From: Kees Cook <keescook@chromium.org>
To: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc: Kees Cook <keescook@chromium.org>,
	Nicolas Ferre <nicolas.ferre@microchip.com>,
	Alexandre Belloni <alexandre.belloni@bootlin.com>,
	Claudiu Beznea <claudiu.beznea@tuxon.dev>,
	linux-arm-kernel@lists.infradead.org,
	Nathan Chancellor <nathan@kernel.org>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Tom Rix <trix@redhat.com>,
	linux-kernel@vger.kernel.org,
	llvm@lists.linux.dev,
	linux-hardening@vger.kernel.org
Subject: [PATCH] memory: atmel-ebi: Annotate struct atmel_ebi_dev with __counted_by
Date: Fri, 22 Sep 2023 10:52:15 -0700
Message-Id: <20230922175215.work.122-kees@kernel.org>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit

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 atmel_ebi_dev.

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

Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Claudiu Beznea <claudiu.beznea@tuxon.dev>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/memory/atmel-ebi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/memory/atmel-ebi.c b/drivers/memory/atmel-ebi.c
index 635966d705cb..ec6100bc94c5 100644
--- a/drivers/memory/atmel-ebi.c
+++ b/drivers/memory/atmel-ebi.c
@@ -30,7 +30,7 @@ struct atmel_ebi_dev {
 	struct atmel_ebi *ebi;
 	u32 mode;
 	int numcs;
-	struct atmel_ebi_dev_config configs[];
+	struct atmel_ebi_dev_config configs[] __counted_by(numcs);
 };
 
 struct atmel_ebi_caps {
-- 
2.34.1