X-Git-Url: https://git.karo-electronics.de/?a=blobdiff_plain;f=drivers%2Fchar%2Frandom.c;h=1ef26403bcc83f6a0c26f20d67b74e7fe6331635;hb=bb1181c9a8b46b6f10e749d9ed94480336445d7f;hp=3efb3bf0ab839578156e33907eb20c741c08155f;hpb=2161a2a644a6d33a29d68395518d103ed805758f;p=karo-tx-linux.git

diff --git a/drivers/char/random.c b/drivers/char/random.c
index 3efb3bf0ab83..1ef26403bcc8 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -265,7 +265,7 @@
 #include <crypto/chacha20.h>
 
 #include <asm/processor.h>
-#include <asm/uaccess.h>
+#include <linux/uaccess.h>
 #include <asm/irq.h>
 #include <asm/irq_regs.h>
 #include <asm/io.h>
@@ -479,8 +479,8 @@ static ssize_t _extract_entropy(struct entropy_store *r, void *buf,
 
 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],
@@ -2100,23 +2100,37 @@ unsigned long get_random_long(void)
 }
 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.