refactor: clean up the virtual memory mappings

[lunaix-os.git] / lunaix-os / kernel / asm / x86 / pfault.c

diff --git a/lunaix-os/kernel/asm/x86/pfault.c b/lunaix-os/kernel/asm/x86/pfault.c
index 9d5e1d1bdbe2bc10fab8514bec0fe71f6b915bb7..fcd52cc26480058f3a83b2144e8b46ee0b2c949a 100644 (file)
--- a/lunaix-os/kernel/asm/x86/pfault.c
+++ b/lunaix-os/kernel/asm/x86/pfault.c
@@ -1,5 +1,6 @@
 #include <arch/x86/interrupts.h>
 #include <lunaix/common.h>
 #include <arch/x86/interrupts.h>
 #include <lunaix/common.h>

+#include <lunaix/lxsignal.h>

 #include <lunaix/mm/mm.h>
 #include <lunaix/mm/pmm.h>
 #include <lunaix/mm/region.h>
 #include <lunaix/mm/mm.h>
 #include <lunaix/mm/pmm.h>
 #include <lunaix/mm/region.h>


@@ -17,6 +18,8 @@ kprintf(const char* fmt, ...)
     va_end(args);
 }
 
     va_end(args);
 }
 

+#define COW_MASK (REGION_RSHARED | REGION_READ | REGION_WRITE)
+

 extern void
 __print_panic_msg(const char* msg, const isr_param* param);
 
 extern void
 __print_panic_msg(const char* msg, const isr_param* param);
 


@@ -28,24 +31,36 @@ intr_routine_page_fault(const isr_param* param)
         goto segv_term;
     }
 
         goto segv_term;
     }
 

-    struct mm_region* hit_region = region_get(__current, ptr);
+    v_mapping mapping;
+    if (!vmm_lookup(ptr, &mapping)) {
+        goto segv_term;
+    }
+
+    if (!SEL_RPL(param->cs)) {
+        // 如果是内核页错误……
+        if (do_kernel(&mapping)) {
+            return;
+        }
+        // 如果不是，那么看看内核是不是需要用户页。
+    }
+
+    struct mm_region* hit_region = region_get(&__current->mm.regions, ptr);

 
     if (!hit_region) {
 
     if (!hit_region) {

-        // Into the void...
+        // 当你凝视深渊时……

         goto segv_term;
     }
 
         goto segv_term;
     }
 

-    x86_pte_t* pte = PTE_MOUNTED(PD_REFERENCED, ptr >> 12);
-    if (*pte & PG_PRESENT) {
-        if ((hit_region->attr & REGION_PERM_MASK) ==
-            (REGION_RSHARED | REGION_READ)) {
+    volatile x86_pte_t* pte = &PTE_MOUNTED(PD_REFERENCED, ptr >> 12);
+    if ((*pte & PG_PRESENT)) {
+        if ((hit_region->attr & COW_MASK) == COW_MASK) {

             // normal page fault, do COW
             cpu_invplg(pte);
             uintptr_t pa =
               (uintptr_t)vmm_dup_page(__current->pid, PG_ENTRY_ADDR(*pte));
             pmm_free_page(__current->pid, *pte & ~0xFFF);
             *pte = (*pte & 0xFFF) | pa | PG_WRITE;
             // normal page fault, do COW
             cpu_invplg(pte);
             uintptr_t pa =
               (uintptr_t)vmm_dup_page(__current->pid, PG_ENTRY_ADDR(*pte));
             pmm_free_page(__current->pid, *pte & ~0xFFF);
             *pte = (*pte & 0xFFF) | pa | PG_WRITE;

-            return;
+            goto resolved;

         }
         // impossible cases or accessing privileged page
         goto segv_term;
         }
         // impossible cases or accessing privileged page
         goto segv_term;


@@ -55,15 +70,18 @@ intr_routine_page_fault(const isr_param* param)
         // Invalid location
         goto segv_term;
     }
         // Invalid location
         goto segv_term;
     }

+

     uintptr_t loc = *pte & ~0xfff;
     uintptr_t loc = *pte & ~0xfff;

-    // a writable page, not present, pte attr is not null
-    //   and no indication of cached page -> a new page need to be alloc
+
+    // a writable page, not present, not cached, pte attr is not null
+    //   -> a new page need to be alloc

     if ((hit_region->attr & REGION_WRITE) && (*pte & 0xfff) && !loc) {
         cpu_invplg(pte);
         uintptr_t pa = pmm_alloc_page(__current->pid, 0);
         *pte = *pte | pa | PG_PRESENT;
     if ((hit_region->attr & REGION_WRITE) && (*pte & 0xfff) && !loc) {
         cpu_invplg(pte);
         uintptr_t pa = pmm_alloc_page(__current->pid, 0);
         *pte = *pte | pa | PG_PRESENT;

-        return;
+        goto resolved;

     }
     }

+

     // page not present, bring it from disk or somewhere else
     __print_panic_msg("WIP page fault route", param);
     while (1)
     // page not present, bring it from disk or somewhere else
     __print_panic_msg("WIP page fault route", param);
     while (1)


@@ -75,6 +93,25 @@ segv_term:
             ptr,
             param->cs,
             param->eip);
             ptr,
             param->cs,
             param->eip);

-    terminate_proc(LXSEGFAULT);
+    __SIGSET(__current->sig_pending, _SIGSEGV);
+    schedule();

     // should not reach
     // should not reach

+    while (1)
+        ;
+
+resolved:
+    cpu_invplg(ptr);
+    return;
+}
+
+int
+do_kernel(v_mapping* mapping)
+{
+    uintptr_t addr = mapping->va;
+
+    // TODO
+
+    return 0;
+done:
+    return 1;

 }
\ No newline at end of file
 }
\ No newline at end of file