blob: 743a2e775147ffb319e288badd35079aa9528fd1 [file] [log] [blame]
/*
* 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.
*/
#define LOG_TAG "DEBUG"
#include "libdebuggerd/open_files_list.h"
#include <android/fdsan.h>
#include <dirent.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>
#include <string>
#include <utility>
#include <vector>
#include <android-base/file.h>
#include <log/log.h>
#include <unwindstack/Memory.h>
#include "libdebuggerd/utility.h"
#include "private/bionic_fdsan.h"
void populate_open_files_list(OpenFilesList* list, pid_t pid) {
std::string fd_dir_name = "/proc/" + std::to_string(pid) + "/fd";
std::unique_ptr<DIR, int (*)(DIR*)> dir(opendir(fd_dir_name.c_str()), closedir);
if (dir == nullptr) {
ALOGE("failed to open directory %s: %s", fd_dir_name.c_str(), strerror(errno));
return;
}
struct dirent* de;
while ((de = readdir(dir.get())) != nullptr) {
if (*de->d_name == '.') {
continue;
}
int fd = atoi(de->d_name);
std::string path = fd_dir_name + "/" + std::string(de->d_name);
std::string target;
if (android::base::Readlink(path, &target)) {
(*list)[fd].path = target;
} else {
(*list)[fd].path = "???";
ALOGE("failed to readlink %s: %s", path.c_str(), strerror(errno));
}
}
}
void populate_fdsan_table(OpenFilesList* list, std::shared_ptr<unwindstack::Memory> memory,
uint64_t fdsan_table_address) {
constexpr size_t inline_fds = sizeof(FdTable::entries) / sizeof(*FdTable::entries);
static_assert(inline_fds == 128);
size_t entry_offset = offsetof(FdTable, entries);
for (size_t i = 0; i < inline_fds; ++i) {
uint64_t address = fdsan_table_address + entry_offset + sizeof(FdEntry) * i;
FdEntry entry;
if (!memory->Read(address, &entry, sizeof(entry))) {
ALOGE("failed to read fdsan table entry %zu: %s", i, strerror(errno));
return;
}
if (entry.close_tag) {
(*list)[i].fdsan_owner = entry.close_tag.load();
}
}
size_t overflow_offset = offsetof(FdTable, overflow);
uintptr_t overflow = 0;
if (!memory->Read(fdsan_table_address + overflow_offset, &overflow, sizeof(overflow))) {
ALOGE("failed to read fdsan table overflow pointer: %s", strerror(errno));
return;
}
if (!overflow) {
return;
}
size_t overflow_length;
if (!memory->Read(overflow, &overflow_length, sizeof(overflow_length))) {
ALOGE("failed to read fdsan overflow table length: %s", strerror(errno));
return;
}
if (overflow_length > 131072) {
ALOGE("unreasonable large fdsan overflow table size %zu, bailing out", overflow_length);
return;
}
for (size_t i = 0; i < overflow_length; ++i) {
int fd = i + inline_fds;
uint64_t address = overflow + offsetof(FdTableOverflow, entries) + i * sizeof(FdEntry);
FdEntry entry;
if (!memory->Read(address, &entry, sizeof(entry))) {
ALOGE("failed to read fdsan overflow entry for fd %d: %s", fd, strerror(errno));
return;
}
if (entry.close_tag) {
(*list)[fd].fdsan_owner = entry.close_tag;
}
}
return;
}
void dump_open_files_list(log_t* log, const OpenFilesList& files, const char* prefix) {
for (auto& [fd, entry] : files) {
const std::optional<std::string>& path = entry.path;
const std::optional<uint64_t>& fdsan_owner = entry.fdsan_owner;
if (path && fdsan_owner) {
const char* type = android_fdsan_get_tag_type(*fdsan_owner);
uint64_t value = android_fdsan_get_tag_value(*fdsan_owner);
_LOG(log, logtype::OPEN_FILES, "%sfd %i: %s (owned by %s %#" PRIx64 ")\n", prefix, fd,
path->c_str(), type, value);
} else if (path && !fdsan_owner) {
_LOG(log, logtype::OPEN_FILES, "%sfd %i: %s (unowned)\n", prefix, fd, path->c_str());
} else if (!path && fdsan_owner) {
_LOG(log, logtype::OPEN_FILES, "%sfd %i: <MISSING> (owned by %#" PRIx64 ")\n", prefix, fd,
*fdsan_owner);
} else {
ALOGE("OpenFilesList contains an entry (fd %d) with no path or owner", fd);
}
}
}