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 063/101] fbdev/pvr2fb: Duplicate video-mode option string
Date:   Thu,  9 Mar 2023 17:01:23 +0100
Message-Id: <20230309160201.5163-64-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,
as well as the init function's error handling.

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/pvr2fb.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/video/fbdev/pvr2fb.c b/drivers/video/fbdev/pvr2fb.c
index 6888127a5eb8..f6be2649840d 100644
--- a/drivers/video/fbdev/pvr2fb.c
+++ b/drivers/video/fbdev/pvr2fb.c
@@ -225,6 +225,7 @@ static struct fb_videomode pvr2_modedb[] = {
 #define DEFMODE_VGA	2
 
 static int defmode = DEFMODE_NTSC;
+static char *mode_option_buf;
 static char *mode_option = NULL;
 
 static inline void pvr2fb_set_pal_type(unsigned int type)
@@ -1049,7 +1050,9 @@ static int __init pvr2fb_setup(char *options)
 		} else if (!strncmp(this_opt, "nowrap", 6)) {
 			nowrap = 1;
 		} else {
-			mode_option = this_opt;
+			kfree(mode_option_buf);
+			mode_option_buf = kstrdup(this_opt, GFP_KERNEL); // ignore errors
+			mode_option = mode_option_buf;
 		}
 	}
 
@@ -1094,8 +1097,11 @@ static int __init pvr2fb_init(void)
 #endif
 
 	fb_info = framebuffer_alloc(sizeof(struct pvr2fb_par), NULL);
-	if (!fb_info)
+	if (!fb_info) {
+		kfree(mode_option_buf);
+		mode_option_buf = NULL;
 		return -ENOMEM;
+	}
 
 	currentpar = fb_info->par;
 
@@ -1111,6 +1117,8 @@ static int __init pvr2fb_init(void)
 			printk(KERN_ERR "pvr2fb: Failed init of %s device\n",
 				pvr_board->name);
 			framebuffer_release(fb_info);
+			kfree(mode_option_buf);
+			mode_option_buf = NULL;
 			break;
 		}
 	}
@@ -1135,6 +1143,7 @@ static void __exit pvr2fb_exit(void)
 
 	unregister_framebuffer(fb_info);
 	framebuffer_release(fb_info);
+	kfree(mode_option_buf);
 }
 
 module_init(pvr2fb_init);
-- 
2.39.2