Patch "zsmalloc: expand class bit" has been added to the 4.10-stable tree

Patch "zsmalloc: expand class bit" has been added to the 4.10-stable tree

[gregkh]

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

    zsmalloc: expand class bit

to the 4.10-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:
     zsmalloc-expand-class-bit.patch
and it can be found in the queue-4.10 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 85d492f28d056c40629fc25d79f54da618a29dc4 Mon Sep 17 00:00:00 2001
From: Minchan Kim <minchan@kernel.org>
Date: Thu, 13 Apr 2017 14:56:40 -0700
Subject: zsmalloc: expand class bit

From: Minchan Kim <minchan@kernel.org>

commit 85d492f28d056c40629fc25d79f54da618a29dc4 upstream.

Now 64K page system, zsamlloc has 257 classes so 8 class bit is not
enough.  With that, it corrupts the system when zsmalloc stores
65536byte data(ie, index number 256) so that this patch increases class
bit for simple fix for stable backport.  We should clean up this mess
soon.

  index	size
  0	32
  1	288
  ..
  ..
  204	52256
  256	65536

Fixes: 3783689a1 ("zsmalloc: introduce zspage structure")
Link: http://lkml.kernel.org/r/1492042622-12074-3-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 mm/zsmalloc.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -280,7 +280,7 @@ struct zs_pool {
 struct zspage {
 	struct {
 		unsigned int fullness:FULLNESS_BITS;
-		unsigned int class:CLASS_BITS;
+		unsigned int class:CLASS_BITS + 1;
 		unsigned int isolated:ISOLATED_BITS;
 		unsigned int magic:MAGIC_VAL_BITS;
 	};


Patches currently in stable-queue which might be from minchan@kernel.org are

queue-4.10/zram-do-not-use-copy_page-with-non-page-aligned-address.patch
queue-4.10/zram-fix-operator-precedence-to-get-offset.patch
queue-4.10/thp-fix-madv_dontneed-vs.-madv_free-race.patch
queue-4.10/zsmalloc-expand-class-bit.patch