Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

As found with Coccinelle[1], add __counted_by for struct ec_event_queue.

[1] 
https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Benson Leung <[email protected]>
Cc: Tzung-Bi Shih <[email protected]>
Cc: Dawei Li <[email protected]>
Cc: Dmitry Torokhov <[email protected]>
Cc: Maximilian Luz <[email protected]>
Cc: "Uwe Kleine-König" <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Jiang Jian <[email protected]>
Cc: [email protected]
Signed-off-by: Kees Cook <[email protected]>
---
 drivers/platform/chrome/wilco_ec/event.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/platform/chrome/wilco_ec/event.c 
b/drivers/platform/chrome/wilco_ec/event.c
index a40f60bcefb6..f80a7c83cfba 100644
--- a/drivers/platform/chrome/wilco_ec/event.c
+++ b/drivers/platform/chrome/wilco_ec/event.c
@@ -95,7 +95,7 @@ struct ec_event_queue {
        int capacity;
        int head;
        int tail;
-       struct ec_event *entries[];
+       struct ec_event *entries[] __counted_by(capacity);
 };
 
 /* Maximum number of events to store in ec_event_queue */
-- 
2.34.1


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