There are plenty of places in the kernel that aren't
checking if they actually got their allocation.
This fixes some of them, but definitely not all.
Fixes#3390Fixes#3391
Also, let's make find_one_free_page() return nullptr
if it doesn't get a free index. This stops the kernel
crashing when out of memory and allows memory purging
to take place again.
Fixes#3487
Since the CPU already does almost all necessary validation steps
for us, we don't really need to attempt to do this. Doing it
ourselves doesn't really work very reliably, because we'd have to
account for other processors modifying virtual memory, and we'd
have to account for e.g. pages not being able to be allocated
due to insufficient resources.
So change the copy_to/from_user (and associated helper functions)
to use the new safe_memcpy, which will return whether it succeeded
or not. The only manual validation step needed (which the CPU
can't perform for us) is making sure the pointers provided by user
mode aren't pointing to kernel mappings.
To make it easier to read/write from/to either kernel or user mode
data add the UserOrKernelBuffer helper class, which will internally
either use copy_from/to_user or directly memcpy, or pass the data
through directly using a temporary buffer on the stack.
Last but not least we need to keep syscall params trivial as we
need to copy them from/to user mode using copy_from/to_user.
MemoryManager cannot use the Singleton class because
MemoryManager::initialize is called before the global constructors
are run. That caused the Singleton to be re-initialized, causing
it to create another MemoryManager instance.
Fixes#3226
When trying to scroll up on virtualizers that don't use the VMware
backdoor and instead use PS2MouseDevice, it would actually scroll
down rapidly.
Looking into it, the mouse delta for scrolling down was 1 and 15
for scrolling up. 15 is suspiciously -1 for a nibble.
According to https://isdaman.com/alsos/hardware/mouse/ps2interface.htm
the Z is actually 4 bits for Intellimouse.
This fixes scrolling up on virtualizers such as VirtualBox.
Use copy_{to,from}_user() in the various File::ioctl() implementations
instead of disabling SMAP wholesale in sys$ioctl().
This patch does not port IPv4Socket::ioctl() to those API's since that
will be more involved. That function now creates a local SmapDisabler.
Add all 6 shortcuts even if the switch between VirtualConsoles is
currently not available in the graphical console.
Also make the case statement more compact.
The Lock class still permits no reason, but for everything else
require a reason to be passed to Thread::wait_on. This makes it
easier to diagnose why a Thread is in Queued state.
Random now gets entropy from the following drivers:
- KeyboardDevice
- PATAChannel
- PS2MouseDevice
- E1000NetworkAdapter
- RTL8139NetworkAdapter
Of these devices, PS2MouseDevice and PATAChannel provide the vast
majority of the entropy.
We were not setting the DMA transfer mode correctly. I have absolutely
no clue how this could ever have worked, but it did work for months
until it suddenly didn't.
Anyways, this fixes that. The sound is still a little bit glitchy and
that could probably be fixed by using the SB16's auto-initialized mode.
.. and make travis run it.
I renamed check-license-headers.sh to check-style.sh and expanded it so
that it now also checks for the presence of "#pragma once" in .h files.
It also checks the presence of a (single) blank line above and below the
"#pragma once" line.
I also added "#pragma once" to all the files that need it: even the ones
we are not check.
I also added/removed blank lines in order to make the script not fail.
I also ran clang-format on the files I modified.
This was supposed to be the foundation for some kind of pre-kernel
environment, but nobody is working on it right now, so let's move
everything back into the kernel and remove all the confusion.
The detection works very similarly to how we detect a mouse wheel, just
another magical sequence of "set sample rate" requests to the mouse
followed by an ID check.
Since a Region is basically a view into a potentially larger VMObject,
it was always necessary to include the Region starting offset when
accessing its underlying physical pages.
Until now, you had to do that manually, but this patch adds a simple
Region::physical_page() for read-only access and a physical_page_slot()
when you want a mutable reference to the RefPtr<PhysicalPage> itself.
A lot of code is simplified by making use of this.
The IOAPIC manual states that "Interrupt Mask-R/W. When this bit is 1,
the interrupt signal is masked. Edge-sensitive interrupts signaled on
a masked interrupt pin are ignored." - Therefore we have to ensure that
we disable interrupts globally with cli(), but also to ensure that we
invoke enable_irq() before sending the hardware command that generates
an IRQ almost immediately.
First, before this change, specifying 'force_pio' in the kernel
commandline was meaningless because we nevertheless set the DMA flag to
be enabled.
Also, we had a problem in which we used IO::repeated_out16() in PIO
write method. This might work on buggy emulators, but I suspect that on
real hardware this code will fail.
The most difficult problem was to restore the PIO read operation.
Apparently, it seems that we can't use IO::repeated_in16() here because
it will read zeroed data. Currently we rely on a simple loop that
invokes IO::in16() to a buffer. Also, the interrupt handling stage in
the PIO read method is moved to be handled inside the loop of reading
the requested sectors.
