[PATCH] randomize_range: use random long instead of int

From: william.c.roberts@intel.com
To: linux-mm@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: linux@arm.linux.org.uk, akpm@linux-foundation.org,
	keescook@chromium.org, tytso@mit.edu, arnd@arndb.de,
	gregkh@linuxfoundation.org, catalin.marinas@arm.com,
	will.deacon@arm.com, ralf@linux-mips.org,
	benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au,
	davem@davemloft.net, tglx@linutronix.de, mingo@redhat.com,
	hpa@zytor.com, x86@kernel.org, viro@zeniv.linux.org.uk,
	nnk@google.com, jeffv@google.com, salyzyn@android.com,
	dcashman@android.com,
	William Roberts <william.c.roberts@intel.com>
Subject: [PATCH] randomize_range: use random long instead of int
Date: Mon, 25 Jul 2016 11:25:41 -0700	[thread overview]
Message-ID: <1469471141-25669-1-git-send-email-william.c.roberts@intel.com> (raw)

From: William Roberts <william.c.roberts@intel.com>

Use a long when generating the random range rather than
an int. This will produce better random distributions as
well as matching all the types at hand.

Signed-off-by: William Roberts <william.c.roberts@intel.com>
---
 drivers/char/random.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/char/random.c b/drivers/char/random.c
index 0158d3b..bbf11b5 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -1837,7 +1837,8 @@ randomize_range(unsigned long start, unsigned long end, unsigned long len)
 
 	if (end <= start + len)
 		return 0;
-	return PAGE_ALIGN(get_random_int() % range + start);
+
+	return PAGE_ALIGN(get_random_long() % range + start);
 }
 
 /* Interface for in-kernel drivers of true hardware RNGs.
-- 
1.9.1
