| /* Communicate dynamic linker state to the debugger at runtime. |
| Copyright (C) 1996-2018 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/>. */ |
| |
| #include <ldsodefs.h> |
| |
| |
| /* These are the members in the public `struct link_map' type. |
| Sanity check that the internal type and the public type match. */ |
| #define VERIFY_MEMBER(name) \ |
| (offsetof (struct link_map_public, name) == offsetof (struct link_map, name)) |
| extern const int verify_link_map_members[(VERIFY_MEMBER (l_addr) |
| && VERIFY_MEMBER (l_name) |
| && VERIFY_MEMBER (l_ld) |
| && VERIFY_MEMBER (l_next) |
| && VERIFY_MEMBER (l_prev)) |
| ? 1 : -1]; |
| |
| /* This structure communicates dl state to the debugger. The debugger |
| normally finds it via the DT_DEBUG entry in the dynamic section, but in |
| a statically-linked program there is no dynamic section for the debugger |
| to examine and it looks for this particular symbol name. */ |
| struct r_debug _r_debug; |
| |
| |
| /* Initialize _r_debug if it has not already been done. The argument is |
| the run-time load address of the dynamic linker, to be put in |
| _r_debug.r_ldbase. Returns the address of _r_debug. */ |
| |
| struct r_debug * |
| _dl_debug_initialize (ElfW(Addr) ldbase, Lmid_t ns) |
| { |
| struct r_debug *r; |
| |
| if (ns == LM_ID_BASE) |
| r = &_r_debug; |
| else |
| r = &GL(dl_ns)[ns]._ns_debug; |
| |
| if (r->r_map == NULL || ldbase != 0) |
| { |
| /* Tell the debugger where to find the map of loaded objects. */ |
| r->r_version = 1 /* R_DEBUG_VERSION XXX */; |
| r->r_ldbase = ldbase ?: _r_debug.r_ldbase; |
| r->r_map = (void *) GL(dl_ns)[ns]._ns_loaded; |
| r->r_brk = (ElfW(Addr)) &_dl_debug_state; |
| } |
| |
| return r; |
| } |
| |
| |
| void (*_google_dl_debug_state_hook)(const struct r_debug *); |
| |
| /* This function exists solely to have a breakpoint set on it by the |
| debugger. The debugger is supposed to find this function's address by |
| examining the r_brk member of struct r_debug, but GDB 4.15 in fact looks |
| for this particular symbol name in the PT_INTERP file. */ |
| void |
| _dl_debug_state (void) |
| { |
| if (_google_dl_debug_state_hook) |
| _google_dl_debug_state_hook(&_r_debug); |
| } |
| rtld_hidden_def (_dl_debug_state) |