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 076/101] fbdev/sstfb: Duplicate video-mode option string
Date:   Thu,  9 Mar 2023 17:01:36 +0100
Message-Id: <20230309160201.5163-77-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/sstfb.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/video/fbdev/sstfb.c b/drivers/video/fbdev/sstfb.c
index da296b2ab54a..f422b1882950 100644
--- a/drivers/video/fbdev/sstfb.c
+++ b/drivers/video/fbdev/sstfb.c
@@ -106,6 +106,7 @@ static bool slowpci;		/* slow PCI settings */
 */
 #define DEFAULT_VIDEO_MODE "640x480@60"
 
+static char *mode_option_buf;
 static char *mode_option = DEFAULT_VIDEO_MODE;
 
 enum {
@@ -1301,8 +1302,11 @@ static int sstfb_setup(char *options)
 			mem = simple_strtoul (this_opt+4, NULL, 0);
 		else if (!strncmp(this_opt, "gfxclk:",7))
 			gfxclk = simple_strtoul (this_opt+7, NULL, 0);
-		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;
 }
@@ -1516,6 +1520,7 @@ static int sstfb_init(void)
 static void sstfb_exit(void)
 {
 	pci_unregister_driver(&sstfb_driver);
+	kfree(mode_option_buf);
 }
 
 
-- 
2.39.2