tools/env: fix environment alignment tests for block devices

commit 183923d3e412500bdc597d1745e2fb6f7f679ec7 enforces that the environment must start at an erase block boundary.

For block devices the sample fw_env.config does not mandate a erase block size for block devices. A missing setting defaults to the full env size.

Depending on the environment location the alignment check now errors out for perfectly legal settings.

Fix this by defaulting to the standard blocksize of 0x200 for environments stored in a block device.
That keeps the fw_env.config files for block devices working even with that new check.

Signed-off-by Max Krummenacher <[email protected]>

---

Changes in v2:
- move default value handling from parse_config(), get_config() to check_device_config(), so that !defined(CONFIG_FILE) is covered also.
- use DIV_ROUND_UP instead of doing this manually
- move the check after the setting of default values in check_device_config().
- use 0 as the marker for default values to be used.

  tools/env/fw_env.c | 60 ++++++++++++++++++++++++++++++------------------------
  1 file changed, 33 insertions(+), 27 deletions(-)

tools/env/fw_env.c +0 -12

index 3dc0d53..862a0b1 100644
@@ -1291,18 +1291,6 @@ static int check_device_config(int dev)
  	struct stat st;
  	int fd, rc = 0;
 
-	if (DEVOFFSET(dev) % DEVESIZE(dev) != 0) {
-		fprintf(stderr, "Environment does not start on (erase) block boundary\n");
-		errno = EINVAL;
-		return -1;
-	}
-
-	if (ENVSIZE(dev) > ENVSECTORS(dev) * DEVESIZE(dev)) {
-		fprintf(stderr, "Environment does not fit into available sectors\n");
-		errno = EINVAL;
-		return -1;
-	}
-
  	fd = open(DEVNAME(dev), O_RDONLY);
  	if (fd < 0) {
  		fprintf(stderr,

tools/env/fw_env.c +27 -15

  		/*
  		 * Check for negative offsets, treat it as backwards offset

@@ -1359,6 +1353,22 @@ static int check_device_config(int dev)
  		}
  	}
 
+	if (ENVSECTORS(dev) == 0)
+		/* Assume enough sectors to cover the environment */
+		ENVSECTORS(dev) = DIV_ROUND_UP(ENVSIZE(dev), DEVESIZE(dev));
+
+	if (DEVOFFSET(dev) % DEVESIZE(dev) != 0) {
+		fprintf(stderr, "Environment does not start on (erase) block boundary\n");
+		errno = EINVAL;
+		return -1;
+	}
+
+	if (ENVSIZE(dev) > ENVSECTORS(dev) * DEVESIZE(dev)) {
+		fprintf(stderr, "Environment does not fit into available sectors\n");
+		errno = EINVAL;
+		return -1;
+	}
+
  err:
  	close(fd);
  	return rc;

@@ -1382,10 +1392,10 @@ static int parse_config(struct env_opts *opts)
  	DEVNAME (0) = DEVICE1_NAME;
  	DEVOFFSET (0) = DEVICE1_OFFSET;
  	ENVSIZE (0) = ENV1_SIZE;
-	/* Default values are: erase-size=env-size */
-	DEVESIZE (0) = ENVSIZE (0);
-	/* #sectors=env-size/erase-size (rounded up) */
-	ENVSECTORS (0) = (ENVSIZE(0) + DEVESIZE(0) - 1) / DEVESIZE(0);
+
+	/* Set defaults for DEVESIZE, ENVSECTORS later once we
+	 * know DEVTYPE
+	 */
  #ifdef DEVICE1_ESIZE
  	DEVESIZE (0) = DEVICE1_ESIZE;
  #endif

@@ -1397,10 +1407,10 @@ static int parse_config(struct env_opts *opts)
  	DEVNAME (1) = DEVICE2_NAME;
  	DEVOFFSET (1) = DEVICE2_OFFSET;
  	ENVSIZE (1) = ENV2_SIZE;
-	/* Default values are: erase-size=env-size */
-	DEVESIZE (1) = ENVSIZE (1);
-	/* #sectors=env-size/erase-size (rounded up) */
-	ENVSECTORS (1) = (ENVSIZE(1) + DEVESIZE(1) - 1) / DEVESIZE(1);
+
+	/* Set defaults for DEVESIZE, ENVSECTORS later once we
+	 * know DEVTYPE
+	 */
  #ifdef DEVICE2_ESIZE
  	DEVESIZE (1) = DEVICE2_ESIZE;
  #endif

@@ -1466,13 +1476,9 @@ static int get_config (char *fname)
 
  		DEVNAME(i) = devname;
 
-		if (rc < 4)
-			/* Assume the erase size is the same as the env-size */
-			DEVESIZE(i) = ENVSIZE(i);
-
-		if (rc < 5)
-			/* Assume enough env sectors to cover the environment */
-			ENVSECTORS (i) = (ENVSIZE(i) + DEVESIZE(i) - 1) / DEVESIZE(i);
+		/* Set defaults for DEVESIZE, ENVSECTORS later once we
+		 * know DEVTYPE
+		 */
 
  		i++;
  	}

Hi Max,

LGTM, see one nit below, can fixed later

Quoted 9 lines · Max Krummenacher

commit 183923d3e412500bdc597d1745e2fb6f7f679ec7 enforces that the environment must start at an erase block boundary.

For block devices the sample fw_env.config does not mandate a erase block size
for block devices. A missing setting defaults to the full env size.

  tools/env/fw_env.c | 60

Quoted 6 lines

                }
                DEVTYPE(dev) = mtdinfo.type;

(quoted diff) +2 -0

+               if (DEVESIZE(dev) == 0)
+                       /* Assume the erase size is the same as the

env-size */
+ DEVESIZE(dev) = ENVSIZE(dev);

Since we already checked for character devices, we could use the mtdinfo.erasesize. I guess we can relay on mtdinfo on new kernels, and if not there is still the fallback to specify it in fw_env.config.

tools/env/fw_env.c static int check_device_config(int dev) · line 1334

Quoted 7 lines

        } else {
                uint64_t size;
                DEVTYPE(dev) = MTD_ABSENT;

tools/env/fw_env.c +3 -0

+               if (DEVESIZE(dev) == 0)
+                       /* Assume the erase size to be 512 bytes */
+                       DEVESIZE(dev) = 0x200;

It doesn't even matter. In case of MTD_ABSENT, erasize is never used itself, only the tuple (DEVESIZE * ENVSECTORS) matters.

commit 183923d3e412500bdc597d1745e2fb6f7f679ec7 enforces that the environment must start at an erase block boundary.

For block devices the sample fw_env.config does not mandate a erase block size for block devices. A missing setting defaults to the full env size.

Depending on the environment location the alignment check now errors out for perfectly legal settings.

Fix this by defaulting to the standard blocksize of 0x200 for environments stored in a block device.
That keeps the fw_env.config files for block devices working even with that new check.

Signed-off-by Max Krummenacher <[email protected]>