Re: [PATCH] gpio: uniphier: Replace zero-length array with flexible-array member
From: Masahiro Yamada <masahiroy@kernel.org>
Date: 2020-02-18 01:25:50
Also in:
linux-gpio, lkml
On Wed, Feb 12, 2020 at 6:03 AM Gustavo A. R. Silva [off-list ref] wrote:
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertenly introduced[3] to the codebase from now on.
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <redacted>Acked-by: Masahiro Yamada <redacted>
quoted hunk ↗ jump to hunk
--- drivers/gpio/gpio-uniphier.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)diff --git a/drivers/gpio/gpio-uniphier.c b/drivers/gpio/gpio-uniphier.c index 0f662b297a95..9843638d99d0 100644 --- a/drivers/gpio/gpio-uniphier.c +++ b/drivers/gpio/gpio-uniphier.c@@ -33,7 +33,7 @@ struct uniphier_gpio_priv { struct irq_domain *domain; void __iomem *regs; spinlock_t lock; - u32 saved_vals[0]; + u32 saved_vals[]; }; static unsigned int uniphier_gpio_bank_to_reg(unsigned int bank) --2.25.0
-- Best Regards Masahiro Yamada _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel