nginx: [error] failed to initialize Lua VM - nginx

Question

I am trying to check memory leaks in my modules of nginx with valgrind.I am trying the following command
valgrind --leak-check=full --tool=memcheck --show-reachable=yes --log-file="/tmp/val.out" -v /usr/local/nginx -c /usr/local/conf/nginx.conf
I am getting the error nginx: [error] failed to initialize Lua VM
I am using nginx-1.6.2 on Cent OS 7 wit lua 0.9.15.

Answer 1

I had the same problem and it was fixed by upgrading Valgrind and adding some additional flags to LuaJIT compilation.
Look into:
https://github.com/openresty/lua-nginx-module/issues/681
Specifically:
==52538== Using Valgrind-3.10.0 and LibVEX;
Your version of valgrind does not support the MAP_32BIT flag required by LuaJIT's own allocator. You need either an older version of valgrind (like 3.8.1) or a newer version (like 3.11.0).
https://groups.google.com/forum/#!topic/openresty/riEO_YXTwz4
Specifically (using Google translate):
This is because LuaJIT own memory allocator MAP_32BIT use this flag in Linux x86_64 above to call mmap ()
System call. And Valgrind 3.9.0 is no longer supported from the mmap MAP_32BIT this flag, it will make LuaJIT
Initialization failed.
The solution is to re-compile a special version of LuaJIT, force it to use a dispenser system, using a command like this at compile time LuaJIT:
make CCDEBUG=-g Q= XCFLAGS='-DLUAJIT_USE_VALGRIND -DLUAJIT_USE_SYSMALLOC'
Here the most important thing is LUAJIT_USE_SYSMALLOC this macro. Of course, for best results, you should also specify the following C compiler options:
-DLUA_USE_APICHECK -DLUA_USE_ASSERT