Allow making setpgid return EACCESS, e.g. after execv.

Cargo.lock

@@ -46,7 +46,7 @@ checksum = "d9c4f5dac5e15c24eb999c26181a6ca40b39fe946cbe4c263c7209467bc83af2"
 [[package]]
 name = "generic-rt"
 version = "0.1.0"
-source = "git+https://gitlab.redox-os.org/redox-os/relibc.git#040009ab3d384e75d62b7e7dd3176d910203501a"
+source = "git+https://gitlab.redox-os.org/redox-os/relibc.git#696ae4eca1df5e3b76a57f62903ee1a94b9c6aa6"
 
 [[package]]
 name = "goblin"
@@ -151,7 +151,7 @@ checksum = "436d45c2b6a5b159d43da708e62b25be3a4a3d5550d654b72216ade4c4bfd717"
 [[package]]
 name = "redox-rt"
 version = "0.1.0"
-source = "git+https://gitlab.redox-os.org/redox-os/relibc.git#040009ab3d384e75d62b7e7dd3176d910203501a"
+source = "git+https://gitlab.redox-os.org/redox-os/relibc.git#696ae4eca1df5e3b76a57f62903ee1a94b9c6aa6"
 dependencies = [
  "bitflags",
  "generic-rt",
@@ -162,9 +162,9 @@ dependencies = [
 
 [[package]]
 name = "redox-scheme"
-version = "0.6.0"
+version = "0.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6469e083bf650071e9a80003c53171dfccc5ef17ae1d24972396c3c792e7c709"
+checksum = "a14f94bc95b388d8f40a61f25577863f1cf151aaf600a5b7778d1a2018ff7742"
 dependencies = [
  "libredox",
  "redox_syscall",

src/procmgr.rs

@@ -35,7 +35,7 @@ use syscall::schemev2::NewFdFlags;
 use syscall::{
     sig_bit, ContextStatus, ContextVerb, CtxtStsBuf, Error, Event, EventFlags, FobtainFdFlags,
     MapFlags, ProcSchemeAttrs, Result, SenderInfo, SetSighandlerData, SigProcControl, Sigcontrol,
-    EAGAIN, EBADF, EBADFD, ECHILD, EEXIST, EINTR, EINVAL, EIO, ENOENT, ENOSYS, EOPNOTSUPP,
+    EACCES, EAGAIN, EBADF, EBADFD, ECHILD, EEXIST, EINTR, EINVAL, EIO, ENOENT, ENOSYS, EOPNOTSUPP,
     EOWNERDEAD, EPERM, ERESTART, ESRCH, EWOULDBLOCK, O_CLOEXEC, O_CREAT, PAGE_SIZE,
 };
 
@@ -336,6 +336,7 @@ struct Process {
     ens: u32,
 
     status: ProcessStatus,
+    disabled_setpgid: bool,
 
     awaiting_threads_term: Vec<VirtualId>,
 
@@ -581,6 +582,7 @@ impl<'a> ProcScheme<'a> {
                     name: ArrayString::<32>::from_str("[init]").unwrap(),
 
                     status: ProcessStatus::PossiblyRunnable,
+                    disabled_setpgid: false,
                     awaiting_threads_term: Vec::new(),
                     waitpid: BTreeMap::new(),
                     waitpid_waiting: VecDeque::new(),
@@ -659,6 +661,7 @@ impl<'a> ProcScheme<'a> {
             name,
 
             status: ProcessStatus::PossiblyRunnable,
+            disabled_setpgid: false,
             awaiting_threads_term: Vec::new(),
 
             waitpid: BTreeMap::new(),
@@ -990,6 +993,14 @@ impl<'a> ProcScheme<'a> {
                         self.on_proc_rename(fd_pid, payload).map(|()| 0),
                         op,
                     )),
+                    ProcCall::DisableSetpgid => {
+                        if let Some(proc) = self.processes.get(&fd_pid) {
+                            proc.borrow_mut().disabled_setpgid = true;
+                            Response::ready_ok(0, op)
+                        } else {
+                            Response::ready_err(ESRCH, op)
+                        }
+                    }
                 }
             }
             Handle::Ps(_) => Response::ready_err(EOPNOTSUPP, op),
@@ -1114,24 +1125,30 @@ impl<'a> ProcScheme<'a> {
             )
         };
 
-        // Cannot change the pgid of a process in a different session.
-        if caller_sid != proc.sid {
-            return Err(Error::new(EPERM));
-        }
-
         // Session leaders cannot have their pgid changed.
         if proc.sid == target_pid {
             return Err(Error::new(EPERM));
         }
 
-        if proc.pgid == new_pgid {
-            return Ok(());
+        // Cannot change the pgid of a process in a different session.
+        if caller_sid != proc.sid {
+            return Err(Error::new(EPERM));
         }
 
+        // New pgid must either already exit, or be the same as the target pid.
         if new_pgid != target_pid && !self.groups.contains_key(&new_pgid) {
             return Err(Error::new(EPERM));
         }
 
+        // After execv(), i.e. ProcCall::DisableSetpgid, setpgid shall return EACCESS
+        if proc.disabled_setpgid {
+            return Err(Error::new(EACCES));
+        }
+
+        if proc.pgid == new_pgid {
+            return Ok(());
+        }
+
         Self::set_pgid(
             proc_rc,
             &mut *proc,