Commit 6fd47eff authored by Benjamin Tissoires's avatar Benjamin Tissoires
Browse files

HID: bpf: allow write access to quirks field in struct hid_device 



This allows to give more control from BPF during report descriptor fixup.
We already reset the quirks before calling ->probe(), so now we reset
it once before calling hid_bpf_rdesc_fixup().

Reviewed-by: default avatarPeter Hutterer <peter.hutterer@who-t.net>
Link: https://patch.msgid.link/20241001-hid-bpf-hid-generic-v3-4-2ef1019468df@kernel.org


Signed-off-by: default avatarBenjamin Tissoires <bentiss@kernel.org>
parent 7316fef4

drivers/hid/bpf/hid_bpf_struct_ops.c

+1 −0
Original line number Diff line number Diff line
@@ -79,6 +79,7 @@ static int hid_bpf_ops_btf_struct_access(struct bpf_verifier_log *log, 
		WRITE_RANGE(hid_device, name, true),

		WRITE_RANGE(hid_device, uniq, true),

		WRITE_RANGE(hid_device, phys, true),

		WRITE_RANGE(hid_device, quirks, false),

	};

#undef WRITE_RANGE

	const struct btf_type *state = NULL;

drivers/hid/hid-core.c

+9 −2
Original line number Diff line number Diff line
@@ -2709,6 +2709,12 @@ static int __hid_device_probe(struct hid_device *hdev, struct hid_driver *hdrv) 
	int ret;



	if (!hdev->bpf_rsize) {

		unsigned int quirks;



		/* reset the quirks that has been previously set */

		quirks = hid_lookup_quirk(hdev);

		hdev->quirks = quirks;



		/* in case a bpf program gets detached, we need to free the old one */

		hid_free_bpf_rdesc(hdev);
@@ -2718,6 +2724,9 @@ static int __hid_device_probe(struct hid_device *hdev, struct hid_driver *hdrv) 
		/* call_hid_bpf_rdesc_fixup will always return a valid pointer */

		hdev->bpf_rdesc = call_hid_bpf_rdesc_fixup(hdev, hdev->dev_rdesc,

							   &hdev->bpf_rsize);

		if (quirks ^ hdev->quirks)

			hid_info(hdev, "HID-BPF toggled quirks on the device: %04x",

				 quirks ^ hdev->quirks);

	}



	if (!hid_check_device_match(hdev, hdrv, &id))
@@ -2727,8 +2736,6 @@ static int __hid_device_probe(struct hid_device *hdev, struct hid_driver *hdrv) 
	if (!hdev->devres_group_id)

		return -ENOMEM;



	/* reset the quirks that has been previously set */

	hdev->quirks = hid_lookup_quirk(hdev);

	hdev->driver = hdrv;



	if (hdrv->probe) {