From 0f3ef390d863b432fdd18f2e281688c0efa096b8 Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" Date: Tue, 1 Mar 2022 20:03:49 +0100 Subject: random: replace custom notifier chain with standard one commit 5acd35487dc911541672b3ffc322851769c32a56 upstream. We previously rolled our own randomness readiness notifier, which only has two users in the whole kernel. Replace this with a more standard atomic notifier block that serves the same purpose with less code. Also unexport the symbols, because no modules use it, only unconditional builtins. The only drawback is that it's possible for a notification handler returning the "stop" code to prevent further processing, but given that there are only two users, and that we're unexporting this anyway, that doesn't seem like a significant drawback for the simplification we receive here. Cc: Greg Kroah-Hartman Cc: Theodore Ts'o Reviewed-by: Dominik Brodowski [Jason: for stable, also backported to crypto/drbg.c, not unexporting.] Signed-off-by: Jason A. Donenfeld Signed-off-by: Greg Kroah-Hartman --- crypto/drbg.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) diff --git a/crypto/drbg.c b/crypto/drbg.c index 04379ca6..7c8d9ac9 100644 --- a/crypto/drbg.c +++ b/crypto/drbg.c @@ -1478,12 +1478,13 @@ static int drbg_generate_long(struct drbg_state *drbg, return 0; } -static void drbg_schedule_async_seed(struct random_ready_callback *rdy) +static int drbg_schedule_async_seed(struct notifier_block *nb, unsigned long action, void *data) { - struct drbg_state *drbg = container_of(rdy, struct drbg_state, + struct drbg_state *drbg = container_of(nb, struct drbg_state, random_ready); schedule_work(&drbg->seed_work); + return 0; } static int drbg_prepare_hrng(struct drbg_state *drbg) @@ -1496,10 +1497,8 @@ static int drbg_prepare_hrng(struct drbg_state *drbg) INIT_WORK(&drbg->seed_work, drbg_async_seed); - drbg->random_ready.owner = THIS_MODULE; - drbg->random_ready.func = drbg_schedule_async_seed; - - err = add_random_ready_callback(&drbg->random_ready); + drbg->random_ready.notifier_call = drbg_schedule_async_seed; + err = register_random_ready_notifier(&drbg->random_ready); switch (err) { case 0: @@ -1510,7 +1509,7 @@ static int drbg_prepare_hrng(struct drbg_state *drbg) /* fall through */ default: - drbg->random_ready.func = NULL; + drbg->random_ready.notifier_call = NULL; return err; } @@ -1616,8 +1615,8 @@ free_everything: */ static int drbg_uninstantiate(struct drbg_state *drbg) { - if (drbg->random_ready.func) { - del_random_ready_callback(&drbg->random_ready); + if (drbg->random_ready.notifier_call) { + unregister_random_ready_notifier(&drbg->random_ready); cancel_work_sync(&drbg->seed_work); crypto_free_rng(drbg->jent); drbg->jent = NULL; -- cgit v1.2.3