Re: [PATCH] drivers: pci: Fix flexible array usage

[Keith Busch <kbusch@kernel.org>]

On Mon, Feb 10, 2025 at 06:57:40PM +0530, Purva Yeshi wrote:
> Fix warning detected by smatch tool:
> Array of flexible structure occurs in 'pci_saved_state' struct
> 
> The warning occurs because struct pci_saved_state contains struct
> pci_cap_saved_data cap[], where cap[] has a flexible array member (data[]).
> Arrays of structures with flexible members are not allowed, leading to this
> warning.
> 
> Replaced cap[] with a pointer (*cap), allowing dynamic memory allocation
> instead of embedding an invalid array of flexible structures.
> 
> Signed-off-by: Purva Yeshi <purvayeshi550@gmail.com>
> ---
>  drivers/pci/pci.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 869d204a7..648a080ef 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -1929,7 +1929,7 @@ EXPORT_SYMBOL(pci_restore_state);
>  
>  struct pci_saved_state {
>  	u32 config_space[16];
> -	struct pci_cap_saved_data cap[];
> +	struct pci_cap_saved_data *cap;
>  };

I don't think this is right. Previously the space for "cap" was
allocated at the end of the pci_saved_state, but now it's just an
uninitialized pointer.