From: Mark Rutland mark.rutland@arm.com
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 --- drivers/char/random.c | 34 ++++++++++++++++++++++------------ 1 file changed, 22 insertions(+), 12 deletions(-)
--- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -783,27 +783,37 @@ static int __init parse_trust_cpu(char * } 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 && crng == &primary_crng) { + + 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; @@ -854,7 +864,7 @@ static void do_numa_crng_init(struct wor 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() */ @@ -1792,7 +1802,7 @@ 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;