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authorAlex Shi <alex.shi@linaro.org>2016-09-20 10:17:00 +0800
committerAlex Shi <alex.shi@linaro.org>2016-09-20 10:17:00 +0800
commitd2d693d1ba7d93ec7c5db8aca2da29a4c91f6782 (patch)
tree41920dcc166c491e7192eb1e3ba3861dff479abf /drivers/char/random.c
parent573787341e57a73bf027c2ea3bdf18dc298ae0a0 (diff)
parent1d074db69c46d62ce82b331c2080e2fcb710bf4a (diff)
Merge remote-tracking branch 'lts/linux-4.4.y' into linux-linaro-lsk-v4.4
Conflicts: set ARM64_WORKAROUND_CAVIUM_27456 to 12 in arch/arm64/include/asm/cpufeature.h and add asm/memory.h in arch/arm64/kernel/entry.S
Diffstat (limited to 'drivers/char/random.c')
-rw-r--r--drivers/char/random.c29
1 files changed, 20 insertions, 9 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c
index 0227b0465b40..491a4dce13fe 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -948,6 +948,7 @@ void add_interrupt_randomness(int irq, int irq_flags)
/* award one bit for the contents of the fast pool */
credit_entropy_bits(r, credit + 1);
}
+EXPORT_SYMBOL_GPL(add_interrupt_randomness);
#ifdef CONFIG_BLOCK
void add_disk_randomness(struct gendisk *disk)
@@ -1460,12 +1461,16 @@ random_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos)
static ssize_t
urandom_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos)
{
+ static int maxwarn = 10;
int ret;
- if (unlikely(nonblocking_pool.initialized == 0))
- printk_once(KERN_NOTICE "random: %s urandom read "
- "with %d bits of entropy available\n",
- current->comm, nonblocking_pool.entropy_total);
+ if (unlikely(nonblocking_pool.initialized == 0) &&
+ maxwarn > 0) {
+ maxwarn--;
+ printk(KERN_NOTICE "random: %s: uninitialized urandom read "
+ "(%zd bytes read, %d bits of entropy available)\n",
+ current->comm, nbytes, nonblocking_pool.entropy_total);
+ }
nbytes = min_t(size_t, nbytes, INT_MAX >> (ENTROPY_SHIFT + 3));
ret = extract_entropy_user(&nonblocking_pool, buf, nbytes);
@@ -1847,12 +1852,18 @@ void add_hwgenerator_randomness(const char *buffer, size_t count,
{
struct entropy_store *poolp = &input_pool;
- /* Suspend writing if we're above the trickle threshold.
- * We'll be woken up again once below random_write_wakeup_thresh,
- * or when the calling thread is about to terminate.
- */
- wait_event_interruptible(random_write_wait, kthread_should_stop() ||
+ if (unlikely(nonblocking_pool.initialized == 0))
+ poolp = &nonblocking_pool;
+ else {
+ /* Suspend writing if we're above the trickle
+ * threshold. We'll be woken up again once below
+ * random_write_wakeup_thresh, or when the calling
+ * thread is about to terminate.
+ */
+ wait_event_interruptible(random_write_wait,
+ kthread_should_stop() ||
ENTROPY_BITS(&input_pool) <= random_write_wakeup_bits);
+ }
mix_pool_bytes(poolp, buffer, count);
credit_entropy_bits(poolp, entropy);
}