Don't create these device nodes in the Kernel, so we essentially enforce
userspace (SystemServer) to take control of this operation and to decide
how to create these device nodes.
This makes the DevFS to resemble linux devtmpfs, and allows us to remove
a bunch of unneeded overriding implementations of device name creation
in the Kernel.
TmpFS inodes rely on the call to Inode::one_ref_left() to unregister
themselves from the inode cache in TmpFS.
When moving various kernel classes to ListedRefCounted for safe unref()
while participating on lists, I forgot to make ListedRefCounted check
for (and call) one_ref_left() & will_be_destroyed() on the CRTP class.
This patch moves everything from KBufferImpl into KBuffer instead.
One layer of indirection is removed, and the whole thing is massively
simplified. :^)
This patch adds KBufferBuilder::try_create() and treats it like anything
else that can fail. And so, failure to allocate the initial internal
buffer of the builder will now propagate an ENOMEM to the caller. :^)
This was a weird KBuffer API that assumed failure was impossible.
This patch converts it to a modern KResultOr<NonnullOwnPtr<KBuffer>> API
and updates the two clients to the new style.
Sockets remember their last error code in the SO_ERROR field, so we need
to take special care to remember this when returning an error.
This patch adds a SOCKET_TRY() that works like TRY() but also calls
set_so_error() on the failure path.
There's probably a lot more code that should be using this, but that's
outside the scope of this patch.
We don't really have anywhere to propagate the error in NetworkTask at
the moment, since it runs in its own kernel thread and has no direct
userspace caller.
Make use of the new FileDescription::try_serialize_absolute_path() to
avoid String in favor of KString throughout much of sys$execve() and
its helpers.
A couple of things were changed:
1. Semantic changes - PCI segments are now called PCI domains, to better
match what they are really. It's also the name that Linux gave, and it
seems that Wikipedia also uses this name.
We also remove PCI::ChangeableAddress, because it was used in the past
but now it's no longer being used.
2. There are no WindowedMMIOAccess or MMIOAccess classes anymore, as
they made a bunch of unnecessary complexity. Instead, Windowed access is
removed entirely (this was tested, but never was benchmarked), so we are
left with IO access and memory access options. The memory access option
is essentially mapping the PCI bus (from the chosen PCI domain), to
virtual memory as-is. This means that unless needed, at any time, there
is only one PCI bus being mapped, and this is changed if access to
another PCI bus in the same PCI domain is needed. For now, we don't
support mapping of different PCI buses from different PCI domains at the
same time, because basically it's still a non-issue for most machines
out there.
2. OOM-safety is increased, especially when constructing the Access
object. It means that we pre-allocating any needed resources, and we try
to find PCI domains (if requested to initialize memory access) after we
attempt to construct the Access object, so it's possible to fail at this
point "gracefully".
3. All PCI API functions are now separated into a different header file,
which means only "clients" of the PCI subsystem API will need to include
that header file.
4. Functional changes - we only allow now to enumerate the bus after
a hardware scan. This means that the old method "enumerate_hardware"
is removed, so, when initializing an Access object, the initializing
function must call rescan on it to force it to find devices. This makes
it possible to fail rescan, and also to defer it after construction from
both OOM-safety terms and hotplug capabilities.
This change adds a static lock hierarchy / ranking to the Kernel with
the goal of reducing / finding deadlocks when running with SMP enabled.
We have seen quite a few lock ordering deadlocks (locks taken in a
different order, on two different code paths). As we properly annotate
locks in the system, then these facilities will find these locking
protocol violations automatically
The `LockRank` enum documents the various locks in the system and their
rank. The implementation guarantees that a thread holding one or more
locks of a lower rank cannot acquire an additional lock with rank that
is greater or equal to any of the currently held locks.
