debuggerd: Dump list of open files on process crash.
Test: Open a bunch of files, wait for the process to crash, verify dubuggerd
includes the list of open files the tombstone it generates.
Test: Added OpenFilesListTest to debuggerd_test.
Bug: 32013594
Change-Id: I6f939ae1d04dc58dc99abff0ed930da9e0ef0d1c
diff --git a/debuggerd/Android.mk b/debuggerd/Android.mk
index 155b309..607745d 100644
--- a/debuggerd/Android.mk
+++ b/debuggerd/Android.mk
@@ -18,6 +18,7 @@
debuggerd.cpp \
elf_utils.cpp \
getevent.cpp \
+ open_files_list.cpp \
signal_sender.cpp \
tombstone.cpp \
utility.cpp \
@@ -108,9 +109,11 @@
debuggerd_test_src_files := \
utility.cpp \
+ open_files_list.cpp \
test/dump_memory_test.cpp \
test/elf_fake.cpp \
test/log_fake.cpp \
+ test/open_files_list_test.cpp \
test/property_fake.cpp \
test/ptrace_fake.cpp \
test/tombstone_test.cpp \
diff --git a/debuggerd/debuggerd.cpp b/debuggerd/debuggerd.cpp
index 5ae66db..272fbf6 100644
--- a/debuggerd/debuggerd.cpp
+++ b/debuggerd/debuggerd.cpp
@@ -55,6 +55,7 @@
#include "backtrace.h"
#include "getevent.h"
+#include "open_files_list.h"
#include "signal_sender.h"
#include "tombstone.h"
#include "utility.h"
@@ -452,7 +453,8 @@
}
static bool perform_dump(const debugger_request_t& request, int fd, int tombstone_fd,
- BacktraceMap* backtrace_map, const std::set<pid_t>& siblings,
+ BacktraceMap* backtrace_map, const OpenFilesList& open_files,
+ const std::set<pid_t>& siblings,
int* crash_signal, std::string* amfd_data) {
if (TEMP_FAILURE_RETRY(write(fd, "\0", 1)) != 1) {
ALOGE("debuggerd: failed to respond to client: %s\n", strerror(errno));
@@ -471,7 +473,8 @@
case SIGSTOP:
if (request.action == DEBUGGER_ACTION_DUMP_TOMBSTONE) {
ALOGV("debuggerd: stopped -- dumping to tombstone");
- engrave_tombstone(tombstone_fd, backtrace_map, request.pid, request.tid, siblings,
+ engrave_tombstone(tombstone_fd, backtrace_map, open_files,
+ request.pid, request.tid, siblings,
request.abort_msg_address, amfd_data);
} else if (request.action == DEBUGGER_ACTION_DUMP_BACKTRACE) {
ALOGV("debuggerd: stopped -- dumping to fd");
@@ -498,7 +501,8 @@
case SIGTRAP:
ALOGV("stopped -- fatal signal\n");
*crash_signal = signal;
- engrave_tombstone(tombstone_fd, backtrace_map, request.pid, request.tid, siblings,
+ engrave_tombstone(tombstone_fd, backtrace_map, open_files,
+ request.pid, request.tid, siblings,
request.abort_msg_address, amfd_data);
break;
@@ -593,6 +597,10 @@
// Generate the backtrace map before dropping privileges.
std::unique_ptr<BacktraceMap> backtrace_map(BacktraceMap::Create(request.pid));
+ // Collect the list of open files before dropping privileges.
+ OpenFilesList open_files;
+ populate_open_files_list(request.pid, &open_files);
+
int amfd = -1;
std::unique_ptr<std::string> amfd_data;
if (request.action == DEBUGGER_ACTION_CRASH) {
@@ -610,8 +618,8 @@
}
int crash_signal = SIGKILL;
- succeeded = perform_dump(request, fd, tombstone_fd, backtrace_map.get(), siblings,
- &crash_signal, amfd_data.get());
+ succeeded = perform_dump(request, fd, tombstone_fd, backtrace_map.get(), open_files,
+ siblings, &crash_signal, amfd_data.get());
if (succeeded) {
if (request.action == DEBUGGER_ACTION_DUMP_TOMBSTONE) {
if (!tombstone_path.empty()) {
diff --git a/debuggerd/open_files_list.cpp b/debuggerd/open_files_list.cpp
new file mode 100644
index 0000000..5ef2abc
--- /dev/null
+++ b/debuggerd/open_files_list.cpp
@@ -0,0 +1,69 @@
+/*
+ * 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 <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 <android/log.h>
+
+#include "open_files_list.h"
+
+#include "utility.h"
+
+void populate_open_files_list(pid_t pid, OpenFilesList* list) {
+ 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->emplace_back(fd, target);
+ } else {
+ ALOGE("failed to readlink %s: %s", path.c_str(), strerror(errno));
+ list->emplace_back(fd, "???");
+ }
+ }
+}
+
+void dump_open_files_list_to_log(const OpenFilesList& files, log_t* log, const char* prefix) {
+ for (auto& file : files) {
+ _LOG(log, logtype::OPEN_FILES, "%sfd %i: %s\n", prefix, file.first, file.second.c_str());
+ }
+}
+
diff --git a/debuggerd/open_files_list.h b/debuggerd/open_files_list.h
new file mode 100644
index 0000000..b37228d
--- /dev/null
+++ b/debuggerd/open_files_list.h
@@ -0,0 +1,36 @@
+/*
+ * 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.
+ */
+
+#ifndef _DEBUGGERD_OPEN_FILES_LIST_H
+#define _DEBUGGERD_OPEN_FILES_LIST_H
+
+#include <sys/types.h>
+
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "utility.h"
+
+typedef std::vector<std::pair<int, std::string>> OpenFilesList;
+
+/* Populates the given list with open files for the given process. */
+void populate_open_files_list(pid_t pid, OpenFilesList* list);
+
+/* Dumps the open files list to the log. */
+void dump_open_files_list_to_log(const OpenFilesList& files, log_t* log, const char* prefix);
+
+#endif // _DEBUGGERD_OPEN_FILES_LIST_H
diff --git a/debuggerd/test/open_files_list_test.cpp b/debuggerd/test/open_files_list_test.cpp
new file mode 100644
index 0000000..85e0695
--- /dev/null
+++ b/debuggerd/test/open_files_list_test.cpp
@@ -0,0 +1,49 @@
+/*
+ * 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 <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <string>
+
+#include <gtest/gtest.h>
+
+#include "android-base/test_utils.h"
+
+#include "open_files_list.h"
+
+// Check that we can produce a list of open files for the current process, and
+// that it includes a known open file.
+TEST(OpenFilesListTest, BasicTest) {
+ // Open a temporary file that we can check for in the list of open files.
+ TemporaryFile tf;
+
+ // Get the list of open files for this process.
+ OpenFilesList list;
+ populate_open_files_list(getpid(), &list);
+
+ // Verify our open file is in the list.
+ bool found = false;
+ for (auto& file : list) {
+ if (file.first == tf.fd) {
+ EXPECT_EQ(file.second, std::string(tf.path));
+ found = true;
+ break;
+ }
+ }
+ EXPECT_TRUE(found);
+}
diff --git a/debuggerd/tombstone.cpp b/debuggerd/tombstone.cpp
index 1e47483..03b3a17 100644
--- a/debuggerd/tombstone.cpp
+++ b/debuggerd/tombstone.cpp
@@ -46,6 +46,7 @@
#include "backtrace.h"
#include "elf_utils.h"
#include "machine.h"
+#include "open_files_list.h"
#include "tombstone.h"
#define STACK_WORDS 16
@@ -620,7 +621,8 @@
}
// Dumps all information about the specified pid to the tombstone.
-static void dump_crash(log_t* log, BacktraceMap* map, pid_t pid, pid_t tid,
+static void dump_crash(log_t* log, BacktraceMap* map,
+ const OpenFilesList& open_files, pid_t pid, pid_t tid,
const std::set<pid_t>& siblings, uintptr_t abort_msg_address) {
// don't copy log messages to tombstone unless this is a dev device
bool want_logs = __android_log_is_debuggable();
@@ -639,6 +641,9 @@
}
}
+ _LOG(log, logtype::OPEN_FILES, "\nopen files:\n");
+ dump_open_files_list_to_log(open_files, log, " ");
+
if (want_logs) {
dump_logs(log, pid, 0);
}
@@ -697,7 +702,8 @@
return fd;
}
-void engrave_tombstone(int tombstone_fd, BacktraceMap* map, pid_t pid, pid_t tid,
+void engrave_tombstone(int tombstone_fd, BacktraceMap* map,
+ const OpenFilesList& open_files, pid_t pid, pid_t tid,
const std::set<pid_t>& siblings, uintptr_t abort_msg_address,
std::string* amfd_data) {
log_t log;
@@ -711,5 +717,5 @@
log.tfd = tombstone_fd;
log.amfd_data = amfd_data;
- dump_crash(&log, map, pid, tid, siblings, abort_msg_address);
+ dump_crash(&log, map, open_files, pid, tid, siblings, abort_msg_address);
}
diff --git a/debuggerd/tombstone.h b/debuggerd/tombstone.h
index e1c39c5..126f804 100644
--- a/debuggerd/tombstone.h
+++ b/debuggerd/tombstone.h
@@ -32,7 +32,8 @@
int open_tombstone(std::string* path);
/* Creates a tombstone file and writes the crash dump to it. */
-void engrave_tombstone(int tombstone_fd, BacktraceMap* map, pid_t pid, pid_t tid,
+void engrave_tombstone(int tombstone_fd, BacktraceMap* map,
+ const OpenFilesList& open_files, pid_t pid, pid_t tid,
const std::set<pid_t>& siblings, uintptr_t abort_msg_address,
std::string* amfd_data);
diff --git a/debuggerd/utility.h b/debuggerd/utility.h
index d820f0f..f7a3f73 100644
--- a/debuggerd/utility.h
+++ b/debuggerd/utility.h
@@ -70,7 +70,8 @@
MAPS,
MEMORY,
STACK,
- LOGS
+ LOGS,
+ OPEN_FILES
};
// Log information onto the tombstone.