[PATCH 1/2] test: compression: check with trailing garbage in input

[Brandon Maier]

The Linux kernel appends 4 bytes to the end of compressed kernel Images
containing the uncompressed image size. They are used to make
self-decompressing Images easier. However for archs that don't support
self-decompression, like ARM64, U-Boot must be able to decompress the
image with the garbage data.

The existing decompressors already support this. This unit test was
added while working on zstd support as upstream zstd will error if there
is garbage data in the input buffer, and special care was needed to
support this.

Signed-off-by: Brandon Maier <brandon.maier at collins.com>
---
 test/compression.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/test/compression.c b/test/compression.c
index 82e29c9b86b..6c2a43fbed7 100644
--- a/test/compression.c
+++ b/test/compression.c
@@ -350,6 +350,15 @@ static int run_test_internal(struct unit_test_state *uts, char *name,
 			buf->orig_size) == 0);
 	errcheck(((char *)buf->uncompressed_buf)[buf->orig_size] == 'A');
 
+	/* Uncompresses with trailing garbage in input buffer. */
+	memset(buf->uncompressed_buf, 'A', TEST_BUFFER_SIZE);
+	errcheck(uncompress(uts, buf->compressed_buf, buf->compressed_size + 4,
+			    buf->uncompressed_buf, buf->uncompressed_size,
+			    &buf->uncompressed_size) == 0);
+	errcheck(buf->uncompressed_size == buf->orig_size);
+	errcheck(memcmp(buf->orig_buf, buf->uncompressed_buf,
+			buf->orig_size) == 0);
+
 	/* Make sure compression does not over-run. */
 	memset(buf->compare_buf, 'A', TEST_BUFFER_SIZE);
 	ret = compress(uts, buf->orig_buf, buf->orig_size,
-- 
2.39.0