Each process has a 1-level lookup cache for fast repeated lookups of
the same VM region (which tends to be the majority of lookups.)
The cache is used by the following syscalls: munmap, madvise, mprotect
and set_mmap_name.
After a succesful exec(), there could be a stale Region* in the lookup
cache, and the new executable was able to manipulate it using a number
of use-after-free code paths.
Now the ACPI & PCI code is more safer, because we don't use raw pointers
or references to objects or data that are located in the physical
address space, so an accidental dereference cannot happen easily.
Instead, we use the PhysicalAddress class to represent those addresses.
Now we use the GenericInterruptHandler class instead of IRQHandler in
the CPU functions.
This commit adds an include to the ISR stub macros header file.
Also, this commit adds support for IRQ sharing, so when an IRQHandler
will try to register to already-assigned IRQ number, a SharedIRQHandler
will be created to register both IRQHandlers.
Also, the enable() function is now correct and will use the right
registers and values. In addition to that, write_register() and
read_registers() are not relying on identity mapping anymore.
Also, update the class implementation to use PCI::Device class
accordingly.
The create() helper will now search for an IDE controller in the
PCI bus, allowing to simplify the initialize() method.
This class represents a shared interrupt handler. This class will not be
created automatically but only if two IRQ Handlers are sharing the same
IRQ number.
The GenericInterruptHandler class will be used to represent
an abstract interrupt handler. The InterruptManagement class will
represent a centralized component to manage interrupts.
I probably would've done INI config removal in another commit, but it
fit well here because I didn't want to pledge wpath for SystemMenu if I
didn't need to.
Frankly, that's something that I think should be done: allow ConfigFile
to be used read-only.
Each allocation header was tracking its index into the chunk bitmap,
but that index can be computed from the allocation address anyway.
Removing this means that each allocation gets 4 more bytes of memory
and this avoids allocating an extra chunk in many cases. :^)
When committing to a new executable, disown any shared buffers that the
process was previously co-owning.
Otherwise accessing the same shared buffer ID from the new program
would cause the kernel to find a cached (and stale!) reference to the
previous program's VM region corresponding to that shared buffer,
leading to a Region* use-after-free.
Fixes#1270.
Since we're gonna throw away these stacks at the end of exec anyway,
we might as well disable profiling before starting to mess with the
process page tables. One less weird situation to worry about in the
sampling code.
