[PATCH 02/18] cxl/test: Simplify fw_buf_checksum_show()

Eric Biggers
2025-06-25T07:10:28Z

First, just use sha256() instead of a sequence of sha256_init(),
sha256_update(), and sha256_final(). The result is the same.

Second, use *phN instead of open-coding the conversion of bytes to hex.

Signed-off-by: Eric Biggers <ebiggers@kernel.org>
---
tools/testing/cxl/test/mem.c | 21 ++-------------------
1 file changed, 2 insertions(+), 19 deletions(-)

diff --git a/tools/testing/cxl/test/mem.c b/tools/testing/cxl/test/mem.c
index 0f1d91f57ba34..d533481672b78 100644
--- a/tools/testing/cxl/test/mem.c
+++ b/tools/testing/cxl/test/mem.c
@@ -1826,31 +1826,14 @@ static DEVICE_ATTR_RW(security_lock);
static ssize_t fw_buf_checksum_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct cxl_mockmem_data *mdata = dev_get_drvdata(dev);
u8 hash[SHA256_DIGEST_SIZE];
- unsigned char *hstr, *hptr;
- struct sha256_state sctx;
- ssize_t written = 0;
- int i;
-
- sha256_init(&sctx);
- sha256_update(&sctx, mdata->fw, mdata->fw_size);
- sha256_final(&sctx, hash);
-
- hstr = kzalloc((SHA256_DIGEST_SIZE * 2) + 1, GFP_KERNEL);
- if (!hstr)
- return -ENOMEM;
-
- hptr = hstr;
- for (i = 0; i < SHA256_DIGEST_SIZE; i++)
- hptr += sprintf(hptr, "%02x", hash[i]);

- written = sysfs_emit(buf, "%s\n", hstr);
+ sha256(mdata->fw, mdata->fw_size, hash);

- kfree(hstr);
- return written;
+ return sysfs_emit(buf, "%*phN\n", SHA256_DIGEST_SIZE, hash);
}

static DEVICE_ATTR_RO(fw_buf_checksum);

static ssize_t sanitize_timeout_show(struct device *dev,
--
2.50.0