embed to C failed

[hhm152800]

os: vmware ubuntu
toolchain: wasi-sdk-20
wasm-app src:

int add (int a, int b)
{
	return a+b;
}

command:
$CC test.c -o test.wasm -O0 -Wl,--export=add -Wl,--strip-all,--no-entry -nostdlib --target=wasm32-wasi -O0 -z stack-size=4096 -Wl,--initial-memory=65536 -Wl,--allow-undefined -Wl,--allow-undefined-file=${WAMR_DIR}/wamr-sdk/app/libc-builtin-sysroot/share/defined-symbols.txt

cmakelist flag:

 project (wasmtest C ASM)
enable_language (ASM_MASM)
set (CMAKE_SHARED_LIBRARY_LINK_C_FLAGS "")
set (CMAKE_SHARED_LIBRARY_LINK_CXX_FLAGS "")
set (WAMR_BUILD_PLATFORM "linux")
set (WAMR_BUILD_TARGET "X86_64")
set (WAMR_BUILD_INTERP 1)
set (WAMR_BUILD_FAST_INTERP 1)
set (WAMR_BUILD_AOT 1)
set (WAMR_BUILD_JIT 0)
set (WAMR_BUILD_LIBC_BUILTIN 1)
set (WAMR_BUILD_LIBC_WASI 1)
set (WAMR_BUILD_SIMD 0)
set (WAMR_DISABLE_HW_BOUND_CHECK 1)
set (WAMR_DISABLE_STACK_HW_BOUND_CHECK 1)
set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Wextra -Wformat -Wformat-security")
set(WAMR_ROOT_DIR /home/ubuntu/workspace/wasm-micro-runtime)
include (${WAMR_ROOT_DIR}/build-scripts/runtime_lib.cmake)
add_library(vmlib ${WAMR_RUNTIME_LIB_SOURCE})
include (${SHARED_DIR}/utils/uncommon/shared_uncommon.cmake)
add_executable(wasmtest main.c ${UNCOMMON_SHARED_SOURCE})
target_link_libraries (wasmtest vmlib -lm -ldl -lpthread -lrt)

c src:

wasm_runtime_init();
  buffer = bh_read_file_to_buffer("test.wasm", &buf_size);
  module = wasm_runtime_load((unsigned char*)buffer, buf_size, error_buf, sizeof(error_buf));
  if (!module)
      return -1;
  module_inst = wasm_runtime_instantiate(module, stack_size, heap_size,
                                             error_buf, sizeof(error_buf));
  if (!module_inst) {
      return -1;
  }
  exec_env = wasm_runtime_create_exec_env(module_inst, stack_size);
  if (!exec_env) {
      return -1;
  }
  if (!(func = wasm_runtime_lookup_function(module_inst, "add",
                                            NULL))) {
      return -1;
  }
  wasm_val_t results[1];
  wasm_val_t params[2];
  params[0].kind = WASM_I32;
  params[0].of.i32 = 4;
  params[1].kind = WASM_I32;
  params[1].of.i32 = 4;
  wasm_runtime_call_wasm_a(exec_env, func, 1, results, 2, params);

exception :

#if defined(os_writegsbase)
    {
        WASMMemoryInstance *memory_inst = wasm_get_default_memory(module_inst);
        if (memory_inst)
            /* write base addr of linear memory to GS segment register */
            os_writegsbase(memory_inst->memory_data);
    }
#endif

when try to do , always exception on os_writegsbase, why, how to deal with it

[wenyongh]

Hi, you can manually remove these lines:
https://github.com/bytecodealliance/wasm-micro-runtime/blob/main/core/shared/platform/linux/platform_internal.h#L67-L71

This is to write the linear memory base address to the x86 segment register GS so that it may speed up the linear memory access for AOT/JIT. I found that your os is vmware ubuntu, writing that register may be disabled by your platform so you encountered the error. Maybe we can add control for that, e.g. add cmake -DWAMR_DISABLE_WRITE_GS_BASE=1 to disable it (like cmake -DWAMR_DISABLE_HW_BOUND_CHECK).

[hhm152800]

thanks, it work when i remove code, i think will be more easy to resolve that add some note in os_writegsbase

[wenyongh]

Yes, do you know whether there is some compiler macro related to vmware ubuntu so we can use it to disable the os_writegsbase in the platform_internal.h?

[hhm152800]

Yes, do you know whether there is some compiler macro related to vmware ubuntu so we can use it to disable the os_writegsbase in the platform_internal.h?

sorry , i don't know that, i try it on ubuntu only a week...

[hhm152800]

Yes, do you know whether there is some compiler macro related to vmware ubuntu so we can use it to disable the os_writegsbase in the platform_internal.h?

may vmware cause , i try ubuntu18, ubuntu20, get the same result