platform_bionic/libc/malloc_debug/Unreachable.cpp
Christopher Ferris b42e8b4dec Add option to force memunreachable check.
The new option is named check_unreachable_on_signal. It is meant
to duplicate dumpsys meminfo --unreachable <PID> for non-java
processes. When enabled, a user can send a signal to a process
which will trigger the unreachable check on the next allocation
call.

Added new unit tests.

Test: New unit tests pass.
Test: Enabled for the entire system, then dumped on the netd
Test: process and also system_server.
Change-Id: I73561b408a947a11ce21a211b065d59fcc39097b
2022-05-10 17:37:19 -07:00

80 lines
2.8 KiB
C++

/*
* Copyright (C) 2022 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <errno.h>
#include <signal.h>
#include <stdint.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>
#include <atomic>
#include <string>
#include <memunreachable/memunreachable.h>
#include <platform/bionic/macros.h>
#include "Config.h"
#include "Unreachable.h"
#include "debug_log.h"
std::atomic_bool Unreachable::do_check_;
static void EnableUnreachableCheck(int, struct siginfo*, void*) {
Unreachable::EnableCheck();
}
void Unreachable::CheckIfRequested(const Config& config) {
if ((config.options() & CHECK_UNREACHABLE_ON_SIGNAL) && do_check_.exchange(false)) {
info_log("Starting to check for unreachable memory.");
if (!LogUnreachableMemory(false, 100)) {
error_log("Unreachable check failed, run setenforce 0 and try again.");
}
}
}
bool Unreachable::Initialize(const Config& config) {
if (!(config.options() & CHECK_UNREACHABLE_ON_SIGNAL)) {
return true;
}
struct sigaction64 unreachable_act = {};
unreachable_act.sa_sigaction = EnableUnreachableCheck;
unreachable_act.sa_flags = SA_RESTART | SA_SIGINFO | SA_ONSTACK;
if (sigaction64(config.check_unreachable_signal(), &unreachable_act, nullptr) != 0) {
error_log("Unable to set up check unreachable signal function: %s", strerror(errno));
return false;
}
if (config.options() & VERBOSE) {
info_log("%s: Run: 'kill -%d %d' to check for unreachable memory.", getprogname(),
config.check_unreachable_signal(), getpid());
}
return true;
}