From 473becac4b310dd720a0f5e07ce149a09467f1a4 Mon Sep 17 00:00:00 2001 From: Miaoqing Pan Date: Tue, 27 Jun 2017 17:31:54 +0300 Subject: [PATCH] ath9k: avoid potential freezing during random generator read In the worst case, ath9k_rng_stop() may take 10s to stop rng kthread. The time is too long for users, use wait_event_interruptible_timeout() instead of msleep_interruptible(), wakup immediately once kthread_should_stop() is true. Signed-off-by: Miaoqing Pan Signed-off-by: Kalle Valo --- drivers/net/wireless/ath/ath9k/rng.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/ath/ath9k/rng.c b/drivers/net/wireless/ath/ath9k/rng.c index 73f46fb3e83a..f9d3d6eedd3c 100644 --- a/drivers/net/wireless/ath/ath9k/rng.c +++ b/drivers/net/wireless/ath/ath9k/rng.c @@ -24,6 +24,8 @@ #define ATH9K_RNG_BUF_SIZE 320 #define ATH9K_RNG_ENTROPY(x) (((x) * 8 * 10) >> 5) /* quality: 10/32 */ +static DECLARE_WAIT_QUEUE_HEAD(rng_queue); + static int ath9k_rng_data_read(struct ath_softc *sc, u32 *buf, u32 buf_size) { int i, j; @@ -85,7 +87,9 @@ static int ath9k_rng_kthread(void *data) ATH9K_RNG_BUF_SIZE); if (unlikely(!bytes_read)) { delay = ath9k_rng_delay_get(++fail_stats); - msleep_interruptible(delay); + wait_event_interruptible_timeout(rng_queue, + kthread_should_stop(), + msecs_to_jiffies(delay)); continue; }