[PATCH 6.18 192/752] drm/amdgpu: validate user queue size constraints

Sasha Levin
2026-02-28T17:50:52Z

From: "Jesse.Zhang" <Jesse.Zhang@amd.com>

[ Upstream commit 8079b87c02e531cc91601f72ea8336dd2262fdf1 ]

Add validation to ensure user queue sizes meet hardware requirements:
- Size must be a power of two for efficient ring buffer wrapping
- Size must be at least AMDGPU_GPU_PAGE_SIZE to prevent undersized allocations

This prevents invalid configurations that could lead to GPU faults or
unexpected behavior.

Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Jesse Zhang <jesse.zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c | 11 +++++++++++
1 file changed, 11 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c
index 8c41951feb437..eef65833a1c99 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c
@@ -656,6 +656,17 @@ static int amdgpu_userq_input_args_validate(struct drm_device *dev,
drm_file_err(filp, "invalidate userq queue va or size\n");
return -EINVAL;
}
+
+ if (!is_power_of_2(args->in.queue_size)) {
+ drm_file_err(filp, "Queue size must be a power of 2\n");
+ return -EINVAL;
+ }
+
+ if (args->in.queue_size < AMDGPU_GPU_PAGE_SIZE) {
+ drm_file_err(filp, "Queue size smaller than AMDGPU_GPU_PAGE_SIZE\n");
+ return -EINVAL;
+ }
+
if (!args->in.wptr_va || !args->in.rptr_va) {
drm_file_err(filp, "invalidate userq queue rptr or wptr\n");
return -EINVAL;
--
2.51.0