Messages in this thread Patch in this message |  | | From | "Jason A. Donenfeld" <> | Subject | [PATCH v2] random: make consistent usage of crng_ready() | Date | Sat, 12 Mar 2022 17:00:56 -0700 |
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Rather than sometimes checking `crng_init < 2`, we should always use the crng_ready() macro, so that should we change anything later, it's consistent. Additionally, that macro already has a likely() around it, which means we don't need to open code our own likely() and unlikely() annotations.
Cc: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> --- drivers/char/random.c | 19 +++++++------------ 1 file changed, 7 insertions(+), 12 deletions(-)
diff --git a/drivers/char/random.c b/drivers/char/random.c index edb5b06544da..596dc664b5bd 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -123,18 +123,13 @@ static void try_to_generate_entropy(void); */ int wait_for_random_bytes(void) { - if (likely(crng_ready())) - return 0; - - do { + while (!crng_ready()) { int ret; ret = wait_event_interruptible_timeout(crng_init_wait, crng_ready(), HZ); if (ret) return ret > 0 ? 0 : ret; - try_to_generate_entropy(); - } while (!crng_ready()); - + } return 0; } EXPORT_SYMBOL(wait_for_random_bytes); @@ -289,7 +284,7 @@ static void crng_reseed(bool force) ++next_gen; WRITE_ONCE(base_crng.generation, next_gen); WRITE_ONCE(base_crng.birth, jiffies); - if (crng_init < 2) { + if (!crng_ready()) { crng_init = 2; finalize_init = true; } @@ -352,7 +347,7 @@ static void crng_make_state(u32 chacha_state[CHACHA_STATE_WORDS], * ready, we do fast key erasure with the base_crng directly, because * this is what crng_pre_init_inject() mutates during early init. */ - if (unlikely(!crng_ready())) { + if (!crng_ready()) { bool ready; spin_lock_irqsave(&base_crng.lock, flags); @@ -795,7 +790,7 @@ static void credit_entropy_bits(size_t nbits) entropy_count = min_t(unsigned int, POOL_BITS, orig + add); } while (cmpxchg(&input_pool.entropy_count, orig, entropy_count) != orig); - if (crng_init < 2 && entropy_count >= POOL_MIN_BITS) + if (!crng_ready() && entropy_count >= POOL_MIN_BITS) crng_reseed(false); } @@ -957,7 +952,7 @@ int __init rand_initialize(void) extract_entropy(base_crng.key, sizeof(base_crng.key)); ++base_crng.generation; - if (arch_init && trust_cpu && crng_init < 2) { + if (arch_init && trust_cpu && !crng_ready()) { crng_init = 2; pr_notice("crng init done (trusting CPU's manufacturer)\n"); } @@ -1551,7 +1546,7 @@ static long random_ioctl(struct file *f, unsigned int cmd, unsigned long arg) case RNDRESEEDCRNG: if (!capable(CAP_SYS_ADMIN)) return -EPERM; - if (crng_init < 2) + if (!crng_ready()) return -ENODATA; crng_reseed(false); return 0; -- 2.35.1
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