Patch "lib: lz4: fixed zram with lz4 on big endian machines" has been added to the 4.4-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    lib: lz4: fixed zram with lz4 on big endian machines

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     lib-lz4-fixed-zram-with-lz4-on-big-endian-machines.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 3e26a691fe3fe1e02a76e5bab0c143ace4b137b4 Mon Sep 17 00:00:00 2001
From: Rui Salvaterra <rsalvaterra@gmail.com>
Date: Sat, 9 Apr 2016 22:05:34 +0100
Subject: lib: lz4: fixed zram with lz4 on big endian machines

From: Rui Salvaterra <rsalvaterra@gmail.com>

commit 3e26a691fe3fe1e02a76e5bab0c143ace4b137b4 upstream.

Based on Sergey's test patch [1], this fixes zram with lz4 compression
on big endian cpus.

Note that the 64-bit preprocessor test is not a cleanup, it's part of
the fix, since those identifiers are bogus (for example, __ppc64__
isn't defined anywhere else in the kernel, which means we'd fall into
the 32-bit definitions on ppc64).

Tested on ppc64 with no regression on x86_64.

[1] http://marc.info/?l=linux-kernel&m=145994470805853&w=4

Suggested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Rui Salvaterra <rsalvaterra@gmail.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 lib/lz4/lz4defs.h |   21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

--- a/lib/lz4/lz4defs.h
+++ b/lib/lz4/lz4defs.h
@@ -11,8 +11,7 @@
 /*
  * Detects 64 bits mode
  */
-#if (defined(__x86_64__) || defined(__x86_64) || defined(__amd64__) \
-	|| defined(__ppc64__) || defined(__LP64__))
+#if defined(CONFIG_64BIT)
 #define LZ4_ARCH64 1
 #else
 #define LZ4_ARCH64 0
@@ -35,6 +34,10 @@ typedef struct _U64_S { u64 v; } U64_S;
 
 #define PUT4(s, d) (A32(d) = A32(s))
 #define PUT8(s, d) (A64(d) = A64(s))
+
+#define LZ4_READ_LITTLEENDIAN_16(d, s, p)	\
+	(d = s - A16(p))
+
 #define LZ4_WRITE_LITTLEENDIAN_16(p, v)	\
 	do {	\
 		A16(p) = v; \
@@ -51,10 +54,13 @@ typedef struct _U64_S { u64 v; } U64_S;
 #define PUT8(s, d) \
 	put_unaligned(get_unaligned((const u64 *) s), (u64 *) d)
 
-#define LZ4_WRITE_LITTLEENDIAN_16(p, v)	\
-	do {	\
-		put_unaligned(v, (u16 *)(p)); \
-		p += 2; \
+#define LZ4_READ_LITTLEENDIAN_16(d, s, p)	\
+	(d = s - get_unaligned_le16(p))
+
+#define LZ4_WRITE_LITTLEENDIAN_16(p, v)			\
+	do {						\
+		put_unaligned_le16(v, (u16 *)(p));	\
+		p += 2;					\
 	} while (0)
 #endif
 
@@ -140,9 +146,6 @@ typedef struct _U64_S { u64 v; } U64_S;
 
 #endif
 
-#define LZ4_READ_LITTLEENDIAN_16(d, s, p) \
-	(d = s - get_unaligned_le16(p))
-
 #define LZ4_WILDCOPY(s, d, e)		\
 	do {				\
 		LZ4_COPYPACKET(s, d);	\


Patches currently in stable-queue which might be from rsalvaterra@gmail.com are

queue-4.4/lib-lz4-fixed-zram-with-lz4-on-big-endian-machines.patch