Contradictory to the comment above it, this while loop was actually
clearing the selectors above or equal to the edited one (instead of
the selectors that were skipped when the gdt was extended), this wasn't
really an issue so far, as all calls to this function did extend the
GDT, which meant this condition was always false, but future calls to
this function that will try to edit an existing entry would fail.
... instead of returning the maximum number of Processor objects that we
can allocate.
Some ports (e.g. gdb) rely on this information to determine the number
of worker threads to spawn. When gdb spawned 64 threads, the kernel
could not cope with generating backtraces for it, which prevented us
from debugging it properly.
This commit also removes the confusingly named
`Processor::processor_count` function so that this mistake can't happen
again.
Add a kernel data segment and make the user code segment come after
the data segment. We need the GDT to be in a certain order to support
the syscall and sysret instruction pair.
In order to reduce our reliance on __builtin_{ffs, clz, ctz, popcount},
this commit removes all calls to these functions and replaces them with
the equivalent functions in AK/BuiltinWrappers.h.
Unsurprisingly, the /proc/PID/stacks/TID stack walk had the same
arbitrary memory read problem as the perf event stack walk.
It would be nice if the kernel had a single stack walk implementation,
but that's outside the scope of this commit.
Clang rejects binding a reference to a null pointer at compile-time.
Let's just crash explicitly, instead of waiting for a null dereference
to mess things up.
SIGSTKFLT is a signal that signifies a stack fault in a x87 coprocessor,
this signal is not POSIX and also unused by Linux and the BSDs, so let's
use SIGSEGV so programs that setup signal handlers for the common
signals could still handle them in serenity.
This isn't a complete conversion to ErrorOr<void>, but a good chunk.
The end goal here is to propagate buffer allocation failures to the
caller, and allow the use of TRY() with formatting functions.
... In files included from Kernel/Thread.cpp or Kernel/Process.cpp
Some places the warning is suppressed, because we do not want a const
object do have non-const access to the returned sub-object.
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. :^)
Storing assigning a string literal to a String object just to pass it to
a function expecting a StringView is wasteful. Let's just not do that.
For consistency's sake, this commit changes all of the other invocations
to use StringView literals, too.
