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android_system_core/init/init.cpp
caozhiyuan 876ad4571e init: Fix sync issue on property trigger. 
This issue reproduces in the following senario.
 1. ("", "") is added to queue;
 2. property_triggers_enabled is set to 1;
 3. user defined property is triggered, like sys.usb.config=adb;
 4. ("sys.usb.config", "adb") is added to queue;
 5. main loop interpret ("", "") and queue all current triggers to execution,
    so ("sys.usb.config", "adb") is queued for execution for the first time.
 6. main loop interpret ("sys.usb.config", "adb"), it is queued for
    execution for a second time.
The second time makes ASIT fail.

(cherry pick from AOSP commit b104c502e1)

Bug: http://b/28218187
Change-Id: I230e175e0dca8989f1e5bd812398da90082d0ec1
Signed-off-by: caozhiyuan <cao.zhiyuan@zte.com.cn>
2016-11-30 09:51:38 -08:00

755 lines
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/*
* Copyright (C) 2008 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 <ctype.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <fstream>
#include <libgen.h>
#include <paths.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/epoll.h>
#include <sys/mount.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/un.h>
#include <sys/wait.h>
#include <unistd.h>
#include <mtd/mtd-user.h>
#include <selinux/selinux.h>
#include <selinux/label.h>
#include <selinux/android.h>
#include <android-base/file.h>
#include <android-base/stringprintf.h>
#include <android-base/strings.h>
#include <cutils/android_reboot.h>
#include <cutils/fs.h>
#include <cutils/iosched_policy.h>
#include <cutils/list.h>
#include <cutils/sockets.h>
#include <private/android_filesystem_config.h>
#include <memory>
#include "action.h"
#include "bootchart.h"
#include "devices.h"
#include "import_parser.h"
#include "init.h"
#include "init_parser.h"
#include "keychords.h"
#include "log.h"
#include "property_service.h"
#include "service.h"
#include "signal_handler.h"
#include "ueventd.h"
#include "util.h"
#include "watchdogd.h"
struct selabel_handle *sehandle;
struct selabel_handle *sehandle_prop;
static int property_triggers_enabled = 0;
static char qemu[32];
int have_console;
std::string console_name = "/dev/console";
static time_t process_needs_restart;
const char *ENV[32];
bool waiting_for_exec = false;
static int epoll_fd = -1;
void register_epoll_handler(int fd, void (*fn)()) {
epoll_event ev;
ev.events = EPOLLIN;
ev.data.ptr = reinterpret_cast<void*>(fn);
if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, fd, &ev) == -1) {
ERROR("epoll_ctl failed: %s\n", strerror(errno));
}
}
/* add_environment - add "key=value" to the current environment */
int add_environment(const char *key, const char *val)
{
size_t n;
size_t key_len = strlen(key);
/* The last environment entry is reserved to terminate the list */
for (n = 0; n < (ARRAY_SIZE(ENV) - 1); n++) {
/* Delete any existing entry for this key */
if (ENV[n] != NULL) {
size_t entry_key_len = strcspn(ENV[n], "=");
if ((entry_key_len == key_len) && (strncmp(ENV[n], key, entry_key_len) == 0)) {
free((char*)ENV[n]);
ENV[n] = NULL;
}
}
/* Add entry if a free slot is available */
if (ENV[n] == NULL) {
char* entry;
asprintf(&entry, "%s=%s", key, val);
ENV[n] = entry;
return 0;
}
}
ERROR("No env. room to store: '%s':'%s'\n", key, val);
return -1;
}
void property_changed(const char *name, const char *value)
{
if (property_triggers_enabled)
ActionManager::GetInstance().QueuePropertyTrigger(name, value);
}
static void restart_processes()
{
process_needs_restart = 0;
ServiceManager::GetInstance().
ForEachServiceWithFlags(SVC_RESTARTING, [] (Service* s) {
s->RestartIfNeeded(process_needs_restart);
});
}
void handle_control_message(const std::string& msg, const std::string& name) {
Service* svc = ServiceManager::GetInstance().FindServiceByName(name);
if (svc == nullptr) {
ERROR("no such service '%s'\n", name.c_str());
return;
}
if (msg == "start") {
svc->Start();
} else if (msg == "stop") {
svc->Stop();
} else if (msg == "restart") {
svc->Restart();
} else {
ERROR("unknown control msg '%s'\n", msg.c_str());
}
}
static int wait_for_coldboot_done_action(const std::vector<std::string>& args) {
Timer t;
NOTICE("Waiting for %s...\n", COLDBOOT_DONE);
// Any longer than 1s is an unreasonable length of time to delay booting.
// If you're hitting this timeout, check that you didn't make your
// sepolicy regular expressions too expensive (http://b/19899875).
if (wait_for_file(COLDBOOT_DONE, 1)) {
ERROR("Timed out waiting for %s\n", COLDBOOT_DONE);
}
NOTICE("Waiting for %s took %.2fs.\n", COLDBOOT_DONE, t.duration());
return 0;
}
/*
* Writes 512 bytes of output from Hardware RNG (/dev/hw_random, backed
* by Linux kernel's hw_random framework) into Linux RNG's via /dev/urandom.
* Does nothing if Hardware RNG is not present.
*
* Since we don't yet trust the quality of Hardware RNG, these bytes are not
* mixed into the primary pool of Linux RNG and the entropy estimate is left
* unmodified.
*
* If the HW RNG device /dev/hw_random is present, we require that at least
* 512 bytes read from it are written into Linux RNG. QA is expected to catch
* devices/configurations where these I/O operations are blocking for a long
* time. We do not reboot or halt on failures, as this is a best-effort
* attempt.
*/
static int mix_hwrng_into_linux_rng_action(const std::vector<std::string>& args)
{
int result = -1;
int hwrandom_fd = -1;
int urandom_fd = -1;
char buf[512];
ssize_t chunk_size;
size_t total_bytes_written = 0;
hwrandom_fd = TEMP_FAILURE_RETRY(
open("/dev/hw_random", O_RDONLY | O_NOFOLLOW | O_CLOEXEC));
if (hwrandom_fd == -1) {
if (errno == ENOENT) {
ERROR("/dev/hw_random not found\n");
/* It's not an error to not have a Hardware RNG. */
result = 0;
} else {
ERROR("Failed to open /dev/hw_random: %s\n", strerror(errno));
}
goto ret;
}
urandom_fd = TEMP_FAILURE_RETRY(
open("/dev/urandom", O_WRONLY | O_NOFOLLOW | O_CLOEXEC));
if (urandom_fd == -1) {
ERROR("Failed to open /dev/urandom: %s\n", strerror(errno));
goto ret;
}
while (total_bytes_written < sizeof(buf)) {
chunk_size = TEMP_FAILURE_RETRY(
read(hwrandom_fd, buf, sizeof(buf) - total_bytes_written));
if (chunk_size == -1) {
ERROR("Failed to read from /dev/hw_random: %s\n", strerror(errno));
goto ret;
} else if (chunk_size == 0) {
ERROR("Failed to read from /dev/hw_random: EOF\n");
goto ret;
}
chunk_size = TEMP_FAILURE_RETRY(write(urandom_fd, buf, chunk_size));
if (chunk_size == -1) {
ERROR("Failed to write to /dev/urandom: %s\n", strerror(errno));
goto ret;
}
total_bytes_written += chunk_size;
}
INFO("Mixed %zu bytes from /dev/hw_random into /dev/urandom",
total_bytes_written);
result = 0;
ret:
if (hwrandom_fd != -1) {
close(hwrandom_fd);
}
if (urandom_fd != -1) {
close(urandom_fd);
}
return result;
}
static void security_failure() {
ERROR("Security failure; rebooting into recovery mode...\n");
android_reboot(ANDROID_RB_RESTART2, 0, "recovery");
while (true) { pause(); } // never reached
}
#define MMAP_RND_PATH "/proc/sys/vm/mmap_rnd_bits"
#define MMAP_RND_COMPAT_PATH "/proc/sys/vm/mmap_rnd_compat_bits"
/* __attribute__((unused)) due to lack of mips support: see mips block
* in set_mmap_rnd_bits_action */
static bool __attribute__((unused)) set_mmap_rnd_bits_min(int start, int min, bool compat) {
std::string path;
if (compat) {
path = MMAP_RND_COMPAT_PATH;
} else {
path = MMAP_RND_PATH;
}
std::ifstream inf(path, std::fstream::in);
if (!inf) {
return false;
}
while (start >= min) {
// try to write out new value
std::string str_val = std::to_string(start);
std::ofstream of(path, std::fstream::out);
if (!of) {
return false;
}
of << str_val << std::endl;
of.close();
// check to make sure it was recorded
inf.seekg(0);
std::string str_rec;
inf >> str_rec;
if (str_val.compare(str_rec) == 0) {
break;
}
start--;
}
inf.close();
return (start >= min);
}
/*
* Set /proc/sys/vm/mmap_rnd_bits and potentially
* /proc/sys/vm/mmap_rnd_compat_bits to the maximum supported values.
* Returns -1 if unable to set these to an acceptable value. Apply
* upstream patch-sets https://lkml.org/lkml/2015/12/21/337 and
* https://lkml.org/lkml/2016/2/4/831 to enable this.
*/
static int set_mmap_rnd_bits_action(const std::vector<std::string>& args)
{
int ret = -1;
/* values are arch-dependent */
#if defined(__aarch64__)
/* arm64 supports 18 - 33 bits depending on pagesize and VA_SIZE */
if (set_mmap_rnd_bits_min(33, 24, false)
&& set_mmap_rnd_bits_min(16, 16, true)) {
ret = 0;
}
#elif defined(__x86_64__)
/* x86_64 supports 28 - 32 bits */
if (set_mmap_rnd_bits_min(32, 32, false)
&& set_mmap_rnd_bits_min(16, 16, true)) {
ret = 0;
}
#elif defined(__arm__) || defined(__i386__)
/* check to see if we're running on 64-bit kernel */
bool h64 = !access(MMAP_RND_COMPAT_PATH, F_OK);
/* supported 32-bit architecture must have 16 bits set */
if (set_mmap_rnd_bits_min(16, 16, h64)) {
ret = 0;
}
#elif defined(__mips__) || defined(__mips64__)
// TODO: add mips support b/27788820
ret = 0;
#else
ERROR("Unknown architecture\n");
#endif
#ifdef __BRILLO__
// TODO: b/27794137
ret = 0;
#endif
if (ret == -1) {
ERROR("Unable to set adequate mmap entropy value!\n");
security_failure();
}
return ret;
}
static int keychord_init_action(const std::vector<std::string>& args)
{
keychord_init();
return 0;
}
static int console_init_action(const std::vector<std::string>& args)
{
std::string console = property_get("ro.boot.console");
if (!console.empty()) {
console_name = "/dev/" + console;
}
int fd = open(console_name.c_str(), O_RDWR | O_CLOEXEC);
if (fd >= 0)
have_console = 1;
close(fd);
fd = open("/dev/tty0", O_WRONLY | O_CLOEXEC);
if (fd >= 0) {
const char *msg;
msg = "\n"
"\n"
"\n"
"\n"
"\n"
"\n"
"\n" // console is 40 cols x 30 lines
"\n"
"\n"
"\n"
"\n"
"\n"
"\n"
"\n"
" A N D R O I D ";
write(fd, msg, strlen(msg));
close(fd);
}
return 0;
}
static void import_kernel_nv(const std::string& key, const std::string& value, bool for_emulator) {
if (key.empty()) return;
if (for_emulator) {
// In the emulator, export any kernel option with the "ro.kernel." prefix.
property_set(android::base::StringPrintf("ro.kernel.%s", key.c_str()).c_str(), value.c_str());
return;
}
if (key == "qemu") {
strlcpy(qemu, value.c_str(), sizeof(qemu));
} else if (android::base::StartsWith(key, "androidboot.")) {
property_set(android::base::StringPrintf("ro.boot.%s", key.c_str() + 12).c_str(),
value.c_str());
}
}
static void export_oem_lock_status() {
if (property_get("ro.oem_unlock_supported") != "1") {
return;
}
std::string value = property_get("ro.boot.verifiedbootstate");
if (!value.empty()) {
property_set("ro.boot.flash.locked", value == "orange" ? "0" : "1");
}
}
static void export_kernel_boot_props() {
struct {
const char *src_prop;
const char *dst_prop;
const char *default_value;
} prop_map[] = {
{ "ro.boot.serialno", "ro.serialno", "", },
{ "ro.boot.mode", "ro.bootmode", "unknown", },
{ "ro.boot.baseband", "ro.baseband", "unknown", },
{ "ro.boot.bootloader", "ro.bootloader", "unknown", },
{ "ro.boot.hardware", "ro.hardware", "unknown", },
{ "ro.boot.revision", "ro.revision", "0", },
};
for (size_t i = 0; i < ARRAY_SIZE(prop_map); i++) {
std::string value = property_get(prop_map[i].src_prop);
property_set(prop_map[i].dst_prop, (!value.empty()) ? value.c_str() : prop_map[i].default_value);
}
}
static void process_kernel_dt() {
static const char android_dir[] = "/proc/device-tree/firmware/android";
std::string file_name = android::base::StringPrintf("%s/compatible", android_dir);
std::string dt_file;
android::base::ReadFileToString(file_name, &dt_file);
if (!dt_file.compare("android,firmware")) {
ERROR("firmware/android is not compatible with 'android,firmware'\n");
return;
}
std::unique_ptr<DIR, int(*)(DIR*)>dir(opendir(android_dir), closedir);
if (!dir) return;
struct dirent *dp;
while ((dp = readdir(dir.get())) != NULL) {
if (dp->d_type != DT_REG || !strcmp(dp->d_name, "compatible") || !strcmp(dp->d_name, "name")) {
continue;
}
file_name = android::base::StringPrintf("%s/%s", android_dir, dp->d_name);
android::base::ReadFileToString(file_name, &dt_file);
std::replace(dt_file.begin(), dt_file.end(), ',', '.');
std::string property_name = android::base::StringPrintf("ro.boot.%s", dp->d_name);
property_set(property_name.c_str(), dt_file.c_str());
}
}
static void process_kernel_cmdline() {
// Don't expose the raw commandline to unprivileged processes.
chmod("/proc/cmdline", 0440);
// The first pass does the common stuff, and finds if we are in qemu.
// The second pass is only necessary for qemu to export all kernel params
// as properties.
import_kernel_cmdline(false, import_kernel_nv);
if (qemu[0]) import_kernel_cmdline(true, import_kernel_nv);
}
static int property_enable_triggers_action(const std::vector<std::string>& args)
{
/* Enable property triggers. */
property_triggers_enabled = 1;
return 0;
}
static int queue_property_triggers_action(const std::vector<std::string>& args)
{
ActionManager::GetInstance().QueueBuiltinAction(property_enable_triggers_action, "enable_property_trigger");
ActionManager::GetInstance().QueueAllPropertyTriggers();
return 0;
}
static void selinux_init_all_handles(void)
{
sehandle = selinux_android_file_context_handle();
selinux_android_set_sehandle(sehandle);
sehandle_prop = selinux_android_prop_context_handle();
}
enum selinux_enforcing_status { SELINUX_PERMISSIVE, SELINUX_ENFORCING };
static selinux_enforcing_status selinux_status_from_cmdline() {
selinux_enforcing_status status = SELINUX_ENFORCING;
import_kernel_cmdline(false, [&](const std::string& key, const std::string& value, bool in_qemu) {
if (key == "androidboot.selinux" && value == "permissive") {
status = SELINUX_PERMISSIVE;
}
});
return status;
}
static bool selinux_is_enforcing(void)
{
if (ALLOW_PERMISSIVE_SELINUX) {
return selinux_status_from_cmdline() == SELINUX_ENFORCING;
}
return true;
}
int selinux_reload_policy(void)
{
INFO("SELinux: Attempting to reload policy files\n");
if (selinux_android_reload_policy() == -1) {
return -1;
}
if (sehandle)
selabel_close(sehandle);
if (sehandle_prop)
selabel_close(sehandle_prop);
selinux_init_all_handles();
return 0;
}
static int audit_callback(void *data, security_class_t /*cls*/, char *buf, size_t len) {
property_audit_data *d = reinterpret_cast<property_audit_data*>(data);
if (!d || !d->name || !d->cr) {
ERROR("audit_callback invoked with null data arguments!");
return 0;
}
snprintf(buf, len, "property=%s pid=%d uid=%d gid=%d", d->name,
d->cr->pid, d->cr->uid, d->cr->gid);
return 0;
}
static void selinux_initialize(bool in_kernel_domain) {
Timer t;
selinux_callback cb;
cb.func_log = selinux_klog_callback;
selinux_set_callback(SELINUX_CB_LOG, cb);
cb.func_audit = audit_callback;
selinux_set_callback(SELINUX_CB_AUDIT, cb);
if (in_kernel_domain) {
INFO("Loading SELinux policy...\n");
if (selinux_android_load_policy() < 0) {
ERROR("failed to load policy: %s\n", strerror(errno));
security_failure();
}
bool kernel_enforcing = (security_getenforce() == 1);
bool is_enforcing = selinux_is_enforcing();
if (kernel_enforcing != is_enforcing) {
if (security_setenforce(is_enforcing)) {
ERROR("security_setenforce(%s) failed: %s\n",
is_enforcing ? "true" : "false", strerror(errno));
security_failure();
}
}
if (write_file("/sys/fs/selinux/checkreqprot", "0") == -1) {
security_failure();
}
NOTICE("(Initializing SELinux %s took %.2fs.)\n",
is_enforcing ? "enforcing" : "non-enforcing", t.duration());
} else {
selinux_init_all_handles();
}
}
int main(int argc, char** argv) {
if (!strcmp(basename(argv[0]), "ueventd")) {
return ueventd_main(argc, argv);
}
if (!strcmp(basename(argv[0]), "watchdogd")) {
return watchdogd_main(argc, argv);
}
// Clear the umask.
umask(0);
add_environment("PATH", _PATH_DEFPATH);
bool is_first_stage = (argc == 1) || (strcmp(argv[1], "--second-stage") != 0);
// Get the basic filesystem setup we need put together in the initramdisk
// on / and then we'll let the rc file figure out the rest.
if (is_first_stage) {
mount("tmpfs", "/dev", "tmpfs", MS_NOSUID, "mode=0755");
mkdir("/dev/pts", 0755);
mkdir("/dev/socket", 0755);
mount("devpts", "/dev/pts", "devpts", 0, NULL);
#define MAKE_STR(x) __STRING(x)
mount("proc", "/proc", "proc", 0, "hidepid=2,gid=" MAKE_STR(AID_READPROC));
mount("sysfs", "/sys", "sysfs", 0, NULL);
}
// We must have some place other than / to create the device nodes for
// kmsg and null, otherwise we won't be able to remount / read-only
// later on. Now that tmpfs is mounted on /dev, we can actually talk
// to the outside world.
open_devnull_stdio();
klog_init();
klog_set_level(KLOG_NOTICE_LEVEL);
NOTICE("init %s started!\n", is_first_stage ? "first stage" : "second stage");
if (!is_first_stage) {
// Indicate that booting is in progress to background fw loaders, etc.
close(open("/dev/.booting", O_WRONLY | O_CREAT | O_CLOEXEC, 0000));
property_init();
// If arguments are passed both on the command line and in DT,
// properties set in DT always have priority over the command-line ones.
process_kernel_dt();
process_kernel_cmdline();
// Propagate the kernel variables to internal variables
// used by init as well as the current required properties.
export_kernel_boot_props();
}
// Set up SELinux, including loading the SELinux policy if we're in the kernel domain.
selinux_initialize(is_first_stage);
// If we're in the kernel domain, re-exec init to transition to the init domain now
// that the SELinux policy has been loaded.
if (is_first_stage) {
if (restorecon("/init") == -1) {
ERROR("restorecon failed: %s\n", strerror(errno));
security_failure();
}
char* path = argv[0];
char* args[] = { path, const_cast<char*>("--second-stage"), nullptr };
if (execv(path, args) == -1) {
ERROR("execv(\"%s\") failed: %s\n", path, strerror(errno));
security_failure();
}
}
// These directories were necessarily created before initial policy load
// and therefore need their security context restored to the proper value.
// This must happen before /dev is populated by ueventd.
NOTICE("Running restorecon...\n");
restorecon("/dev");
restorecon("/dev/socket");
restorecon("/dev/__properties__");
restorecon("/property_contexts");
restorecon_recursive("/sys");
epoll_fd = epoll_create1(EPOLL_CLOEXEC);
if (epoll_fd == -1) {
ERROR("epoll_create1 failed: %s\n", strerror(errno));
exit(1);
}
signal_handler_init();
property_load_boot_defaults();
export_oem_lock_status();
start_property_service();
const BuiltinFunctionMap function_map;
Action::set_function_map(&function_map);
Parser& parser = Parser::GetInstance();
parser.AddSectionParser("service",std::make_unique<ServiceParser>());
parser.AddSectionParser("on", std::make_unique<ActionParser>());
parser.AddSectionParser("import", std::make_unique<ImportParser>());
parser.ParseConfig("/init.rc");
ActionManager& am = ActionManager::GetInstance();
am.QueueEventTrigger("early-init");
// Queue an action that waits for coldboot done so we know ueventd has set up all of /dev...
am.QueueBuiltinAction(wait_for_coldboot_done_action, "wait_for_coldboot_done");
// ... so that we can start queuing up actions that require stuff from /dev.
am.QueueBuiltinAction(mix_hwrng_into_linux_rng_action, "mix_hwrng_into_linux_rng");
am.QueueBuiltinAction(set_mmap_rnd_bits_action, "set_mmap_rnd_bits");
am.QueueBuiltinAction(keychord_init_action, "keychord_init");
am.QueueBuiltinAction(console_init_action, "console_init");
// Trigger all the boot actions to get us started.
am.QueueEventTrigger("init");
// Repeat mix_hwrng_into_linux_rng in case /dev/hw_random or /dev/random
// wasn't ready immediately after wait_for_coldboot_done
am.QueueBuiltinAction(mix_hwrng_into_linux_rng_action, "mix_hwrng_into_linux_rng");
// Don't mount filesystems or start core system services in charger mode.
std::string bootmode = property_get("ro.bootmode");
if (bootmode == "charger") {
am.QueueEventTrigger("charger");
} else {
am.QueueEventTrigger("late-init");
}
// Run all property triggers based on current state of the properties.
am.QueueBuiltinAction(queue_property_triggers_action, "queue_property_triggers");
while (true) {
if (!waiting_for_exec) {
am.ExecuteOneCommand();
restart_processes();
}
int timeout = -1;
if (process_needs_restart) {
timeout = (process_needs_restart - gettime()) * 1000;
if (timeout < 0)
timeout = 0;
}
if (am.HasMoreCommands()) {
timeout = 0;
}
bootchart_sample(&timeout);
epoll_event ev;
int nr = TEMP_FAILURE_RETRY(epoll_wait(epoll_fd, &ev, 1, timeout));
if (nr == -1) {
ERROR("epoll_wait failed: %s\n", strerror(errno));
} else if (nr == 1) {
((void (*)()) ev.data.ptr)();
}
}
return 0;
}
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