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Subject[PATCH 4.19 084/234] random: inline leaves of rand_initialize()
Date
From: "Jason A. Donenfeld" <Jason@zx2c4.com>

commit 8566417221fcec51346ec164e920dacb979c6b5f upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/char/random.c | 90 ++++++++++++++++++--------------------------------
1 file changed, 33 insertions(+), 57 deletions(-)

--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -476,42 +476,6 @@ static DECLARE_WAIT_QUEUE_HEAD(crng_init

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
@@ -1220,17 +1184,28 @@ int __must_check get_random_bytes_arch(v
}
EXPORT_SYMBOL(get_random_bytes_arch);

+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);
+
/*
- * 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.
+ * Note that setup_arch() may call add_device_randomness()
+ * long before we get here. This allows seeding of the pools
+ * with some platform dependent data very early in the boot
+ * process. But it limits our options here. We must use
+ * statically allocated structures that already have all
+ * initializations complete at compile time. We should also
+ * take care not to overwrite the precious per platform data
+ * we were given.
*/
-static void __init init_std_data(void)
+int __init rand_initialize(void)
{
int i;
ktime_t now = ktime_get_real();
+ bool arch_init = true;
unsigned long rv;

mix_pool_bytes(&now, sizeof(now));
@@ -1241,22 +1216,23 @@ static void __init init_std_data(void)
mix_pool_bytes(&rv, sizeof(rv));
}
mix_pool_bytes(utsname(), sizeof(*(utsname())));
-}

-/*
- * Note that setup_arch() may call add_device_randomness()
- * long before we get here. This allows seeding of the pools
- * with some platform dependent data very early in the boot
- * process. But it limits our options here. We must use
- * statically allocated structures that already have all
- * initializations complete at compile time. We should also
- * take care not to overwrite the precious per platform data
- * we were given.
- */
-int __init rand_initialize(void)
-{
- init_std_data();
- crng_initialize();
+ 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;

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