We currently throw out the return values from builtin functions and
occasionally log errors with no supporting context. This change uses
the newly introduced Result<T> class to communicate a successful result
or an error back to callers in order to print an error with clear
context when a builtin fails.
Example:
init: Command 'write /sys/class/leds/vibrator/trigger transient' action=init (/init.rc:245) took 0ms and failed: Unable to write to file '/sys/class/leds/vibrator/trigger': open() failed: No such file or directory
Test: boot bullhead
Change-Id: Idc18f331d2d646629c6093c1e0f2996cf9b42aec
init tries to propagate error information up to build context before
logging errors. This is a good thing, however too often init has the
overly verbose paradigm for error handling, below:
bool CalculateResult(const T& input, U* output, std::string* err)
bool CalculateAndUseResult(const T& input, std::string* err) {
U output;
std::string calculate_result_err;
if (!CalculateResult(input, &output, &calculate_result_err)) {
*err = "CalculateResult " + input + " failed: " +
calculate_result_err;
return false;
}
UseResult(output);
return true;
}
Even more common are functions that return only true/false but also
require passing a std::string* err in order to see the error message.
This change introduces a Result<T> that is use to either hold a
successful return value of type T or to hold an error message as a
std::string. If the functional only returns success or a failure with
an error message, Result<Success> may be used. The classes Error and
ErrnoError are used to indicate a failed Result<T>.
A successful Result<T> is constructed implicitly from any type that
can be implicitly converted to T or from the constructor arguments for
T. This allows you to return a type T directly from a function that
returns Result<T>.
Error and ErrnoError are used to construct a Result<T> has
failed. Each of these classes take an ostream as an input and are
implicitly cast to a Result<T> containing that failure. ErrnoError()
additionally appends ": " + strerror(errno) to the end of the failure
string to aid in interacting with C APIs.
The end result is that the above code snippet is turned into the much
clearer example below:
Result<U> CalculateResult(const T& input);
Result<Success> CalculateAndUseResult(const T& input) {
auto output = CalculateResult(input);
if (!output) {
return Error() << "CalculateResult " << input << " failed: "
<< output.error();
}
UseResult(*output);
return Success();
}
This change also makes this conversion for some of the util.cpp
functions that used the old paradigm.
Test: boot bullhead, init unit tests
Change-Id: I1e7d3a8820a79362245041251057fbeed2f7979b
This change splits out the selinux initialization and supporting
functionality into selinux.cpp and splits the security related
initialization of the rng, etc to security.cpp. It also provides
additional documentation for SEPolicy loading as this has been
requested by some teams.
It additionally cleans up sehandle and sehandle_prop. The former is
static within selinux.cpp and new wrapper functions are created around
selabel_lookup*() to better serve the users. The latter is moved to
property_service.cpp as it is isolated to that file for its usage.
Test: boot bullhead
Merged-In: Idc95d493cebc681fbe686b5160502f36af149f60
Change-Id: Idc95d493cebc681fbe686b5160502f36af149f60
(cherry picked from commit 9afb86b25d8675927cb37c86119a7ecf19f74819)
This change splits out the selinux initialization and supporting
functionality into selinux.cpp and splits the security related
initialization of the rng, etc to security.cpp. It also provides
additional documentation for SEPolicy loading as this has been
requested by some teams.
It additionally cleans up sehandle and sehandle_prop. The former is
static within selinux.cpp and new wrapper functions are created around
selabel_lookup*() to better serve the users. The latter is moved to
property_service.cpp as it is isolated to that file for its usage.
Test: boot bullhead
Merged-In: Idc95d493cebc681fbe686b5160502f36af149f60
Change-Id: Idc95d493cebc681fbe686b5160502f36af149f60
(cherry picked from commit 9afb86b25d8675927cb37c86119a7ecf19f74819)
Crashes that happen before tombstoned is running are extremely hard to
diagnose, because tombstones aren't written to disk, and the window of
opportunity to get logs via `adb logcat` is small (potentially
nonexistent).
Solve this by adding a world-writable /dev/kmsg_debug on userdebug
builds, and writing to it in addition to logcat when tombstoned hasn't
started yet.
Bug: http://b/36574794
Test: stop tombstoned; crasher; dmesg
Change-Id: I46ba2dd67c188be74bd931f8a5536b6342d537f2
Inspired by ag/2659809/, this CL add readahead built-in command in init
to let files be prefetched into pagecache for faster reading.
Readahead happens in background but due to filesystem limitation it
might take small amount of time in it reading the filesystem metadata
needed to locate the requested blocks. So the command is executed in a
forked process to not block init execution.
Bug: 62413151
Test: boottime, dumpcache
Change-Id: I56c86e2ebc20efda4aa509e6efb736bd1d92baa5
service.cpp, which is part of libinit, references symbols in
property_service.cpp, which causes the linker to complain when linking
libinit.a in some situations.
Therefore, we move property_service.cpp to libinit.
Separately, this will make it easier to write tests for
property_service.cpp, which we will want to do in the future.
Test: build, init unit tests
Change-Id: If1cffa8510b97e9436efed3c8ea0724272383eba
The shared libselinux library does not export all of the symbols that
we use in init and the linker is now complaining about this, so let's
use the static libselinux library in init_tests to match init itself.
Test: build, init unit tests
Change-Id: I9011a959a7c49446b3529740e606140a4ee8c32d
selabel_lookup() must be threadsafe, but had failed in the past.
Bug: 63861738
Test: this newly added test
Change-Id: I78bdb8e555433e8217ac6d4be112ba91de9f03bb
* changes:
init: rename ServiceManager to ServiceList and clean it up
init: move reaping from ServiceManager to signal_handler.cpp
init: move exec operations out of ServiceManager
ServiceManager is essentially just a list now that the rest of its
functionality has been moved elsewhere, so the class is renamed
appropriately.
The ServiceList::Find* functions have been cleaned up into a single
smaller interface.
The ServiceList::ForEach functions have been removed in favor of
ServiceList itself being directly iterable.
Test: boot bullhead
Change-Id: Ibd57c103338f03b83d81e8b48ea0e46cd48fd8f0
signal_handler.cpp itself needs to be cleaned up, but this is a step
to clean up ServiceManager.
Test: boot bullhead
Change-Id: I81f1e8ac4d09692cfb364bc702cbd3deb61aa55a
These can be implemented without ServiceManager, so we remove them and
make ServiceManager slightly less of a God class.
Test: boot bullhead
Test: init unit tests
Change-Id: Ia6e546fe5292255412245256f7d230af4ece135f
