platform_bionic/linker/linker_gdb_support.cpp
Dimitry Ivanov 6b788eeff2 Move gdb support functions to a separate file
Move gdb support functions and variables to
linker_gdb_support.h/cpp

Change-Id: I96c6592a7055715b18f1137367470fe80987263f
2016-02-18 12:32:56 -08:00

94 lines
2.6 KiB
C++

/*
* 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();
}