From 316ef2c7e41960f38fd358c35310c3aedc958035 Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" Date: Wed, 12 Jan 2022 15:22:30 +0100 Subject: [PATCH] random: remove incomplete last_data logic There were a few things added under the "if (fips_enabled)" banner, which never really got completed, and the FIPS people anyway are choosing a different direction. Rather than keep around this halfbaked code, get rid of it so that we can focus on a single design of the RNG rather than two designs. Reviewed-by: Dominik Brodowski Signed-off-by: Jason A. Donenfeld --- drivers/char/random.c | 39 ++++----------------------------------- 1 file changed, 4 insertions(+), 35 deletions(-) diff --git a/drivers/char/random.c b/drivers/char/random.c index 8b7567b5a6e6f..07354e2283412 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -337,7 +337,6 @@ #include #include #include -#include #include #include #include @@ -517,14 +516,12 @@ struct entropy_store { u16 add_ptr; u16 input_rotate; int entropy_count; - unsigned int last_data_init:1; - u8 last_data[EXTRACT_SIZE]; }; static ssize_t extract_entropy(struct entropy_store *r, void *buf, size_t nbytes, int min, int rsvd); static ssize_t _extract_entropy(struct entropy_store *r, void *buf, - size_t nbytes, int fips); + size_t nbytes); static void crng_reseed(struct crng_state *crng, struct entropy_store *r); static u32 input_pool_data[INPUT_POOL_WORDS] __latent_entropy; @@ -821,7 +818,7 @@ static void crng_initialize_secondary(struct crng_state *crng) static void __init crng_initialize_primary(struct crng_state *crng) { - _extract_entropy(&input_pool, &crng->state[4], sizeof(u32) * 12, 0); + _extract_entropy(&input_pool, &crng->state[4], sizeof(u32) * 12); if (crng_init_try_arch_early(crng) && trust_cpu && crng_init < 2) { invalidate_batched_entropy(); numa_crng_init(); @@ -1426,22 +1423,13 @@ static void extract_buf(struct entropy_store *r, u8 *out) } static ssize_t _extract_entropy(struct entropy_store *r, void *buf, - size_t nbytes, int fips) + size_t nbytes) { ssize_t ret = 0, i; u8 tmp[EXTRACT_SIZE]; - unsigned long flags; while (nbytes) { extract_buf(r, tmp); - - if (fips) { - spin_lock_irqsave(&r->lock, flags); - if (!memcmp(tmp, r->last_data, EXTRACT_SIZE)) - panic("Hardware RNG duplicated output!\n"); - memcpy(r->last_data, tmp, EXTRACT_SIZE); - spin_unlock_irqrestore(&r->lock, flags); - } i = min_t(int, nbytes, EXTRACT_SIZE); memcpy(buf, tmp, i); nbytes -= i; @@ -1467,28 +1455,9 @@ static ssize_t _extract_entropy(struct entropy_store *r, void *buf, static ssize_t extract_entropy(struct entropy_store *r, void *buf, size_t nbytes, int min, int reserved) { - u8 tmp[EXTRACT_SIZE]; - unsigned long flags; - - /* if last_data isn't primed, we need EXTRACT_SIZE extra bytes */ - if (fips_enabled) { - spin_lock_irqsave(&r->lock, flags); - if (!r->last_data_init) { - r->last_data_init = 1; - spin_unlock_irqrestore(&r->lock, flags); - trace_extract_entropy(r->name, EXTRACT_SIZE, - ENTROPY_BITS(r), _RET_IP_); - extract_buf(r, tmp); - spin_lock_irqsave(&r->lock, flags); - memcpy(r->last_data, tmp, EXTRACT_SIZE); - } - spin_unlock_irqrestore(&r->lock, flags); - } - trace_extract_entropy(r->name, nbytes, ENTROPY_BITS(r), _RET_IP_); nbytes = account(r, nbytes, min, reserved); - - return _extract_entropy(r, buf, nbytes, fips_enabled); + return _extract_entropy(r, buf, nbytes); } #define warn_unseeded_randomness(previous) \ -- 2.39.5