linux-kernel - [PATCH v2 087/101] fbdev/uvesafb: Duplicate video-mode option string

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Message-Id: <20230309160201.5163-88-tzimmermann@suse.de>
Date:   Thu,  9 Mar 2023 17:01:47 +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 087/101] fbdev/uvesafb: 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/uvesafb.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/video/fbdev/uvesafb.c b/drivers/video/fbdev/uvesafb.c
index f09f483c219b..ff8f511a00c2 100644
--- a/drivers/video/fbdev/uvesafb.c
+++ b/drivers/video/fbdev/uvesafb.c
@@ -56,6 +56,7 @@ static u16 maxclk;		/* maximum pixel clock */
 static u16 maxvf;		/* maximum vertical frequency */
 static u16 maxhf;		/* maximum horizontal frequency */
 static u16 vbemode;		/* force use of a specific VBE mode */
+static char *mode_option_buf;
 static char *mode_option;
 static u8  dac_width	= 6;
 
@@ -1851,7 +1852,9 @@ static int uvesafb_setup(char *options)
 		else if (!strncmp(this_opt, "vbemode:", 8))
 			vbemode = simple_strtoul(this_opt + 8, NULL, 0);
 		else if (this_opt[0] >= '0' && this_opt[0] <= '9') {
-			mode_option = this_opt;
+			kfree(mode_option_buf);
+			mode_option_buf = kstrdup(this_opt, GFP_KERNEL); // ignore errors
+			mode_option = mode_option_buf;
 		} else {
 			pr_warn("unrecognized option %s\n", this_opt);
 		}
@@ -1937,6 +1940,7 @@ static void uvesafb_exit(void)
 	driver_remove_file(&uvesafb_driver.driver, &driver_attr_v86d);
 	platform_device_unregister(uvesafb_device);
 	platform_driver_unregister(&uvesafb_driver);
+	kfree(mode_option_buf);
 }
 
 module_exit(uvesafb_exit);
-- 
2.39.2