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gpio: uniphier: Replace zero-length array with flexible-array member

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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 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
This commit is contained in:
Gustavo A. R. Silva
2020-02-11 15:06:18 -06:00
committed by Bartosz Golaszewski
parent 869233f813
commit ec18d7e7d2
1 changed files with 1 additions and 1 deletions
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2
drivers/gpio/gpio-uniphier.c
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@@ -30,7 +30,7 @@ struct uniphier_gpio_priv {
struct irq_domain *domain; struct irq_domain *domain;
void __iomem *regs; void __iomem *regs;
spinlock_t lock; spinlock_t lock;
u32 saved_vals[0]; u32 saved_vals[];
}; };
static unsigned int uniphier_gpio_bank_to_reg(unsigned int bank) static unsigned int uniphier_gpio_bank_to_reg(unsigned int bank)