bianbu-repo-mirror/bianbu-linux-6.6
1
0
Fork 0
mirror of https://gitee.com/bianbu-linux/linux-6.6 synced 2025-07-04 00:03:25 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions

random: credit architectural init the exact amount

Browse source 
RDRAND and RDSEED can fail sometimes, which is fine. We currently
initialize the RNG with 512 bits of RDRAND/RDSEED. We only need 256 bits
of those to succeed in order to initialize the RNG. Instead of the
current "all or nothing" approach, actually credit these contributions
the amount that is actually contributed.

Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
This commit is contained in:
Jason A. Donenfeld 2022-05-12 15:32:26 +02:00
parent 2f14062bb1
commit 12e45a2a63
1 changed files with 6 additions and 6 deletions
Download patch file Download diff file Expand all files Collapse all files

12
drivers/char/random.c
View file

@ -927,9 +927,8 @@ static struct notifier_block pm_notifier = { .notifier_call = random_pm_notifica
*/ */
int __init random_init(const char *command_line) int __init random_init(const char *command_line)
{ {
size_t i;
ktime_t now = ktime_get_real(); ktime_t now = ktime_get_real();
bool arch_init = true; unsigned int i, arch_bytes;
unsigned long rv; unsigned long rv;
#if defined(LATENT_ENTROPY_PLUGIN) #if defined(LATENT_ENTROPY_PLUGIN)
@ -937,11 +936,12 @@ int __init random_init(const char *command_line)
_mix_pool_bytes(compiletime_seed, sizeof(compiletime_seed)); _mix_pool_bytes(compiletime_seed, sizeof(compiletime_seed));
#endif #endif
for (i = 0; i < BLAKE2S_BLOCK_SIZE; i += sizeof(rv)) { for (i = 0, arch_bytes = BLAKE2S_BLOCK_SIZE;
i < BLAKE2S_BLOCK_SIZE; i += sizeof(rv)) {
if (!arch_get_random_seed_long_early(&rv) && if (!arch_get_random_seed_long_early(&rv) &&
!arch_get_random_long_early(&rv)) { !arch_get_random_long_early(&rv)) {
rv = random_get_entropy(); rv = random_get_entropy();
arch_init = false; arch_bytes -= sizeof(rv);
} }
_mix_pool_bytes(&rv, sizeof(rv)); _mix_pool_bytes(&rv, sizeof(rv));
} }
@ -952,8 +952,8 @@ int __init random_init(const char *command_line)
if (crng_ready()) if (crng_ready())
crng_reseed(); crng_reseed();
else if (arch_init && trust_cpu) else if (trust_cpu)
credit_init_bits(BLAKE2S_BLOCK_SIZE * 8); credit_init_bits(arch_bytes * 8);
WARN_ON(register_pm_notifier(&pm_notifier)); WARN_ON(register_pm_notifier(&pm_notifier));