try to fix page fault

kernel/src/exec/elf.c

@@ -65,7 +65,7 @@ program_t *elf_load(char *data) {
         if (!(phdr[i].p_flags & PF_X))
             flags |= VMM_NX;
 
-        flags |= VMM_USER; // User mode access
+        flags |= VMM_USER;
 
         log("elf - loading ELF program header %u: vaddr 0x%llx - 0x%llx, offset 0x%llx, filesz 0x%llx, size 0x%llx, flags 0x%llx\n",
               i, vaddr_start, vaddr_end, offset, phdr[i].p_filesz, phdr[i].p_memsz, flags);
@@ -81,7 +81,9 @@ program_t *elf_load(char *data) {
                 return 0;
             }
 
+            log("elf - vmm_map(%p, %p, %p, %d)\n", pm, vaddr, phys, flags);
             vmm_map(pm, vaddr, phys, flags);
+            log("elf - memset(%p, 0, 0x1000)\n", HIGHER_HALF(phys));
             memset((void *)HIGHER_HALF(phys), 0, PMM_PAGE_SIZE);
 
             uint64_t file_page_offset = offset + (vaddr - vaddr_start);
@@ -109,6 +111,7 @@ program_t *elf_load(char *data) {
                 {
                     void *dest = (void *)(HIGHER_HALF(phys) + page_data_offset);
                     void *src = (uint8_t *)data + copy_offset;
+                    log("elf - memcpy(%p, %p, %d)\n", dest, src, copy_size);
                     memcpy(dest, src, copy_size);
 
                     //log("elf - copied 0x%llx bytes from ELF file offset 0x%llx to vaddr 0x%llx (phys 0x%llx)\n",

kernel/src/mm/vmm.c

@@ -171,18 +171,19 @@ uint64_t vmm_get_flags(pagemap_t* pm, uint64_t vaddr) {
 
     return pml1[pml1_entry] & 0x7000000000000FFF;
 }
-  
+
 uint64_t virt_to_phys(pagemap_t *pagemap, uint64_t virt)
 {
-    uint64_t pml1_idx = (virt & (uint64_t)0x1ff << 12) >> 12;
+    uint64_t pml4_idx = (virt >> 39) & 0x1FF; 
-    uint64_t pml2_idx = (virt & (uint64_t)0x1ff << 21) >> 21;
+    uint64_t pml3_idx = (virt >> 30) & 0x1FF; 
-    uint64_t pml3_idx = (virt & (uint64_t)0x1ff << 30) >> 30;
+    uint64_t pml2_idx = (virt >> 21) & 0x1FF; 
-    uint64_t pml4_idx = (virt & (uint64_t)0x1ff << 39) >> 39;
+    uint64_t pml1_idx = (virt >> 12) & 0x1FF; 
 
     uint64_t *pml3 = __vmm_get_next_lvl(pagemap->toplevel, pml4_idx, 0);
     uint64_t *pml2 = __vmm_get_next_lvl(pml3, pml3_idx, 0);
     uint64_t *pml1 = __vmm_get_next_lvl(pml2, pml2_idx, 0);
-    uint64_t phys_addr = pml1[pml1_idx] & 0x000FFFFFFFFFF000;
+    
+    uint64_t phys_addr = pml1[pml1_idx] & 0x000FFFFFFFFFF000;  // Masque pour obtenir l'adresse physique (en retirant les bits de flags)
 
     return phys_addr;
 }

kernel/src/sys/arch/x86_64/interrupts.c

@@ -1,5 +1,6 @@
 //#include "mm/pmm.h"
 //#include "mm/vmm.h"
+#include "mm/pmm.h"
 #include "mm/vmm.h"
 #include "sched/sched.h"
 #include "sys/arch/x86_64/pic.h"
@@ -44,8 +45,9 @@ void exception_handler(registers_t *regs) {
         if(regs->int_no == 0xe) {
             uint64_t cr2;
             asm ("mov %%cr2, %0" : "=r"(cr2));
-            log("ints - PF: Faulting location: %p\n", cr2);
+            log("ints - PF: Faulting location: %p (%p)\n", cr2, virt_to_phys(vmm_current_pm, cr2));
             log("ints - PF: Faulting page flags: %p\n", vmm_get_flags(vmm_current_pm, cr2));
+            log("ints - PF: Faulting page map: %p\n", PHYSICAL(vmm_current_pm));
         }
 
         // dump_backtrace(regs);

testing/build.sh

@@ -0,0 +1,3 @@
+nasm -f elf64 test.asm -o test.o
+ld -T link.ld -nostdlib --no-dynamic-linker --strip-all test.o -o sk-hello.elf
+echo "Test executable has been built successfully."

testing/test.asm

@@ -4,5 +4,7 @@ section .text
 
 _start:
     int 0x80
-lol:
+    ; tell the kernel to exit the process.
-    jmp lol
+    mov rax, 10
+    int 0x80
+    ret

util/get_vaddr_info.py

@@ -0,0 +1,19 @@
+#!/usr/bin/env python3
+
+import sys
+
+if len(sys.argv) != 2:
+    print(f"Usage: {sys.argv[0]} <virtual_address (hex)>")
+    sys.exit(1)
+
+va = int(sys.argv[1], 16)
+
+def extract_index(name, shift):
+    return (va >> shift) & 0x1FF
+
+print(f"Virtual address : 0x{va:016x}")
+print(f"PML4 index : {extract_index('PML4', 39)}")
+print(f"PDPT index : {extract_index('PDPT', 30)}")
+print(f" PD  index : {extract_index('PD', 21)}")
+print(f" PT  index : {extract_index('PT', 12)}")
+print(f" Offset    : {va & 0xFFF}")