thinkpad-acpi: lock down size of hotkey keymap

Use a safer coding style for the hotkey keymap.  This does not fix any
problems, as the current code is correct.  But it might help avoid
mistakes in the future.

Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

1 files changed, 15 insertions, 4 deletions

diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
index b9430e887e9..b0b66fbd796 100644
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -1911,6 +1911,17 @@ enum {	/* hot key scan codes (derived from ACPI DSDT) */
         TP_ACPI_HOTKEYSCAN_VOLUMEDOWN,
         TP_ACPI_HOTKEYSCAN_MUTE,
         TP_ACPI_HOTKEYSCAN_THINKPAD,
+        TP_ACPI_HOTKEYSCAN_UNK1,
+        TP_ACPI_HOTKEYSCAN_UNK2,
+        TP_ACPI_HOTKEYSCAN_UNK3,
+        TP_ACPI_HOTKEYSCAN_UNK4,
+        TP_ACPI_HOTKEYSCAN_UNK5,
+        TP_ACPI_HOTKEYSCAN_UNK6,
+        TP_ACPI_HOTKEYSCAN_UNK7,
+        TP_ACPI_HOTKEYSCAN_UNK8,
+
+        /* Hotkey keymap size */
+        TPACPI_HOTKEY_MAP_LEN
 };
 
 enum {  /* Keys/events available through NVRAM polling */
@@ -3113,7 +3124,7 @@ static int __init hotkey_init(struct ibm_init_struct *iibm)
          * If the above is too much to ask, don't change the keymap.
          * Ask the thinkpad-acpi maintainer to do it, instead.
          */
-        static u16 ibm_keycode_map[] __initdata = {
+        static u16 ibm_keycode_map[TPACPI_HOTKEY_MAP_LEN] __initdata = {
                 /* Scan Codes 0x00 to 0x0B: ACPI HKEY FN+F1..F12 */
                 KEY_FN_F1,      KEY_FN_F2,      KEY_COFFEE,     KEY_SLEEP,
                 KEY_WLAN,       KEY_FN_F6, KEY_SWITCHVIDEOMODE, KEY_FN_F8,
@@ -3147,7 +3158,7 @@ static int __init hotkey_init(struct ibm_init_struct *iibm)
                 KEY_UNKNOWN, KEY_UNKNOWN, KEY_UNKNOWN, KEY_UNKNOWN,
                 KEY_UNKNOWN, KEY_UNKNOWN, KEY_UNKNOWN, KEY_UNKNOWN,
         };
-        static u16 lenovo_keycode_map[] __initdata = {
+        static u16 lenovo_keycode_map[TPACPI_HOTKEY_MAP_LEN] __initdata = {
                 /* Scan Codes 0x00 to 0x0B: ACPI HKEY FN+F1..F12 */
                 KEY_FN_F1,      KEY_COFFEE,     KEY_BATTERY,    KEY_SLEEP,
                 KEY_WLAN,       KEY_FN_F6, KEY_SWITCHVIDEOMODE, KEY_FN_F8,
@@ -3191,7 +3202,6 @@ static int __init hotkey_init(struct ibm_init_struct *iibm)
                 KEY_UNKNOWN, KEY_UNKNOWN, KEY_UNKNOWN, KEY_UNKNOWN,
         };
 
-#define TPACPI_HOTKEY_MAP_LEN           ARRAY_SIZE(ibm_keycode_map)
 #define TPACPI_HOTKEY_MAP_SIZE          sizeof(ibm_keycode_map)
 #define TPACPI_HOTKEY_MAP_TYPESIZE      sizeof(ibm_keycode_map[0])
 
@@ -3469,7 +3479,8 @@ static bool hotkey_notify_hotkey(const u32 hkey,
         *send_acpi_ev = true;
         *ignore_acpi_ev = false;
 
-        if (scancode > 0 && scancode < 0x21) {
+        /* HKEY event 0x1001 is scancode 0x00 */
+        if (scancode > 0 && scancode <= TPACPI_HOTKEY_MAP_LEN) {
                 scancode--;
                 if (!(hotkey_source_mask & (1 << scancode))) {
                         tpacpi_input_send_key_masked(scancode);