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 085/101] fbdev/tridentfb: Duplicate video-mode option string
Date:   Thu,  9 Mar 2023 17:01:45 +0100
Message-Id: <20230309160201.5163-86-tzimmermann@suse.de>
In-Reply-To: <20230309160201.5163-1-tzimmermann@suse.de>
References: <20230309160201.5163-1-tzimmermann@suse.de>
MIME-Version: 1.0
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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/tridentfb.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/video/fbdev/tridentfb.c b/drivers/video/fbdev/tridentfb.c
index 6099b9768ba1..dbde64aef91f 100644
--- a/drivers/video/fbdev/tridentfb.c
+++ b/drivers/video/fbdev/tridentfb.c
@@ -61,6 +61,7 @@ static struct fb_fix_screeninfo tridentfb_fix = {
 /* defaults which are normally overriden by user values */
 
 /* video mode */
+static char *mode_option_buf;
 static char *mode_option;
 static int bpp = 8;
 
@@ -1800,8 +1801,11 @@ static int __init tridentfb_setup(char *options)
 			memdiff = simple_strtoul(opt + 8, NULL, 0);
 		else if (!strncmp(opt, "nativex=", 8))
 			nativex = simple_strtoul(opt + 8, NULL, 0);
-		else
-			mode_option = opt;
+		else {
+			kfree(mode_option_buf);
+			mode_option_buf = kstrdup(opt, GFP_KERNEL); // ignore errors
+			mode_option = mode_option_buf;
+		}
 	}
 	return 0;
 }
@@ -1827,6 +1831,7 @@ static int __init tridentfb_init(void)
 static void __exit tridentfb_exit(void)
 {
 	pci_unregister_driver(&tridentfb_pci_driver);
+	kfree(mode_option_buf);
 }
 
 module_init(tridentfb_init);
-- 
2.39.2