diff options
| -rw-r--r-- | drivers/char/random.c | 1 | ||||
| -rw-r--r-- | include/linux/random.h | 3 | ||||
| -rw-r--r-- | kernel/time/timer.c | 8 | ||||
| -rw-r--r-- | lib/random32.c | 2 |
4 files changed, 13 insertions, 1 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c index 8ff28c14af7e..e877c20e0ee0 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1330,6 +1330,7 @@ void add_interrupt_randomness(int irq, int irq_flags) fast_mix(fast_pool); add_interrupt_bench(cycles); + this_cpu_add(net_rand_state.s1, fast_pool->pool[cycles & 3]); if (unlikely(crng_init == 0)) { if ((fast_pool->count >= 64) && diff --git a/include/linux/random.h b/include/linux/random.h index f189c927fdea..4d080e5ef6eb 100644 --- a/include/linux/random.h +++ b/include/linux/random.h @@ -9,6 +9,7 @@ #include <linux/list.h> #include <linux/once.h> +#include <linux/percpu.h> #include <uapi/linux/random.h> @@ -117,6 +118,8 @@ struct rnd_state { __u32 s1, s2, s3, s4; }; +DECLARE_PER_CPU(struct rnd_state, net_rand_state) __latent_entropy; + u32 prandom_u32_state(struct rnd_state *state); void prandom_bytes_state(struct rnd_state *state, void *buf, size_t nbytes); void prandom_seed_full_state(struct rnd_state __percpu *pcpu_state); diff --git a/kernel/time/timer.c b/kernel/time/timer.c index 1e9b81a930c0..a3ae244b1bcd 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -43,6 +43,7 @@ #include <linux/sched/debug.h> #include <linux/slab.h> #include <linux/compat.h> +#include <linux/random.h> #include <linux/uaccess.h> #include <asm/unistd.h> @@ -1742,6 +1743,13 @@ void update_process_times(int user_tick) scheduler_tick(); if (IS_ENABLED(CONFIG_POSIX_TIMERS)) run_posix_cpu_timers(); + + /* The current CPU might make use of net randoms without receiving IRQs + * to renew them often enough. Let's update the net_rand_state from a + * non-constant value that's not affine to the number of calls to make + * sure it's updated when there's some activity (we don't care in idle). + */ + this_cpu_add(net_rand_state.s1, rol32(jiffies, 24) + user_tick); } /** diff --git a/lib/random32.c b/lib/random32.c index 763b920a6206..c4d317be2997 100644 --- a/lib/random32.c +++ b/lib/random32.c @@ -48,7 +48,7 @@ static inline void prandom_state_selftest(void) } #endif -static DEFINE_PER_CPU(struct rnd_state, net_rand_state) __latent_entropy; +DEFINE_PER_CPU(struct rnd_state, net_rand_state) __latent_entropy; /** * prandom_u32_state - seeded pseudo-random number generator. |