@@ -53,6 +53,7 @@
#include <linux/uuid.h>
#include <linux/siphash.h>
#include <linux/uio.h>
+#include <linux/locallock.h>
#include <crypto/chacha20.h>
#include <crypto/blake2s.h>
#include <asm/processor.h>
@@ -230,10 +231,12 @@ static struct {
struct crng {
u8 key[CHACHA20_KEY_SIZE];
unsigned long generation;
+ struct local_irq_lock lock;
};
static DEFINE_PER_CPU(struct crng, crngs) = {
- .generation = ULONG_MAX
+ .generation = ULONG_MAX,
+ .lock.lock = __SPIN_LOCK_UNLOCKED(crngs.lock.lock),
};
/* Used by crng_reseed() and crng_make_state() to extract a new seed from the input pool. */
@@ -363,7 +366,7 @@ static void crng_make_state(u32 chacha_state[CHACHA20_BLOCK_SIZE / sizeof(u32)],
if (unlikely(crng_has_old_seed()))
crng_reseed();
- local_irq_save(flags);
+ local_lock_irqsave(crngs.lock, flags);
crng = raw_cpu_ptr(&crngs);
/*
@@ -388,7 +391,7 @@ static void crng_make_state(u32 chacha_state[CHACHA20_BLOCK_SIZE / sizeof(u32)],
* should wind up here immediately.
*/
crng_fast_key_erasure(crng->key, chacha_state, random_data, random_data_len);
- local_irq_restore(flags);
+ local_unlock_irqrestore(crngs.lock, flags);
}
static void _get_random_bytes(void *buf, size_t len)
@@ -506,11 +509,13 @@ struct batch_ ##type { \
* formula of (integer_blocks + 0.5) * CHACHA20_BLOCK_SIZE. \
*/ \
type entropy[CHACHA20_BLOCK_SIZE * 3 / (2 * sizeof(type))]; \
+ struct local_irq_lock lock; \
unsigned long generation; \
unsigned int position; \
}; \
\
static DEFINE_PER_CPU(struct batch_ ##type, batched_entropy_ ##type) = { \
+ .lock.lock = __SPIN_LOCK_UNLOCKED(batched_entropy_ ##type.lock.lock), \
.position = UINT_MAX \
}; \
\
@@ -528,7 +533,7 @@ type get_random_ ##type(void) \
return ret; \
} \
\
- local_irq_save(flags); \
+ local_lock_irqsave(batched_entropy_ ##type.lock, flags); \
batch = raw_cpu_ptr(&batched_entropy_##type); \
\
next_gen = READ_ONCE(base_crng.generation); \
@@ -542,7 +547,7 @@ type get_random_ ##type(void) \
ret = batch->entropy[batch->position]; \
batch->entropy[batch->position] = 0; \
++batch->position; \
- local_irq_restore(flags); \
+ local_unlock_irqrestore(batched_entropy_ ##type.lock, flags); \
return ret; \
} \
EXPORT_SYMBOL(get_random_ ##type);
As part of the backports the random code lost its local_lock_t type and the whole operation became a local_irq_{disable|enable}() simply because the older kernel did not provide those primitives. RT as of v4.9 has a slightly different variant of local_locks. Replace the local_irq_*() operations with matching local_lock_irq*() operations which were there as part of commit 77760fd7f7ae3 ("random: remove batched entropy locking") Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> --- drivers/char/random.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-)