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path: root/drivers/char/random.c
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Diffstat (limited to 'drivers/char/random.c')
-rw-r--r--drivers/char/random.c14
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c
index 8c7444857a4b..d8a9255e1a3f 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -240,6 +240,7 @@
#include <linux/spinlock.h>
#include <linux/percpu.h>
#include <linux/cryptohash.h>
+#include <linux/fips.h>
#ifdef CONFIG_GENERIC_HARDIRQS
# include <linux/irq.h>
@@ -413,6 +414,7 @@ struct entropy_store {
unsigned add_ptr;
int entropy_count;
int input_rotate;
+ __u8 *last_data;
};
static __u32 input_pool_data[INPUT_POOL_WORDS];
@@ -852,12 +854,21 @@ static ssize_t extract_entropy(struct entropy_store *r, void *buf,
{
ssize_t ret = 0, i;
__u8 tmp[EXTRACT_SIZE];
+ unsigned long flags;
xfer_secondary_pool(r, nbytes);
nbytes = account(r, nbytes, min, reserved);
while (nbytes) {
extract_buf(r, tmp);
+
+ if (r->last_data) {
+ spin_lock_irqsave(&r->lock, flags);
+ if (!memcmp(tmp, r->last_data, EXTRACT_SIZE))
+ panic("Hardware RNG duplicated output!\n");
+ memcpy(r->last_data, tmp, EXTRACT_SIZE);
+ spin_unlock_irqrestore(&r->lock, flags);
+ }
i = min_t(int, nbytes, EXTRACT_SIZE);
memcpy(buf, tmp, i);
nbytes -= i;
@@ -940,6 +951,9 @@ static void init_std_data(struct entropy_store *r)
now = ktime_get_real();
mix_pool_bytes(r, &now, sizeof(now));
mix_pool_bytes(r, utsname(), sizeof(*(utsname())));
+ /* Enable continuous test in fips mode */
+ if (fips_enabled)
+ r->last_data = kmalloc(EXTRACT_SIZE, GFP_KERNEL);
}
static int rand_initialize(void)