gpio: uniphier: Replace zero-length array with flexible-array member
Subsystems (2)
PATCH 1/1 gpio: uniphier: Replace zero-length array with flexible-array member
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")
--- drivers/gpio/gpio-uniphier.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/gpio/gpio-uniphier.c +1 -1
@@ -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)
Signature · 1 line
2.25.0
wt., 11 lut 2020 o 22:03 Gustavo A. R. Silva <[email protected]> napisał(a):
Quoted 16 lines
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.
Quoted 7 lines
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] commit76497732932f("cxgb3/l2t: Fix undefined behaviour")Signed-off-by Gustavo A. R. Silva <[email protected]>
Patch applied, thanks!
Bartosz
Quoted 16 lines · Gustavo A. R. Silva
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.
Quoted 7 lines
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] commit76497732932f("cxgb3/l2t: Fix undefined behaviour")Signed-off-by Gustavo A. R. Silva <[email protected]>
Quoted 20 lines
--- drivers/gpio/gpio-uniphier.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)drivers/gpio/gpio-uniphier.c +1
-2@@ -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
Signature · 2 lines
Best Regards Masahiro Yamada