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-rw-r--r--drivers/char/random.c56
1 files changed, 39 insertions, 17 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c
index fa5bbd5a7ca0..799d37981d99 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -436,6 +436,7 @@ static void _extract_crng(struct crng_state *crng,
static void _crng_backtrack_protect(struct crng_state *crng,
__u8 tmp[CHACHA20_BLOCK_SIZE], int used);
static void process_random_ready_list(void);
+static void _get_random_bytes(void *buf, int nbytes);
/**********************************************************************
*
@@ -776,7 +777,7 @@ static void crng_initialize(struct crng_state *crng)
_extract_entropy(&input_pool, &crng->state[4],
sizeof(__u32) * 12, 0);
else
- get_random_bytes(&crng->state[4], sizeof(__u32) * 12);
+ _get_random_bytes(&crng->state[4], sizeof(__u32) * 12);
for (i = 4; i < 16; i++) {
if (!arch_get_random_seed_long(&rv) &&
!arch_get_random_long(&rv))
@@ -1466,6 +1467,30 @@ static ssize_t extract_entropy_user(struct entropy_store *r, void __user *buf,
return ret;
}
+#define warn_unseeded_randomness(previous) \
+ _warn_unseeded_randomness(__func__, (void *) _RET_IP_, (previous))
+
+static void _warn_unseeded_randomness(const char *func_name, void *caller,
+ void **previous)
+{
+#ifdef CONFIG_WARN_ALL_UNSEEDED_RANDOM
+ const bool print_once = false;
+#else
+ static bool print_once __read_mostly;
+#endif
+
+ if (print_once ||
+ crng_ready() ||
+ (previous && (caller == READ_ONCE(*previous))))
+ return;
+ WRITE_ONCE(*previous, caller);
+#ifndef CONFIG_WARN_ALL_UNSEEDED_RANDOM
+ print_once = true;
+#endif
+ pr_notice("random: %s called from %pF with crng_init=%d\n",
+ func_name, caller, crng_init);
+}
+
/*
* This function is the exported kernel interface. It returns some
* number of good random numbers, suitable for key generation, seeding
@@ -1476,15 +1501,10 @@ static ssize_t extract_entropy_user(struct entropy_store *r, void __user *buf,
* wait_for_random_bytes() should be called and return 0 at least once
* at any point prior.
*/
-void get_random_bytes(void *buf, int nbytes)
+static void _get_random_bytes(void *buf, int nbytes)
{
__u8 tmp[CHACHA20_BLOCK_SIZE];
-#ifdef CONFIG_WARN_UNSEEDED_RANDOM
- if (!crng_ready())
- printk(KERN_NOTICE "random: %pF get_random_bytes called "
- "with crng_init = %d\n", (void *) _RET_IP_, crng_init);
-#endif
trace_get_random_bytes(nbytes, _RET_IP_);
while (nbytes >= CHACHA20_BLOCK_SIZE) {
@@ -1501,6 +1521,14 @@ void get_random_bytes(void *buf, int nbytes)
crng_backtrack_protect(tmp, CHACHA20_BLOCK_SIZE);
memzero_explicit(tmp, sizeof(tmp));
}
+
+void get_random_bytes(void *buf, int nbytes)
+{
+ static void *previous;
+
+ warn_unseeded_randomness(&previous);
+ _get_random_bytes(buf, nbytes);
+}
EXPORT_SYMBOL(get_random_bytes);
/*
@@ -2064,6 +2092,7 @@ u64 get_random_u64(void)
bool use_lock = READ_ONCE(crng_init) < 2;
unsigned long flags = 0;
struct batched_entropy *batch;
+ static void *previous;
#if BITS_PER_LONG == 64
if (arch_get_random_long((unsigned long *)&ret))
@@ -2074,11 +2103,7 @@ u64 get_random_u64(void)
return ret;
#endif
-#ifdef CONFIG_WARN_UNSEEDED_RANDOM
- if (!crng_ready())
- printk(KERN_NOTICE "random: %pF get_random_u64 called "
- "with crng_init = %d\n", (void *) _RET_IP_, crng_init);
-#endif
+ warn_unseeded_randomness(&previous);
batch = &get_cpu_var(batched_entropy_u64);
if (use_lock)
@@ -2102,15 +2127,12 @@ u32 get_random_u32(void)
bool use_lock = READ_ONCE(crng_init) < 2;
unsigned long flags = 0;
struct batched_entropy *batch;
+ static void *previous;
if (arch_get_random_int(&ret))
return ret;
-#ifdef CONFIG_WARN_UNSEEDED_RANDOM
- if (!crng_ready())
- printk(KERN_NOTICE "random: %pF get_random_u32 called "
- "with crng_init = %d\n", (void *) _RET_IP_, crng_init);
-#endif
+ warn_unseeded_randomness(&previous);
batch = &get_cpu_var(batched_entropy_u32);
if (use_lock)