This matches out general macro use, and specifically other verification
macros like VERIFY(), VERIFY_NOT_REACHED(), VERIFY_INTERRUPTS_ENABLED(),
and VERIFY_INTERRUPTS_DISABLED().
Instead of locking it twice, we now frontload all the work that doesn't
touch the fd table, and then only lock it towards the end of the
syscall.
The benefit here is simplicity. The downside is that we do a bit of
unnecessary work in the EMFILE error case, but we don't need to optimize
that case anyway.
If the final copy_to_user() call fails when writing the file descriptors
to the output array, we have to make sure the file descriptors don't
remain in the process file descriptor table. Otherwise they are
basically leaked, as userspace is not aware of them.
This matches the behavior of our sys$socketpair() implementation.
We don't need to explicitly check for EMFILE conditions before doing
anything in sys$pipe(). The fd allocation code will take care of it
for us anyway.
This fixes an issue where failing the fork due to OOM or other error,
we'd end up destroying the Process too early. By the time we got to
WaitBlockerSet::finalize(), it was long gone.
This argument is always set to description.is_blocking(), but
description is also given as a separate argument, so there's no point
to piping it through separately.
While null StringViews are just as bad, these prevent the removal of
StringView(char const*) as that constructor accepts a nullptr.
No functional changes.
Each of these strings would previously rely on StringView's char const*
constructor overload, which would call __builtin_strlen on the string.
Since we now have operator ""sv, we can replace these with much simpler
versions. This opens the door to being able to remove
StringView(char const*).
No functional changes.
Until the thread is first set as Runnable at the end of sys$fork, its
state is Invalid, and as a result, the Finalizer which is searching for
Dying threads will never find it if the syscall short-circuits due to
an error condition like OOM. This also meant the parent Process of the
thread would be leaked as well.
The extra argument to fcntl is a pointer in the case of F_GETLK/F_SETLK
and we were pulling out a u32, leading to pointer truncation on x86_64.
Among other things, this fixes Assistant on x86_64 :^)
The previous check for valid how values assumed this field was a bitmap
and that SHUT_RDWR was simply a bitwise or of SHUT_RD and SHUT_WR,
which is not the case.
`sigsuspend` was previously implemented using a poll on an empty set of
file descriptors. However, this broke quite a few assumptions in
`SelectBlocker`, as it verifies at least one file descriptor to be
ready after waking up and as it relies on being notified by the file
descriptor.
A bare-bones `sigsuspend` may also be implemented by relying on any of
the `sigwait` functions, but as `sigsuspend` features several (currently
unimplemented) restrictions on how returns work, it is a syscall on its
own.
When updating the signal mask, there is a small frame where we might set
up the receiving process for handing the signal and therefore remove
that signal from the list of pending signals before SignalBlocker has a
chance to block. In turn, this might cause SignalBlocker to never notice
that the signal arrives and it will never unblock once blocked.
Track the currently handled signal separately and include it when
determining if SignalBlocker should be unblocking.
As with the previous commit, we put a distinction between filesystems
that require a file description and those which don't, but now in a much
more readable mechanism - all initialization properties as well as the
create static method are grouped to create the FileSystemInitializer
structure. Then when we need to initialize an instance, we iterate over
a table of these structures, checking for matching structure and then
validating the given arguments from userspace against the requirements
to ensure we can create a valid instance of the requested filesystem.
We do this by putting a distinction between two types of filesystems -
the first type is backed in RAM, and includes TmpFS, ProcFS, SysFS,
DevPtsFS and DevTmpFS. Because these filesystems are backed in RAM,
trying to mount them doesn't require source open file description.
The second type is filesystems that are backed by a file, therefore the
userspace program has to open them (hence it has a open file description
on them) and provide the appropriate source open file description.
By putting this distinction, we can early check if the user tried to
mount the second type of filesystems without a valid file description,
and fail with EBADF then.
Otherwise, we can proceed to either mount either type of filesystem,
provided that the fs_type is valid.
Implement futimes() in terms of utimensat(). Now, utimensat() strays
from POSIX compliance because it also accepts a combination of a file
descriptor of a regular file and an empty path. utimensat() then uses
this file descriptor instead of the path to update the last access
and/or modification time of a file. That being said, its prior behavior
remains intact.
With the new behavior of utimensat(), `path` must point to a valid
string; given a null pointer instead of an empty string, utimensat()
sets `errno` to `EFAULT` and returns a failure.
Coverage tools like LLVM's source-based coverage or GNU's --coverage
need to be able to write out coverage files from any binary, regardless
of its security posture. Not ignoring these pledges and veils means we
can't get our coverage data out without playing some serious tricks.
However this is pretty terrible for normal exeuction, so only skip these
checks when we explicitly configured userspace for coverage.
This keeps us from accidentally overwriting an already set region name,
for example when we are mapping a file (as, in this case, the file name
is already stored in the region).
