lua: build as a standalone tool with static libbcc

src/lua/CMakeLists.txt

@@ -19,6 +19,7 @@ if (LUAJIT_LIBRARIES AND LUAJIT)
 	include_directories(${LUAJIT_INCLUDE_DIR})
 	add_executable(bcc-lua src/main.c bcc.o)
 	target_link_libraries(bcc-lua ${LUAJIT_LIBRARIES})
+	target_link_libraries(bcc-lua -Wl,--whole-archive bcc-static -Wl,--no-whole-archive)
 
 	install(TARGETS bcc-lua RUNTIME DESTINATION bin)
 endif()

src/lua/bcc-probe

@@ -17,5 +17,4 @@ limitations under the License.
 local str = require("debug").getinfo(1, "S").source:sub(2)
 local script_path = str:match("(.*/)").."/?.lua;"
 package.path = script_path..package.path
-rawset(_G, "BCC_STANDALONE_NAME", "bcc-probe")
 require("bcc.run")()

src/lua/bcc/libbcc.lua

@@ -112,4 +112,11 @@ int bcc_symcache_resolve(void *symcache, uint64_t addr, struct bcc_symbol *sym);
 void bcc_symcache_refresh(void *resolver);
 ]]
 
-return ffi.load(os.getenv("LIBBCC_SO_PATH") or rawget(_G, "LIBBCC_SO_PATH") or "bcc")
+if rawget(_G, "BCC_STANDALONE") then
+  return ffi.C
+else
+  return ffi.load(
+    os.getenv("LIBBCC_SO_PATH") or
+    rawget(_G, "LIBBCC_SO_PATH") or
+    "bcc")
+end

src/lua/bcc/run.lua

@@ -16,11 +16,12 @@ limitations under the License.
 
 return function()
   require("bcc.vendor.helpers")
-  local progname = rawget(_G, "BCC_STANDALONE_NAME") or "bcc-lua"
+  local standalone = rawget(_G, "BCC_STANDALONE")
+  local progname = standalone or "bcc-probe"
 
   local function print_usage()
     io.stderr:write(string.format(
-      "usage: %s [[--so-path=PATH|--version|--verbose] --] path_to_script.lua [...]\n",
+      "usage: %s [[--version|--verbose] --] path_to_script.lua [...]\n",
       progname))
     os.exit(1)
   end
@@ -37,7 +38,7 @@ return function()
     local k = table.remove(arg, 1)
     if k == "--" then
       break
-    elseif string.starts(k, "--so-path=") then
+    elseif standalone == nil and string.starts(k, "--so-path=") then
       rawset(_G, "LIBBCC_SO_PATH", string.lstrip(k, "--so-path="))
     elseif k == "--llvm-debug" then
       rawset(_G, "LIBBCC_LLVM_DEBUG", 1)

src/lua/src/main.c

@@ -125,27 +125,6 @@ static void pushargv(lua_State *L, char **argv, int argc, int offset)
 	}
 }
 
-static void find_local_libbcc(lua_State *L)
-{
-	char buffer[4096];
-	char *dirname;
-
-	if (readlink("/proc/self/exe", buffer, sizeof(buffer)) < 0)
-		return;
-
-	dirname = strrchr(buffer, '/');
-	if (dirname == NULL)
-		return;
-
-	strcpy(dirname + 1, "libbcc.so");
-
-	if (access(buffer, F_OK|R_OK|X_OK) != 0)
-		return;
-
-	lua_pushstring(L, buffer);
-	lua_setglobal(L, "LIBBCC_SO_PATH");
-}
-
 static int pmain(lua_State *L)
 {
 	struct Smain *s = (struct Smain *)lua_touserdata(L, 1);
@@ -154,14 +133,13 @@ static int pmain(lua_State *L)
 	lua_gc(L, LUA_GCSTOP, 0);
 	luaL_openlibs(L);
 	lua_gc(L, LUA_GCRESTART, 0);
-	find_local_libbcc(L);
 
 	s->status = dolibrary(L, "bcc", 0);
 	if (s->status)
 		return 0;
 
 	lua_pushstring(L, progname);
-	lua_setglobal(L, "BCC_STANDALONE_NAME");
+	lua_setglobal(L, "BCC_STANDALONE");
 
 	pushargv(L, s->argv, s->argc, 1);
 	lua_setglobal(L, "arg");
@@ -181,6 +159,11 @@ int main(int argc, char **argv)
 		return EXIT_FAILURE;
 	}
 
+	if (geteuid() != 0) {
+		l_message(argv[0], "bcc-lua must be ran as root");
+		return EXIT_FAILURE;
+	}
+
 	progname = argv[0];
 	s.argc = argc;
 	s.argv = argv;