Do not treat ppid as constant.

redox-rt/src/lib.rs

@@ -203,7 +203,6 @@ pub unsafe fn initialize(#[cfg(feature = "proc")] proc_fd: FdGuard) {
 
     STATIC_PROC_INFO.get().write(StaticProcInfo {
         pid: metadata.pid,
-        ppid: metadata.ppid,
 
         #[cfg(feature = "proc")]
         proc_fd: MaybeUninit::new(proc_fd),
@@ -228,10 +227,9 @@ pub unsafe fn initialize(#[cfg(feature = "proc")] proc_fd: FdGuard) {
     }
 }
 
-#[repr(C)] // TODO: is this required?
+#[repr(C)] // TODO: is repr(C) required?
 pub(crate) struct StaticProcInfo {
     pid: u32,
-    ppid: u32, // TODO: dynamic
     proc_fd: MaybeUninit<FdGuard>,
     has_proc_fd: bool,
 }
@@ -292,7 +290,6 @@ unsafe fn child_hook_common(args: ChildHookCommonArgs) {
         .get()
         .replace(StaticProcInfo {
             pid: metadata.pid,
-            ppid: metadata.ppid,
             has_proc_fd: args.new_proc_fd.is_some(),
             proc_fd: args
                 .new_proc_fd

redox-rt/src/proc.rs

@@ -970,7 +970,6 @@ pub unsafe fn make_init() -> [&'static FdGuard; 2] {
 
     STATIC_PROC_INFO.get().write(crate::StaticProcInfo {
         pid: 1,
-        ppid: 1,
         proc_fd: MaybeUninit::new(proc_fd),
         has_proc_fd: true,
     });
@@ -991,7 +990,6 @@ pub unsafe fn make_init() -> [&'static FdGuard; 2] {
 pub(crate) static STATIC_PROC_INFO: SyncUnsafeCell<StaticProcInfo> =
     SyncUnsafeCell::new(StaticProcInfo {
         pid: 0,
-        ppid: 0,
         proc_fd: MaybeUninit::zeroed(),
         has_proc_fd: false,
     });

redox-rt/src/protocol.rs

@@ -34,6 +34,7 @@ pub enum ProcCall {
     // TODO: replace with sendfd equivalent syscall for sending memory
     SyncSigPctl = 10,
     Sigdeq = 11,
+    Getppid = 12,
 }
 #[derive(Clone, Copy, Debug, Eq, PartialEq)]
 #[repr(usize)]
@@ -59,6 +60,7 @@ impl ProcCall {
             9 => Self::Sigq,
             10 => Self::SyncSigPctl,
             11 => Self::Sigdeq,
+            12 => Self::Getppid,
             _ => return None,
         })
     }

redox-rt/src/sys.rs

@@ -5,7 +5,7 @@ use core::{
 };
 
 use syscall::{
-    error::{Error, Result, EINTR},
+    error::{self, Error, Result, EINTR},
     CallFlags, TimeSpec, EINVAL, ERESTART,
 };
 
@@ -76,7 +76,10 @@ pub fn posix_sigqueue(pid: usize, sig: usize, arg: usize) -> Result<()> {
             &[ProcCall::Sigq as u64, pid as u64, sig as u64],
         )
     }) {
-        Ok(_) | Err(Error { errno: EINTR }) => Ok(()),
+        Ok(_)
+        | Err(Error {
+            errno: error::EINTR,
+        }) => Ok(()),
         Err(error) => Err(error),
     }
 }
@@ -87,8 +90,8 @@ pub fn posix_getpid() -> u32 {
 }
 #[inline]
 pub fn posix_getppid() -> u32 {
-    // SAFETY: read-only except during program/fork child initialization
-    unsafe { addr_of!((*crate::STATIC_PROC_INFO.get()).ppid).read() }
+    this_proc_call(&mut [], CallFlags::empty(), &[ProcCall::Getppid as u64]).expect("cannot fail")
+        as u32
 }
 #[inline]
 pub unsafe fn sys_futex_wait(addr: *mut u32, val: u32, deadline: Option<&TimeSpec>) -> Result<()> {