diff options
| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2017-05-12 15:46:17 +0200 |
|---|---|---|
| committer | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2018-10-29 18:20:20 +0100 |
| commit | 8cedb96a0df6c976bcd4bc3f20d7cdec07593628 (patch) | |
| tree | 5322ea4f7a67a490d4ab89136447eae48c4c45dd /drivers/char | |
| parent | fc79dea1e61b8bf477f5b7581db063dfea51ec3c (diff) | |
random: avoid preempt_disable()ed section
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 <bigeasy@linutronix.de>
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/random.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c index 4c20da67edd5..91c1972b6a17 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -265,6 +265,7 @@ #include <linux/syscalls.h> #include <linux/completion.h> #include <linux/uuid.h> +#include <linux/locallock.h> #include <crypto/chacha20.h> #include <asm/processor.h> @@ -2223,6 +2224,7 @@ static rwlock_t batched_entropy_reset_lock = __RW_LOCK_UNLOCKED(batched_entropy_ * at any point prior. */ static DEFINE_PER_CPU(struct batched_entropy, batched_entropy_u64); +static DEFINE_LOCAL_IRQ_LOCK(batched_entropy_u64_lock); u64 get_random_u64(void) { u64 ret; @@ -2243,7 +2245,7 @@ u64 get_random_u64(void) warn_unseeded_randomness(&previous); use_lock = READ_ONCE(crng_init) < 2; - batch = &get_cpu_var(batched_entropy_u64); + batch = &get_locked_var(batched_entropy_u64_lock, batched_entropy_u64); if (use_lock) read_lock_irqsave(&batched_entropy_reset_lock, flags); if (batch->position % ARRAY_SIZE(batch->entropy_u64) == 0) { @@ -2253,12 +2255,13 @@ u64 get_random_u64(void) ret = batch->entropy_u64[batch->position++]; if (use_lock) read_unlock_irqrestore(&batched_entropy_reset_lock, flags); - put_cpu_var(batched_entropy_u64); + put_locked_var(batched_entropy_u64_lock, batched_entropy_u64); return ret; } EXPORT_SYMBOL(get_random_u64); static DEFINE_PER_CPU(struct batched_entropy, batched_entropy_u32); +static DEFINE_LOCAL_IRQ_LOCK(batched_entropy_u32_lock); u32 get_random_u32(void) { u32 ret; @@ -2273,7 +2276,7 @@ u32 get_random_u32(void) warn_unseeded_randomness(&previous); use_lock = READ_ONCE(crng_init) < 2; - batch = &get_cpu_var(batched_entropy_u32); + batch = &get_locked_var(batched_entropy_u32_lock, batched_entropy_u32); if (use_lock) read_lock_irqsave(&batched_entropy_reset_lock, flags); if (batch->position % ARRAY_SIZE(batch->entropy_u32) == 0) { @@ -2283,7 +2286,7 @@ u32 get_random_u32(void) ret = batch->entropy_u32[batch->position++]; if (use_lock) read_unlock_irqrestore(&batched_entropy_reset_lock, flags); - put_cpu_var(batched_entropy_u32); + put_locked_var(batched_entropy_u32_lock, batched_entropy_u32); return ret; } EXPORT_SYMBOL(get_random_u32); |