random: convert get_random_int/long into get_random_u32/u64

Many times, when a user wants a random number, he wants a random number
of a guaranteed size. So, thinking of get_random_int and get_random_long
in terms of get_random_u32 and get_random_u64 makes it much easier to
achieve this. It also makes the code simpler.

On 32-bit platforms, get_random_int and get_random_long are both aliased
to get_random_u32. On 64-bit platforms, int->u32 and long->u64.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

1 files changed, 27 insertions, 28 deletions

diff --git a/drivers/char/random.c b/drivers/char/random.c
index b800e5479b7d..066ae125f2c8 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -2018,8 +2018,8 @@ struct ctl_table random_table[] = {
 
 struct batched_entropy {
         union {
-                unsigned long entropy_long[CHACHA20_BLOCK_SIZE / sizeof(unsigned long)];
-                unsigned int entropy_int[CHACHA20_BLOCK_SIZE / sizeof(unsigned int)];
+                u64 entropy_u64[CHACHA20_BLOCK_SIZE / sizeof(u64)];
+                u32 entropy_u32[CHACHA20_BLOCK_SIZE / sizeof(u32)];
         };
         unsigned int position;
 };
@@ -2029,52 +2029,51 @@ struct batched_entropy {
  * number is either as good as RDRAND or as good as /dev/urandom, with the
  * goal of being quite fast and not depleting entropy.
  */
-static DEFINE_PER_CPU(struct batched_entropy, batched_entropy_long);
-unsigned long get_random_long(void)
+static DEFINE_PER_CPU(struct batched_entropy, batched_entropy_u64);
+u64 get_random_u64(void)
 {
-        unsigned long ret;
+        u64 ret;
         struct batched_entropy *batch;
 
-        if (arch_get_random_long(&ret))
+#if BITS_PER_LONG == 64
+        if (arch_get_random_long((unsigned long *)&ret))
                 return ret;
+#else
+        if (arch_get_random_long((unsigned long *)&ret) &&
+            arch_get_random_long((unsigned long *)&ret + 1))
+            return ret;
+#endif
 
-        batch = &get_cpu_var(batched_entropy_long);
-        if (batch->position % ARRAY_SIZE(batch->entropy_long) == 0) {
-                extract_crng((u8 *)batch->entropy_long);
+        batch = &get_cpu_var(batched_entropy_u64);
+        if (batch->position % ARRAY_SIZE(batch->entropy_u64) == 0) {
+                extract_crng((u8 *)batch->entropy_u64);
                 batch->position = 0;
         }
-        ret = batch->entropy_long[batch->position++];
-        put_cpu_var(batched_entropy_long);
+        ret = batch->entropy_u64[batch->position++];
+        put_cpu_var(batched_entropy_u64);
         return ret;
 }
-EXPORT_SYMBOL(get_random_long);
+EXPORT_SYMBOL(get_random_u64);
 
-#if BITS_PER_LONG == 32
-unsigned int get_random_int(void)
-{
-        return get_random_long();
-}
-#else
-static DEFINE_PER_CPU(struct batched_entropy, batched_entropy_int);
-unsigned int get_random_int(void)
+static DEFINE_PER_CPU(struct batched_entropy, batched_entropy_u32);
+u32 get_random_u32(void)
 {
-        unsigned int ret;
+        u32 ret;
         struct batched_entropy *batch;
 
         if (arch_get_random_int(&ret))
                 return ret;
 
-        batch = &get_cpu_var(batched_entropy_int);
-        if (batch->position % ARRAY_SIZE(batch->entropy_int) == 0) {
-                extract_crng((u8 *)batch->entropy_int);
+        batch = &get_cpu_var(batched_entropy_u32);
+        if (batch->position % ARRAY_SIZE(batch->entropy_u32) == 0) {
+                extract_crng((u8 *)batch->entropy_u32);
                 batch->position = 0;
         }
-        ret = batch->entropy_int[batch->position++];
-        put_cpu_var(batched_entropy_int);
+        ret = batch->entropy_u32[batch->position++];
+        put_cpu_var(batched_entropy_u32);
         return ret;
 }
-#endif
-EXPORT_SYMBOL(get_random_int);
+EXPORT_SYMBOL(get_random_u32);
 
 /**
  * randomize_page - Generate a random, page aligned address