From: Roland McGrath Date: Tue, 7 May 2013 21:51:54 +0000 (-0700) Subject: Part way to rtld startup. X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=64dbb4e1c1f83872bfea14c3ce2dbe2d8ed30289;p=thirdparty%2Fglibc.git Part way to rtld startup. --- diff --git a/sysdeps/arm/nacl/dl-machine.h b/sysdeps/arm/nacl/dl-machine.h index aa9202f80de..97a06f4d407 100644 --- a/sysdeps/arm/nacl/dl-machine.h +++ b/sysdeps/arm/nacl/dl-machine.h @@ -20,7 +20,7 @@ /* This is only needed for handling TEXTRELs and NaCl will never support TEXTRELs at all. */ -#define CLEAR_CACHE(start, end) abort () +#define CLEAR_CACHE(start, end) __builtin_trap () #endif @@ -28,3 +28,25 @@ This #include is outside the #ifndef because the parts of dl-machine.h used only by dynamic-link.h are outside the guard. */ #include + +#ifdef dl_machine_h + +/* Initial entry point code for the dynamic linker. + The C function `_dl_start' is the real entry point; + its return value is the user program's entry point. */ +#undef RTLD_START +#define RTLD_START asm ("\ +.text\n\ +.globl _start\n\ +.type _start, %function\n\ +_start:\n\ + @ r0 has the pointer to the info block (see nacl_startup.h)\n\ + mov r1, sp @ Save stack base for __libc_stack_end.\n\ + push {r0-r3} @ Push those, maintaining alignment to 16.\n\ + mov r0, sp @ Pointer to {info, sp} is argument.\n\ + sfi_bl _dl_start\n\ + pop {r1-r4} @ Restore stack, getting info block into r1.\n\ + mov lr, #0 @ Return address for noreturn call.\n\ + b _dl_start_user"); + +#endif diff --git a/sysdeps/nacl/dl-osinfo.h b/sysdeps/nacl/dl-osinfo.h index 505eb4ba864..0aacf4ec45f 100644 --- a/sysdeps/nacl/dl-osinfo.h +++ b/sysdeps/nacl/dl-osinfo.h @@ -23,11 +23,12 @@ #include "nacl-interfaces.h" +#ifndef SHARED /* This doesn't really have anything to do with the purpose for which this macro is used in Linux configurations. But it is called at the right place in __libc_start_main. */ - -#define DL_SYSDEP_OSCHECK(fatal) __nacl_initialize_interfaces () +# define DL_SYSDEP_OSCHECK(fatal) __nacl_initialize_interfaces () +#endif #endif /* dl-osinfo.h */ diff --git a/sysdeps/nacl/dl-sysdep.c b/sysdeps/nacl/dl-sysdep.c new file mode 100644 index 00000000000..7e6a0929afc --- /dev/null +++ b/sysdeps/nacl/dl-sysdep.c @@ -0,0 +1,83 @@ +/* Operating system support for run-time dynamic linker. NaCl version. + Copyright (C) 2013 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#ifdef SHARED + +#include +#include +#include + +/* NaCl's elf32.h is incompatible with the real . */ +#define NATIVE_CLIENT_SRC_INCLUDE_ELF32_H_ +#include + +/* The RTLD_START code sets up the pointer that gets to these + macros as COOKIE to point to two words: + [0] the argument to the entry point from the system (see nacl_startup.h) + [1] the stack base +*/ + +#define DL_FIND_ARG_COMPONENTS(cookie, argc, argv, envp, auxp) \ + do { \ + uint32_t *_info = ((void **) (cookie))[0]; \ + (argc) = nacl_startup_argc (_info); \ + (argv) = nacl_startup_argv (_info); \ + (envp) = nacl_startup_envp (_info); \ + (auxp) = nacl_startup_auxv (_info); \ + } while (0) + +#define DL_STACK_END(cookie) (((void **) (cookie))[1]) + +/* This is called from the entry point (_start), defined by the RTLD_START + macro in the machine-specific dl-machine.h file. At this point, dynamic + linking has been completed and the first argument is the application's + entry point. */ +attribute_hidden internal_function +void +_dl_start_user (void (*user_entry) (uint32_t info[]), uint32_t info[]) +{ + if (_dl_skip_args > 0) + { + /* There are some arguments that the user program should not see. + Just slide up the INFO pointer so its NACL_STARTUP_ARGV points + to what should now be argv[0], and copy back the earlier fields. */ + assert (nacl_startup_argc (info) >= _dl_skip_args); + assert (NACL_STARTUP_ARGV == 3); + uint32_t envc = info[NACL_STARTUP_ENVC]; + uint32_t argc = info[NACL_STARTUP_ARGC]; + info += _dl_skip_args; + info[NACL_STARTUP_ENVC] = envc; + info[NACL_STARTUP_ARGC] = argc - _dl_skip_args; + } + + /* Pass our finalizer function to the user. */ + info[NACL_STARTUP_FINI] = (uintptr_t) &_dl_fini; + + /* Run initializers. */ + _dl_init (GL(dl_ns)[0]._ns_loaded, + nacl_startup_argc (info), + nacl_startup_argv (info), + nacl_startup_envp (info)); + + /* Call the user's entry point. This should never return. */ + (*user_entry) (info); +} + +#endif /* SHARED */ + +#include diff --git a/sysdeps/nacl/dl-sysdep.h b/sysdeps/nacl/dl-sysdep.h index 19c23cb0ac4..86813dde5ec 100644 --- a/sysdeps/nacl/dl-sysdep.h +++ b/sysdeps/nacl/dl-sysdep.h @@ -25,3 +25,6 @@ but we too want to store its value. */ #define NEED_DL_SYSINFO 1 #define DL_SYSINFO_DEFAULT 0 + +/* sysdeps/arm/dl-sysdep.h defines this but it does not apply to NaCl. */ +#undef DL_ARGV_NOT_RELRO diff --git a/sysdeps/nacl/entry.h b/sysdeps/nacl/entry.h new file mode 100644 index 00000000000..e9dc190e34b --- /dev/null +++ b/sysdeps/nacl/entry.h @@ -0,0 +1,6 @@ +#ifndef __ASSEMBLY__ +# include +extern void _start (uint32_t info[]) attribute_hidden; +#endif + +#define ENTRY_POINT _start