From 3db86a30644d3eb3a964202dbfd7e91c432bda7b Mon Sep 17 00:00:00 2001
From: Ian Moffett <ian@osmora.org>
Date: Sat, 16 Mar 2024 12:42:25 -0400
Subject: kernel: syscall: Remove syscall_args.ret

It is better to just return a value within the syscall handler and
have that passed down to __syscall() like that

Signed-off-by: Ian Moffett <ian@osmora.org>
---
 sys/arch/amd64/amd64/syscall.c | 7 ++-----
 sys/include/sys/syscall.h      | 3 +--
 sys/kern/kern_syscall.c        | 8 +++++---
 3 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/sys/arch/amd64/amd64/syscall.c b/sys/arch/amd64/amd64/syscall.c
index 9b1f988..e80fe94 100644
--- a/sys/arch/amd64/amd64/syscall.c
+++ b/sys/arch/amd64/amd64/syscall.c
@@ -39,13 +39,10 @@ __syscall(struct trapframe *tf)
         .arg2 = tf->rcx,
         .arg3 = tf->r8,
         .arg4 = tf->r9,
-        .sp = tf->rsp,
-        .ret = tf->rax,
+        .sp = tf->rsp
     };
 
     if (args.code < __MAX_SYSCALLS) {
-        g_syscall_table[tf->rax](&args);
+        tf->rax = g_syscall_table[tf->rax](&args);
     }
-
-    tf->rax = args.ret;
 }
diff --git a/sys/include/sys/syscall.h b/sys/include/sys/syscall.h
index 98a57f2..03eda0b 100644
--- a/sys/include/sys/syscall.h
+++ b/sys/include/sys/syscall.h
@@ -47,11 +47,10 @@ struct syscall_args {
     uint64_t arg0, arg1, arg2, arg3, arg4;
     uint64_t ip;
     uint64_t sp;
-    uint64_t ret;
 };
 
 #if defined(_KERNEL)
-extern void(*g_syscall_table[__MAX_SYSCALLS])(struct syscall_args *args);
+extern uint64_t(*g_syscall_table[__MAX_SYSCALLS])(struct syscall_args *args);
 void __syscall(struct trapframe *tf);
 #endif
 
diff --git a/sys/kern/kern_syscall.c b/sys/kern/kern_syscall.c
index 2c7215c..5a88bbb 100644
--- a/sys/kern/kern_syscall.c
+++ b/sys/kern/kern_syscall.c
@@ -30,21 +30,23 @@
 #include <sys/syscall.h>
 #include <sys/sched.h>
 #include <sys/cdefs.h>
+#include <sys/types.h>
 
-static void
+static uint64_t
 sys_debug(struct syscall_args *args)
 {
     /* TODO */
+    return 0;
 }
 
-__noreturn static void
+__noreturn static uint64_t
 sys_exit(struct syscall_args *args)
 {
     sched_exit();
     __builtin_unreachable();
 }
 
-void(*g_syscall_table[__MAX_SYSCALLS])(struct syscall_args *args) = {
+uint64_t(*g_syscall_table[__MAX_SYSCALLS])(struct syscall_args *args) = {
     sys_debug,
     sys_exit,
 };
-- 
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