From:   Thomas Zimmermann <tzimmermann@suse.de>
To:     deller@gmx.de, geert+renesas@glider.be, timur@kernel.org,
        rdunlap@infradead.org, paulus@samba.org, benh@kernel.crashing.org,
        linux@armlinux.org.uk, pjones@redhat.com, adaplas@gmail.com,
        s.hauer@pengutronix.de, shawnguo@kernel.org, mbroemme@libmpq.org,
        thomas@winischhofer.net, James.Bottomley@HansenPartnership.com,
        sudipm.mukherjee@gmail.com, teddy.wang@siliconmotion.com,
        corbet@lwn.net
Cc:     linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org,
        linux-kernel@vger.kernel.org,
        Thomas Zimmermann <tzimmermann@suse.de>
Subject: [PATCH v2 008/101] fbdev/arkfb: Duplicate video-mode option string
Date:   Thu,  9 Mar 2023 17:00:28 +0100
Message-Id: <20230309160201.5163-9-tzimmermann@suse.de>
In-Reply-To: <20230309160201.5163-1-tzimmermann@suse.de>
References: <20230309160201.5163-1-tzimmermann@suse.de>
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Assume that the driver does not own the option string or its substrings
and hence duplicate the option string for the video mode. Allocate the
copy's memory with kstrdup() and free it in the module's exit function.

Done in preparation of switching the driver to struct option_iter and
constifying the option string.

v2:
	* replace static memory with kstrdup()/kfree() (Geert)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/video/fbdev/arkfb.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/video/fbdev/arkfb.c b/drivers/video/fbdev/arkfb.c
index 60a96fdb5dd8..98c710cadaab 100644
--- a/drivers/video/fbdev/arkfb.c
+++ b/drivers/video/fbdev/arkfb.c
@@ -97,6 +97,7 @@ static const struct svga_timing_regs ark_timing_regs     = {
 
 /* Module parameters */
 
+static char *mode_option_buf;
 static char *mode_option = "640x480-8@60";
 
 MODULE_AUTHOR("(c) 2007 Ondrej Zajicek <santiago@crfreenet.org>");
@@ -1178,6 +1179,7 @@ static void __exit arkfb_cleanup(void)
 {
 	pr_debug("arkfb: cleaning up\n");
 	pci_unregister_driver(&arkfb_pci_driver);
+	kfree(mode_option_buf);
 }
 
 /* Driver Initialisation */
@@ -1196,8 +1198,10 @@ static int __init arkfb_init(void)
 	if (fb_get_options("arkfb", &option))
 		return -ENODEV;
 
-	if (option && *option)
-		mode_option = option;
+	if (option && *option) {
+		mode_option_buf = kstrdup(option, GFP_KERNEL); // ignore errors
+		mode_option = mode_option_buf;
+	}
 #endif
 
 	pr_debug("arkfb: initializing\n");
-- 
2.39.2