irqchip/imx-intmux: Annotate struct intmux_data 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 intmux_data.

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

Cc Thomas Gleixner <[email protected]>

Cc Marc Zyngier <[email protected]>

Cc Shawn Guo <[email protected]>

Cc Sascha Hauer <[email protected]>

Cc Pengutronix Kernel Team <[email protected]>

Cc Fabio Estevam <[email protected]>

Cc NXP Linux Team <[email protected]>

Cc [email protected]

Signed-off-by Kees Cook <[email protected]>

---
  drivers/irqchip/irq-imx-intmux.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

drivers/irqchip/irq-imx-intmux.c +1 -1

index 6d9a08238c9d..aa041e4dfee0 100644
@@ -73,7 +73,7 @@ struct intmux_data {
  	void __iomem			*regs;
  	struct clk			*ipg_clk;
  	int				channum;
-	struct intmux_irqchip_data	irqchip_data[];
+	struct intmux_irqchip_data	irqchip_data[] __counted_by(channum);
  };
 
  static void imx_intmux_irq_mask(struct irq_data *d)

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 intmux_data.

[...]