init: fix FILETABLE desync causing EEXIST on all daemon spawns

create_pipe() used raw syscall::openat() (SYS_OPENAT) and syscall::dup()
which bypass relibc's FILETABLE-managed fd allocation (SYS_OPENAT_INTO).
This created phantom fds known to the kernel but not to relibc's userspace
FILETABLE. When Command::spawn() later called relibc's pipe2() for
fork+exec error reporting, the FILETABLE allocated a position it thought
was free, but the kernel rejected it with EEXIST (errno 17).

This killed EVERY daemon spawn during boot: logd, randd, zerod, rtcd,
nulld, acpid, pcid, inputd, lived, redoxfs, pcid-spawner, fbcond, vesad,
fbbootlogd, hwd, ps2d — all failed with 'File exists (os error 17)'.

Fix: use libc::pipe2() which goes through relibc's FILETABLE-managed
path (FdGuard::open → SYS_OPENAT_INTO), keeping tables in sync.

init/src/service.rs

@@ -37,25 +37,20 @@ pub enum ServiceType {
 }
 
 fn create_pipe() -> io::Result<(File, OwnedFd)> {
-    let ns_fd = libredox::call::getns()
-        .map_err(|e| io::Error::from_raw_os_error(e.errno()))?;
-
-    let rd_fd = syscall::openat(
-        ns_fd,
-        "/scheme/pipe",
-        syscall::flag::O_RDONLY | syscall::flag::O_CLOEXEC,
-        0,
-    )
-    .map_err(|e| io::Error::from_raw_os_error(e.errno))?;
-
-    let wr_raw = syscall::dup(rd_fd, b"write")
-        .map_err(|e| {
-            let _ = syscall::close(rd_fd);
-            io::Error::from_raw_os_error(e.errno)
-        })?;
-
-    let wr = unsafe { OwnedFd::from_raw_fd(wr_raw as i32) };
-    let rd = unsafe { File::from_raw_fd(rd_fd as i32) };
+    let mut fds = [0; 2];
+    // Use libc::pipe2() which goes through relibc's FILETABLE-managed path
+    // (FdGuard::open → SYS_OPENAT_INTO), keeping the userspace file table in
+    // sync with the kernel's file table. Using raw syscall::openat()
+    // (SYS_OPENAT) here would bypass the FILETABLE and create phantom fds
+    // that later cause EEXIST collisions when relibc's own pipe2() (called
+    // during Command::spawn fork+exec) tries to insert at a position the
+    // FILETABLE incorrectly thinks is free.
+    let ret = unsafe { libc::pipe2(fds.as_mut_ptr(), libc::O_CLOEXEC) };
+    if ret != 0 {
+        return Err(io::Error::last_os_error());
+    }
+    let rd = unsafe { File::from_raw_fd(fds[0]) };
+    let wr = unsafe { OwnedFd::from_raw_fd(fds[1]) };
     Ok((rd, wr))
 }