console: newport_con: fix an issue about leak related system resources

A call of the function do_take_over_console() can fail here.
The corresponding system resources were not released then.
Thus add a call of iounmap() and release_mem_region()
together with the check of a failure predicate. and also
add release_mem_region() on device removal.

Fixes: e86bb8acc0fdc ("[PATCH] VT binding: Make newport_con support binding")
Suggested-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Dejin Zheng <zhengdejin5@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@osdl.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200423164251.3349-1-zhengdejin5@gmail.com

diff --git a/drivers/video/console/newport_con.c b/drivers/video/console/newport_con.c
index 00dddf6e08b0c5def98f86f59765efe78018278e..2d2ee17052e837a0f3ccda509765552f69b53c0f 100644 (file)
--- a/drivers/video/console/newport_con.c
+++ b/drivers/video/console/newport_con.c
@@ -32,6 +32,8 @@
 #include <linux/linux_logo.h>
 #include <linux/font.h>
 
+#define NEWPORT_LEN    0x10000
+
 #define FONT_DATA ((unsigned char *)font_vga_8x16.data)
 
 /* borrowed from fbcon.c */
@@ -43,6 +45,7 @@
 static unsigned char *font_data[MAX_NR_CONSOLES];
 
 static struct newport_regs *npregs;
+static unsigned long newport_addr;
 
 static int logo_active;
 static int topscan;
@@ -702,7 +705,6 @@ const struct consw newport_con = {
 static int newport_probe(struct gio_device *dev,
                         const struct gio_device_id *id)
 {
-       unsigned long newport_addr;
        int err;
 
        if (!dev->resource.start)
@@ -712,7 +714,7 @@ static int newport_probe(struct gio_device *dev,
                return -EBUSY; /* we only support one Newport as console */
 
        newport_addr = dev->resource.start + 0xF0000;
-       if (!request_mem_region(newport_addr, 0x10000, "Newport"))
+       if (!request_mem_region(newport_addr, NEWPORT_LEN, "Newport"))
                return -ENODEV;
 
        npregs = (struct newport_regs *)/* ioremap cannot fail */
@@ -720,6 +722,11 @@ static int newport_probe(struct gio_device *dev,
        console_lock();
        err = do_take_over_console(&newport_con, 0, MAX_NR_CONSOLES - 1, 1);
        console_unlock();
+
+       if (err) {
+               iounmap((void *)npregs);
+               release_mem_region(newport_addr, NEWPORT_LEN);
+       }
        return err;
 }
 
@@ -727,6 +734,7 @@ static void newport_remove(struct gio_device *dev)
 {
        give_up_console(&newport_con);
        iounmap((void *)npregs);
+       release_mem_region(newport_addr, NEWPORT_LEN);
 }
 
 static struct gio_device_id newport_ids[] = {