Commit fed2ef7a authored by Kees Cook's avatar Kees Cook
Browse files

reset: Annotate struct reset_control_array with __counted_by 

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 reset_control_array.
Additionally, since the element count member must be set before accessing
the annotated flexible array member, move its initialization earlier.

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



Cc: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: default avatar"Gustavo A. R. Silva" <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20230922175229.work.838-kees@kernel.org


Signed-off-by: default avatarKees Cook <keescook@chromium.org>
parent 15fcedd4

drivers/reset/core.c

+2 −2
Original line number Diff line number Diff line
@@ -60,7 +60,7 @@ struct reset_control { 
struct reset_control_array {

	struct reset_control base;

	unsigned int num_rstcs;

	struct reset_control *rstc[];

	struct reset_control *rstc[] __counted_by(num_rstcs);

};



static const char *rcdev_name(struct reset_controller_dev *rcdev)
@@ -1185,6 +1185,7 @@ of_reset_control_array_get(struct device_node *np, bool shared, bool optional, 
	resets = kzalloc(struct_size(resets, rstc, num), GFP_KERNEL);

	if (!resets)

		return ERR_PTR(-ENOMEM);

	resets->num_rstcs = num;



	for (i = 0; i < num; i++) {

		rstc = __of_reset_control_get(np, NULL, i, shared, optional,
@@ -1193,7 +1194,6 @@ of_reset_control_array_get(struct device_node *np, bool shared, bool optional, 
			goto err_rst;

		resets->rstc[i] = rstc;

	}

	resets->num_rstcs = num;

	resets->base.array = true;



	return &resets->base;