Organize set*id functions into their own todo module. (#117)

* Organize `set*id` functions into their own todo module.

* Leave `setuid` and `setgid` outside of the todo module.

They're depended on by libstd.

Author: sunfishcode

c-scape/src/process/egid.rs

@@ -1,13 +1,7 @@
-use libc::{c_int, gid_t};
+use libc::gid_t;
 
 #[no_mangle]
 unsafe extern "C" fn getegid() -> gid_t {
     libc!(libc::getegid());
     rustix::process::getegid().as_raw()
 }
-
-#[no_mangle]
-unsafe extern "C" fn setegid(_gid: gid_t) -> c_int {
-    libc!(libc::setegid(_gid));
-    todo!("setegid")
-}

c-scape/src/process/euid.rs

@@ -1,13 +1,7 @@
-use libc::{c_int, uid_t};
+use libc::uid_t;
 
 #[no_mangle]
 unsafe extern "C" fn geteuid() -> uid_t {
     libc!(libc::geteuid());
     rustix::process::geteuid().as_raw()
 }
-
-#[no_mangle]
-unsafe extern "C" fn seteuid(_uid: uid_t) -> c_int {
-    libc!(libc::seteuid(_uid));
-    todo!("seteuid")
-}

c-scape/src/todo.rs

@@ -11,6 +11,7 @@ mod long_double;
 mod long_double_complex;
 mod pthread_cancel;
 mod pthread_spin;
+mod set_id;
 mod sysv;
 mod wchar;
 
@@ -838,14 +839,6 @@ unsafe extern "C" fn __isoc99_vsscanf() {
     todo!("__isoc99_vsscanf")
 }
 #[no_mangle]
-unsafe extern "C" fn setregid() {
-    todo!("setregid")
-}
-#[no_mangle]
-unsafe extern "C" fn setreuid() {
-    todo!("setreuid")
-}
-#[no_mangle]
 unsafe extern "C" fn times() {
     todo!("times")
 }
@@ -926,14 +919,6 @@ unsafe extern "C" fn setns() {
     todo!("setns")
 }
 #[no_mangle]
-unsafe extern "C" fn setresgid() {
-    todo!("setresgid")
-}
-#[no_mangle]
-unsafe extern "C" fn setresuid() {
-    todo!("setresuid")
-}
-#[no_mangle]
 unsafe extern "C" fn mq_close() {
     todo!("mq_close")
 }

c-scape/src/todo/set_id.rs

@@ -0,0 +1,32 @@
+//! Linux's system calls for these functions only set the IDs for one thread,
+//! and we need to set the IDs for all threads in a process.
+//!
+//! This would typically entail taking a lock that prevents thread creation,
+//! setting the IDs for each thread manually by sending signals to them and
+//! having signal handlers that perform the set operation, waitinig for all
+//! the handlers to run, and then releasing the lock.
+
+#[no_mangle]
+unsafe extern "C" fn seteuid() {
+    todo!("seteuid")
+}
+#[no_mangle]
+unsafe extern "C" fn setegid() {
+    todo!("setegid")
+}
+#[no_mangle]
+unsafe extern "C" fn setreuid() {
+    todo!("setreuid")
+}
+#[no_mangle]
+unsafe extern "C" fn setregid() {
+    todo!("setregid")
+}
+#[no_mangle]
+unsafe extern "C" fn setresuid() {
+    todo!("setresuid")
+}
+#[no_mangle]
+unsafe extern "C" fn setresgid() {
+    todo!("setresgid")
+}