[PATCH AUTOSEL 4.19 193/206] mtd: parser: cmdline: Support MTD names containing one or more colons

From: Sasha Levin
Date: Thu Sep 17 2020 - 22:39:10 EST


From: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>

[ Upstream commit eb13fa0227417e84aecc3bd9c029d376e33474d3 ]

Looks like some drivers define MTD names with a colon in it, thus
making mtdpart= parsing impossible. Let's fix the parser to gracefully
handle that case: the last ':' in a partition definition sequence is
considered instead of the first one.

Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
Signed-off-by: Ron Minnich <rminnich@xxxxxxxxxx>
Tested-by: Ron Minnich <rminnich@xxxxxxxxxx>
Signed-off-by: Richard Weinberger <richard@xxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/mtd/cmdlinepart.c | 23 ++++++++++++++++++++---
1 file changed, 20 insertions(+), 3 deletions(-)

diff --git a/drivers/mtd/cmdlinepart.c b/drivers/mtd/cmdlinepart.c
index 3ea44cff9b759..c29205ee82e20 100644
--- a/drivers/mtd/cmdlinepart.c
+++ b/drivers/mtd/cmdlinepart.c
@@ -231,12 +231,29 @@ static int mtdpart_setup_real(char *s)
struct cmdline_mtd_partition *this_mtd;
struct mtd_partition *parts;
int mtd_id_len, num_parts;
- char *p, *mtd_id;
+ char *p, *mtd_id, *semicol;
+
+ /*
+ * Replace the first ';' by a NULL char so strrchr can work
+ * properly.
+ */
+ semicol = strchr(s, ';');
+ if (semicol)
+ *semicol = '\0';

mtd_id = s;

- /* fetch <mtd-id> */
- p = strchr(s, ':');
+ /*
+ * fetch <mtd-id>. We use strrchr to ignore all ':' that could
+ * be present in the MTD name, only the last one is interpreted
+ * as an <mtd-id>/<part-definition> separator.
+ */
+ p = strrchr(s, ':');
+
+ /* Restore the ';' now. */
+ if (semicol)
+ *semicol = ';';
+
if (!p) {
pr_err("no mtd-id\n");
return -EINVAL;
--
2.25.1