video: imsttfb: check for ioremap() failures

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: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210503115736.2104747-68-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/video/fbdev/imsttfb.c b/drivers/video/fbdev/imsttfb.c
index e04411701ec85f55dacec2d010b9a7de7b4fd0bb..16f272a508112c91a6381f2d08081ced787de643 100644 (file)
--- 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)