From b39f4c5c9b5e0c7a0b08d4a1ce7b69fe429663be Mon Sep 17 00:00:00 2001
From: Xu Jun <693788454@qq.com>
Date: Thu, 16 Jun 2022 09:51:01 +0800
Subject: [PATCH 1/2] Fix drop opcode issue in fast interpreter (#1231)

Fix fast interpreter issue reported in #1230
---
 core/iwasm/interpreter/wasm_loader.c      | 22 +++++++++++++++++----
 core/iwasm/interpreter/wasm_mini_loader.c | 24 ++++++++++++++++++-----
 2 files changed, 37 insertions(+), 9 deletions(-)

diff --git a/core/iwasm/interpreter/wasm_loader.c b/core/iwasm/interpreter/wasm_loader.c
index fecf75773..bc3cf1a89 100644
--- a/core/iwasm/interpreter/wasm_loader.c
+++ b/core/iwasm/interpreter/wasm_loader.c
@@ -6552,6 +6552,16 @@ wasm_loader_prepare_bytecode(WASMModule *module, WASMFunction *func,
     }
 
 #if WASM_ENABLE_FAST_INTERP != 0
+    /* For the first traverse, the initial value of preserved_local_offset has
+     * not been determined, we use the INT16_MAX to represent that a slot has
+     * been copied to preserve space. For second traverse, this field will be
+     * set to the appropriate value in wasm_loader_ctx_reinit.
+     * This is for Issue #1230,
+     * https://github.com/bytecodealliance/wasm-micro-runtime/issues/1230, the
+     * drop opcodes need to know which slots are preserved, so those slots will
+     * not be treated as dynamically allocated slots */
+    loader_ctx->preserved_local_offset = INT16_MAX;
+
 re_scan:
     if (loader_ctx->code_compiled_size > 0) {
         if (!wasm_loader_ctx_reinit(loader_ctx)) {
@@ -7209,8 +7219,10 @@ re_scan:
 #if WASM_ENABLE_FAST_INTERP != 0
                         skip_label();
                         loader_ctx->frame_offset--;
-                        if (*(loader_ctx->frame_offset)
-                            > loader_ctx->start_dynamic_offset)
+                        if ((*(loader_ctx->frame_offset)
+                             > loader_ctx->start_dynamic_offset)
+                            && (*(loader_ctx->frame_offset)
+                                < loader_ctx->max_dynamic_offset))
                             loader_ctx->dynamic_offset--;
 #endif
                     }
@@ -7223,8 +7235,10 @@ re_scan:
 #if WASM_ENABLE_FAST_INTERP != 0
                         skip_label();
                         loader_ctx->frame_offset -= 2;
-                        if (*(loader_ctx->frame_offset)
-                            > loader_ctx->start_dynamic_offset)
+                        if ((*(loader_ctx->frame_offset)
+                             > loader_ctx->start_dynamic_offset)
+                            && (*(loader_ctx->frame_offset)
+                                < loader_ctx->max_dynamic_offset))
                             loader_ctx->dynamic_offset -= 2;
 #endif
                     }
diff --git a/core/iwasm/interpreter/wasm_mini_loader.c b/core/iwasm/interpreter/wasm_mini_loader.c
index f33adaf1c..e39b1af7e 100644
--- a/core/iwasm/interpreter/wasm_mini_loader.c
+++ b/core/iwasm/interpreter/wasm_mini_loader.c
@@ -4870,6 +4870,16 @@ wasm_loader_prepare_bytecode(WASMModule *module, WASMFunction *func,
     }
 
 #if WASM_ENABLE_FAST_INTERP != 0
+    /* For the first traverse, the initial value of preserved_local_offset has
+     * not been determined, we use the INT16_MAX to represent that a slot has
+     * been copied to preserve space. For second traverse, this field will be
+     * set to the appropriate value in wasm_loader_ctx_reinit.
+     * This is for Issue #1230,
+     * https://github.com/bytecodealliance/wasm-micro-runtime/issues/1230, the
+     * drop opcodes need to know which slots are preserved, so those slots will
+     * not be treated as dynamically allocated slots */
+    loader_ctx->preserved_local_offset = INT16_MAX;
+
 re_scan:
     if (loader_ctx->code_compiled_size > 0) {
         if (!wasm_loader_ctx_reinit(loader_ctx)) {
@@ -5446,8 +5456,10 @@ re_scan:
 #if WASM_ENABLE_FAST_INTERP != 0
                         skip_label();
                         loader_ctx->frame_offset--;
-                        if (*(loader_ctx->frame_offset)
-                            > loader_ctx->start_dynamic_offset)
+                        if ((*(loader_ctx->frame_offset)
+                             > loader_ctx->start_dynamic_offset)
+                            && (*(loader_ctx->frame_offset)
+                                < loader_ctx->max_dynamic_offset))
                             loader_ctx->dynamic_offset--;
 #endif
                     }
@@ -5460,9 +5472,11 @@ re_scan:
 #if WASM_ENABLE_FAST_INTERP != 0
                         skip_label();
                         loader_ctx->frame_offset -= 2;
-                        if (*(loader_ctx->frame_offset)
-                            > loader_ctx->start_dynamic_offset)
-                            loader_ctx->dynamic_offset -= 2;
+                        if ((*(loader_ctx->frame_offset)
+                             > loader_ctx->start_dynamic_offset)
+                            && (*(loader_ctx->frame_offset)
+                                < loader_ctx->max_dynamic_offset))
+                            loader_ctx->dynamic_offset--;
 #endif
                     }
                     else {

From 188d5e70e9ab887685c99f808f6528d9f7e0d163 Mon Sep 17 00:00:00 2001
From: Xu Jun <693788454@qq.com>
Date: Thu, 16 Jun 2022 12:07:32 +0800
Subject: [PATCH 2/2] Fix typo in wasm_mini_loader.c (#1232)

---
 core/iwasm/interpreter/wasm_mini_loader.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/core/iwasm/interpreter/wasm_mini_loader.c b/core/iwasm/interpreter/wasm_mini_loader.c
index e39b1af7e..c7dc6ab8f 100644
--- a/core/iwasm/interpreter/wasm_mini_loader.c
+++ b/core/iwasm/interpreter/wasm_mini_loader.c
@@ -5476,7 +5476,7 @@ re_scan:
                              > loader_ctx->start_dynamic_offset)
                             && (*(loader_ctx->frame_offset)
                                 < loader_ctx->max_dynamic_offset))
-                            loader_ctx->dynamic_offset--;
+                            loader_ctx->dynamic_offset -= 2;
 #endif
                     }
                     else {