If we crashed in the middle of mapping in Regions, some of the regions
may not have a page directory yet, and will result in a crash when
Region::remap() is called.
As PROT_NONE regions can't be accessed by processes, and their only real
use is for reserving ranges of virtual memory, there's no point in
including them in coredumps.
We now use AK::Error and AK::ErrorOr<T> in both kernel and userspace!
This was a slightly tedious refactoring that took a long time, so it's
not unlikely that some bugs crept in.
Nevertheless, it does pass basic functionality testing, and it's just
real nice to finally see the same pattern in all contexts. :^)
When a process with a large heap crashes (e.g WebContent), it gets very
cumbersome to dump out a huge amount of memory.
In the vast majority of cases, we're only interested in generating a
nice backtrace from the coredump, so let's have the kernel skip over
userspace heap regions when dumping memory for now.
This is not ideal, and almost a little bit ugly, but it does make
investigating 500 MiB WebContent crashes significantly easier for now.
This patch converts all the usage of AK::String around sys$execve() to
using KString instead, allowing us to catch and propagate OOM errors.
It also required changing the kernel CommandLine helper class to return
a vector of KString for the userspace init program arguments.
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. :^)
Instead of creating a bunch of ByteBuffers and concatenating them to
generate the "notes" segment, we now simply create a KBufferBuilder
and tell each of the notes generator helpers to write into the builder.
This allows the code to flow more naturally, with some bonus additional
error propagation. :^)
