egltrace: Don't intercept dlopen calls done by EGL/GL/GLES implementation.

Certain EGL implementations do this.

4 files changed, 150 insertions, 117 deletions

diff --git a/wrappers/CMakeLists.txt b/wrappers/CMakeLists.txt
index 5e29b1ac..4bd3ef19 100644
--- a/wrappers/CMakeLists.txt
+++ b/wrappers/CMakeLists.txt
@@ -418,6 +418,8 @@ if (ENABLE_EGL AND NOT WIN32 AND NOT APPLE)
         PREFIX ""
     )
 
+    target_compile_definitions (egltrace PRIVATE -DEGLTRACE=1)
+
     target_link_libraries (egltrace
         gltrace_common
         glproc_egl
diff --git a/wrappers/dlsym.cpp b/wrappers/dlsym.cpp
index 118110f2..5f34a2f0 100644
--- a/wrappers/dlsym.cpp
+++ b/wrappers/dlsym.cpp
@@ -25,6 +25,9 @@
  **************************************************************************/
 
 
+#include <assert.h>
+#include <memory>
+
 #include "os.hpp"
 
 
@@ -77,3 +80,148 @@ dlsym(void * handle, const char * symbol)
 
 
 #endif /* __GLIBC__ */
+
+
+#include "dlopen.hpp"
+
+
+extern void * _libGlHandle;
+
+
+
+enum LibClass {
+    LIB_UNKNOWN = 0,
+    LIB_GL,
+    LIB_EGL,
+    LIB_GLES1,
+    LIB_GLES2,
+};
+
+
+inline LibClass
+classifyLibrary(const char *pathname)
+{
+    std::unique_ptr<char, decltype(std::free) *> dupname { strdup(pathname), std::free };
+
+    char *filename = basename(dupname.get());
+    assert(filename);
+
+    if (strcmp(filename, "libGL.so") == 0 ||
+        strcmp(filename, "libGL.so.1") == 0) {
+        return LIB_GL;
+    }
+
+#ifdef EGLTRACE
+    if (strcmp(filename, "libEGL.so") == 0 ||
+        strcmp(filename, "libEGL.so.1") == 0) {
+        return LIB_EGL;
+    }
+
+    if  (strcmp(filename, "libGLESv1_CM.so") == 0 ||
+         strcmp(filename, "libGLESv1_CM.so.1") == 0) {
+        return LIB_GLES1;
+    }
+
+    if (strcmp(filename, "libGLESv2.so") == 0 ||
+        strcmp(filename, "libGLESv2.so.2") == 0) {
+        return LIB_GLES2;
+    }
+#endif
+
+    /*
+     * TODO: Identify driver SOs (e.g, *_dri.so), to prevent intercepting
+     * dlopen calls from them.
+     *
+     * Another alternative is to ignore dlopen calls when inside wrapped calls.
+     */
+
+    return LIB_UNKNOWN;
+}
+
+
+/*
+ * 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;
+}
diff --git a/wrappers/egltrace.py b/wrappers/egltrace.py
index 333809b9..8e658141 100644
--- a/wrappers/egltrace.py
+++ b/wrappers/egltrace.py
@@ -113,7 +113,6 @@ if __name__ == '__main__':
     print '#define GL_GLEXT_PROTOTYPES'
     print '#define EGL_EGLEXT_PROTOTYPES'
     print
-    print '#include "dlopen.hpp"'
     print '#include "glproc.hpp"'
     print '#include "glsize.hpp"'
     print '#include "eglsize.hpp"'
@@ -128,70 +127,6 @@ if __name__ == '__main__':
     tracer.traceApi(api)
 
     print r'''
-
-
-
-/*
- * 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)
-{
-    bool intercept = false;
-
-    if (filename) {
-        intercept =
-            strcmp(filename, "libEGL.so") == 0 ||
-            strcmp(filename, "libEGL.so.1") == 0 ||
-            strcmp(filename, "libGLESv1_CM.so") == 0 ||
-            strcmp(filename, "libGLESv1_CM.so.1") == 0 ||
-            strcmp(filename, "libGLESv2.so") == 0 ||
-            strcmp(filename, "libGLESv2.so.2") == 0 ||
-            strcmp(filename, "libGL.so") == 0 ||
-            strcmp(filename, "libGL.so.1") == 0;
-
-        if (intercept) {
-            os::log("apitrace: redirecting dlopen(\"%s\", 0x%x)\n", filename, flag);
-
-            /* 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;
-        }
-    }
-
-    void *handle = _dlopen(filename, flag);
-
-    if (intercept) {
-        // 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");
-        }
-
-        // 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);
-        }
-    }
-
-    return handle;
-}
-
-
 #if defined(ANDROID)
 
 /*
@@ -251,6 +186,4 @@ void APIENTRY glWeightPointerOESBounds(GLint size, GLenum type, GLsizei stride,
  */
 
 #endif /* ANDROID */
-
-
 '''
diff --git a/wrappers/glxtrace.py b/wrappers/glxtrace.py
index e9c43a9c..d9dce953 100644
--- a/wrappers/glxtrace.py
+++ b/wrappers/glxtrace.py
@@ -166,7 +166,6 @@ if __name__ == '__main__':
     print '#define GL_GLEXT_PROTOTYPES'
     print '#define GLX_GLXEXT_PROTOTYPES'
     print
-    print '#include "dlopen.hpp"'
     print '#include "glproc.hpp"'
     print '#include "glsize.hpp"'
     print
@@ -178,52 +177,3 @@ if __name__ == '__main__':
     api.addModule(module)
     tracer = GlxTracer()
     tracer.traceApi(api)
-
-    print r'''
-
-
-/*
- * 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;
-
-    handle = _dlopen(filename, flag);
-
-    const char * libgl_filename = getenv("TRACE_LIBGL");
-
-    if (filename && handle && !libgl_filename) {
-        if (0) {
-            os::log("apitrace: warning: dlopen(\"%s\", 0x%x)\n", filename, flag);
-        }
-
-        // FIXME: handle absolute paths and other versions
-        if (strcmp(filename, "libGL.so") == 0 ||
-            strcmp(filename, "libGL.so.1") == 0) {
-
-            // 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)) {
-                os::log("apitrace: redirecting dlopen(\"%s\", 0x%x)\n", filename, flag);
-                handle = _dlopen(info.dli_fname, flag);
-            } else {
-                os::log("apitrace: warning: dladdr() failed\n");
-            }
-        }
-    }
-
-    return handle;
-}
-
-
-
-'''