ci: add ubsan check (#101)

Author: spacewander

.github/workflows/test.yml

@@ -8,7 +8,7 @@ on:
 
 jobs:
   test:
-    runs-on: "ubuntu-18.04"
+    runs-on: "ubuntu-20.04"
     env:
       OPENRESTY_PREFIX: "/usr/local/openresty"
 
@@ -39,7 +39,7 @@ jobs:
 
       - name: Get dependencies
         run: |
-          sudo apt install -y cpanminus build-essential libncurses5-dev libreadline-dev libssl-dev perl luarocks
+          sudo apt install -y cpanminus build-essential libncurses5-dev libreadline-dev libssl-dev perl luarocks libubsan0
           sudo luarocks install lua-resty-http > build.log 2>&1 || (cat build.log && exit 1)
 
           wget https://github.com/tinygo-org/tinygo/releases/download/v0.20.0/tinygo_0.20.0_amd64.deb
@@ -55,7 +55,9 @@ jobs:
           wget https://raw.githubusercontent.com/api7/apisix-build-tools/master/build-apisix-base.sh
           chmod +x build-apisix-base.sh
           OR_PREFIX=$OPENRESTY_PREFIX CC="clang -fsanitize=address -fcolor-diagnostics -Qunused-arguments" \
-              cc_opt="-Werror" ./build-apisix-base.sh latest
+              cc_opt="-Werror -fsanitize=undefined" \
+              ld_opt="-lubsan" \
+              ./build-apisix-base.sh latest
 
       - name: Script
         run: |

src/http/ngx_http_wasm_module.c

@@ -199,6 +199,10 @@ ngx_http_wasm_init(ngx_conf_t *cf)
 }
 
 
+/* To avoid complex error handling, we choose to allocate several objects together.
+ * The downside is that the objects are not alignment, but it is fine under x86 & ARM64, which
+ * are the only platforms supported by most of the Wasm VM. */
+__attribute__((no_sanitize("undefined")))
 void *
 ngx_http_wasm_load_plugin(const char *name, size_t name_len,
                           const char *bytecode, size_t size)