From eec8b6cae586451deadf30c371f7b5e4c9d573d1 Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Sat, 27 Mar 2004 03:40:33 +0000 Subject: Update. 2004-03-26 Ulrich Drepper * elf/dl-caller.c: New file. * include/caller.h: New file. * Makefile (distribute): Add include/caller.h. * elf/Makefile (dl-routines): Add dl-caller. * elf/dl-load.c (_dl_map_object_from_fd): Record l_text_end. * elf/dl-open.c (check_libc_caller): Removed. (dl_open_worker): Use __check_caller instead. * elf/rtld.c (_rtld_global_ro): Initialize _dl_check_caller. (_dl_start_final): Record l_text_end for ld.so map. (dl_main): Record l_text_end for main object and vdso. * include/link.h (struct link_map): Add l_text_end field. * sysdeps/generic/ldsodefs.h (struct rtld_global_ro): Add _dl_check_caller field. Define enum allowmask. Add declaration of _dl_check_caller. * sysdeps/unix/sysv/linux/dl-execstack.c: Also use __check_caller test. --- elf/dl-caller.c | 85 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 85 insertions(+) create mode 100644 elf/dl-caller.c (limited to 'elf/dl-caller.c') diff --git a/elf/dl-caller.c b/elf/dl-caller.c new file mode 100644 index 0000000000..ddabbd0f2d --- /dev/null +++ b/elf/dl-caller.c @@ -0,0 +1,85 @@ +/* Check whether caller comes from the right place. + Copyright (C) 2004 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, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include +#include +#include +#include +#include + + +int +attribute_hidden +_dl_check_caller (const void *caller, enum allowmask mask) +{ + static const char expected1[] = LIBC_SO; + static const char expected2[] = LIBDL_SO; +#ifdef LIBPTHREAD_SO + static const char expected3[] = LIBPTHREAD_SO; +#endif + static const char expected4[] = LD_SO; + + for (struct link_map *l = GL(dl_loaded); l != NULL; l = l->l_next) + if (caller >= (const void *) l->l_map_start + && caller < (const void *) l->l_text_end) + { + /* The address falls into this DSO's address range. Check the + name. */ + if ((mask & allow_libc) && strcmp (expected1, l->l_name) == 0) + return 0; + if ((mask & allow_libdl) && strcmp (expected2, l->l_name) == 0) + return 0; +#ifdef LIBPTHREAD_SO + if ((mask & allow_libpthread) && strcmp (expected3, l->l_name) == 0) + return 0; +#endif + if ((mask & allow_ldso) && strcmp (expected4, l->l_name) == 0) + return 0; + + struct libname_list *runp = l->l_libname; + + while (runp != NULL) + { + if ((mask & allow_libc) && strcmp (expected1, runp->name) == 0) + return 0; + if ((mask & allow_libdl) && strcmp (expected2, runp->name) == 0) + return 0; +#ifdef LIBPTHREAD_SO + if ((mask & allow_libpthread) + && strcmp (expected3, runp->name) == 0) + return 0; +#endif + if ((mask & allow_ldso) && strcmp (expected4, runp->name) == 0) + return 0; + + runp = runp->next; + } + + break; + } + + /* Maybe the dynamic linker is not yet on the list. */ + if ((mask & allow_ldso) != 0 + && caller >= (const void *) GL(dl_rtld_map).l_map_start + && caller < (const void *) GL(dl_rtld_map).l_text_end) + return 0; + + /* No valid caller. */ + return 1; +} -- cgit v1.2.3