void *
dlopen (const char *path, int mode)
{
void *(*_dlopen) (const char *path, int mode);
char *new_path = NULL;
void *result;
_dlopen = (void *(*)(const char *path, int mode)) dlsym (RTLD_NEXT, "dlopen");
if (path && path[0] == '/') {
new_path = redirect_path (path);
result = _dlopen (new_path, mode);
free (new_path);
} else {
// non-absolute library paths aren't simply relative paths, they need
// a whole lookup algorithm
result = _dlopen (path, mode);
}
return result;
}
/*
* Several applications, such as Quake3, use dlopen("libGL.so.1"), but
* LD_PRELOAD does not intercept symbols obtained via dlopen/dlsym, therefore
* we need to intercept the dlopen() call here, and redirect to our wrapper
* shared object.
*/
extern "C" PUBLIC
void * dlopen(const char *filename, int flag)
{
void *handle;
if (!filename) {
return _dlopen(filename, flag);
}
LibClass libClass = classifyLibrary(filename);
bool intercept = libClass != LIB_UNKNOWN;
if (intercept) {
void *caller = __builtin_return_address(0);
Dl_info info;
const char *caller_module = "<unknown>";
if (dladdr(caller, &info)) {
caller_module = info.dli_fname;
intercept = classifyLibrary(caller_module) == LIB_UNKNOWN;
}
const char * libgl_filename = getenv("TRACE_LIBGL");
if (libgl_filename) {
// Don't intercept when using LD_LIBRARY_PATH instead of LD_PRELOAD
intercept = false;
}
os::log("apitrace: %s dlopen(\"%s\", 0x%x) from %s\n",
intercept ? "redirecting" : "ignoring",
filename, flag, caller_module);
}
#ifdef EGLTRACE
if (intercept) {
/* The current dispatch implementation relies on core entry-points to be globally available, so force this.
*
* TODO: A better approach would be note down the entry points here and
* use them latter. Another alternative would be to reopen the library
* with RTLD_NOLOAD | RTLD_GLOBAL.
*/
flag &= ~RTLD_LOCAL;
flag |= RTLD_GLOBAL;
}
#endif
handle = _dlopen(filename, flag);
if (!handle) {
return handle;
}
if (intercept) {
if (libClass == LIB_GL) {
// Use the true libGL.so handle instead of RTLD_NEXT from now on
_libGlHandle = handle;
}
// Get the file path for our shared object, and use it instead
static int dummy = 0xdeedbeef;
Dl_info info;
if (dladdr(&dummy, &info)) {
handle = _dlopen(info.dli_fname, flag);
} else {
os::log("apitrace: warning: dladdr() failed\n");
}
#ifdef EGLTRACE
// SDL will skip dlopen'ing libEGL.so after it spots EGL symbols on our
// wrapper, so force loading it here.
// (https://github.com/apitrace/apitrace/issues/291#issuecomment-59734022)
if (strcmp(filename, "libEGL.so") != 0 &&
strcmp(filename, "libEGL.so.1") != 0) {
_dlopen("libEGL.so.1", RTLD_GLOBAL | RTLD_LAZY);
}
#endif
}
return handle;
}
