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From:   "Ronald G. Minnich" <rminnich@gmail.com>
Cc:     Boris Brezillon <boris.brezillon@collabora.com>,
        Ron Minnich <rminnich@google.com>,
        David Woodhouse <dwmw2@infradead.org>,
        Brian Norris <computersforpeace@gmail.com>,
        Boris Brezillon <boris.brezillon@free-electrons.com>,
        Marek Vasut <marek.vasut@gmail.com>,
        Richard Weinberger <richard@nod.at>,
        Cyrille Pitchen <cyrille.pitchen@wedev4u.fr>,
        linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH] mtd: parser: cmdline: Support MTD names containing one or more colons
Date:   Wed, 29 Apr 2020 09:53:47 -0700
Message-Id: <20200429165347.48909-1-rminnich@google.com>
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From: Boris Brezillon <boris.brezillon@collabora.com>

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@collabora.com>
Signed-off-by: Ron Minnich <rminnich@google.com>
Tested-by: Ron Minnich <rminnich@google.com>
---
 drivers/mtd/parsers/cmdlinepart.c | 23 ++++++++++++++++++++---
 1 file changed, 20 insertions(+), 3 deletions(-)

diff --git a/drivers/mtd/parsers/cmdlinepart.c b/drivers/mtd/parsers/cmdlinepart.c
index c86f2db8c882..0625b25620ca 100644
--- a/drivers/mtd/parsers/cmdlinepart.c
+++ b/drivers/mtd/parsers/cmdlinepart.c
@@ -218,12 +218,29 @@ 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;