2 24/28] HID: bpf: only call hid_bpf_raw_event() if a ctx is available

Benjamin Tissoires
2022-03-04T17:35:46Z

the context is allocated the first time a program of type DEVICE_EVENT
is attached to the device. To not add too much jumps in the code for
the general device handling, call hid_bpf_raw_event() only if we know
that a program has been attached once during the life of the device.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>

---

new in v2
---
drivers/hid/hid-core.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index d0e015986e17..2b49f6064a40 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -1751,10 +1751,13 @@ int hid_report_raw_event(struct hid_device *hid, int type, u8 *data, u32 size,
u8 *cdata;
int ret = 0;

- data = hid_bpf_raw_event(hid, data, &size);
- if (IS_ERR(data)) {
- ret = PTR_ERR(data);
- goto out;
+ /* we pre-test if ctx is available here to cut the calls at the earliest */
+ if (hid->bpf.ctx) {
+ data = hid_bpf_raw_event(hid, data, &size);
+ if (IS_ERR(data)) {
+ ret = PTR_ERR(data);
+ goto out;
+ }
}

report = hid_get_report(report_enum, data);
--
2.35.1