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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Finn Thain <fthain@telegraphics.com.au>,
        Rob Herring <robh@kernel.org>,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Subject: [PATCH 67/69] video: imsttfb: check for ioremap() failures
Date:   Mon,  3 May 2021 13:57:34 +0200
Message-Id: <20210503115736.2104747-68-gregkh@linuxfoundation.org>
In-Reply-To: <20210503115736.2104747-1-gregkh@linuxfoundation.org>
References: <20210503115736.2104747-1-gregkh@linuxfoundation.org>
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We should check if ioremap() were to somehow fail in imsttfb_probe() and
handle the unwinding of the resources allocated here properly.

Ideally if anyone cares about this driver (it's for a PowerMac era PCI
display card), they wouldn't even be using fbdev anymore.  Or the devm_*
apis could be used, but that's just extra work for diminishing
returns...

Cc: Finn Thain <fthain@telegraphics.com.au>
Cc: Rob Herring <robh@kernel.org>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/video/fbdev/imsttfb.c | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/drivers/video/fbdev/imsttfb.c b/drivers/video/fbdev/imsttfb.c
index e04411701ec8..16f272a50811 100644
--- a/drivers/video/fbdev/imsttfb.c
+++ b/drivers/video/fbdev/imsttfb.c
@@ -1469,6 +1469,7 @@ static int imsttfb_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	struct imstt_par *par;
 	struct fb_info *info;
 	struct device_node *dp;
+	int ret = -ENOMEM;
 	
 	dp = pci_device_to_OF_node(pdev);
 	if(dp)
@@ -1504,23 +1505,37 @@ static int imsttfb_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 		default:
 			printk(KERN_INFO "imsttfb: Device 0x%x unknown, "
 					 "contact maintainer.\n", pdev->device);
-			release_mem_region(addr, size);
-			framebuffer_release(info);
-			return -ENODEV;
+			ret = -ENODEV;
+			goto error;
 	}
 
 	info->fix.smem_start = addr;
 	info->screen_base = (__u8 *)ioremap(addr, par->ramdac == IBM ?
 					    0x400000 : 0x800000);
+	if (!info->screen_base)
+		goto error;
 	info->fix.mmio_start = addr + 0x800000;
 	par->dc_regs = ioremap(addr + 0x800000, 0x1000);
+	if (!par->dc_regs)
+		goto error;
 	par->cmap_regs_phys = addr + 0x840000;
 	par->cmap_regs = (__u8 *)ioremap(addr + 0x840000, 0x1000);
+	if (!par->cmap_regs)
+		goto error;
 	info->pseudo_palette = par->palette;
 	init_imstt(info);
 
 	pci_set_drvdata(pdev, info);
 	return 0;
+
+error:
+	if (par->dc_regs)
+		iounmap(par->dc_regs);
+	if (info->screen_base)
+		iounmap(info->screen_base);
+	release_mem_region(addr, size);
+	framebuffer_release(info);
+	return ret;
 }
 
 static void imsttfb_remove(struct pci_dev *pdev)
-- 
2.31.1