The old message system was very dependent on syscalls, and the overall
structure made it hard to implement new features.
The new message system is pretty expandible, where each message has its
own dedicated class. As well as this, we now use Core::File and
AK::Stream for reading and writing messages.
Using AK::Stream also allows us to change the actual data source
(in this case, Core::File) without having to update a whole lot of code
in the future.
The callee that we're passing it to expects a GCPtr anyway, so there's
no need to explicitly dereference this.
Fixes a crash when loading https://spotify.com/
Using HashTable of grid positions to represent OccupationGrid allows to
simplify positioning code. For example maybe_add_row() and
maybe_add_column() calls are not needed anymore because there is no
Vector<Vector<bool>> that need to be resized.
No observable changes in grid layout are expected :)
It's not safe to allocate from the GC heap while in the constructor of a
GC heap cell. (Because if this ends up triggering a collection, we may
end up trying to call through an uninitialized vtable).
This was already done safely in the initialize() virtual in much of
LibJS and LibWeb. This patch moves the logic for prototypes, mixins,
and CSSStyleDeclaration as well.
Fixes a long-standing GC crash that was pretty easy to reproduce by
refreshing https://vercel.com/
This commit lets us differentiate whether access faults are caused by
accessing junk memory addresses given to us by userspace or if we hit a
kernel bug.
The stub implementations of the `safe_*` functions currently don't let
us jump back into them and return a value indicating failure, so we
panic if such a fault happens. Practically, this means that we still
crash, but if the access violation was caused by something else, we take
the usual kernel crash code path and print a register and memory dump,
rather than hitting the `TODO_AARCH64` in `handle_safe_access_fault`.
These are used in futexes, which are needed if we want to get further in
`run-tests`.
For now, we have no way to return a non-fatal error if an access fault
is raised while executing these, so the kernel will panic. Some would
consider this a DoS vulnerability where a malicious userspace app can
crash the kernel by passing bogus pointers to it, but I prefer to call
it progress :^)
Since the specifications indicate that the algorithm for sizing tracks
without any spanning items is a simplified version of the more general
algorithm used for sizing tracks with spanning items, we can reuse the
code to size both cases.
Implements more parts of sizing algorithm for tracks with spanning
items to archive parity with implementation for sizing of tracks
with non-spanning items.
