From ab2da499da9cd9f833fb59e41033fbc15ccbf522 Mon Sep 17 00:00:00 2001
From: Ruslan Isaev <ubijca16@gmail.com>
Date: Wed, 15 Apr 2026 23:44:11 +0300
Subject: [PATCH] mm: kill current task on usermode pagefault and fix
 destroy_page_dir destroying kernel space mappings

---
 src/kernel/isr.c | 7 +++++++
 src/mm/paging.c  | 2 +-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/kernel/isr.c b/src/kernel/isr.c
index 887fdf5..444431c 100644
--- a/src/kernel/isr.c
+++ b/src/kernel/isr.c
@@ -101,6 +101,13 @@ void handle_page_fault(uint32_t error_code, uint32_t faulting_address)
 
     printf("ERR: 0x%X\n", error_code);
 
+    if (user) {
+        printf("page fault, killing task %x\n", current->pid);
+        task_kill(current);
+        asm volatile("sti");
+        while (1) {}
+    }
+
     asm("hlt");
 }
 
diff --git a/src/mm/paging.c b/src/mm/paging.c
index 2e7de6f..9c925ca 100644
--- a/src/mm/paging.c
+++ b/src/mm/paging.c
@@ -169,7 +169,7 @@ void destroy_page_dir(uint32_t* page_dir_virt) {
 
     // Iterate through user-space page directory entries (PDEs 0-767).
     // Kernel space (768+) is shared and should not be freed.
-    for (int i = 0; i < 768; i++) {
+    for (int i = 1; i < 768; i++) {
         uint32_t pde = page_dir_virt[i];
 
         // Check if the page directory entry is present