linux-kernel - [PATCH v2 034/101] fbdev/i810: Duplicate video-mode option string

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Message-Id: <20230309160201.5163-35-tzimmermann@suse.de>
Date:   Thu,  9 Mar 2023 17:00:54 +0100
From:   Thomas Zimmermann <tzimmermann@...e.de>
To:     deller@....de, geert+renesas@...der.be, timur@...nel.org,
        rdunlap@...radead.org, paulus@...ba.org, benh@...nel.crashing.org,
        linux@...linux.org.uk, pjones@...hat.com, adaplas@...il.com,
        s.hauer@...gutronix.de, shawnguo@...nel.org, mbroemme@...mpq.org,
        thomas@...ischhofer.net, James.Bottomley@...senPartnership.com,
        sudipm.mukherjee@...il.com, teddy.wang@...iconmotion.com,
        corbet@....net
Cc:     linux-fbdev@...r.kernel.org, dri-devel@...ts.freedesktop.org,
        linux-kernel@...r.kernel.org,
        Thomas Zimmermann <tzimmermann@...e.de>
Subject: [PATCH v2 034/101] fbdev/i810: Duplicate video-mode option string

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@...e.de>
---
 drivers/video/fbdev/i810/i810_main.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/video/fbdev/i810/i810_main.c b/drivers/video/fbdev/i810/i810_main.c
index 85abb65f07d7..3b2648a2de29 100644
--- a/drivers/video/fbdev/i810/i810_main.c
+++ b/drivers/video/fbdev/i810/i810_main.c
@@ -134,6 +134,7 @@ static struct pci_driver i810fb_driver = {
 	.resume   =     i810fb_resume,
 };
 
+static char *mode_option_buf;
 static char *mode_option = NULL;
 static int vram = 4;
 static int bpp = 8;
@@ -2002,8 +2003,11 @@ static int i810fb_setup(char *options)
 			dcolor = true;
 		else if (!strncmp(this_opt, "ddc3", 4))
 			ddc3 = true;
-		else
-			mode_option = this_opt;
+		else {
+			kfree(mode_option_buf);
+			mode_option_buf = kstrdup(this_opt, GFP_KERNEL); // ignore errors
+			mode_option = mode_option_buf;
+		}
 	}
 	return 0;
 }
@@ -2224,6 +2228,7 @@ MODULE_LICENSE("GPL");
 static void __exit i810fb_exit(void)
 {
 	pci_unregister_driver(&i810fb_driver);
+	kfree(mode_option_buf);
 }
 module_exit(i810fb_exit);
 
-- 
2.39.2