On Fri, Apr 01, 2022 at 07:57:47AM +0000, cgel.zte@xxxxxxxxx wrote:
> From: Lv Ruyi <lv.ruyi@xxxxxxxxxx>
>
> The use of zero-sized array causes undefined behaviour when it is not
> the last member in a structure. As it happens to be in this case.
What do you mean by "undefined behavior" here? How is this working now?
> Also, the current code makes use of a language extension to the C90
> standard, but the preferred mechanism to declare variable-length
> types such as this one is a flexible array member, introduced in
> C99:
>
> struct foo {
> int stuff;
> struct boo array[];
> };
gcc and clang both support [0] for a very long time so this isn't an
issue.
> By making use of the mechanism above, we will get a compiler warning
> in case the flexible array does not occur last. Which is beneficial
> to cultivate a high-quality code.
>
> Reported-by: Zeal Robot <zealci@xxxxxxxxxx>
> Signed-off-by: Lv Ruyi <lv.ruyi@xxxxxxxxxx>
> ---
> drivers/usb/misc/ftdi-elan.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/usb/misc/ftdi-elan.c b/drivers/usb/misc/ftdi-elan.c
> index 6c38c62d29b2..e818d2ed6831 100644
> --- a/drivers/usb/misc/ftdi-elan.c
> +++ b/drivers/usb/misc/ftdi-elan.c
> @@ -171,7 +171,6 @@ struct usb_ftdi {
> struct delayed_work command_work;
> struct delayed_work respond_work;
> struct u132_platform_data platform_data;
> - struct resource resources[0];
> struct platform_device platform_dev;
> unsigned char *bulk_in_buffer;
> size_t bulk_in_size;
> @@ -185,6 +184,7 @@ struct usb_ftdi {
> int expected;
> int received;
> int ed_found;
> + struct resource resources[];
How did you test and verify that this change is correct?
thanks,
greg k-h
