random: mark bootloader randomness code as __init

add_bootloader_randomness() and the variables it touches are only used
during __init and not after, so mark these as __init. At the same time,
unexport this, since it's only called by other __init code that's
built-in.

Cc: stable@vger.kernel.org
Fixes: 428826f5 ("fdt: add support for rng-seed")
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

drivers/char/random.c

@@ -725,8 +725,8 @@ static void __cold _credit_init_bits(size_t bits)
  **********************************************************************/
 
 static bool used_arch_random;
-static bool trust_cpu __ro_after_init = IS_ENABLED(CONFIG_RANDOM_TRUST_CPU);
-static bool trust_bootloader __ro_after_init = IS_ENABLED(CONFIG_RANDOM_TRUST_BOOTLOADER);
+static bool trust_cpu __initdata = IS_ENABLED(CONFIG_RANDOM_TRUST_CPU);
+static bool trust_bootloader __initdata = IS_ENABLED(CONFIG_RANDOM_TRUST_BOOTLOADER);
 static int __init parse_trust_cpu(char *arg)
 {
 	return kstrtobool(arg, &trust_cpu);
@@ -865,13 +865,12 @@ EXPORT_SYMBOL_GPL(add_hwgenerator_randomness);
  * Handle random seed passed by bootloader, and credit it if
  * CONFIG_RANDOM_TRUST_BOOTLOADER is set.
  */
-void __cold add_bootloader_randomness(const void *buf, size_t len)
+void __init add_bootloader_randomness(const void *buf, size_t len)
 {
 	mix_pool_bytes(buf, len);
 	if (trust_bootloader)
 		credit_init_bits(len * 8);
 }
-EXPORT_SYMBOL_GPL(add_bootloader_randomness);
 
 #if IS_ENABLED(CONFIG_VMGENID)
 static BLOCKING_NOTIFIER_HEAD(vmfork_chain);

include/linux/random.h

@@ -13,7 +13,7 @@
 struct notifier_block;
 
 void add_device_randomness(const void *buf, size_t len);
-void add_bootloader_randomness(const void *buf, size_t len);
+void __init add_bootloader_randomness(const void *buf, size_t len);
 void add_input_randomness(unsigned int type, unsigned int code,
 			  unsigned int value) __latent_entropy;
 void add_interrupt_randomness(int irq) __latent_entropy;