iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

random: account for arch randomness in bits

Browse Source 
commit 77fc95f8c0dc9e1f8e620ec14d2fb65028fb7adc upstream.

Rather than accounting in bytes and multiplying (shifting), we can just
account in bits and avoid the shift. The main motivation for this is
there are other patches in flux that expand this code a bit, and
avoiding the duplication of "* 8" everywhere makes things a bit clearer.

Cc: stable@vger.kernel.org
Fixes: 12e45a2a6308 ("random: credit architectural init the exact amount")
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jason A. Donenfeld 2022-06-13 10:07:49 +02:00 committed by Greg Kroah-Hartman
parent e59a120f2d
commit 51e5572724
1 changed files with 4 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
drivers/char/random.c
View File

@ -813,7 +813,7 @@ early_param("random.trust_bootloader", parse_trust_bootloader);
int __init random_init(const char *command_line)
{
ktime_t now = ktime_get_real();
unsigned int i, arch_bytes;
unsigned int i, arch_bits;
unsigned long entropy;
#if defined(LATENT_ENTROPY_PLUGIN)
@ -821,12 +821,12 @@ int __init random_init(const char *command_line)
_mix_pool_bytes(compiletime_seed, sizeof(compiletime_seed));
#endif
for (i = 0, arch_bytes = BLAKE2S_BLOCK_SIZE;
for (i = 0, arch_bits = BLAKE2S_BLOCK_SIZE * 8;
i < BLAKE2S_BLOCK_SIZE; i += sizeof(entropy)) {
if (!arch_get_random_seed_long_early(&entropy) &&
!arch_get_random_long_early(&entropy)) {
entropy = random_get_entropy();
arch_bytes -= sizeof(entropy);
arch_bits -= sizeof(entropy) * 8;
}
_mix_pool_bytes(&entropy, sizeof(entropy));
}
@ -838,7 +838,7 @@ int __init random_init(const char *command_line)
if (crng_ready())
crng_reseed();
else if (trust_cpu)
_credit_init_bits(arch_bytes * 8);
_credit_init_bits(arch_bits);
return 0;
}