Previously we were only checking that each of the virtual pages in the
specified range were valid.
This made it possible to pass in negative buffer sizes to some syscalls
as long as (address) and (address+size) were on the same page.
There's no sense in allowing arbitrarily huge resolutions. Instead, we
now cap the screen size at 4K DCI resolution and will reject attempts
to go bigger with EINVAL.
Previously it was not possible for this function to fail. You could
exploit this by triggering the creation of a VMObject whose physical
memory range would wrap around the 32-bit limit.
It was quite easy to map kernel memory into userspace and read/write
whatever you wanted in it.
Test: Kernel/bxvga-mmap-kernel-into-userspace.cpp
This is a complete reimplementation of CArgsParser with a different API.
Now, CArgsParser properly supports and distinguishes between:
* Positional arguments (required or not)
* Options
Options can be short and/or long.
The API allows you to add custom option and argument types. A few types are
pre-implemented for convenience:
* Boolean options (take no value)
* String and integer options (take a required value)
* String and integer arguments
* Vector-of-string arguments
This commit doesn't include changes for all the users of CArgsParser (see next
commit for that).
When a single item is selected and it happens to be a symlink pointing
somewhere, we now show where it points to in the status bar. :^)
There is a big ugly FIXME here about how DirectoryView has to work
around the fact that there's a GSortingProxyModel attached to the table
view widget.
If the waitee process is dead, we don't need to inspect the thread.
This fixes an issue with sys$waitpid() failing before reap() since
dead processes will have no remaining threads alive.
There was a race window in a bunch of syscalls between calling
Thread::from_tid() and checking if the found thread was in the same
process as the calling thread.
If the found thread object was destroyed at that point, there was a
use-after-free that could be exploited by filling the kernel heap with
something that looked like a thread object.
While I was bringing up multitasking, I put the current PID in the SS2
(ring 2 stack segment) slot of the TSS. This was so I could see which
PID was currently running when just inspecting the CPU state.
Memory validation is used to verify that user syscalls are allowed to
access a given memory range. Ring 0 threads never make syscalls, and
so will never end up in validation anyway.
The reason we were allowing kmalloc memory accesses is because kernel
thread stacks used to be allocated in kmalloc memory. Since that's no
longer the case, we can stop making exceptions for kmalloc in the
validation code.
Move timeout management to the ReadBlocker and WriteBlocker classes.
Also get rid of the specialized ReceiveBlocker since it no longer does
anything that ReadBlocker can't do.
