[v2,4/7] HID: constify params and return value of fetch_item()

Commit Message

Thomas Weißschuh Aug. 3, 2024, 12:34 p.m. UTC

fetch_item() does not modify the descriptor it operates on.
As a prerequisite for the constification of hid_driver::dev_rdesc,
mark the parameters and return value of fetch_item() as const.

Also adapt the variable types in the callers to match this
constification.

Signed-off-by: Thomas Weißschuh <[e-mail]>
---
 drivers/hid/hid-core.c | 12 ++++++------
 include/linux/hid.h    |  2 +-
 2 files changed, 7 insertions(+), 7 deletions(-)

Patch

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 0d2cbe491708..311069588321 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -723,7 +723,7 @@  static void hid_device_release(struct device *dev)
  * items, though they are not used yet.
  */
 
-static u8 *fetch_item(__u8 *start, __u8 *end, struct hid_item *item)
+static const u8 *fetch_item(const __u8 *start, const __u8 *end, struct hid_item *item)
 {
 	u8 b;
 
@@ -880,8 +880,8 @@  static int hid_scan_report(struct hid_device *hid)
 {
 	struct hid_parser *parser;
 	struct hid_item item;
-	__u8 *start = hid->dev_rdesc;
-	__u8 *end = start + hid->dev_rsize;
+	const __u8 *start = hid->dev_rdesc;
+	const __u8 *end = start + hid->dev_rsize;
 	static int (*dispatch_type[])(struct hid_parser *parser,
 				      struct hid_item *item) = {
 		hid_scan_main,
@@ -1204,10 +1204,10 @@  int hid_open_report(struct hid_device *device)
 	struct hid_parser *parser;
 	struct hid_item item;
 	unsigned int size;
-	__u8 *start;
+	const __u8 *start;
 	__u8 *buf;
-	__u8 *end;
-	__u8 *next;
+	const __u8 *end;
+	const __u8 *next;
 	int ret;
 	int i;
 	static int (*dispatch_type[])(struct hid_parser *parser,
diff --git a/include/linux/hid.h b/include/linux/hid.h
index dda34d8cad19..502bbc6f078c 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -46,7 +46,7 @@  struct hid_item {
 	    __s16  s16;
 	    __u32  u32;
 	    __s32  s32;
-	    __u8  *longdata;
+	    const __u8  *longdata;
 	} data;
 };