From: Johannes Gäßler <redacted>
Date: Mon, 19 May 2025 07:33:35 +0000 (+0200)
Subject: mnist: fix segmentation fault (#1227)
X-Git-Url: https://git.djapps.eu/?a=commitdiff_plain;h=7c06c10c532a6cda913c17fc56341e8880ae341d;p=pkg%2Fggml%2Fsources%2Fggml

mnist: fix segmentation fault (#1227)
---

diff --git a/examples/mnist/mnist-common.cpp b/examples/mnist/mnist-common.cpp
index 6bf369f5..a303bcec 100644
--- a/examples/mnist/mnist-common.cpp
+++ b/examples/mnist/mnist-common.cpp
@@ -385,7 +385,10 @@ ggml_opt_result_t mnist_model_eval(mnist_model & model, ggml_opt_dataset_t datas
     ggml_opt_result_t result = ggml_opt_result_init();
 
     ggml_opt_params params = ggml_opt_default_params(model.backend_sched, GGML_OPT_LOSS_TYPE_CROSS_ENTROPY);
-    params.build_type = GGML_OPT_BUILD_TYPE_FORWARD;
+    params.ctx_compute = model.ctx_compute;
+    params.inputs      = model.images;
+    params.outputs     = model.logits;
+    params.build_type  = GGML_OPT_BUILD_TYPE_FORWARD;
     ggml_opt_context_t opt_ctx = ggml_opt_init(params);
 
     {
diff --git a/include/ggml-opt.h b/include/ggml-opt.h
index da0c24b4..74ec080a 100644
--- a/include/ggml-opt.h
+++ b/include/ggml-opt.h
@@ -128,6 +128,8 @@ extern "C" {
     // set gradients to zero, initilize loss, and optionally reset the optimizer
     GGML_API void ggml_opt_reset(ggml_opt_context_t opt_ctx, bool optimizer);
 
+    GGML_API bool ggml_opt_static_graphs(ggml_opt_context_t opt_ctx); // whether the graphs are allocated_statically
+
     // get underlying tensors that store data
     // if not using static graphs these pointers become invalid with the next call to ggml_opt_alloc
     GGML_API struct ggml_tensor * ggml_opt_inputs(  ggml_opt_context_t opt_ctx); // forward graph input tensor
diff --git a/src/ggml-opt.cpp b/src/ggml-opt.cpp
index 58d77578..a3c82d67 100644
--- a/src/ggml-opt.cpp
+++ b/src/ggml-opt.cpp
@@ -576,6 +576,10 @@ void ggml_opt_reset(ggml_opt_context_t opt_ctx, bool optimizer) {
     }
 }
 
+bool ggml_opt_static_graphs(ggml_opt_context_t opt_ctx) {
+    return opt_ctx->static_graphs;
+}
+
 struct ggml_tensor * ggml_opt_inputs(ggml_opt_context_t opt_ctx) {
     return opt_ctx->inputs;
 }
@@ -842,6 +846,7 @@ void ggml_opt_epoch(
         int64_t                 idata_split,
         ggml_opt_epoch_callback callback_train,
         ggml_opt_epoch_callback callback_eval) {
+    GGML_ASSERT(ggml_opt_static_graphs(opt_ctx) && "ggml_opt_epoch requires static graphs");
     struct ggml_tensor * inputs = ggml_opt_inputs(opt_ctx);
     struct ggml_tensor * labels = ggml_opt_labels(opt_ctx);
     struct ggml_tensor * data   = ggml_opt_dataset_data(dataset);