improve killing processes/threads, test

+ Remove sys_kill() as we should be using a two-stage process where a
  thread is first orphaned by sys_detach(), and then the thread itself
  calls sys_exit() after it has done all necessary cleanup in init.

3 files changed, 8 insertions, 23 deletions

diff --git a/include/kmi/syscalls.h b/include/kmi/syscalls.h
index 28e7505..a4d2c52 100644
--- a/include/kmi/syscalls.h
+++ b/include/kmi/syscalls.h
@@ -120,9 +120,6 @@ enum sys_code {
 	/** Execute new binary in new process space. */
 	SYS_SPAWN,
 
-	/** Kill thread. */
-	SYS_KILL,
-
 	/** Switch running process. */
 	SYS_SWAP,
 
diff --git a/include/kmi/tcb.h b/include/kmi/tcb.h
index 6cc63b5..d61845f 100644
--- a/include/kmi/tcb.h
+++ b/include/kmi/tcb.h
@@ -354,27 +354,28 @@ bool running(struct tcb *t);
 bool zombie(struct tcb *t);
 
 /**
- * Add a reference to a process.
+ * Add a reference to a thread.
  * Instead of lists of threads that belong to a process, we give the process'
  * owning thread a reference counter. When a process is killed, a 'dead' bit is
  * set, and the thread that owns the process is unreferenced. All data
  * associated with the process can immediately be freed, but the tid is still
- * reserved until the reference count reaches zero.
+ * reserved until the reference count reaches zero. In this sense, a process is
+ * seen as some memory that some thread happens to own.
  *
  * We have to make sure that all ways a process might be entered check that the
  * process is still alive, and unmapping pages causes other threads to update
  * their page tables as well. Then if a segfault happens, we can check if it was
  * due to being in a dead process. This is still largely TODO.
  *
- * @param p Process to reference.
+ * @param t Thread to reference.
  */
-void reference_proc(struct tcb *p);
+void reference_thread(struct tcb *t);
 
 /**
- * Unreference a process.
+ * Unreference a thread.
  *
- * @param p Process to unreference.
+ * @param t Thread to unreference.
  */
-void unreference_proc(struct tcb *p);
+void unreference_thread(struct tcb *t);
 
 #endif /* KMI_TCB_H */
diff --git a/include/kmi/uapi.h b/include/kmi/uapi.h
index 6e5f865..b0740a9 100644
--- a/include/kmi/uapi.h
+++ b/include/kmi/uapi.h
@@ -656,19 +656,6 @@ SYSCALL_DECLARE2(exec, bin, interp);
 SYSCALL_DECLARE2(spawn, bin, interp);
 
 /**
- * Kill syscall. Requests that all memory in process \p pid is freed and all
- * threads are orphaned. If \p pid is not a process, nothing is done.
- *
- * @param t Current tcb.
- * @param pid Thread ID to kill. 0 if self.
- * @param b Unused.
- * @param c Unused.
- * @param d Unused.
- * @param e Unused.
- */
-SYSCALL_DECLARE1(kill, pid);
-
-/**
  * Swap syscall.
  *
  * Swap currently running thread.