Re: [kbuild-all] Re: [PATCH v43 01/15] Linux Random Number Generator

On 11/22/2021 7:47 PM, Stephan Mueller wrote:

Am Montag, 22. November 2021, 11:33:26 CET schrieb kernel test robot:

Hi,

quoted

All errors (new ones prefixed by >>):

quoted

quoted

drivers/char/lrng/lrng_chacha20.c:32:8: error: structure variable
'chacha20' with 'latent_entropy' attribute has a non-integer field
'block'

       32 | struct chacha20_state chacha20 __latent_entropy;

          |        ^~~~~~~~~~~~~~

vim +32 drivers/char/lrng/lrng_chacha20.c

Thanks for the notification.

I think this is a false-positive discussed before. __latent_entropy is
seemingly allowed for an entire linear buffer as seen in the declaration of
the variable input_pool_data in driver/char/random.c which is an array of u32.

The struct chacha20_state is a linear buffer of u32 words.

struct chacha20_block {
         u32 constants[4];
         union {
                 u32 u[CHACHA_KEY_SIZE_WORDS];
                 u8  b[CHACHA_KEY_SIZE];
         } key;
         u32 counter;
         u32 nonce[3];
};

Therefore it should be identical to the aforementioned example. The
__latent_entropy marker therefore seems to be appropriate for this structure.

Ciao
Stephan

Hi Stephan,

Thanks for the explanation, we'll add the error to the ignore list.

Best Regards,
Rong Chen