From: Minchan Kim <minchan@xxxxxxxxxx>
Subject: zsmalloc: expand class bit
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@xxxxxxxxxx
Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/zsmalloc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff -puN mm/zsmalloc.c~zsmalloc-expand-class-bit mm/zsmalloc.c
--- a/mm/zsmalloc.c~zsmalloc-expand-class-bit
+++ a/mm/zsmalloc.c
@@ -276,7 +276,7 @@ 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;
};
_