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-rw-r--r--drivers/char/mem.c4
-rw-r--r--drivers/char/random.c25
2 files changed, 19 insertions, 10 deletions
diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index 54b86490d..9f1caa7eb 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -893,8 +893,8 @@ static const struct memdev {
#endif
[5] = { "zero", 0666, &zero_fops, 0 },
[7] = { "full", 0666, &full_fops, 0 },
- [8] = { "random", 0666, &random_fops, 0 },
- [9] = { "urandom", 0666, &urandom_fops, 0 },
+ [8] = { "random", 0666, &random_fops, FMODE_NOWAIT },
+ [9] = { "urandom", 0666, &urandom_fops, FMODE_NOWAIT },
#ifdef CONFIG_PRINTK
[11] = { "kmsg", 0644, &kmsg_fops, 0 },
#endif
diff --git a/drivers/char/random.c b/drivers/char/random.c
index 2be38780a..6aea12fa4 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -890,20 +890,23 @@ void __init add_bootloader_randomness(const void *buf, size_t len)
}
struct fast_pool {
- struct work_struct mix;
unsigned long pool[4];
unsigned long last;
unsigned int count;
+ struct timer_list mix;
};
+static void mix_interrupt_randomness(struct timer_list *work);
+
static DEFINE_PER_CPU(struct fast_pool, irq_randomness) = {
#ifdef CONFIG_64BIT
#define FASTMIX_PERM SIPHASH_PERMUTATION
- .pool = { SIPHASH_CONST_0, SIPHASH_CONST_1, SIPHASH_CONST_2, SIPHASH_CONST_3 }
+ .pool = { SIPHASH_CONST_0, SIPHASH_CONST_1, SIPHASH_CONST_2, SIPHASH_CONST_3 },
#else
#define FASTMIX_PERM HSIPHASH_PERMUTATION
- .pool = { HSIPHASH_CONST_0, HSIPHASH_CONST_1, HSIPHASH_CONST_2, HSIPHASH_CONST_3 }
+ .pool = { HSIPHASH_CONST_0, HSIPHASH_CONST_1, HSIPHASH_CONST_2, HSIPHASH_CONST_3 },
#endif
+ .mix = __TIMER_INITIALIZER(mix_interrupt_randomness, 0)
};
/*
@@ -945,7 +948,7 @@ int __cold random_online_cpu(unsigned int cpu)
}
#endif
-static void mix_interrupt_randomness(struct work_struct *work)
+static void mix_interrupt_randomness(struct timer_list *work)
{
struct fast_pool *fast_pool = container_of(work, struct fast_pool, mix);
/*
@@ -976,7 +979,7 @@ static void mix_interrupt_randomness(struct work_struct *work)
local_irq_enable();
mix_pool_bytes(pool, sizeof(pool));
- credit_init_bits(max(1u, (count & U16_MAX) / 64));
+ credit_init_bits(clamp_t(unsigned int, (count & U16_MAX) / 64, 1, sizeof(pool) * 8));
memzero_explicit(pool, sizeof(pool));
}
@@ -999,10 +1002,11 @@ void add_interrupt_randomness(int irq)
if (new_count < 1024 && !time_is_before_jiffies(fast_pool->last + HZ))
return;
- if (unlikely(!fast_pool->mix.func))
- INIT_WORK(&fast_pool->mix, mix_interrupt_randomness);
fast_pool->count |= MIX_INFLIGHT;
- queue_work_on(raw_smp_processor_id(), system_highpri_wq, &fast_pool->mix);
+ if (!timer_pending(&fast_pool->mix)) {
+ fast_pool->mix.expires = jiffies;
+ add_timer_on(&fast_pool->mix, raw_smp_processor_id());
+ }
}
EXPORT_SYMBOL_GPL(add_interrupt_randomness);
@@ -1294,6 +1298,11 @@ static ssize_t random_read_iter(struct kiocb *kiocb, struct iov_iter *iter)
{
int ret;
+ if (!crng_ready() &&
+ ((kiocb->ki_flags & IOCB_NOWAIT) ||
+ (kiocb->ki_filp->f_flags & O_NONBLOCK)))
+ return -EAGAIN;
+
ret = wait_for_random_bytes();
if (ret != 0)
return ret;