From 1d5e56659af7945daac0f79a06b839bfd59c8f1f Mon Sep 17 00:00:00 2001
From: dzwdz
Date: Mon, 4 Oct 2021 21:01:31 +0200
Subject: remove support for processes returning strings on exit

This isn't really all that useful, it doesn't enable anything that
wasn't possible before. With it removed I'll be able to implement
process_exit() in a much simpler way.
---
 src/kernel/syscalls.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

(limited to 'src/kernel/syscalls.c')

diff --git a/src/kernel/syscalls.c b/src/kernel/syscalls.c
index 1b91eb7..c89efc7 100644
--- a/src/kernel/syscalls.c
+++ b/src/kernel/syscalls.c
@@ -8,28 +8,22 @@
 #include <shared/syscalls.h>
 #include <stdint.h>
 
-_Noreturn void _syscall_exit(const char __user *msg, size_t len) {
+_Noreturn void _syscall_exit(int ret) {
 	process_current->state = PS_DEAD;
-	process_current->death_msg.buf = (userptr_t) msg; // discarding const
-	process_current->death_msg.len = len;
+	process_current->death_msg = ret;
 	process_try2collect(process_current);
 	process_switch_any();
 }
 
-int _syscall_await(char __user *buf, int len) {
+int _syscall_await(void) {
 	bool has_children = false;
 	process_current->state = PS_WAITS4CHILDDEATH;
-	process_current->death_msg.buf = buf;
-	process_current->death_msg.len = len;
 
 	// find any already dead children
 	for (struct process *iter = process_current->child;
 			iter; iter = iter->sibling) {
-		if (iter->state == PS_DEAD) {
-			int ret = process_try2collect(iter);
-			assert(ret >= 0);
-			return ret;
-		}
+		if (iter->state == PS_DEAD)
+			return process_try2collect(iter);
 		if (iter->state != PS_DEADER)
 			has_children = true;
 	}
@@ -38,7 +32,7 @@ int _syscall_await(char __user *buf, int len) {
 		process_switch_any(); // wait until a child dies
 	else {
 		process_current->state = PS_RUNNING;
-		return -1; // error
+		return ~0; // TODO errno
 	}
 }
 
@@ -276,9 +270,9 @@ int _syscall_memflag(void __user *addr, size_t len, int flags) {
 int _syscall(int num, int a, int b, int c, int d) {
 	switch (num) {
 		case _SYSCALL_EXIT:
-			_syscall_exit((userptr_t)a, b);
+			_syscall_exit(a);
 		case _SYSCALL_AWAIT:
-			return _syscall_await((userptr_t)a, b);
+			return _syscall_await();
 		case _SYSCALL_FORK:
 			return _syscall_fork();
 		case _SYSCALL_OPEN:
-- 
cgit v1.2.3


From 33ef18732abb1ec03469b7c0fe271a6599318682 Mon Sep 17 00:00:00 2001
From: dzwdz
Date: Mon, 4 Oct 2021 21:37:01 +0200
Subject: implement process_kill()

---
 src/kernel/proc.c     | 6 ++++++
 src/kernel/proc.h     | 2 ++
 src/kernel/syscalls.c | 4 +---
 3 files changed, 9 insertions(+), 3 deletions(-)

(limited to 'src/kernel/syscalls.c')

diff --git a/src/kernel/proc.c b/src/kernel/proc.c
index b1dc5c1..47fd2ec 100644
--- a/src/kernel/proc.c
+++ b/src/kernel/proc.c
@@ -103,6 +103,12 @@ handle_t process_find_handle(struct process *proc) {
 	return handle;
 }
 
+void process_kill(struct process *proc, int ret) {
+	proc->state = PS_DEAD;
+	proc->death_msg = ret;
+	process_try2collect(proc);
+}
+
 int process_try2collect(struct process *dead) {
 	struct process *parent = dead->parent;
 	int len, ret;
diff --git a/src/kernel/proc.h b/src/kernel/proc.h
index 592451c..7c338bb 100644
--- a/src/kernel/proc.h
+++ b/src/kernel/proc.h
@@ -53,6 +53,8 @@ _Noreturn void process_switch_any(void); // switches to any running process
 struct process *process_find(enum process_state);
 handle_t process_find_handle(struct process *proc); // finds the first free handle
 
+void process_kill(struct process *proc, int ret);
+
 /** Tries to transistion from PS_DEAD to PS_DEADER.
  * @return a nonnegative length of the quit message if successful, a negative val otherwise*/
 int process_try2collect(struct process *dead);
diff --git a/src/kernel/syscalls.c b/src/kernel/syscalls.c
index c89efc7..22bf1f6 100644
--- a/src/kernel/syscalls.c
+++ b/src/kernel/syscalls.c
@@ -9,9 +9,7 @@
 #include <stdint.h>
 
 _Noreturn void _syscall_exit(int ret) {
-	process_current->state = PS_DEAD;
-	process_current->death_msg = ret;
-	process_try2collect(process_current);
+	process_kill(process_current, ret);
 	process_switch_any();
 }
 
-- 
cgit v1.2.3