radeon: Do not directly dereference pointers to BIOS area.

Use readb() and memcpy_fromio() accessors instead.

Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

1 files changed, 7 insertions, 3 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_bios.c b/drivers/gpu/drm/radeon/radeon_bios.c
index 63ccb8fa799c..d27e4ccb848c 100644
--- a/drivers/gpu/drm/radeon/radeon_bios.c
+++ b/drivers/gpu/drm/radeon/radeon_bios.c
@@ -76,7 +76,7 @@ static bool igp_read_bios_from_vram(struct radeon_device *rdev)
 
 static bool radeon_read_bios(struct radeon_device *rdev)
 {
-        uint8_t __iomem *bios;
+        uint8_t __iomem *bios, val1, val2;
         size_t size;
 
         rdev->bios = NULL;
@@ -86,15 +86,19 @@ static bool radeon_read_bios(struct radeon_device *rdev)
                 return false;
         }
 
-        if (size == 0 || bios[0] != 0x55 || bios[1] != 0xaa) {
+        val1 = readb(&bios[0]);
+        val2 = readb(&bios[1]);
+
+        if (size == 0 || val1 != 0x55 || val2 != 0xaa) {
                 pci_unmap_rom(rdev->pdev, bios);
                 return false;
         }
-        rdev->bios = kmemdup(bios, size, GFP_KERNEL);
+        rdev->bios = kzalloc(size, GFP_KERNEL);
         if (rdev->bios == NULL) {
                 pci_unmap_rom(rdev->pdev, bios);
                 return false;
         }
+        memcpy_fromio(rdev->bios, bios, size);
         pci_unmap_rom(rdev->pdev, bios);
         return true;
 }