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-rw-r--r--drivers/char/random.c50
-rw-r--r--include/linux/random.h3
-rw-r--r--init/main.c17
3 files changed, 40 insertions, 30 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c
index e591c6aadca4..1427f66252c6 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -772,18 +772,13 @@ static int random_pm_notification(struct notifier_block *nb, unsigned long actio
static struct notifier_block pm_notifier = { .notifier_call = random_pm_notification };
/*
- * The first collection of entropy occurs at system boot while interrupts
- * are still turned off. Here we push in latent entropy, RDSEED, a timestamp,
- * utsname(), and the command line. Depending on the above configuration knob,
- * RDSEED may be considered sufficient for initialization. Note that much
- * earlier setup may already have pushed entropy into the input pool by the
- * time we get here.
+ * This is called extremely early, before time keeping functionality is
+ * available, but arch randomness is. Interrupts are not yet enabled.
*/
-int __init random_init(const char *command_line)
+void __init random_init_early(const char *command_line)
{
- ktime_t now = ktime_get_real();
- size_t i, longs, arch_bits;
unsigned long entropy[BLAKE2S_BLOCK_SIZE / sizeof(long)];
+ size_t i, longs, arch_bits;
#if defined(LATENT_ENTROPY_PLUGIN)
static const u8 compiletime_seed[BLAKE2S_BLOCK_SIZE] __initconst __latent_entropy;
@@ -803,34 +798,49 @@ int __init random_init(const char *command_line)
i += longs;
continue;
}
- entropy[0] = random_get_entropy();
- _mix_pool_bytes(entropy, sizeof(*entropy));
arch_bits -= sizeof(*entropy) * 8;
++i;
}
- _mix_pool_bytes(&now, sizeof(now));
- _mix_pool_bytes(utsname(), sizeof(*(utsname())));
+
_mix_pool_bytes(command_line, strlen(command_line));
+
+ /* Reseed if already seeded by earlier phases. */
+ if (crng_ready())
+ crng_reseed();
+ else if (trust_cpu)
+ _credit_init_bits(arch_bits);
+}
+
+/*
+ * This is called a little bit after the prior function, and now there is
+ * access to timestamps counters. Interrupts are not yet enabled.
+ */
+void __init random_init(void)
+{
+ unsigned long entropy = random_get_entropy();
+ ktime_t now = ktime_get_real();
+
+ _mix_pool_bytes(utsname(), sizeof(*(utsname())));
+ _mix_pool_bytes(&now, sizeof(now));
+ _mix_pool_bytes(&entropy, sizeof(entropy));
add_latent_entropy();
/*
- * If we were initialized by the bootloader before jump labels are
- * initialized, then we should enable the static branch here, where
+ * If we were initialized by the cpu or bootloader before jump labels
+ * are initialized, then we should enable the static branch here, where
* it's guaranteed that jump labels have been initialized.
*/
if (!static_branch_likely(&crng_is_ready) && crng_init >= CRNG_READY)
crng_set_ready(NULL);
+ /* Reseed if already seeded by earlier phases. */
if (crng_ready())
crng_reseed();
- else if (trust_cpu)
- _credit_init_bits(arch_bits);
WARN_ON(register_pm_notifier(&pm_notifier));
- WARN(!random_get_entropy(), "Missing cycle counter and fallback timer; RNG "
- "entropy collection will consequently suffer.");
- return 0;
+ WARN(!entropy, "Missing cycle counter and fallback timer; RNG "
+ "entropy collection will consequently suffer.");
}
/*
diff --git a/include/linux/random.h b/include/linux/random.h
index 3fec206487f6..a9e6e16f9774 100644
--- a/include/linux/random.h
+++ b/include/linux/random.h
@@ -72,7 +72,8 @@ static inline unsigned long get_random_canary(void)
return get_random_long() & CANARY_MASK;
}
-int __init random_init(const char *command_line);
+void __init random_init_early(const char *command_line);
+void __init random_init(void);
bool rng_is_initialized(void);
int wait_for_random_bytes(void);
diff --git a/init/main.c b/init/main.c
index 1fe7942f5d4a..0866e5d0d467 100644
--- a/init/main.c
+++ b/init/main.c
@@ -976,6 +976,9 @@ asmlinkage __visible void __init __no_sanitize_address start_kernel(void)
parse_args("Setting extra init args", extra_init_args,
NULL, 0, -1, -1, NULL, set_init_arg);
+ /* Architectural and non-timekeeping rng init, before allocator init */
+ random_init_early(command_line);
+
/*
* These use large bootmem allocations and must precede
* kmem_cache_init()
@@ -1035,17 +1038,13 @@ asmlinkage __visible void __init __no_sanitize_address start_kernel(void)
hrtimers_init();
softirq_init();
timekeeping_init();
- kfence_init();
time_init();
- /*
- * For best initial stack canary entropy, prepare it after:
- * - setup_arch() for any UEFI RNG entropy and boot cmdline access
- * - timekeeping_init() for ktime entropy used in random_init()
- * - time_init() for making random_get_entropy() work on some platforms
- * - random_init() to initialize the RNG from from early entropy sources
- */
- random_init(command_line);
+ /* This must be after timekeeping is initialized */
+ random_init();
+
+ /* These make use of the fully initialized rng */
+ kfence_init();
boot_init_stack_canary();
perf_event_init();