[PATCH 3.2 159/221] radeon: Do not directly dereference pointers to BIOS area.

Ben Hutchings
2015-05-05T01:25:28Z

From: David Miller <davem@davemloft.net>

commit f2c9e560b406f2f6b14b345c7da33467dee9cdf2 upstream.

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>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/gpu/drm/radeon/radeon_bios.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

--- 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(stru

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 rade
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;
}