Right now, cosmopolitan uses Linux Landlock ABI version 2 on Linux,
meaning that the polyfill for unveil() cannot restrict operations such
as truncate() (a limitation of Landlock's ABI from then). This means
that to restrict truncation operations Cosmopolitan instead has to ban
the syscall through a SECCOMP BPF filter, meaning that completely
legitimate truncate() calls are blocked
However, the newest version of the Landlock ABI (version 3) introduced
in Linux 6.2, released in February 2023, implements support for controlling truncation
operations. As such, the previous SECCOMP BPF truncate() filtering is
no longer needed when the new ABI is available
This patch implements unveil truncate support for Linux Landlock ABI
version 3
The rpath pledge as currently implemented in cosmopolitan does not
allow for usage of the old getdents syscall (0x4e), which is different
from the newer getdents syscall (0xd9) solely in that it does not
support 64-bit filesystems.
This means that, for example, old statically linked binaries cannot
use `readdir` and other such functions which use this syscall instead
of the more modern one, even though there is no threat in allowing
that syscall alongside the more modern one (except that the binary may
have issues with 64-bit filesystems, but that's a separate problem).
This patch fixes this.
This fixes a bug where the caller's timeval will be clobbered on Linux.
The Kernel ABI *always* modifies the timeout argument but POSIX says it
should be a const parameter. The wrapper now handles the difference and
sys_select() may be used if obtaining the remainder on Linux is needed.
The system call wrapper was wrongfully reinterpreting kernel data. The
examples/sysinfo.c program is now updated to show how to correctly use
what's returned.
* [metal] Copy program pages to extended memory at startup
* [metal] Reclaim base memory pages for later app use
* [metal] Load program pages beyond 1st 440 KiB to extended memory
o//examples/hellolua.com now runs correctly under QEMU (in
legacy BIOS mode).
* [metal] Place GDT in read/write segment
The CPU absolutely needs to alter the GDT when loading the
task register (via ltr). To account for this, I move the
GDT into a read/write data section. There is still a "rump"
read-only GDT in the text section that is used by the real
mode bootloader.
We also delay the loading of the task register (ltr) until
after the IDT and TSS are finally set up.
* [metal] Get examples/vga2.c serial output working for UEFI boot
* [metal] Get examples/vga2.c VGA output working for UEFI boot
* [metal] Allow munmap() to reclaim dynamically allocated pages
* Place TLS sections right after .text, not after embedded zip file
Co-authored-by: tkchia <tkchia-cosmo@gmx.com>
- Improve compatibility with Blink virtual machine
- Add non-POSIX APIs for joining threads and signal masks
- Never ever use anything except 32-bit integers for atomics
- Add some `#undef` statements to workaround `ctags` problems
- clock_nanosleep() is now much faster on OpenBSD and NetBSD
- Thread joining is now much faster on NetBSD
- FreeBSD timestamps are now more accurate
- Thread spawning now goes faster on XNU
- Clean up the clone() code
- Clean up sigaction() code
- Add a port scanner example
- Introduce a ParseCidr() API
- Clean up our futex abstraction code
- Fix a harmless integer overflow in ParseIp()
- Use kernel semaphores on NetBSD to make threads much faster
- Exhaustively document cancellation points
- Rename SIGCANCEL to SIGTHR just like BSDs
- Further improve POSIX thread cancellations
- Ensure asynchronous cancellations work correctly
- Elevate the quality of getrandom() and getentropy()
- Make futexes cancel correctly on OpenBSD 6.x and 7.x
- Add reboot.com and shutdown.com to examples directory
- Remove underscore prefix from awesome timespec_*() APIs
- Create assertions that help verify our cancellation points
- Remove bad timespec APIs (cmp generalizes eq/ne/gt/gte/lt/lte)
This change makes some miracle modifications to the System Five system
call support, which lets us have safe, correct, and atomic handling of
thread cancellations. It all turned out to be cheaper than anticipated
because it wasn't necessary to modify the system call veneers. We were
able to encode the cancellability of each system call into the magnums
found in libc/sysv/syscalls.sh. Since cancellations are so waq, we are
also supporting a lovely Musl Libc mask feature for raising ECANCELED.
This change includes a fix to Fetch() where an out of bounds memory read
could happen, when the reverse proxied endpoint omits the content-length
header. This caused a bunch of NUL chars to appear on TurfWar's /statusz
since it wouldn't actually overrun the buffer, and if it did it would've
been caught by MODE=asan builds.
