lz4: fix compression/decompression signedness mismatch

LZ4 compression and decompression functions require different in
signedness input/output parameters: unsigned char for compression and
signed char for decompression.

Change decompression API to require "(const) unsigned char *".

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Kyungsik Lee <kyungsik.lee@lge.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Yann Collet <yann.collet.73@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 8 insertions, 8 deletions

diff --git a/include/linux/lz4.h b/include/linux/lz4.h
index d21c13f10a64..4356686b0a39 100644
--- a/include/linux/lz4.h
+++ b/include/linux/lz4.h
@@ -67,8 +67,8 @@ int lz4hc_compress(const unsigned char *src, size_t src_len,
  *      note :  Destination buffer must be already allocated.
  *              slightly faster than lz4_decompress_unknownoutputsize()
  */
-int lz4_decompress(const char *src, size_t *src_len, char *dest,
-                size_t actual_dest_len);
+int lz4_decompress(const unsigned char *src, size_t *src_len,
+                unsigned char *dest, size_t actual_dest_len);
 
 /*
  * lz4_decompress_unknownoutputsize()
@@ -82,6 +82,6 @@ int lz4_decompress(const char *src, size_t *src_len, char *dest,
  *                Error if return (< 0)
  *      note :  Destination buffer must be already allocated.
  */
-int lz4_decompress_unknownoutputsize(const char *src, size_t src_len,
-                char *dest, size_t *dest_len);
+int lz4_decompress_unknownoutputsize(const unsigned char *src, size_t src_len,
+                unsigned char *dest, size_t *dest_len);
 #endif
diff --git a/lib/lz4/lz4_decompress.c b/lib/lz4/lz4_decompress.c
index 411be80ddb46..df6839e3ce08 100644
--- a/lib/lz4/lz4_decompress.c
+++ b/lib/lz4/lz4_decompress.c
@@ -283,8 +283,8 @@ _output_error:
         return (int) (-(((char *) ip) - source));
 }
 
-int lz4_decompress(const char *src, size_t *src_len, char *dest,
-                size_t actual_dest_len)
+int lz4_decompress(const unsigned char *src, size_t *src_len,
+                unsigned char *dest, size_t actual_dest_len)
 {
         int ret = -1;
         int input_len = 0;
@@ -302,8 +302,8 @@ exit_0:
 EXPORT_SYMBOL(lz4_decompress);
 #endif
 
-int lz4_decompress_unknownoutputsize(const char *src, size_t src_len,
-                char *dest, size_t *dest_len)
+int lz4_decompress_unknownoutputsize(const unsigned char *src, size_t src_len,
+                unsigned char *dest, size_t *dest_len)
 {
         int ret = -1;
         int out_len = 0;