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random: inline leaves of rand_initialize()

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This is a preparatory commit for the following one. We simply inline the
various functions that rand_initialize() calls that have no other
callers. The compiler was doing this anyway before. Doing this will
allow us to reorganize this after. We can then move the trust_cpu and
parse_trust_cpu definitions a bit closer to where they're actually used,
which makes the code easier to read.

Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
This commit is contained in:
Jason A. Donenfeld 2022-02-08 12:40:14 +01:00
parent a9412d510a
commit 8566417221
1 changed files with 34 additions and 58 deletions
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92
drivers/char/random.c
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@ -476,42 +476,6 @@ static DECLARE_WAIT_QUEUE_HEAD(crng_init_wait);
static void invalidate_batched_entropy(void);
static bool trust_cpu __ro_after_init = IS_ENABLED(CONFIG_RANDOM_TRUST_CPU);
static int __init parse_trust_cpu(char *arg)
{
return kstrtobool(arg, &trust_cpu);
}
early_param("random.trust_cpu", parse_trust_cpu);
static bool __init crng_init_try_arch_early(void)
{
int i;
bool arch_init = true;
unsigned long rv;
for (i = 4; i < 16; i++) {
if (!arch_get_random_seed_long_early(&rv) &&
!arch_get_random_long_early(&rv)) {
rv = random_get_entropy();
arch_init = false;
}
primary_crng.state[i] ^= rv;
}
return arch_init;
}
static void __init crng_initialize(void)
{
extract_entropy(&primary_crng.state[4], sizeof(u32) * 12);
if (crng_init_try_arch_early() && trust_cpu && crng_init < 2) {
invalidate_batched_entropy();
crng_init = 2;
pr_notice("crng init done (trusting CPU's manufacturer)\n");
}
primary_crng.init_time = jiffies - CRNG_RESEED_INTERVAL - 1;
}
/*
* crng_fast_load() can be called by code in the interrupt service
* path. So we can't afford to dilly-dally. Returns the number of
@ -1220,28 +1184,12 @@ int __must_check get_random_bytes_arch(void *buf, int nbytes)
}
EXPORT_SYMBOL(get_random_bytes_arch);
/*
* init_std_data - initialize pool with system data
*
* This function clears the pool's entropy count and mixes some system
* data into the pool to prepare it for use. The pool is not cleared
* as that can only decrease the entropy in the pool.
*/
static void __init init_std_data(void)
static bool trust_cpu __ro_after_init = IS_ENABLED(CONFIG_RANDOM_TRUST_CPU);
static int __init parse_trust_cpu(char *arg)
{
int i;
ktime_t now = ktime_get_real();
unsigned long rv;
mix_pool_bytes(&now, sizeof(now));
for (i = BLAKE2S_BLOCK_SIZE; i > 0; i -= sizeof(rv)) {
if (!arch_get_random_seed_long(&rv) &&
!arch_get_random_long(&rv))
rv = random_get_entropy();
mix_pool_bytes(&rv, sizeof(rv));
}
mix_pool_bytes(utsname(), sizeof(*(utsname())));
return kstrtobool(arg, &trust_cpu);
}
early_param("random.trust_cpu", parse_trust_cpu);
/*
* Note that setup_arch() may call add_device_randomness()
@ -1255,8 +1203,36 @@ static void __init init_std_data(void)
*/
int __init rand_initialize(void)
{
init_std_data();
crng_initialize();
int i;
ktime_t now = ktime_get_real();
bool arch_init = true;
unsigned long rv;
mix_pool_bytes(&now, sizeof(now));
for (i = BLAKE2S_BLOCK_SIZE; i > 0; i -= sizeof(rv)) {
if (!arch_get_random_seed_long(&rv) &&
!arch_get_random_long(&rv))
rv = random_get_entropy();
mix_pool_bytes(&rv, sizeof(rv));
}
mix_pool_bytes(utsname(), sizeof(*(utsname())));
extract_entropy(&primary_crng.state[4], sizeof(u32) * 12);
for (i = 4; i < 16; i++) {
if (!arch_get_random_seed_long_early(&rv) &&
!arch_get_random_long_early(&rv)) {
rv = random_get_entropy();
arch_init = false;
}
primary_crng.state[i] ^= rv;
}
if (arch_init && trust_cpu && crng_init < 2) {
invalidate_batched_entropy();
crng_init = 2;
pr_notice("crng init done (trusting CPU's manufacturer)\n");
}
primary_crng.init_time = jiffies - CRNG_RESEED_INTERVAL - 1;
if (ratelimit_disable) {
urandom_warning.interval = 0;
unseeded_warning.interval = 0;