mirror of
https://github.com/linuxkit/linuxkit.git
synced 2025-10-22 13:12:04 +00:00
75 lines
2.5 KiB
Diff
75 lines
2.5 KiB
Diff
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
|
|
Date: Fri, 12 May 2017 15:46:17 +0200
|
|
Subject: [PATCH] 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>
|
|
---
|
|
drivers/char/random.c | 11 +++++++----
|
|
1 file changed, 7 insertions(+), 4 deletions(-)
|
|
|
|
--- a/drivers/char/random.c
|
|
+++ b/drivers/char/random.c
|
|
@@ -264,6 +264,7 @@
|
|
#include <linux/syscalls.h>
|
|
#include <linux/completion.h>
|
|
#include <linux/uuid.h>
|
|
+#include <linux/locallock.h>
|
|
#include <crypto/chacha20.h>
|
|
|
|
#include <asm/processor.h>
|
|
@@ -2086,6 +2087,7 @@ static rwlock_t batched_entropy_reset_lo
|
|
* 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;
|
|
@@ -2106,7 +2108,7 @@ 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) {
|
|
@@ -2116,12 +2118,13 @@ 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;
|
|
@@ -2136,7 +2139,7 @@ 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) {
|
|
@@ -2146,7 +2149,7 @@ 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);
|