glibc/sysdeps/nacl/dl-sysdep.c
2015-04-17 09:02:19 -07:00

90 lines
3.1 KiB
C

/* Operating system support for run-time dynamic linker. NaCl version.
Copyright (C) 2015 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
<http://www.gnu.org/licenses/>. */
#ifdef SHARED
# include <assert.h>
# include <ldsodefs.h>
# include <stdint.h>
# include <nacl-interfaces.h>
/* NaCl's elf32.h is incompatible with the real <elf.h>. */
# define NATIVE_CLIENT_SRC_INCLUDE_ELF32_H_
# include <native_client/src/untrusted/nacl/nacl_startup.h>
/* 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 __attribute__ ((noreturn))
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);
/* Fail clearly just in case it did return. */
__builtin_trap ();
}
# define DL_SYSDEP_INIT __nacl_initialize_interfaces ()
#endif /* SHARED */
#include <elf/dl-sysdep.c>