[BugFix][Kernel]: fix illegal memory access in causal_conv1d when conv_states is None (#10928)

Signed-off-by: xffxff <1247714429@qq.com>

csrc/mamba/causal_conv1d/causal_conv1d.cu

@@ -424,7 +424,7 @@ void causal_conv1d_fwd_kernel(ConvParamsBase params) {
         // and the one before it (chunk = n_chunks - 1 and chunk = n_chunks - 2), 
         // (which occurs when `final_state_position` is a non-positivie index)
         // we load the correct data from smem_exchange from both chunks, the last chunk iteration and the one before it
-        if (final_state_position < 0 && seqlen > kWidth){
+        if (conv_states != nullptr && final_state_position < 0 && seqlen > kWidth){
             input_t vals_load[kNElts] = {0};
             if ((chunk == n_chunks - 2) && (tidx == kNThreads - 1)){
                 // chunk = n_chunks - 2, a segment of the final state sits in the last index

tests/kernels/test_causal_conv1d.py

@@ -149,13 +149,14 @@ def causal_conv1d_opcheck_fn(x: torch.Tensor,
 @pytest.mark.parametrize("itype", [torch.bfloat16, torch.float])
 @pytest.mark.parametrize("silu_activation", [True])
 @pytest.mark.parametrize("has_bias", [True])
+@pytest.mark.parametrize("has_initial_state", [True, False])
 @pytest.mark.parametrize("width", [4])
 @pytest.mark.parametrize(
     'seqlen', [1, 8, 16, 32, 64, 128, 256, 512, 784, 1024, 1025, 2048, 4096])
 @pytest.mark.parametrize('dim', [64])
 @pytest.mark.parametrize('batch', [1])
 def test_causal_conv1d(batch, dim, seqlen, width, has_bias, silu_activation,
-                       itype):
+                       has_initial_state, itype):
     device = "cuda"
     rtol, atol = (3e-4, 1e-3) if itype == torch.float32 else (3e-3, 5e-3)
     if itype == torch.bfloat16:
@@ -167,11 +168,18 @@ def test_causal_conv1d(batch, dim, seqlen, width, has_bias, silu_activation,
 
     weight = torch.randn(dim, width, device=device, dtype=itype)
     bias = torch.randn(dim, device=device, dtype=itype) if has_bias else None
+    if has_initial_state:
         initial_states = torch.randn(batch,
                                      dim,
                                      width - 1,
                                      device=device,
                                      dtype=itype)
+        has_initial_state_tensor = torch.ones(batch,
+                                              dtype=torch.bool,
+                                              device=x.device)
+    else:
+        initial_states = None
+        has_initial_state_tensor = None
     x_ref = x.clone()
     weight_ref = weight.clone()
     bias_ref = bias.clone() if bias is not None else None
@@ -183,9 +191,7 @@ def test_causal_conv1d(batch, dim, seqlen, width, has_bias, silu_activation,
                            bias,
                            activation=activation,
                            conv_states=initial_states,
-                           has_initial_state=torch.ones(batch,
-                                                        dtype=torch.bool,
-                                                        device=x.device))
+                           has_initial_state=has_initial_state_tensor)
     out_ref, final_states_ref = causal_conv1d_ref(
         x_ref,
         weight_ref,
@@ -193,6 +199,7 @@ def test_causal_conv1d(batch, dim, seqlen, width, has_bias, silu_activation,
         initial_states=initial_states_ref,
         return_final_states=True,
         activation=activation)
+    if has_initial_state:
         assert initial_states is not None and final_states_ref is not None
         assert torch.allclose(initial_states,
                               final_states_ref,
@@ -205,9 +212,7 @@ def test_causal_conv1d(batch, dim, seqlen, width, has_bias, silu_activation,
                              bias,
                              activation=activation,
                              conv_states=initial_states,
-                             has_initial_state=torch.ones(batch,
-                                                          dtype=torch.bool,
-                                                          device=x.device))
+                             has_initial_state=has_initial_state_tensor)
 
 
 @pytest.mark.parametrize("itype", [torch.bfloat16])