Fix mea segmentation fault error (#55408)

* fix mea seg fault develop

* fix bias_grad seg fault

paddle/phi/infermeta/backward.cc

@@ -728,7 +728,7 @@ void MemoryEfficientAttentionGradInferMeta(const MetaTensor& query,
   value_grad->set_dtype(value.dtype());
   value_grad->set_layout(value.layout());
 
-  if (bias) {
+  if (bias && bias_grad) {
     const int64_t bias_batch_size = bias.dims()[0];
     const int64_t bias_seq_length = bias.dims()[1];
     const int64_t bias_num_head = bias.dims()[2];

paddle/phi/kernels/fusion/cutlass/memory_efficient_attention.cu

@@ -202,10 +202,13 @@ void MemoryEfficientAttentionForwardKernel(
 
     if (bias) {
       p.attn_bias_ptr = phi::SafeGetTensorPtr<scalar_t>(bias);
+      const auto& bias_dims = bias.get().dims();
       PD_MEA_CHECK_OVERFLOW(
           p.bias_strideB,
-          GetMemoryEfficientBiasStrideB(bias.get().dims(), q_dims, k_dims));
-      PD_MEA_CHECK_OVERFLOW(p.bias_strideH, q_dims[1] * k_dims[1]);
+          GetMemoryEfficientBiasStrideB(bias_dims, q_dims, k_dims));
+      PD_MEA_CHECK_OVERFLOW(
+          p.bias_strideH,
+          GetMemoryEfficientBiasStrideH(bias_dims, q_dims, k_dims));
       PD_MEA_CHECK_OVERFLOW(p.bias_strideM, k_dims[1]);
     } else {
       p.attn_bias_ptr = nullptr;

paddle/phi/kernels/fusion/cutlass/memory_efficient_attention_backward.cu

@@ -486,10 +486,13 @@ void MemoryEfficientAttentionBackwardKernel(
 
     if (bias) {
       p.bias_ptr = phi::SafeGetTensorPtr<scalar_t>(bias);
+      const auto& bias_dims = bias.get().dims();
       PD_MEA_CHECK_OVERFLOW(
           p.bias_strideB,
-          GetMemoryEfficientBiasStrideB(bias.get().dims(), q_dims, k_dims));
-      PD_MEA_CHECK_OVERFLOW(p.bias_strideH, q_dims[1] * k_dims[1]);
+          GetMemoryEfficientBiasStrideB(bias_dims, q_dims, k_dims));
+      PD_MEA_CHECK_OVERFLOW(
+          p.bias_strideH,
+          GetMemoryEfficientBiasStrideH(bias_dims, q_dims, k_dims));
       PD_MEA_CHECK_OVERFLOW(p.bias_strideM, k_dims[1]);
       VLOG(3) << "p.bias_ptr" << p.bias_ptr;
       if (bias_grad) {

paddle/phi/kernels/fusion/cutlass/memory_efficient_attention_utils.h

@@ -62,6 +62,30 @@ inline int64_t GetMemoryEfficientBiasStrideB(const phi::DDim &bias_dims,
   return 0;
 }
 
+inline int64_t GetMemoryEfficientBiasStrideH(const phi::DDim &bias_dims,
+                                             const phi::DDim &q_dims,
+                                             const phi::DDim &k_dims) {
+  int bias_dims_rank = bias_dims.size();
+  if (bias_dims_rank == 2) {
+    return 0;
+  } else {
+    PADDLE_ENFORCE_EQ(bias_dims_rank,
+                      4,
+                      phi::errors::InvalidArgument(
+                          "The rank of attn_bias should be 2 or 4."));
+    if (bias_dims[1] != q_dims[2]) {
+      PADDLE_ENFORCE_EQ(
+          bias_dims[1],
+          1,
+          phi::errors::InvalidArgument(
+              "The second dim of attn_bias should be 1 or num_heads."));
+      return 0;
+    } else {
+      return q_dims[1] * k_dims[1];
+    }
+  }
+}
+
 #define PD_MEA_CHECK_OVERFLOW(__dst, ...)                                    \
   do {                                                                       \
     auto __src = (__VA_ARGS__);                                              \