4.4.97-rt111-rc1 stable review patch. If anyone has any objections, please let me know. ------------------ From: Sebastian Andrzej Siewior extract_crng() will use sleeping locks while in a preempt_disable() section due to get_cpu_var(). Work around it with local_locks. Cc: stable-rt@vger.kernel.org # where it applies to Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Steven Rostedt (VMware) --- drivers/char/random.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/char/random.c b/drivers/char/random.c index fecc40a69df8..b41745c5962c 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -260,6 +260,7 @@ #include #include #include +#include #include #include @@ -1796,6 +1797,7 @@ int random_int_secret_init(void) static DEFINE_PER_CPU(__u32 [MD5_DIGEST_WORDS], get_random_int_hash) __aligned(sizeof(unsigned long)); +static DEFINE_LOCAL_IRQ_LOCK(hash_entropy_int_lock); /* * Get a random word for internal kernel use only. Similar to urandom but @@ -1811,12 +1813,12 @@ unsigned int get_random_int(void) if (arch_get_random_int(&ret)) return ret; - hash = get_cpu_var(get_random_int_hash); + hash = &get_locked_var(hash_entropy_int_lock, get_random_int_hash); hash[0] += current->pid + jiffies + random_get_entropy(); md5_transform(hash, random_int_secret); ret = hash[0]; - put_cpu_var(get_random_int_hash); + put_locked_var(hash_entropy_int_lock, get_random_int_hash); return ret; } @@ -1833,12 +1835,12 @@ unsigned long get_random_long(void) if (arch_get_random_long(&ret)) return ret; - hash = get_cpu_var(get_random_int_hash); + hash = &get_locked_var(hash_entropy_int_lock, get_random_int_hash); hash[0] += current->pid + jiffies + random_get_entropy(); md5_transform(hash, random_int_secret); ret = *(unsigned long *)hash; - put_cpu_var(get_random_int_hash); + put_locked_var(hash_entropy_int_lock, get_random_int_hash); return ret; } -- 2.13.2