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

Message ID 1467065194-7254-2-git-send-email-andreas.fenkart@digitalstrom.com
State Superseded
Delegated to: Tom Rini
Headers show

Commit Message

Andreas Fenkart June 27, 2016, 10:06 p.m. UTC 
From: Andreas Fenkart <afenkart@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@digitalstrom.com>
---
 tools/env/fw_env.c | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

Comments

Simon Glass July 9, 2016, 2:39 p.m. UTC | #1 
On 27 June 2016 at 16:06, Andreas Fenkart
<andreas.fenkart@digitalstrom.com> wrote:
>
> From: Andreas Fenkart <afenkart@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@digitalstrom.com>
> ---
>  tools/env/fw_env.c | 23 ++++++++++++-----------
>  1 file changed, 12 insertions(+), 11 deletions(-)

Reviewed-by: Simon Glass <sjg@chromium.org>
diff mbox

Patch

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);