VM regions can now be marked as stack regions, which is then validated
on syscall, and on page fault.
If a thread is caught with its stack pointer pointing into anything
that's *not* a Region with its stack bit set, we'll crash the whole
process with SIGSTKFLT.
Userspace must now allocate custom stacks by using mmap() with the new
MAP_STACK flag. This mechanism was first introduced in OpenBSD, and now
we have it too, yay! :^)
This patch adds pthread_create() and pthread_exit(), which currently
simply wrap our existing create_thread() and exit_thread() syscalls.
LibThread is also ported to using LibPthread.
POSIX's openat() is very similar to open(), except you also provide a
file descriptor referring to a directory from which relative paths
should be resolved.
Passing it the magical fd number AT_FDCWD means "resolve from current
directory" (which is indeed also what open() normally does.)
This fixes libarchive's bsdtar, since it was trying to do something
extremely wrong in the absence of openat() support. The issue has
recently been fixed upstream in libarchive:
https://github.com/libarchive/libarchive/issues/1239
However, we should have openat() support anyway, so I went ahead and
implemented it. :^)
Fixes#748.
This just copies the short char into the wide char without any decoding
whatsoever. A proper implementation should look at the current LC_CTYPE
and implement multi-byte decoding.
Files opened with O_DIRECT will now bypass the disk cache in read/write
operations (though metadata operations will still hit the disk cache.)
This will allow us to test actual disk performance instead of testing
disk *cache* performance, if that's what we want. :^)
There's room for improvment here, we're very aggressively flushing any
dirty cache entries for the specific block before reading/writing that
block. This is done by walking the entire cache, which may be slow.
`atof()` has now been implemented as part of the standard C library.
It supports scientific notation such as `1.2e-3` etc, ala the version
found as part of `glibc`.
It's a bit chunky, so there's probably room for optimisations here
and there, however, for now it works as intended (and allows Quake
to run).
Ports/.port_include.sh, Toolchain/BuildIt.sh, Toolchain/UseIt.sh
have been left largely untouched due to use of Bash-exclusive
functions and variables such as $BASH_SOURCE, pushd and popd.
When using the bounded string operations (e.g. snprintf), the null
terminator was always being written even if there was no space for
it (or indeed any valid buffer at all)
This overwriting caused segmentation faults and memory corruption
Thread::make_userspace_stack_for_main_thread is only ever called from
Process::do_exec, after all the fun ELF loading and TSS setup has
occured.
The calculations in there that check if the combined argv + envp
size will exceed the default stack size are not used in the rest of
the stack setup. So, it should be safe to move this to the beginning
of do_exec and bail early with -E2BIG, just like the man pages say.
Additionally, advertise this limit in limits.h to be a good POSIX.1
citizen. :)
This is an implementation of syslog with some OpenBSD extensions.
There is no syslogd support (so it only logs to dbgprintf/stderr),
but otherwise is functional.
Many weird defines are always present, because some syslog users in
the wild check for their existence.
Serenity is really not production ready; I shouldn't have to warn
you not to trust the RNG here. This is for compatibility with
software expecting the interface.
arc4random does expose an annoying flaw with the syscall I want
to discuss with Kling though.
These are basically copy and pasted from the regular string version.
Also add some more multi-byte/wide conversion stub.
libarchive wanted these. There's a lot more, but we can add them
one at a time.
Seems POSIX is odd and unistd also defines SEEK_SET if stdio.h
This simply follows the pattern several other C libraries take of setting
these macros to the same values in stdio if that header is not included.
