[PATCH bpf-next v2 23/28] HID: bpf: compute only the required buffer size for the device
flat view
STALE1669d
From: Benjamin Tissoires <hidden>
Date: 2022-03-04 17:35:50
Also in:
bpf, linux-kselftest, lkml, netdev
Subsystem:
hid core layer, the rest · Maintainers:
Jiri Kosina, Benjamin Tissoires, Linus Torvalds
Revision v2 of 5 in this series.
Revisions (5)
There is no point in using 16 kB of memory if the device needs less for all of its reports (uwhich is usually the case). Signed-off-by: Benjamin Tissoires <redacted> --- new in v2 --- drivers/hid/hid-bpf.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/drivers/hid/hid-bpf.c b/drivers/hid/hid-bpf.c
index b8c0060f3180..d56fbad990ed 100644
--- a/drivers/hid/hid-bpf.c
+++ b/drivers/hid/hid-bpf.c@@ -61,11 +61,24 @@ static int hid_reconnect(struct hid_device *hdev) static int hid_bpf_link_attach(struct hid_device *hdev, enum bpf_hid_attach_type type) { int err = 0; + unsigned int i, j, max_report_len = 0; + + /* compute the maximum report length for this device */ + for (i = 0; i < HID_REPORT_TYPES; i++) { + struct hid_report_enum *report_enum = hdev->report_enum + i; + + for (j = 0; j < HID_MAX_IDS; j++) { + struct hid_report *report = report_enum->report_id_hash[j]; + + if (report) + max_report_len = max(max_report_len, hid_report_len(report)); + } + } switch (type) { case BPF_HID_ATTACH_DEVICE_EVENT: if (!hdev->bpf.ctx) { - hdev->bpf.ctx = bpf_hid_allocate_ctx(hdev, HID_BPF_MAX_BUFFER_SIZE); + hdev->bpf.ctx = bpf_hid_allocate_ctx(hdev, max_report_len); if (IS_ERR(hdev->bpf.ctx)) { err = PTR_ERR(hdev->bpf.ctx); hdev->bpf.ctx = NULL;
--
2.35.1