mirrors
/
linux-stable
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
1
0
Fork 0
Code Issues Releases Wiki Activity

random: account for arch randomness in bits 

commit 77fc95f8c0 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: 12e45a2a63 ("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 56023044b9
commit 9c6c4fca64
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;
}