From c86a9483f4fbb401be4125b7b6ca490a6d3e776c Mon Sep 17 00:00:00 2001 From: Vineet Gupta Date: Tue, 23 Oct 2018 14:58:39 -0700 Subject: [PATCH] ARC: Linux Startup and Dynamic Loading A big shoutout to Cupertino Miranda for his valuable contribution in initial bringup and debugging on Linux and later in solving pesky unwinding/cancelation failures in testsuite. Reviewed-by: Adhemerval Zanella --- sysdeps/unix/sysv/linux/arc/dl-static.c | 84 +++++++++++++++++++++++++ sysdeps/unix/sysv/linux/arc/ldsodefs.h | 32 ++++++++++ 2 files changed, 116 insertions(+) create mode 100644 sysdeps/unix/sysv/linux/arc/dl-static.c create mode 100644 sysdeps/unix/sysv/linux/arc/ldsodefs.h diff --git a/sysdeps/unix/sysv/linux/arc/dl-static.c b/sysdeps/unix/sysv/linux/arc/dl-static.c new file mode 100644 index 0000000000..30bcd899d4 --- /dev/null +++ b/sysdeps/unix/sysv/linux/arc/dl-static.c @@ -0,0 +1,84 @@ +/* Variable initialization. ARC version. + Copyright (C) 2020 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 + . */ + +#include + +#ifdef SHARED + +void +_dl_var_init (void *array[]) +{ + /* It has to match "variables" below. */ + enum + { + DL_PAGESIZE = 0 + }; + + GLRO(dl_pagesize) = *((size_t *) array[DL_PAGESIZE]); +} + +#else + +static void *variables[] = +{ + &GLRO(dl_pagesize) +}; + +static void +_dl_unprotect_relro (struct link_map *l) +{ + ElfW(Addr) start = ((l->l_addr + l->l_relro_addr) + & ~(GLRO(dl_pagesize) - 1)); + ElfW(Addr) end = ((l->l_addr + l->l_relro_addr + l->l_relro_size) + & ~(GLRO(dl_pagesize) - 1)); + + if (start != end) + __mprotect ((void *) start, end - start, PROT_READ | PROT_WRITE); +} + +void +_dl_static_init (struct link_map *l) +{ + struct link_map *rtld_map = l; + struct r_scope_elem **scope; + const ElfW(Sym) *ref = NULL; + lookup_t loadbase; + void (*f) (void *[]); + size_t i; + + loadbase = _dl_lookup_symbol_x ("_dl_var_init", l, &ref, l->l_local_scope, + NULL, 0, 1, NULL); + + for (scope = l->l_local_scope; *scope != NULL; scope++) + for (i = 0; i < (*scope)->r_nlist; i++) + if ((*scope)->r_list[i] == loadbase) + { + rtld_map = (*scope)->r_list[i]; + break; + } + + if (ref != NULL) + { + f = (void (*) (void *[])) DL_SYMBOL_ADDRESS (loadbase, ref); + _dl_unprotect_relro (rtld_map); + f (variables); + _dl_protect_relro (rtld_map); + } +} + +#endif diff --git a/sysdeps/unix/sysv/linux/arc/ldsodefs.h b/sysdeps/unix/sysv/linux/arc/ldsodefs.h new file mode 100644 index 0000000000..204a0ff894 --- /dev/null +++ b/sysdeps/unix/sysv/linux/arc/ldsodefs.h @@ -0,0 +1,32 @@ +/* Run-time dynamic linker data structures for loaded ELF shared objects. ARC + Copyright (C) 2020 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 + . */ + +#ifndef _LDSODEFS_H + +/* Get the real definitions. */ +#include_next + +/* Now define our stuff. */ + +/* We need special support to initialize DSO loaded for statically linked + binaries. */ +extern void _dl_static_init (struct link_map *map); +#undef DL_STATIC_INIT +#define DL_STATIC_INIT(map) _dl_static_init (map) + +#endif /* ldsodefs.h */