diff options
| -rw-r--r-- | dispatch/glproc_egl.cpp | 97 |
1 files changed, 54 insertions, 43 deletions
diff --git a/dispatch/glproc_egl.cpp b/dispatch/glproc_egl.cpp index c1331275..07714ae8 100644 --- a/dispatch/glproc_egl.cpp +++ b/dispatch/glproc_egl.cpp @@ -61,19 +61,29 @@ void *_libGlHandle = NULL; * (extensions) entry-points. Core entry-points should be taken directly from * the API specific libraries. * - * We cannot tell here which API a symbol is meant for here (as some are - * exported by many). So this code assumes that the appropriate shared - * libraries have been loaded previously (either dlopened with RTLD_GLOBAL, or - * as part of the executable dependencies), and that their symbols available - * for quering via dlsym(RTLD_NEXT, ...). */ void * _getPublicProcAddress(const char *procName) { -#if defined(ANDROID) + void *proc; + + /* + * We rely on dlsym(RTLD_NEXT, ...) whenever we can, because certain gl* + * symbols are exported by multiple APIs/SOs, and it's not trivial to + * determine which API/SO we should get the current symbol from. + */ + proc = dlsym(RTLD_NEXT, procName); + if (proc) { + return proc; + } + /* - * Android does not support LD_PRELOAD. It is assumed that applications - * are explicitely loading egltrace.so. + * dlsym(RTLD_NEXT, ...) will fail when the SO containing the symbol was + * loaded with RTLD_LOCAL. We try to override RTLD_LOCAL with RTLD_GLOBAL + * when tracing but this doesn't always work. So we try to guess and load + * the shared object directly. + * + * See https://github.com/apitrace/apitrace/issues/349#issuecomment-113316990 */ if (procName[0] == 'e' && procName[1] == 'g' && procName[2] == 'l') { @@ -87,19 +97,48 @@ _getPublicProcAddress(const char *procName) return dlsym(libEGL, procName); } + /* + * This might happen when: + * + * - the application is querying non-extensions functions via + * eglGetProcAddress (either because EGL_KHR_get_all_proc_addresses + * is advertised, or merely because the EGL implementation supports + * it regardless, like Mesa does) + * + * - libGLES*.so nor libGL*.so was ever loaded. + * + * - we need to resolve entrypoints that application never asked (e.g., + * glGetIntegerv), for internal purposes + * + * Therefore, we try to fallback to eglGetProcAddress. + * + * See https://github.com/apitrace/apitrace/issues/301#issuecomment-68532248 + */ + if (strcmp(procName, "eglGetProcAddress") != 0) { + proc = (void *) _eglGetProcAddress(procName); + if (proc) { + return proc; + } + } + + /* + * TODO: We could futher mitigate against using the wrong SO by: + * - using RTLD_NOLOAD to ensure we only use an existing SO + * - the determine the right SO via eglQueryAPI and glGetString(GL_VERSION) + */ + if (procName[0] == 'g' && procName[1] == 'l') { /* TODO: Use GLESv1/GLESv2 on a per-context basis. */ - static void *sym = NULL; static void *libGLESv2 = NULL; if (!libGLESv2) { libGLESv2 = _dlopen("libGLESv2.so", RTLD_LOCAL | RTLD_LAZY); } if (libGLESv2) { - sym = dlsym(libGLESv2, procName); + proc = dlsym(libGLESv2, procName); } - if (sym) { - return sym; + if (proc) { + return proc; } static void *libGLESv1 = NULL; @@ -107,42 +146,14 @@ _getPublicProcAddress(const char *procName) libGLESv1 = _dlopen("libGLESv1_CM.so", RTLD_LOCAL | RTLD_LAZY); } if (libGLESv1) { - sym = dlsym(libGLESv1, procName); + proc = dlsym(libGLESv1, procName); } - if (sym) { - return sym; + if (proc) { + return proc; } } return NULL; -#else - void *proc; - proc = dlsym(RTLD_NEXT, procName); - if (!proc && - strcmp(procName, "eglGetProcAddress") != 0) { - /* - * This might happen when: - * - * - the application is querying non-extensions functions via - * eglGetProcAddress (either because EGL_KHR_get_all_proc_addresses - * is advertised, or merely because the EGL implementation supports - * it regardless, like Mesa does) - * - * - libGLES*.so nor libGL*.so was ever loaded. - * - * - we need to resolve entrypoints that application never asked (e.g., - * glGetIntegerv), for internal purposes - * - * Therefore, we try to fallback to eglGetProcAddress. - * - * Another alternative would be to dlopen libGL/libGLES ourselves. - * - * See https://github.com/apitrace/apitrace/issues/301#issuecomment-68532248 - */ - proc = (void *) _eglGetProcAddress(procName); - } - return proc; -#endif } /* |