[PATCH] module/decompress: Never use kunmap() for local un-mappings

[Fabio M. De Francesco]

Use kunmap_local() to unmap pages locally mapped with kmap_local_page().

kunmap_local() must be called on the kernel virtual address returned by
kmap_local_page(), differently from how we use kunmap() which instead
expects the mapped page as its argument.

In module_zstd_decompress() we currently map with kmap_local_page() and
unmap with kunmap(). This breaks the code and so it should be fixed.

Cc: Piotr Gorski <piotrgorski@xxxxxxxxxxx>
Cc: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
Cc: Luis Chamberlain <mcgrof@xxxxxxxxxx>
Cc: Stephen Boyd <swboyd@xxxxxxxxxxxx>
Cc: Ira Weiny <ira.weiny@xxxxxxxxx>
Fixes: 169a58ad824d ("module/decompress: Support zstd in-kernel decompression")
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@xxxxxxxxx>
---
 kernel/module/decompress.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/module/decompress.c b/kernel/module/decompress.c
index bb79ac1a6d8f..7ddc87bee274 100644
--- a/kernel/module/decompress.c
+++ b/kernel/module/decompress.c
@@ -267,7 +267,7 @@ static ssize_t module_zstd_decompress(struct load_info *info,
 		zstd_dec.size = PAGE_SIZE;
 
 		ret = zstd_decompress_stream(dstream, &zstd_dec, &zstd_buf);
-		kunmap(page);
+		kunmap_local(zstd_dec.dst);
 		retval = zstd_get_error_code(ret);
 		if (retval)
 			break;
-- 
2.39.2