From a35cc229903441e03d01351defcb885b88781e78 Mon Sep 17 00:00:00 2001
From: Eggert Jung <eggert.s.jung@wischhof13.de>
Date: Tue, 24 Feb 2026 22:42:41 +0100
Subject: [PATCH] some fixes for ipc

---
 kernel/syscall/skeleton.cc | 11 ++++++++---
 user/app1/appl.cc          | 22 ++++++++++++----------
 2 files changed, 20 insertions(+), 13 deletions(-)

diff --git a/kernel/syscall/skeleton.cc b/kernel/syscall/skeleton.cc
index c314a25..738a840 100644
--- a/kernel/syscall/skeleton.cc
+++ b/kernel/syscall/skeleton.cc
@@ -291,7 +291,7 @@ bool copy_from_phys(Vault& vault, uintptr_t phys_ptr, void* virt_ptr, size_t siz
 	
 	size_t offset = Page::offset(phys_ptr); 
 	size_t total_size = size + offset;
-  four_lvl_paging_t* search_table = vault.scheduler.active()->paging_tree;
+    four_lvl_paging_t* search_table = vault.scheduler.active()->paging_tree;
 
 	void* virt_addr =  getFreeVirtSpace(search_table, (total_size/4096)+1); // page aligned pointer 
 	if (virt_addr == nullptr) {
@@ -303,7 +303,7 @@ bool copy_from_phys(Vault& vault, uintptr_t phys_ptr, void* virt_ptr, size_t siz
   }
 
 	memcpy(virt_ptr, (void*)((uintptr_t)(virt_addr)+ (uintptr_t)offset), size);
-	PageFrameAllocator::free((uintptr_t)(virt_addr));
+    setMapping((uintptr_t)(virt_addr), 0, search_table);
 	
 	return true;
 }
@@ -357,8 +357,9 @@ int receive(Vault& v, void* buffer, size_t size) {
 	IpcStruct* ipc = thread->ipc_queue.first();
 	if (ipc == nullptr) return -1;
 	
+    size_t copy_len = (size < ipc->size) ? size:ipc->size;
 	// Buffer holen
-	if (!copy_from_phys(v, ipc->ptr, buffer, size)) {
+	if (!copy_from_phys(v, ipc->ptr, buffer, copy_len)) {
 		return -3;
 	}
 	
@@ -370,6 +371,10 @@ bool reply(Vault& v, const void* buffer, size_t size) {
   Thread* current_thread = v.scheduler.active();
   IpcStruct* ipc = current_thread->ipc_queue.dequeue();
 
+  //noting to reply to
+  if(!ipc)
+      return false;
+
   // if (!ipc || ipc->pid < 0 || static_cast<size_t>(ipc->pid) >= v.thread_count) return false;
 
   Thread* other_thread = v.thread_list[ipc->pid];
diff --git a/user/app1/appl.cc b/user/app1/appl.cc
index 8cd7168..44976bd 100644
--- a/user/app1/appl.cc
+++ b/user/app1/appl.cc
@@ -46,22 +46,24 @@ extern "C" void main() {
 	//sys_test(1,2,3,4,5);
 
 	unsigned id = sys_getpid();
-	char text[] = "appX";
+	char text[] = "appX ";
 	text[3] = 0x30+id;
 
 	write(1, text, sizeof(text), 0, (int)id);
 
 	uint8_t cnt = 0;
 	for (unsigned i = 1;; ++i) {
-		if(id == 2){
-			send(4, text, strlen(text), text, 5);
-			write(1, text, strlen(text), 25, (int)id);
-		}
-		if(id == 4){
-			char blubb[10];
-			receive(blubb, 10);
-			write(1, blubb, strlen(blubb), 25, (int)id);
-			reply("toast", 5);
+		if(i%10 == 0){
+			if(id == 2){
+				send(4, text, strlen(text), text, 5);
+				write(1, text, strlen(text), 25, (int)id);
+			}
+			if(id == 4){
+				char blubb[10];
+				receive(blubb, 10);
+				write(1, blubb, strlen(blubb), 25, (int)id);
+				reply("toast", 5);
+			}
 		}
 
 		//counter to see app running