Round 6 follow-up: extends the stub-replacement work to add
POSIX named semaphore support (sem_open) and fixes two ioctl
helper unsoundness issues.
* sem_open (src/header/semaphore/mod.rs): implements the POSIX
named semaphore API. The cbindgen.toml now includes <bits/valist.h>
for va_list and defines SEM_FAILED ((sem_t *)0). The implementation
uses O_CREAT from fcntl.h and mode_t from the platform types.
This unblocks packages that use sem_open (e.g. Apache Portable
Runtime, glib's GMutex, postgres extensions).
* ioctl dup_read/dup_write (src/header/sys_ioctl/redox/mod.rs):
replaces mem::size_of::<T>() with mem::size_of_val(t) to correctly
handle types whose size is not statically known (e.g. DST arrays).
The dup_write path now uses raw syscall3 to write through the
pointer without constructing a &[u8] reference over potentially
uninitialized padding bytes, removing the FIXME unsoundness
marker. The upstream TODO comment in dup_read was also removed
since the size_of_val fix addresses the padding concern.
These are concurrent changes from an in-progress relibc fork
that landed on the working tree but were never committed.
Red Bear OS
92f9d629c0