Turns out we didn't end up needing this capability, so, commenting it
out because it is a shy too powerful and is like packing a live
mortar shell in a storage unit: eventually, someone is going to
get hurt, even though it seems mostly harmless at the moment.
Code just commented out in case we need this feature in the future,
but, the main reason it was asked for (the PDDB) was accomplished
without it.
Correctly handle transitions to and from exception handling.
Previously, the thread ID was incorrectly set such that the exception
handler became a valid thread. This has been adjusted so that the
exception handler is no longer considered a thread, and all other
threads will cease scheduling during this process.
Signed-off-by: Sean Cross <sean@xobs.io>
Memory is on-demand allocated, meaning it's entirely possible to
allocate and free memory without ever touching physical pages.
Previously, when we attempted to free memory, it would skip over pages
that were never backed by real memory.
With this patch, we continue to free the virtual page even if there is
no associated physical page.
Signed-off-by: Sean Cross <sean@xobs.io>
Memory is on-demand allocated, meaning it's entirely possible to
allocate and free memory without ever touching physical pages.
Previously, when we attempted to free memory, it would skip over pages
that were never backed by real memory.
With this patch, we continue to free the virtual page even if there is
no associated physical page.
Signed-off-by: Sean Cross <sean@xobs.io>
If a process is currently running, it needs to be placed into the
`Debug` state rather than the `Ready` state.
Additionally, the process that's being switched to must enter the
`Running` state.
Signed-off-by: Sean Cross <sean@xobs.io>
If a process fails for some reason (e.g. by performing a fault) and
there is no exception handler, either terminate the process or (if
gdbserver is enabled) have it suspend the process.
Signed-off-by: Sean Cross <sean@xobs.io>
Previously, we were creating a stack beginning at the initial page,
and then growing it upwards. The correct behavior is to begin it at
the top and grow it downwards.
In order to do this, subtract the size of the stack from the initial
pointer.
Signed-off-by: Sean Cross <sean@xobs.io>
This fixes the exception handler so that it can support user-defined
exceptions. Additionally, kernel mode errors are called out now.
Signed-off-by: Sean Cross <sean@xobs.io>
When the program counter is NULL, we can still get exceptions. This
happens when we jump to an invalid address, for example.
Signed-off-by: Sean Cross <sean@xobs.io>
This compresses the entirety of the memory range finder into a single
statement. As a result, duplicate code is removed and we can elide more
range checks.
Signed-off-by: Sean Cross <sean@xobs.io>
