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 097/101] fbdev/vt8623fb: Duplicate video-mode option string
Date:   Thu,  9 Mar 2023 17:01:57 +0100
Message-Id: <20230309160201.5163-98-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 constifying the option string.

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

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/video/fbdev/vt8623fb.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/video/fbdev/vt8623fb.c b/drivers/video/fbdev/vt8623fb.c
index 034333ee6e45..321b1813cf3c 100644
--- a/drivers/video/fbdev/vt8623fb.c
+++ b/drivers/video/fbdev/vt8623fb.c
@@ -95,6 +95,7 @@ static const struct svga_timing_regs vt8623_timing_regs     = {
 
 /* Module parameters */
 
+static char *mode_option_buf;
 static char *mode_option = "640x480-8@60";
 static int mtrr = 1;
 
@@ -911,6 +912,7 @@ static void __exit vt8623fb_cleanup(void)
 {
 	pr_debug("vt8623fb: cleaning up\n");
 	pci_unregister_driver(&vt8623fb_pci_driver);
+	kfree(mode_option_buf);
 }
 
 /* Driver Initialisation */
@@ -929,8 +931,10 @@ static int __init vt8623fb_init(void)
 	if (fb_get_options("vt8623fb", &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("vt8623fb: initializing\n");
-- 
2.39.2