Two new ioctl requests are used to get and set the sample rate of the
sound card. The SB16 device keeps track of the sample rate separately,
because I don't want to figure out how to read the sample rate from the
device; it's easier that way.
The soundcard write doesn't set the sample rate to 44100 Hz every time
anymore, as we want to change it externally.
Now that the old PCI::Device was removed, we can complete the PCI
changes by making the PCI::DeviceController to be named PCI::Device.
Really the entire purpose and the distinction between the two was about
interrupts, but since this is no longer a problem, just rename it to
simplify things further.
I created this class a long time ago just to be able to quickly make a
PCI device to also represent an interrupt handler (because PCI devices
have this capability for most devices).
Then after a while I introduced the PCI::DeviceController, which is
really almost the same thing (a PCI device class that has Address member
in it), but is not tied to interrupts so it can have no interrupts, or
spawn interrupt handlers however it wants to seems fit.
However I decided it's time to say goodbye for this class for
a couple of reasons:
1. It made a whole bunch of weird patterns where you had a PCI::Device
and a PCI::DeviceController being used in the topic of implementation,
where originally, they meant to be used mutually exclusively (you
can't and really don't want to use both).
2. We can really make all the classes that inherit from PCI::Device
to inherit from IRQHandler at this point. Later on, when we have MSI
interrupts support, we can go further and untie things even more.
3. It makes it possible to simplify the VirtIO implementation to a great
extent. While this commit almost doesn't change it, future changes
can untangle some complexity in the VirtIO code.
For UHCIController, E1000NetworkAdapter, NE2000NetworkAdapter,
RTL8139NetworkAdapter, RTL8168NetworkAdapter, E1000ENetworkAdapter we
are simply making them to inherit the IRQHandler. This makes some sense,
because the first 3 devices will never support anything besides IRQs.
For the last 2, they might have MSI support, so when we start to utilize
those, we might need to untie these classes from IRQHandler and spawn
IRQHandler(s) or MSIHandler(s) as needed.
The VirtIODevice class is also a case where we currently need to use
both PCI::DeviceController and IRQHandler classes as parents, but it
could also be untied from the latter.
This has several benefits:
1) We no longer just blindly derefence a null pointer in various places
2) We will get nicer runtime error messages if the current process does
turn out to be null in the call location
3) GCC no longer complains about possible nullptr dereferences when
compiling without KUBSAN
This makes for nicer handling of errors compared to checking whether a
RefPtr is null. Additionally, this will give way to return different
types of errors in the future.
...and also RangeAllocator => VirtualRangeAllocator.
This clarifies that the ranges we're dealing with are *virtual* memory
ranges and not anything else.
Now that all KResult and KResultOr are used consistently throughout the
kernel, it's no longer necessary to return negative error codes.
However, we were still doing that in some places, so let's fix all those
(bugs) by removing the minuses. :^)
It's easy to forget the responsibility of validating and safely copying
kernel parameters in code that is far away from syscalls. ioctl's are
one such example, and bugs there are just as dangerous as at the root
syscall level.
To avoid this case, utilize the AK::Userspace<T> template in the ioctl
kernel interface so that implementors have no choice but to properly
validate and copy ioctl pointer arguments.
GCC and Clang allow us to inject a call to a function named
__sanitizer_cov_trace_pc on every edge. This function has to be defined
by us. By noting down the caller in that function we can trace the code
we have encountered during execution. Such information is used by
coverage guided fuzzers like AFL and LibFuzzer to determine if a new
input resulted in a new code path. This makes fuzzing much more
effective.
Additionally this adds a basic KCOV implementation. KCOV is an API that
allows user space to request the kernel to start collecting coverage
information for a given user space thread. Furthermore KCOV then exposes
the collected program counters to user space via a BlockDevice which can
be mmaped from user space.
This work is required to add effective support for fuzzing SerenityOS to
the Syzkaller syscall fuzzer. :^) :^)
We don't need to have a dedicated API for creating a VMObject with a
single page, the multi-page API option works in all cases.
Also make the API take a Span<NonnullRefPtr<PhysicalPage>> instead of
a NonnullRefPtrVector<PhysicalPage>.
These small changes fix the remaining warnings that come up during
kernel compilation with Clang. These specific fixes were for benign
things: unused lambda captures and braces around scalar initializers.
The `#pragma GCC diagnostic` part is needed because the class has
virtual methods with the same name but different arguments, and Clang
tries to warn us that we are not actually overriding anything with
these.
Weirdly enough, GCC does not seem to care.
This hack allows self-test mode run-tests-and-shutdown.sh to give
TestProcFs a stat(2)-able /proc/self/fd/0. For some reason, when
stdin is a SerialDevice, /proc/self/fd/0 will be a symlink to the device
as expected, but, calling realpath or stat on /proc/self/fd/0 will error
out. realpath will give the string from Device::absolute_path() which
would be something like "device:4,64 (SerialDevice)". When VFS is trying
to resolve_path so that we can stat the file, it would bail out on this
fake-y path.
Change the fake path (that doesn't show up when you ls a device, nor
when checking the devices tab in SystemMonitor) from the major/minor
device number and class_name() to /dev/device_name(). There's probably
a very hairy yak standing behind this issue that was only discovered due
to the ProcFS rework.
The new ProcFS design consists of two main parts:
1. The representative ProcFS class, which is derived from the FS class.
The ProcFS and its inodes are much more lean - merely 3 classes to
represent the common type of inodes - regular files, symbolic links and
directories. They're backed by a ProcFSExposedComponent object, which
is responsible for the functional operation behind the scenes.
2. The backend of the ProcFS - the ProcFSComponentsRegistrar class
and all derived classes from the ProcFSExposedComponent class. These
together form the entire backend and handle all the functions you can
expect from the ProcFS.
The ProcFSExposedComponent derived classes split to 3 types in the
manner of lifetime in the kernel:
1. Persistent objects - this category includes all basic objects, like
the root folder, /proc/bus folder, main blob files in the root folders,
etc. These objects are persistent and cannot die ever.
2. Semi-persistent objects - this category includes all PID folders,
and subdirectories to the PID folders. It also includes exposed objects
like the unveil JSON'ed blob. These object are persistent as long as the
the responsible process they represent is still alive.
3. Dynamic objects - this category includes files in the subdirectories
of a PID folder, like /proc/PID/fd/* or /proc/PID/stacks/*. Essentially,
these objects are always created dynamically and when no longer in need
after being used, they're deallocated.
Nevertheless, the new allocated backend objects and inodes try to use
the same InodeIndex if possible - this might change only when a thread
dies and a new thread is born with a new thread stack, or when a file
descriptor is closed and a new one within the same file descriptor
number is opened. This is needed to actually be able to do something
useful with these objects.
The new design assures that many ProcFS instances can be used at once,
with one backend for usage for all instances.
This does the exact thing as `adopt_ref`, which is a recent addition to
AK.
Note that pointers returned by a bare new (without `nothrow`) are
guaranteed not to return null, so they can safely be converted into
references.
This commit converts naked `new`s to `AK::try_make` and `AK::try_create`
wherever possible. If the called constructor is private, this can not be
done, so we instead now use the standard-defined and compiler-agnostic
`new (nothrow)`.
Instead, try to create the device objects in separate static methods,
and if we fail for some odd reason to allocate memory for such devices,
just panic with that reason.
We now store the device descriptor obtained from the device
during enumeration in the device's object in memory instead
of exposing all of the different members contained within it.
