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random: split primary/secondary crng init paths

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commit 5cbe0f13b51ac2fb2fd55902cff8d0077fc084c0 upstream.

Currently crng_initialize() is used for both the primary CRNG and
secondary CRNGs. While we wish to share common logic, we need to do a
number of additional things for the primary CRNG, and this would be
easier to deal with were these handled in separate functions.

This patch splits crng_initialize() into crng_initialize_primary() and
crng_initialize_secondary(), with common logic factored out into a
crng_init_try_arch() helper.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20200210130015.17664-2-mark.rutland@arm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Mark Rutland 2020-02-10 13:00:12 +00:00 committed by Greg Kroah-Hartman
parent e13ea48b98
commit 3c2691868d
1 changed files with 24 additions and 12 deletions
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36
drivers/char/random.c
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@ -783,27 +783,39 @@ static int __init parse_trust_cpu(char *arg)
}
early_param("random.trust_cpu", parse_trust_cpu);
static void crng_initialize(struct crng_state *crng)
static bool crng_init_try_arch(struct crng_state *crng)
{
int i;
int arch_init = 1;
bool arch_init = true;
unsigned long rv;
memcpy(&crng->state[0], "expand 32-byte k", 16);
if (crng == &primary_crng)
_extract_entropy(&input_pool, &crng->state[4],
sizeof(__u32) * 12, 0);
else
_get_random_bytes(&crng->state[4], sizeof(__u32) * 12);
for (i = 4; i < 16; i++) {
if (!arch_get_random_seed_long(&rv) &&
!arch_get_random_long(&rv)) {
rv = random_get_entropy();
arch_init = 0;
arch_init = false;
}
crng->state[i] ^= rv;
}
if (trust_cpu && arch_init) {
return arch_init;
}
static void crng_initialize_secondary(struct crng_state *crng)
{
memcpy(&crng->state[0], "expand 32-byte k", 16);
_get_random_bytes(&crng->state[4], sizeof(__u32) * 12);
crng_init_try_arch(crng);
crng->init_time = jiffies - CRNG_RESEED_INTERVAL - 1;
}
static void __init crng_initialize_primary(struct crng_state *crng)
{
memcpy(&crng->state[0], "expand 32-byte k", 16);
_extract_entropy(&input_pool, &crng->state[4], sizeof(__u32) * 12, 0);
if (crng_init_try_arch(crng) && trust_cpu) {
invalidate_batched_entropy();
numa_crng_init();
crng_init = 2;
pr_notice("crng done (trusting CPU's manufacturer)\n");
}
@ -852,7 +864,7 @@ static void do_numa_crng_init(struct work_struct *work)
crng = kmalloc_node(sizeof(struct crng_state),
GFP_KERNEL | __GFP_NOFAIL, i);
spin_lock_init(&crng->lock);
crng_initialize(crng);
crng_initialize_secondary(crng);
pool[i] = crng;
}
/* pairs with READ_ONCE() in select_crng() */
@ -1780,7 +1792,7 @@ int __init rand_initialize(void)
init_std_data(&input_pool);
if (crng_need_final_init)
crng_finalize_init(&primary_crng);
crng_initialize(&primary_crng);
crng_initialize_primary(&primary_crng);
crng_global_init_time = jiffies;
if (ratelimit_disable) {
urandom_warning.interval = 0;