linux-kernel - [PATCH v2] mtd: maps: add missing iounmap() in error path

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Date:   Wed, 23 Nov 2016 23:40:36 +0000
From:   Luis Henriques <henrix@...andro.org>
To:     David Woodhouse <dwmw2@...radead.org>,
        Brian Norris <computersforpeace@...il.com>,
        Boris Brezillon <boris.brezillon@...e-electrons.com>,
        Marek Vasut <marek.vasut@...il.com>,
        Richard Weinberger <richard@....at>,
        Cyrille Pitchen <cyrille.pitchen@...el.com>
Cc:     linux-mtd@...ts.infradead.org, linux-kernel@...r.kernel.org,
        Luis Henriques <henrix@...andro.org>
Subject: [PATCH v2] mtd: maps: add missing iounmap() in error path

This patch was triggered by the following Coccinelle error:

./drivers/mtd/maps/sc520cdp.c:246:3-9: \
	ERROR: missing iounmap; ioremap on line 242 \
	and execution via conditional on line 244

Since do_map_probe() is also invoked in this loop, it is also necessary to
map_destroy() any initialised struct mtd_info.

Signed-off-by: Luis Henriques <henrix@...andro.org>
---
Changes since v1:
* Changes according to Brian Norris review:
  - Ensure sc520cdp_map[0].virt is unmaped when needed
  - Use a for loop instead of an 'if (i)'
  - Prevent double-iounmap
* Added map_destroy() in the cleanup

drivers/mtd/maps/sc520cdp.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/maps/sc520cdp.c b/drivers/mtd/maps/sc520cdp.c
index 093edd51bdc7..9b1c13aa9f20 100644
--- a/drivers/mtd/maps/sc520cdp.c
+++ b/drivers/mtd/maps/sc520cdp.c
@@ -227,7 +227,7 @@ static void sc520cdp_setup_par(void)
 
 static int __init init_sc520cdp(void)
 {
-	int i, devices_found = 0;
+	int i, j, devices_found = 0;
 
 #ifdef REPROGRAM_PAR
 	/* reprogram PAR registers so flash appears at the desired addresses */
@@ -243,6 +243,12 @@ static int __init init_sc520cdp(void)
 
 		if (!sc520cdp_map[i].virt) {
 			printk("Failed to ioremap_nocache\n");
+			for (j = 0; j < i; j++) {
+				if (mymtd[j]) {
+					map_destroy(mymtd[j]);
+					iounmap(sc520cdp_map[j].virt);
+				}
+			}
 			return -EIO;
 		}