Rather than polling every second, use the new notifier to do this at exactly the right moment. Cc: Mike Galbraith <efault@xxxxxx> Cc: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> Cc: Petr Mladek <pmladek@xxxxxxxx> Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx> --- lib/vsprintf.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 24f37bab8bc1..890607b32235 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -41,6 +41,7 @@ #include <linux/siphash.h> #include <linux/compiler.h> #include <linux/property.h> +#include <linux/notifier.h> #ifdef CONFIG_BLOCK #include <linux/blkdev.h> #endif @@ -752,26 +753,21 @@ early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable); static bool filled_random_ptr_key __read_mostly; static siphash_key_t ptr_key __read_mostly; -static void fill_ptr_key_workfn(struct work_struct *work); -static DECLARE_DELAYED_WORK(fill_ptr_key_work, fill_ptr_key_workfn); -static void fill_ptr_key_workfn(struct work_struct *work) +static int fill_ptr_key(struct notifier_block *nb, unsigned long action, void *data) { - if (!rng_is_initialized()) { - queue_delayed_work(system_unbound_wq, &fill_ptr_key_work, HZ * 2); - return; - } - get_random_bytes(&ptr_key, sizeof(ptr_key)); /* Pairs with smp_rmb() before reading ptr_key. */ smp_wmb(); WRITE_ONCE(filled_random_ptr_key, true); + return 0; } static int __init vsprintf_init_hashval(void) { - fill_ptr_key_workfn(NULL); + static struct notifier_block fill_ptr_key_nb = { .notifier_call = fill_ptr_key }; + execute_with_initialized_rng(&fill_ptr_key_nb); return 0; } subsys_initcall(vsprintf_init_hashval) -- 2.38.1