The two-step pattern (open full path as scheme root, then open reference
relative to root_fd) failed for namespace-internal paths like
/scheme/namespace/scheme-creation-cap. The namespace scheme resolves the
full path and returns OtherScheme pointing to SchemeList (a kernel scheme
that does not implement kopenat). The second call then hits
SchemeList.kopenat() → EOPNOTSUPP.
The namespace scheme already handles reference resolution internally via
open_scheme_resource(), so a single SYS_OPENAT call with the full path
resolves everything. This also bypasses FILETABLE.insert_upper (which
previously collided with the untracked ns_fd at UPPER index 0).
The open() function used openat_into_upper which calls
FILETABLE.insert_upper() to allocate UPPER fd slots. This can collide
with the namespace fd (ns_fd) that is stored in DYNAMIC_PROC_INFO,
causing the kernel to overwrite the namespace fd entry. All subsequent
open() calls then resolve to the wrong scheme.
Fix: use raw SYS_OPENAT syscalls (which auto-assign POSIX fds) and
register them with register_external_fd, bypassing insert_upper entirely.
validate_kfmap_flags in kernel proc scheme requires exactly one of
MAP_SHARED or MAP_PRIVATE. Without it, shared == private == false,
and the check fails with EINVAL. This was the root cause of the
fexec_impl crash at step 62 (first PT_LOAD segment mapping).
redox-scheme Socket and RawEventQueue create fds via libredox raw
syscalls (SYS_DUP, openat) that bypass the redox-rt userspace
FILETABLE. When FdGuard::dup later reserves a POSIX fd slot via
FILETABLE.add_posix, it can reserve a position occupied by the
untracked socket fd. SYS_DUP_INTO then closes the socket and
replaces it, corrupting the procmgr's fd table.
Add register_external_fd() to redox-rt::sys that marks an
existing kernel fd as occupied in the userspace FILETABLE.
Call it from procmgr::run() for the socket fd and event queue
fd.
Removes all syscall::write(1, b'FK:...') debug trace lines from
fork_impl/fork_inner in redox-rt/src/proc.rs that were polluting
serial output during every fork() call.
Red Bear OS