[PATCH v1] edac: i82975x_edac :- Handle return NULL error from ioremap_nocache

[Arvind Yadav]

Here, If ioremap_nocache will fail. It will return NULL.
Kernel can run into a NULL-pointer dereference.
This error check will avoid NULL pointer dereference.

Signed-off-by: Arvind Yadav <arvind.yadav.cs@xxxxxxxxx>
---
 drivers/edac/i82975x_edac.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/edac/i82975x_edac.c b/drivers/edac/i82975x_edac.c
index 7baa8ac..e747d82 100644
--- a/drivers/edac/i82975x_edac.c
+++ b/drivers/edac/i82975x_edac.c
@@ -494,6 +494,10 @@ static int i82975x_probe1(struct pci_dev *pdev, int dev_idx)
 	}
 	mchbar &= 0xffffc000;	/* bits 31:14 used for 16K window */
 	mch_window = ioremap_nocache(mchbar, 0x1000);
+	if (!mch_window) {
+		edac_dbg(3, "failed to memory map!\n");
+		goto fail0;
+	}
 
 #ifdef i82975x_DEBUG_IOMEM
 	i82975x_printk(KERN_INFO, "MCHBAR real = %0x, remapped = %p\n",
-- 
1.9.1