[Nouveau] [PATCH] drm/nouveau: fix off by one in BIOS boundry checking

[Nick Lopez <github@glowingmonkey.org>]

Bounds checking when parsing init scripts embedded in the BIOS reject
access to the last byte. This causes driver initialization to fail on
Apple eMac's with GeForce 2 MX GPUs, leaving the system with no working
console.

This is probably only seen on OpenFirmware machines like PowerPC Macs
because the BIOS image provides by OF is only the used parts of the ROM,
not a power-of-two blocks read from PCI directly so PCs always have
empty bytes at the end that are never accesseed.

Signed-off-by: Nick Lopez <github@glowingmonkey.org>
---
 drivers/gpu/drm/nouveau/nvkm/subdev/bios/base.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/bios/base.c b/drivers/gpu/drm/nouveau/nvkm/subdev/bios/base.c
index d0f52d59fc2f..64e423dddd9e 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/bios/base.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/bios/base.c
@@ -38,7 +38,7 @@ nvbios_addr(struct nvkm_bios *bios, u32 *addr, u8 size)
 		*addr += bios->imaged_addr;
 	}
 
-	if (unlikely(*addr + size >= bios->size)) {
+	if (unlikely(*addr + size > bios->size)) {
 		nvkm_error(&bios->subdev, "OOB %d %08x %08x\n", size, p, *addr);
 		return false;
 	}
-- 
2.30.2