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| author | John B. Moore <jbmoore61@gmail.com> | 2026-04-28 00:06:28 +0300 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2026-05-05 17:16:09 +0300 |
| commit | 78d2e624fa073c14970aa097adcf3ea31c157a66 (patch) | |
| tree | 860d1a95bfa33fc4befc2ecfac7c8a58fd03f558 | |
| parent | 17223816498f7b117d138d18eb0eba63604dc74e (diff) | |
| download | linux-78d2e624fa073c14970aa097adcf3ea31c157a66.tar.xz | |
drm/amdgpu/sdma4: replace BUG_ON with WARN_ON in fence emission
sdma_v4_0_ring_emit_fence() contains two BUG_ON(addr & 0x3) assertions
that verify fence writeback addresses are dword-aligned. These
assertions can be reached from unprivileged userspace via crafted
DRM_IOCTL_AMDGPU_CS submissions, causing a fatal kernel panic in a
scheduler worker thread.
Replace both BUG_ON() calls with WARN_ON() to log the condition without
crashing the kernel. A misaligned fence address at this point indicates
a driver bug, but crashing the kernel is never the correct response when
the assertion is reachable from userspace.
The CS IOCTL path is the correct place to filter invalid submissions;
the ring emission callback is too late to do anything about it.
Fixes: 2130f89ced2c ("drm/amdgpu: add SDMA v4.0 implementation (v2)")
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: John B. Moore <jbmoore61@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit b90250bd933afd1ba94d86d6b13821997b22b18e)
Cc: stable@vger.kernel.org
| -rw-r--r-- | drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c b/drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c index 44f0f23e1148..e64f2f6df9a9 100644 --- a/drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c +++ b/drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c @@ -889,7 +889,7 @@ static void sdma_v4_0_ring_emit_fence(struct amdgpu_ring *ring, u64 addr, u64 se /* write the fence */ amdgpu_ring_write(ring, SDMA_PKT_HEADER_OP(SDMA_OP_FENCE)); /* zero in first two bits */ - BUG_ON(addr & 0x3); + WARN_ON(addr & 0x3); amdgpu_ring_write(ring, lower_32_bits(addr)); amdgpu_ring_write(ring, upper_32_bits(addr)); amdgpu_ring_write(ring, lower_32_bits(seq)); @@ -899,7 +899,7 @@ static void sdma_v4_0_ring_emit_fence(struct amdgpu_ring *ring, u64 addr, u64 se addr += 4; amdgpu_ring_write(ring, SDMA_PKT_HEADER_OP(SDMA_OP_FENCE)); /* zero in first two bits */ - BUG_ON(addr & 0x3); + WARN_ON(addr & 0x3); amdgpu_ring_write(ring, lower_32_bits(addr)); amdgpu_ring_write(ring, upper_32_bits(addr)); amdgpu_ring_write(ring, upper_32_bits(seq)); |