From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Andi Kleen <ak@linux.intel.com>
Date: Fri, 13 Oct 2017 14:56:41 -0700
Subject: [PATCH] bitops: Add clear/set_bit32() to linux/bitops.h
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

CVE-2017-5754

Add two simple wrappers around set_bit/clear_bit() that accept
the common case of an u32 array. This avoids writing
casts in all callers.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20171013215645.23166-2-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
(cherry picked from commit cbe96375025e14fc76f9ed42ee5225120d7210f8)
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
(cherry picked from commit 06d31c11519ca0e8f9b7cab857f442ef44dfc1b2)
Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
---
 include/linux/bitops.h | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/include/linux/bitops.h b/include/linux/bitops.h
index a83c822c35c2..eb257a96db6d 100644
--- a/include/linux/bitops.h
+++ b/include/linux/bitops.h
@@ -226,6 +226,32 @@ static inline unsigned long __ffs64(u64 word)
 	return __ffs((unsigned long)word);
 }
 
+/*
+ * clear_bit32 - Clear a bit in memory for u32 array
+ * @nr: Bit to clear
+ * @addr: u32 * address of bitmap
+ *
+ * Same as clear_bit, but avoids needing casts for u32 arrays.
+ */
+
+static __always_inline void clear_bit32(long nr, volatile u32 *addr)
+{
+	clear_bit(nr, (volatile unsigned long *)addr);
+}
+
+/*
+ * set_bit32 - Set a bit in memory for u32 array
+ * @nr: Bit to clear
+ * @addr: u32 * address of bitmap
+ *
+ * Same as set_bit, but avoids needing casts for u32 arrays.
+ */
+
+static __always_inline void set_bit32(long nr, volatile u32 *addr)
+{
+	set_bit(nr, (volatile unsigned long *)addr);
+}
+
 #ifdef __KERNEL__
 
 #ifndef set_mask_bits
-- 
2.14.2

