init: cleanup is_first_stage conditionals
A recent change to the is_first_stage conditionals created a unneeded
else { } block as both the code in the else { } block and any code
that runs after it are both in the second stage of init. A first step
to clean this up is to remove this else block.
Secondly, given the above confusion, it makes sense to simplify the two
if (is_first_stage) conditions into one, which only now requires
duplicating one line to initialize logging and the actual "init
first/second stage started!" logs.
Lastly, there are a few commands ran at the beginning of both init
stages that do not need to be,
* boot_clock::time_point start_time = boot_clock::now();
This is only used in the first stage so keep it there
* umask(0);
umasks are preserved across execve() so it only needs to be set in the
first stage
* chmod("/proc/cmdline", 0440);
This needs to be moved until after /proc is mounted in the first
stage, but otherwise only needs to be done once
Test: Boot bullhead, check umask, check cmdline permissions, check
boot time property
Change-Id: Idb7df1d4330960ce282d9609f5c62281ee2638b9
diff --git a/init/init.cpp b/init/init.cpp
index 4e31865..d095685 100644
--- a/init/init.cpp
+++ b/init/init.cpp
@@ -1108,27 +1108,26 @@
return watchdogd_main(argc, argv);
}
- boot_clock::time_point start_time = boot_clock::now();
-
- // Clear the umask.
- umask(0);
-
add_environment("PATH", _PATH_DEFPATH);
bool is_first_stage = (getenv("INIT_SECOND_STAGE") == nullptr);
- // Don't expose the raw commandline to unprivileged processes.
- chmod("/proc/cmdline", 0440);
-
- // 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) {
+ boot_clock::time_point start_time = boot_clock::now();
+
+ // Clear the umask.
+ umask(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.
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));
+ // Don't expose the raw commandline to unprivileged processes.
+ chmod("/proc/cmdline", 0440);
gid_t groups[] = { AID_READPROC };
setgroups(arraysize(groups), groups);
mount("sysfs", "/sys", "sysfs", 0, NULL);
@@ -1136,15 +1135,13 @@
mknod("/dev/kmsg", S_IFCHR | 0600, makedev(1, 11));
mknod("/dev/random", S_IFCHR | 0666, makedev(1, 8));
mknod("/dev/urandom", S_IFCHR | 0666, makedev(1, 9));
- }
- // Now that tmpfs is mounted on /dev and we have /dev/kmsg, we can actually
- // talk to the outside world...
- InitKernelLogging(argv);
+ // Now that tmpfs is mounted on /dev and we have /dev/kmsg, we can actually
+ // talk to the outside world...
+ InitKernelLogging(argv);
- LOG(INFO) << "init " << (is_first_stage ? "first" : "second") << " stage started!";
+ LOG(INFO) << "init first stage started!";
- if (is_first_stage) {
if (!early_mount()) {
LOG(ERROR) << "Failed to mount required partitions early ...";
panic();
@@ -1168,41 +1165,47 @@
char* path = argv[0];
char* args[] = { path, nullptr };
- if (execv(path, args) == -1) {
- PLOG(ERROR) << "execv(\"" << path << "\") failed";
- security_failure();
- }
- } else {
- // Indicate that booting is in progress to background fw loaders, etc.
- close(open("/dev/.booting", O_WRONLY | O_CREAT | O_CLOEXEC, 0000));
+ execv(path, args);
- 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();
-
- // Make the time that init started available for bootstat to log.
- property_set("ro.boottime.init", getenv("INIT_STARTED_AT"));
- property_set("ro.boottime.init.selinux", getenv("INIT_SELINUX_TOOK"));
-
- // Set libavb version for Framework-only OTA match in Treble build.
- property_set("ro.boot.init.avb_version", std::to_string(AVB_MAJOR_VERSION).c_str());
-
- // Clean up our environment.
- unsetenv("INIT_SECOND_STAGE");
- unsetenv("INIT_STARTED_AT");
- unsetenv("INIT_SELINUX_TOOK");
-
- // Now set up SELinux for second stage.
- selinux_initialize(false);
+ // execv() only returns if an error happened, in which case we
+ // panic and never fall through this conditional.
+ PLOG(ERROR) << "execv(\"" << path << "\") failed";
+ security_failure();
}
+ // At this point we're in the second stage of init.
+ InitKernelLogging(argv);
+ LOG(INFO) << "init second stage started!";
+
+ // 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();
+
+ // Make the time that init started available for bootstat to log.
+ property_set("ro.boottime.init", getenv("INIT_STARTED_AT"));
+ property_set("ro.boottime.init.selinux", getenv("INIT_SELINUX_TOOK"));
+
+ // Set libavb version for Framework-only OTA match in Treble build.
+ property_set("ro.boot.init.avb_version", std::to_string(AVB_MAJOR_VERSION).c_str());
+
+ // Clean up our environment.
+ unsetenv("INIT_SECOND_STAGE");
+ unsetenv("INIT_STARTED_AT");
+ unsetenv("INIT_SELINUX_TOOK");
+
+ // Now set up SELinux for second stage.
+ selinux_initialize(false);
+
// 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.