[U-Boot] [PATCH 1/4] tools/env: return with error if redundant environments have unequal size

[Andreas Fenkart]

From: Andreas Fenkart <afenkart at gmail.com>

For double buffering to work, the target buffer must always be big
enough to hold all data. This can only be ensured if buffers are of
equal size, otherwise one must be smaller and we risk data loss
when copying from the bigger to the smaller buffer.

Signed-off-by: Andreas Fenkart <andreas.fenkart at digitalstrom.com>
---
 tools/env/fw_env.c | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/tools/env/fw_env.c b/tools/env/fw_env.c
index 692abda..b1c8217 100644
--- a/tools/env/fw_env.c
+++ b/tools/env/fw_env.c
@@ -1382,18 +1382,19 @@ static int parse_config(struct env_opts *opts)
 		return -1;
 	}
 
-	if (HaveRedundEnv && stat (DEVNAME (1), &st)) {
-		fprintf (stderr,
-			"Cannot access MTD device %s: %s\n",
-			DEVNAME (1), strerror (errno));
-		return -1;
-	}
+	if (HaveRedundEnv) {
+		if (stat(DEVNAME(1), &st)) {
+			fprintf(stderr,
+				"Cannot access MTD device %s: %s\n",
+				DEVNAME(1), strerror(errno));
+			return -1;
+		}
 
-	if (HaveRedundEnv && ENVSIZE(0) != ENVSIZE(1)) {
-		ENVSIZE(0) = ENVSIZE(1) = min(ENVSIZE(0), ENVSIZE(1));
-		fprintf(stderr,
-			"Redundant environments have inequal size, set to 0x%08lx\n",
-			ENVSIZE(1));
+		if (ENVSIZE(0) != ENVSIZE(1)) {
+			fprintf(stderr,
+				"Redundant environments have unequal size");
+			return -1;
+		}
 	}
 
 	usable_envsize = CUR_ENVSIZE - sizeof(uint32_t);
-- 
2.8.1