This commit un-deprecates DeprecatedString, and repurposes it as a byte
string.
As the null state has already been removed, there are no other
particularly hairy blockers in repurposing this type as a byte string
(what it _really_ is).
This commit is auto-generated:
$ xs=$(ack -l \bDeprecatedString\b\|deprecated_string AK Userland \
Meta Ports Ladybird Tests Kernel)
$ perl -pie 's/\bDeprecatedString\b/ByteString/g;
s/deprecated_string/byte_string/g' $xs
$ clang-format --style=file -i \
$(git diff --name-only | grep \.cpp\|\.h)
$ gn format $(git ls-files '*.gn' '*.gni')
Userspace initially didn't have any sort of mechanism to handle
device hotplug (either removing or inserting a device).
This meant that after a short term of scanning all known devices, by
fetching device events (DeviceEvent packets) from /dev/devctl, we
basically never try to read it again after SystemServer initialization
code.
To accommodate hotplug needs, we change SystemServer by ensuring it will
generate a known set of device nodes at their location during the its
main initialization code. This includes devices like /dev/mem, /dev/zero
and /dev/full, etc.
The actual responsible userspace program to handle hotplug events is a
new userspace program called DeviceMapper, with following key points:
- Its current task is to to constantly read the /dev/devctl device node.
Because we already created generic devices, we only handle devices
that are dynamically-generated in nature, like storage devices, audio
channels, etc.
- Since dynamically-generated device nodes could have an infinite minor
numbers, but major numbers are decoded to a device type, we create an
internal registry based on two structures - DeviceNodeFamily, and
RegisteredDeviceNode. DeviceNodeFamily objects are attached in the
main logic code, when handling a DeviceEvent device insertion packet.
A DeviceNodeFamily object has an internal HashTable to hold objects of
RegisteredDeviceNode class.
- Because some device nodes could still share the same major number (TTY
and serial TTY devices), we have two modes of allocation - limited
allocation (so a range is defined for a major number), or infinite
range. Therefore, two (or more) separate DeviceNodeFamily objects can
can exist albeit sharing the same major number, but they are required
to allocate from a different minor numbers' range to ensure there are
no collisions.
- As for KCOV, we handle this device differently. In case the user
compiled the kernel with such support - this happens to be a singular
device node that we usually don't need, so it's dynamically-generated
too, and because it has only one instance, we don't register it in our
internal registry to not make it complicated needlessly.
The Kernel code is modified to allow proper blocking in case of no
events in the DeviceControlDevice class, because otherwise we will need
to poll periodically the device to check if a new event is available,
which would waste CPU time for no good reason.
This change ensures that code in the Service class doesn't try to check
the g_system_mode variable, but instead is asked on whether it supports
a given system mode string value.
Also, don't assume that we should create sockets for any new Service
instance, but instead do that only if the Service should run in the
current system mode.
Just a small cleanup to ensure we can get these pieces of code out to
other files and still have the main.cpp file organized.
The populate_devtmpfs_char_devices_based_on_sysfs() method is removed
because we can simply create the /dev/devctl device node without looking
at the SysFS. This assumed-to-exist device node will be used later on in
an event loop to handle hotplug events.
The name for this directory is a bit awkward. Also, the distinction of
constant information is not really valuable as I thought it would be, so
let's bring that information back into the /sys/kernel directory.
The name "variables" is a bit awkward and what the directory entries are
really about is kernel configuration so let's make it clear with the new
name.
These 2 are an actual separate types of syscalls, so let's stop using
special flags for bind mounting or re-mounting and instead let userspace
calling directly for this kind of actions.
Note that previously, the only check was that at least one byte was read
from /dev/devctl. This is incorrect, as potentially not the entire
struct was read. In practice, this probably never happened, but the new
code at least detects this case and aborts.
This class had slightly confusing semantics and the added weirdness
doesn't seem worth it just so we can say "." instead of "->" when
iterating over a vector of NNRPs.
This patch replaces NonnullRefPtrVector<T> with Vector<NNRP<T>>.
This also removes DirIterator::error_string(), since the same strerror()
string will be included when you print the Error itself. Except in `ls`
which is still using fprintf() for now.
This subdirectory is meant to hold all constant data related to the
kernel. This means that this data is never meant to updated and is
relevant from system boot to system shutdown.
Move the inodes of "load_base", "cmdline" and "system_mode" to that
directory. All nodes under this new subdirectory are generated during
boot, and therefore don't require calling kmalloc each time we need to
read them. Locking is also not necessary, because these nodes and their
data are completely static once being generated.
This filesystem is based on the code of the long-lived TmpFS. It differs
from that filesystem in one keypoint - its root inode doesn't have a
sticky bit on it.
Therefore, we mount it on /dev, to ensure only root can modify files on
that directory. In addition to that, /tmp is mounted directly in the
SystemServer main (start) code, so it's no longer specified in the fstab
file. We ensure that /tmp has a sticky bit and has the value 0777 for
root directory permissions, which is certainly a special case when using
RAM-backed (and in general other) filesystems.
Because of these 2 changes, it's no longer needed to maintain the TmpFS
filesystem, hence it's removed (renamed to RAMFS), because the RAMFS
represents the purpose of this filesystem in a much better way - it
relies on being backed by RAM "storage", and therefore it's easy to
conclude it's temporary and volatile, so its content is gone on either
system shutdown or unmounting of the filesystem.
To do this properly, we also create Strings with formatting of device
nodes' names, taking into consideration errors when doing that.
Also, we use LibCore System mknod method instead of raw LibC functions
to be able to propagate errors from these calls too.
This patch also includes some changes in the way that the environment
and arguments are passed to `exec`. It was needed to fit the signature
of `Core::System::exec`. That's beneficial though, as we are now doing
`String` manipulation in a fallible environment, so we can propagate
more errors.
We have a new, improved string type coming up in AK (OOM aware, no null
state), and while it's going to use UTF-8, the name UTF8String is a
mouthful - so let's free up the String name by renaming the existing
class.
Making the old one have an annoying name will hopefully also help with
quick adoption :^)
Instead, allow userspace to decide on the coredump directory path. By
default, SystemServer sets it to the /tmp/coredump directory, but users
can now change this by writing a new path to the sysfs node at
/sys/kernel/variables/coredump_directory, and also to read this node to
check where coredumps are currently generated at.
For SystemServer, we simply ensure that the /dev mount is now mounted
with MS_NOREGULAR flag to ensure only non-regular files are created,
thus, achieving what DevTmpFS provided in its implementation, but in a
much more sane and clean way than how DevTmpFS did that.
For other userland applications, we simply make them being aware of this
flag so they can show an indication about this flag being used to the
user.
In case of failure when trying to read the system_mode global node, just
use as a default the text mode, so we have bootable system with degraded
functionality.
Because HID devices are not always present in quantities of one per type
it is more elegant and correct to put the representative device nodes in
subdirectories for each HID device type.
Various changes are needed to support this:
- The directory is created by Core::Account on login (and located in
/tmp).
- Service's sockets are now deleted on exit (to allow re-creation)
- SystemServer needs to handle SIGTERM to correctly destroy services.
Each of these strings would previously rely on StringView's char const*
constructor overload, which would call __builtin_strlen on the string.
Since we now have operator ""sv, we can replace these with much simpler
versions. This opens the door to being able to remove
StringView(char const*).
No functional changes.
New propagated errors comes from an endgrent call, and all chown+chmod
calls all over the file. For the two last functions, custom C++ wrappers
were used.
Those wrappers were discarding `ENOENT` errors and naively crashing on
other errors, this change introduced in 76e12a48 was used to prevent a
crash if a mouse wasn't detected. There are no reasons to discard and to
not propagate other errors.
Previously, the device wasn't being created.
The new numbers correspond to those in the FullDevice (which is also
a Linux's full device number).
Also, I've tweaked the permissions to give everyone read-write access
to it.
As the framebuffer devices are gone by now, searching for them makes no
sense, so instead, let's remove this check now. If the user requested to
boot into text mode, he probably knows what he is doing and we should
not try to warn him about this.
SystemServer had safety fallbacks to boot into text mode if the user
errorneously specified graphical mode but no video hardware was present.
As it's now possible to do exactly this intentionally, we should allow
it. This would of course make WindowServer fall over and die if
configured improperly, but if you're messing with the kernel command
line in strange ways, you should be able to fix that.
I've attempted to handle the errors gracefully where it was clear how to
do so, and simple, but a lot of this was just adding
`release_value_but_fixme_should_propagate_errors()` in places.
We first create the /dev/devctl based on the information from the SysFS.
Then, we create block devices and character devices based on the events
we read from that device.
Add them in `<Kernel/API/Device.h>` and use these to provides
`{makedev,major,minor}` in `<sys/sysmacros.h>`. It aims to be more in
line with other Unix implementations and avoid code duplication in user
land.
