static void crng_reseed(struct crng_state *crng, struct entropy_store *r);
static void push_to_pool(struct work_struct *work);
-static __u32 input_pool_data[INPUT_POOL_WORDS];
-static __u32 blocking_pool_data[OUTPUT_POOL_WORDS];
+static __u32 input_pool_data[INPUT_POOL_WORDS] __latent_entropy;
+static __u32 blocking_pool_data[OUTPUT_POOL_WORDS] __latent_entropy;
static struct entropy_store input_pool = {
.poolinfo = &poolinfo_table[0],
}
EXPORT_SYMBOL(get_random_long);
-/*
- * randomize_range() returns a start address such that
+/**
+ * randomize_page - Generate a random, page aligned address
+ * @start: The smallest acceptable address the caller will take.
+ * @range: The size of the area, starting at @start, within which the
+ * random address must fall.
+ *
+ * If @start + @range would overflow, @range is capped.
*
- * [...... <range> .....]
- * start end
+ * NOTE: Historical use of randomize_range, which this replaces, presumed that
+ * @start was already page aligned. We now align it regardless.
*
- * a <range> with size "len" starting at the return value is inside in the
- * area defined by [start, end], but is otherwise randomized.
+ * Return: A page aligned address within [start, start + range). On error,
+ * @start is returned.
*/
unsigned long
-randomize_range(unsigned long start, unsigned long end, unsigned long len)
+randomize_page(unsigned long start, unsigned long range)
{
- unsigned long range = end - len - start;
+ if (!PAGE_ALIGNED(start)) {
+ range -= PAGE_ALIGN(start) - start;
+ start = PAGE_ALIGN(start);
+ }
- if (end <= start + len)
- return 0;
- return PAGE_ALIGN(get_random_int() % range + start);
+ if (start > ULONG_MAX - range)
+ range = ULONG_MAX - start;
+
+ range >>= PAGE_SHIFT;
+
+ if (range == 0)
+ return start;
+
+ return start + (get_random_long() % range << PAGE_SHIFT);
}
/* Interface for in-kernel drivers of true hardware RNGs.