[PATCH 6.1 220/236] drm/amdkfd: dont allow mapping the MMIO HDP page with large pages

Greg Kroah-Hartman
2024-05-14T11:38:54Z

From: Alex Deucher <alexander.deucher@amd.com>

commit be4a2a81b6b90d1a47eaeaace4cc8e2cb57b96c7 upstream.

We don't get the right offset in that case. The GPU has
an unused 4K area of the register BAR space into which you can
remap registers. We remap the HDP flush registers into this
space to allow userspace (CPU or GPU) to flush the HDP when it
updates VRAM. However, on systems with >4K pages, we end up
exposing PAGE_SIZE of MMIO space.

Fixes: d8e408a82704 ("drm/amdkfd: Expose HDP registers to user space")
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/gpu/drm/amd/amdkfd/kfd_chardev.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
@@ -1106,7 +1106,7 @@ static int kfd_ioctl_alloc_memory_of_gpu
goto err_unlock;
}
offset = dev->adev->rmmio_remap.bus_addr;
- if (!offset) {
+ if (!offset || (PAGE_SIZE > 4096)) {
err = -ENOMEM;
goto err_unlock;
}
@@ -2215,7 +2215,7 @@ static int criu_restore_memory_of_gpu(st
return -EINVAL;
}
offset = pdd->dev->adev->rmmio_remap.bus_addr;
- if (!offset) {
+ if (!offset || (PAGE_SIZE > 4096)) {
pr_err("amdgpu_amdkfd_get_mmio_remap_phys_addr failed\n");
return -ENOMEM;
}
@@ -2886,6 +2886,9 @@ static int kfd_mmio_mmap(struct kfd_dev
if (vma->vm_end - vma->vm_start != PAGE_SIZE)
return -EINVAL;

+ if (PAGE_SIZE > 4096)
+ return -EINVAL;
+
address = dev->adev->rmmio_remap.bus_addr;

vma->vm_flags |= VM_IO | VM_DONTCOPY | VM_DONTEXPAND | VM_NORESERVE |