[PATCH] mtd: spi-nor: Reset nor->addr_width when SFDP parsing failed

[Boris Brezillon]

Commit 5390a8df769e ("mtd: spi-nor: add support to non-uniform SFDP SPI
NOR flash memories") removed the 'nor->addr_width = 0;' statement when
spi_nor_parse_sfdp() returns an error, thus leaving ->addr_width in an
undefined state which can cause trouble when spi_nor_scan() checks its
value.

Reported-by: Cyrille Pitchen <***@wedev4u.fr>
Fixes: 5390a8df769e ("mtd: spi-nor: add support to non-uniform SFDP SPI NOR flash memories")
Signed-off-by: Boris Brezillon <***@bootlin.com>
---
drivers/mtd/spi-nor/spi-nor.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index 9407ca5f9443..3e54e31889c7 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -3250,12 +3250,14 @@ static int spi_nor_init_params(struct spi_nor *nor,
memcpy(&sfdp_params, params, sizeof(sfdp_params));
memcpy(&prev_map, &nor->erase_map, sizeof(prev_map));

- if (spi_nor_parse_sfdp(nor, &sfdp_params))
+ if (spi_nor_parse_sfdp(nor, &sfdp_params)) {
+ nor->addr_width = 0;
/* restore previous erase map */
memcpy(&nor->erase_map, &prev_map,
sizeof(nor->erase_map));
- else
+ } else {
memcpy(params, &sfdp_params, sizeof(*params));
+ }
}

return 0;

[Tudor Ambarus]

Post by Boris Brezillon
Commit 5390a8df769e ("mtd: spi-nor: add support to non-uniform SFDP SPI
NOR flash memories") removed the 'nor->addr_width = 0;' statement when
spi_nor_parse_sfdp() returns an error, thus leaving ->addr_width in an
undefined state which can cause trouble when spi_nor_scan() checks its
value.
Fixes: 5390a8df769e ("mtd: spi-nor: add support to non-uniform SFDP SPI NOR flash memories")

Reviewed-by: Tudor Ambarus <***@microchip.com>

Commit 5390a8df769e removed the following:

@@ -2521,20 +2962,20 @@ static int spi_nor_init_params(struct spi_nor *nor,
- /* Override the parameters with data read from SFDP tables. */
- nor->addr_width = 0;
- nor->mtd.erasesize = 0;

this is good because nor is allocated with _kzalloc by all it's callers. Should
we add a comment when declaring spi_nor structure or it's widely known that it
should be initialized with zeros?

[cut]
- if (spi_nor_parse_sfdp(nor, &sfdp_params)) {
- nor->addr_width = 0;

removal of nor->addr_width = 0; is bad, and must be reintroduced because
nor->addr_width is modified inside spi_nor_parse_sfdp()

- nor->mtd.erasesize = 0;
this removal is good, because we don't overwrite nor->mtd.erasesize in
spi_nor_parse_sfdp()

I should have sent this changes in a separate patch, sorry.

Thanks!
ta

Post by Boris Brezillon
---
drivers/mtd/spi-nor/spi-nor.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index 9407ca5f9443..3e54e31889c7 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -3250,12 +3250,14 @@ static int spi_nor_init_params(struct spi_nor *nor,
memcpy(&sfdp_params, params, sizeof(sfdp_params));
memcpy(&prev_map, &nor->erase_map, sizeof(prev_map));
- if (spi_nor_parse_sfdp(nor, &sfdp_params))
+ if (spi_nor_parse_sfdp(nor, &sfdp_params)) {
+ nor->addr_width = 0;
/* restore previous erase map */
memcpy(&nor->erase_map, &prev_map,
sizeof(nor->erase_map));
- else
+ } else {
memcpy(params, &sfdp_params, sizeof(*params));
+ }
}
return 0;

[Boris Brezillon]

On Fri, 19 Oct 2018 11:02:22 +0200

Post by Boris Brezillon
Commit 5390a8df769e ("mtd: spi-nor: add support to non-uniform SFDP SPI
NOR flash memories") removed the 'nor->addr_width = 0;' statement when
spi_nor_parse_sfdp() returns an error, thus leaving ->addr_width in an
undefined state which can cause trouble when spi_nor_scan() checks its
value.
Fixes: 5390a8df769e ("mtd: spi-nor: add support to non-uniform SFDP SPI NOR flash memories")

Queued to the fixes branch.

Post by Boris Brezillon
---
drivers/mtd/spi-nor/spi-nor.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index 9407ca5f9443..3e54e31889c7 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -3250,12 +3250,14 @@ static int spi_nor_init_params(struct spi_nor *nor,
memcpy(&sfdp_params, params, sizeof(sfdp_params));
memcpy(&prev_map, &nor->erase_map, sizeof(prev_map));
- if (spi_nor_parse_sfdp(nor, &sfdp_params))
+ if (spi_nor_parse_sfdp(nor, &sfdp_params)) {
+ nor->addr_width = 0;
/* restore previous erase map */
memcpy(&nor->erase_map, &prev_map,
sizeof(nor->erase_map));
- else
+ } else {
memcpy(params, &sfdp_params, sizeof(*params));
+ }
}
return 0;