To make sure we don't lose changes, shared file mappings will now be
fully synced when they are unmapped, whether explicitly or implicitly
(by the program exiting/crashing/etc.)
This can incur a lot of work, since we don't keep track of dirty pages,
but that's something we can optimize down the road. :^)
This allows userspace to trigger a full (FIXME) flush of a shared file
mapping to disk. We iterate over all the mapped pages in the VMObject
and write them out to the underlying inode, one by one. This is rather
naive, and there's lots of room for improvement.
Note that shared file mappings are currently not possible since mmap()
returns ENOTSUP for PROT_WRITE+MAP_SHARED. That restriction will be
removed in a subsequent commit. :^)
This is a handy helper that copies out the full contents of a physical
page into a caller-provided buffer. It uses quickmapping internally
(and takes the MM lock for the duration.)
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.
We have no way of writing changes to memory-mapped files back to disk,
and software relying on this functionality for output would fail
miserably. Let's just return ENOTSUP instead to allow callers to fall
back to standard file IO instead of silently discarding writes.
This makes the LLD port work, which uses memory-mapped files to write
its output by default.
This feels like it was a refactor transition kind of conversion. The
places that were relying on it can easily be changed to explicitly ask
for the ptr() or a new vaddr() method on Userspace<T*>.
FlatPtr can still implicitly convert to Userspace<T> because the
constructor is not explicit, but there's quite a few more places that
are relying on that conversion.
Some calls of copy_to_user were converting Userspace<T*> to
Userspace<U*> via the implicit conversion to FlatPtr. Change them to use
the static_ptr_cast overload that is designed to express this conversion
A series of refactors changed Threads to always have a name, and to
store their name as a KString. Before the refactors a StringBuilder was
used to format the default thread name for a non-main thread, but it is
since unused. Remove it and the AK/String related header includes from
the thread syscall implementation file.
Two instances of comparing a bool with == true or == false, and one
instance where we can just return an expression instead of checking it
to return true on succeess and false on failure.
... 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.
cert-dcl50-cpp: No variadic functions, suppressed in RefCounted and
ThreadSafeRefCounted for implementing the magic one_ref_left and
will_be_destroyed functions.
cert-dcl58-cpp: No opening ::std, suppressed in the places we put names
in ::std to aid tools (move, forward, nullptr_t, align_val_t, etc).
Instead of repeating ourselves with the pattern of waiting for some
condition to be met, we can have a general method for this task,
and then we can provide the retry count, the required delay and a lambda
function for the checked condition.
Don't use interrupts when trying to reset a device that is connected to
a port on the AHCI controller, and instead poll for changes in status to
break out from the loop. At the worst case scenario we can wait 0.01
seconds for each SATA reset.
Don't use interrupts when trying to identify a device that is connected
to a port on the AHCI controller, and instead poll for changes in status
to end the transaction.
Not only this simplifies the initialization sequence, it ensures that
for whatever reason the controller doesn't send an IRQ, we are never
getting stuck at this point.
Like what happened with the PCI and USB code, this feels like the right
thing to do because we can improve on the ATA capabilities and keep it
distinguished from the rest of the subsystem.
`off_t` is a 64-bit signed integer, so passing it in a register on i686
is not the best idea.
This fix gets us one step closer to making the LLVM port work.
As soon as we enable the first PS/2 port on the I8042 controller, the
output buffer may become full. We need to drain it before attempting
any new commands with the controller (such as enabling the second PS/2
port).
Fixes#10872.
Instead of signalling allocation failure with a bool return value
(false), we now use ErrorOr<void> and return ENOMEM as appropriate.
This allows us to use TRY() and MUST() with Vector. :^)
In particular, fstatvfs used to assume that a file that was earlier
opened using some path will forever be at that path. This is wrong, and
in the meantime new mounts and new filesystems could take up the
filename or directories, leading to a completely inaccurate result.
This commit improves the situation:
- All filesystem information is now always accurate.
- The mount flags *might* be erroneously zero, if the custody for the
open file is not available. I don't know when that might happen, but
it is definitely not the typical case.
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. :^)
