| /* |
| * Copyright (C) 2016 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include "linker_gdb_support.h" |
| |
| #include <pthread.h> |
| |
| #include "private/ScopedPthreadMutexLocker.h" |
| |
| // This function is an empty stub where GDB locates a breakpoint to get notified |
| // about linker activity. |
| extern "C" |
| void __attribute__((noinline)) __attribute__((visibility("default"))) rtld_db_dlactivity(); |
| |
| r_debug _r_debug = |
| {1, nullptr, reinterpret_cast<uintptr_t>(&rtld_db_dlactivity), r_debug::RT_CONSISTENT, 0}; |
| |
| static pthread_mutex_t g__r_debug_mutex = PTHREAD_MUTEX_INITIALIZER; |
| static link_map* r_debug_tail = nullptr; |
| |
| void insert_link_map_into_debug_map(link_map* map) { |
| // Stick the new library at the end of the list. |
| // gdb tends to care more about libc than it does |
| // about leaf libraries, and ordering it this way |
| // reduces the back-and-forth over the wire. |
| if (r_debug_tail != nullptr) { |
| r_debug_tail->l_next = map; |
| map->l_prev = r_debug_tail; |
| map->l_next = nullptr; |
| } else { |
| _r_debug.r_map = map; |
| map->l_prev = nullptr; |
| map->l_next = nullptr; |
| } |
| r_debug_tail = map; |
| } |
| |
| void remove_link_map_from_debug_map(link_map* map) { |
| if (r_debug_tail == map) { |
| r_debug_tail = map->l_prev; |
| } |
| |
| if (map->l_prev) { |
| map->l_prev->l_next = map->l_next; |
| } |
| if (map->l_next) { |
| map->l_next->l_prev = map->l_prev; |
| } |
| } |
| |
| void notify_gdb_of_load(link_map* map) { |
| ScopedPthreadMutexLocker locker(&g__r_debug_mutex); |
| |
| _r_debug.r_state = r_debug::RT_ADD; |
| rtld_db_dlactivity(); |
| |
| insert_link_map_into_debug_map(map); |
| |
| _r_debug.r_state = r_debug::RT_CONSISTENT; |
| rtld_db_dlactivity(); |
| } |
| |
| void notify_gdb_of_unload(link_map* map) { |
| ScopedPthreadMutexLocker locker(&g__r_debug_mutex); |
| |
| _r_debug.r_state = r_debug::RT_DELETE; |
| rtld_db_dlactivity(); |
| |
| remove_link_map_from_debug_map(map); |
| |
| _r_debug.r_state = r_debug::RT_CONSISTENT; |
| rtld_db_dlactivity(); |
| } |
| |
| void notify_gdb_of_libraries() { |
| _r_debug.r_state = r_debug::RT_ADD; |
| rtld_db_dlactivity(); |
| _r_debug.r_state = r_debug::RT_CONSISTENT; |
| rtld_db_dlactivity(); |
| } |
| |