From 16f504a9dca3fe3b70568f67b7d41241ae485288 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 18:49:04 +0200 Subject: Adding upstream version 7.0.6-dfsg. Signed-off-by: Daniel Baumann --- include/iprt/runtime-loader.h | 189 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 189 insertions(+) create mode 100644 include/iprt/runtime-loader.h (limited to 'include/iprt/runtime-loader.h') diff --git a/include/iprt/runtime-loader.h b/include/iprt/runtime-loader.h new file mode 100644 index 00000000..3892ffcf --- /dev/null +++ b/include/iprt/runtime-loader.h @@ -0,0 +1,189 @@ +/** @file + * IPRT - Runtime Loader Generation. + */ + +/* + * Copyright (C) 2008-2022 Oracle and/or its affiliates. + * + * This file is part of VirtualBox base platform packages, as + * available from https://www.virtualbox.org. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation, in version 3 of the + * License. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see . + * + * The contents of this file may alternatively be used under the terms + * of the Common Development and Distribution License Version 1.0 + * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included + * in the VirtualBox distribution, in which case the provisions of the + * CDDL are applicable instead of those of the GPL. + * + * You may elect to license modified versions of this file under the + * terms and conditions of either the GPL or the CDDL or both. + * + * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0 + */ + +#include +#ifdef RT_RUNTIME_LOADER_GENERATE_BODY_STUBS +# include +# include +# include +#endif + +/** @defgroup grp_rt_runtime_loader Runtime Loader Generation + * @ingroup grp_rt + * + * How to use this loader generator + * + * This loader generator can be used to generate stub code for loading a shared + * library and its functions at runtime, or for generating a header file with + * the declaration of the loader function and optionally declarations for the + * functions loaded. It should be included in a header file or a C source + * file, after defining certain macros which it makes use of. + * + * To generate the C source code for function proxy stubs and the library + * loader function, you should define the following macros in your source file + * before including this header: + * + * RT_RUNTIME_LOADER_LIB_NAME - the file name of the library to load + * RT_RUNTIME_LOADER_FUNCTION - the name of the loader function + * RT_RUNTIME_LOADER_INSERT_SYMBOLS - a macro containing the names of the + * functions to be loaded, defined in the + * following pattern: + * @code + * #define RT_RUNTIME_LOADER_INSERT_SYMBOLS \ + * RT_PROXY_STUB(func_name, ret_type, (long_param_list), (short_param_list)) \ + * RT_PROXY_STUB(func_name2, ret_type2, (long_param_list2), (short_param_list2)) \ + * ... + * @endcode + * + * where long_param_list is a parameter list for declaring the function of the + * form (type1 arg1, type2 arg2, ...) and short_param_list for calling it, of + * the form (arg1, arg2, ...). + * + * To generate the header file, you should define RT_RUNTIME_LOADER_FUNCTION + * and if you wish to generate declarations for the functions you should + * additionally define RT_RUNTIME_LOADER_INSERT_SYMBOLS as above and + * RT_RUNTIME_LOADER_GENERATE_DECLS (without a value) before including this + * file. + * + * @{ + */ +/** @todo this is far too complicated. A script for generating the files would + * probably be preferable. + * + * bird> An alternative is to generate assembly jump wrappers, this only + * requires the symbol names and prefix. I've done this ages ago when we forked + * the EMX/GCC toolchain on OS/2... It's a wee bit more annoying in x86 PIC/PIE + * mode, but nothing that cannot be dealt with. + */ +/** @todo r=bird: The use of RTR3DECL here is an unresolved issue. */ +/** @todo r=bird: The lack of RT_C_DECLS_BEGIN/END is an unresolved issue. Here + * we'll get into trouble if we use the same symbol names as the + * original! */ +/** @todo r=bird: The prefix usage here is very confused: RT_RUNTIME_LOADER_XXX, + * RT_PROXY_STUB, etc. */ + +#ifdef RT_RUNTIME_LOADER_GENERATE_BODY_STUBS + +/* The following are the symbols which we need from the library. */ +# define RT_PROXY_STUB(function, rettype, signature, shortsig) \ + void (*function ## _fn)(void); \ + RTR3DECL(rettype) function signature \ + { return ( (rettype (*) signature) function ## _fn ) shortsig; } + +RT_RUNTIME_LOADER_INSERT_SYMBOLS + +# undef RT_PROXY_STUB + +/* Now comes a table of functions to be loaded from the library. */ +typedef struct +{ + const char *pszName; + void (**ppfn)(void); +} RTLDRSHAREDFUNC; + +# define RT_PROXY_STUB(s, dummy1, dummy2, dummy3 ) { #s , & s ## _fn } , +static RTLDRSHAREDFUNC g_aSharedFuncs[] = +{ + RT_RUNTIME_LOADER_INSERT_SYMBOLS + { NULL, NULL } +}; +# undef RT_PROXY_STUB + +/** + * The function which does the actual work for RT_RUNTIME_LOADER_FUNCTION, + * serialised for thread safety. + */ +static DECLCALLBACK(int) rtldrLoadOnce(void *) +{ + RTLDRMOD hLib; + int rc; + + LogFlowFunc(("\n")); + rc = RTLdrLoadEx(RT_RUNTIME_LOADER_LIB_NAME, &hLib, RTLDRLOAD_FLAGS_LOCAL | RTLDRLOAD_FLAGS_NO_UNLOAD, NULL); + for (unsigned i = 0; RT_SUCCESS(rc) && g_aSharedFuncs[i].pszName != NULL; ++i) + rc = RTLdrGetSymbol(hLib, g_aSharedFuncs[i].pszName, (void **)g_aSharedFuncs[i].ppfn); + LogFlowFunc(("rc = %Rrc\n", rc)); + + return rc; +} + +/** + * Load the shared library RT_RUNTIME_LOADER_LIB_NAME and resolve the symbols + * pointed to by RT_RUNTIME_LOADER_INSERT_SYMBOLS. + * + * May safely be called from multiple threads and will not return until the + * library is loaded or has failed to load. + * + * @returns IPRT status code. + */ +RTR3DECL(int) RT_RUNTIME_LOADER_FUNCTION(void) +{ + static RTONCE s_Once = RTONCE_INITIALIZER; + int rc; + + LogFlowFunc(("\n")); + rc = RTOnce(&s_Once, rtldrLoadOnce, NULL); + LogFlowFunc(("rc = %Rrc\n", rc)); + + return rc; +} + +#elif defined(RT_RUNTIME_LOADER_GENERATE_HEADER) +# ifdef RT_RUNTIME_LOADER_GENERATE_DECLS +/* Declarations of the functions that we need from + * RT_RUNTIME_LOADER_LIB_NAME */ +# define RT_PROXY_STUB(function, rettype, signature, shortsig) \ + RTR3DECL(rettype) function signature ; + +RT_RUNTIME_LOADER_INSERT_SYMBOLS + +# undef RT_PROXY_STUB +# endif /* RT_RUNTIME_LOADER_GENERATE_DECLS */ + +/** + * Try to dynamically load the library. This function should be called before + * attempting to use any of the library functions. It is safe to call this + * function multiple times. + * + * @returns iprt status code + */ +RTR3DECL(int) RT_RUNTIME_LOADER_FUNCTION(void); + +#else +# error "One of RT_RUNTIME_LOADER_GENERATE_HEADER or RT_RUNTIME_LOADER_GENERATE_BODY_STUBS must be defined when including this file" +#endif + +/** @} */ + -- cgit v1.2.3