2:49 a.m.
Am Freitag, 18. September 2020, 15:02:17 CEST schrieb kernel test robot:
Hi,
All errors (new ones prefixed by >>):
>> drivers/char/lrng/lrng_chacha20.c:33:8: error: structure variable
>> 'chacha20' with 'latent_entropy' attribute has a non-integer
field
>> 'block'
33 | struct chacha20_state chacha20 __latent_entropy;
| ^~~~~~~~~~~~~~
#
https://github.com/0day-ci/linux/commit/ecb964754fd80cca434d6d2ad6db8f28a15
92fa1 git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review
Stephan-M-ller/dev-random-a-new-approach/20200918-181505 git checkout
ecb964754fd80cca434d6d2ad6db8f28a1592fa1
vim +33 drivers/char/lrng/lrng_chacha20.c
27
28 /*
29 * Have a static memory blocks for the ChaCha20 DRNG instance to
avoid calling 30 * kmalloc too early in the boot cycle. For
subsequent
allocation requests, 31 * such as per-NUMA-node DRNG instances,
kmalloc
will be used. 32 */
> 33 struct chacha20_state chacha20 __latent_entropy;
I do not think this report is valid. The following definitions apply:
struct chacha20_state {
struct chacha20_block block;
};
struct chacha20_block {
u32 constants[4];
union {
#define CHACHA_KEY_SIZE_WORDS (CHACHA_KEY_SIZE / sizeof(u32))
u32 u[CHACHA_KEY_SIZE_WORDS];
u8 b[CHACHA_KEY_SIZE];
} key;
u32 counter;
u32 nonce[3];
};
This implies that struct chacha20_state and thus the chacha20 variable is a
linear buffer with in total 4 + 8 + 1 + 3 = 16 32-bit integers which are at
least aligned on a 32-bit boundary and are designated as u32 integers.
Please let me know if I need to make a tweak to the definitions to convince
the code analyzer it is a flat linear buffer consisting of integers and thus
to understand the structure correctly.
Thanks a lot.
Ciao
Stephan