4.18: add WACOM_HID_REPORT_RAW_EVENT_BUFSIZE flag for API update

In kernel ver 7.0.8, hid_report_raw_event() was updated to accept both
the buffer size and the data size arguments to mitigate potential OOB issues.

This commit adds a check and flag set in configure.ac for this change.
It also adds #ifdef checks in 4.18/wacom_sys.c to handle the flag and safely
pass the extra parameter on newer kernels, while preserving the legacy
signature for older environments.

Signed-off-by: Kori <pedarkasy@gmail.com>

Author: Korikashi

4.18/wacom_sys.c

@@ -96,7 +96,11 @@ static void wacom_wac_queue_flush(struct hid_device *hdev,
 			kfree(buf);
 			continue;
 		}
+#ifdef WACOM_HID_REPORT_RAW_EVENT_BUFSIZE
 		err = hid_report_raw_event(hdev, HID_INPUT_REPORT, buf, size, size, false);
+#else
+		err = hid_report_raw_event(hdev, HID_INPUT_REPORT, buf, size, false);
+#endif
 		if (err) {
 			hid_warn(hdev, "%s: unable to flush event due to error %d\n",
 				 __func__, err);
@@ -339,8 +343,13 @@ static void wacom_feature_mapping(struct hid_device *hdev,
 			ret = wacom_get_report(hdev, HID_FEATURE_REPORT,
 					       data, n, WAC_CMD_RETRIES);
 			if (ret == n && features->type == HID_GENERIC) {
+#ifdef WACOM_HID_REPORT_RAW_EVENT_BUFSIZE
 				ret = hid_report_raw_event(hdev,
 					HID_FEATURE_REPORT, data, n, n, 0);
+#else
+				ret = hid_report_raw_event(hdev,
+					HID_FEATURE_REPORT, data, n, 0);
+#endif
 			} else if (ret == 2 && features->type != HID_GENERIC) {
 				features->touch_max = data[1];
 			} else {
@@ -400,8 +409,13 @@ static void wacom_feature_mapping(struct hid_device *hdev,
 		ret = wacom_get_report(hdev, HID_FEATURE_REPORT,
 					data, n, WAC_CMD_RETRIES);
 		if (ret == n) {
+#ifdef WACOM_HID_REPORT_RAW_EVENT_BUFSIZE
 			ret = hid_report_raw_event(hdev, HID_FEATURE_REPORT,
 						   data, n, n, 0);
+#else
+			ret = hid_report_raw_event(hdev, HID_FEATURE_REPORT,
+						   data, n, 0);
+#endif
 		} else {
 			hid_warn(hdev, "%s: could not retrieve sensor offsets\n",
 				 __func__);

configure.ac

@@ -303,6 +303,35 @@ bool timer_delete_sync(struct timer_list *timer) { return true; }
 	AC_DEFINE([WACOM_TIMER_DELETE_SYNC], [], [kernel defines timer_delete_sync from v6.1.84+])
 ])
 
+
+dnl Check if hid_report_raw_event takes a bufsize parameter or not.
+dnl This is the case in Linux 7.0.8 and later.
+AC_MSG_CHECKING(hid_report_raw_event bufsize parameter)
+WACOM_LINUX_TRY_COMPILE([
+#include <linux/hid.h>
+static int (*test_fn)(
+        struct hid_device *,
+        enum hid_report_type,
+        u8 *,
+        size_t,
+        u32,
+        int
+) = hid_report_raw_event;
+int test(void)
+{
+        return test_fn != NULL;
+}
+],[
+],[
+        HAVE_HID_REPORT_RAW_EVENT_BUFSIZE=yes
+        AC_MSG_RESULT([yes])
+        AC_DEFINE([WACOM_HID_REPORT_RAW_EVENT_BUFSIZE], [],
+                  [kernel hid_report_raw_event() takes a bufsize parameter])
+],[
+        HAVE_HID_REPORT_RAW_EVENT_BUFSIZE=no
+        AC_MSG_RESULT([no])
+])
+
 dnl Check if from_timer has been renamed to timer_container_of or
 dnl not. This is the case in Linux 6.16 and later.
 AC_MSG_CHECKING(timer_container_of)