Re: [PATCH] amba: tegra-ahb: Replace zero-length array with flexible-array member

From: Gustavo A. R. Silva
Date: Thu Mar 19 2020 - 16:03:59 EST


Hi all,

Friendly ping (second time): Who can take this?

Thanks
--
Gustavo

On 2/27/20 1:33 PM, Gustavo A. R. Silva wrote:
> Hi all,
>
> Friendly ping: Who can take this?
>
> Thanks
> --
> Gustavo
>
> On 2/11/20 15:02, Gustavo A. R. Silva 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.
>>
>> [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 <gustavo@xxxxxxxxxxxxxx>
>> ---
>> drivers/amba/tegra-ahb.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/amba/tegra-ahb.c b/drivers/amba/tegra-ahb.c
>> index b0b688c481e8..e9e5c7bb580c 100644
>> --- a/drivers/amba/tegra-ahb.c
>> +++ b/drivers/amba/tegra-ahb.c
>> @@ -129,7 +129,7 @@ static const u32 tegra_ahb_gizmo[] = {
>> struct tegra_ahb {
>> void __iomem *regs;
>> struct device *dev;
>> - u32 ctx[0];
>> + u32 ctx[];
>> };
>>
>> static inline u32 gizmo_readl(struct tegra_ahb *ahb, u32 offset)
>>