X-Git-Url: https://scm.lunaixsky.com/lunaix-os.git/blobdiff_plain/cb529e7c1abcfe6b61241e47a780172031b82840..75339638bc5f21f13d3475374ecbd91065a427c3:/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 9e12444..897a7dd 100644
--- a/lunaix-os/kernel/asm/x86/pfault.c
+++ b/lunaix-os/kernel/asm/x86/pfault.c
@@ -1,14 +1,16 @@
 #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/vmm.h>
 #include <lunaix/sched.h>
+#include <lunaix/signal.h>
 #include <lunaix/status.h>
 #include <lunaix/syslog.h>
 
+#include <klibc/string.h>
+
 static void
 kprintf(const char* fmt, ...)
 {
@@ -36,64 +38,102 @@ intr_routine_page_fault(const isr_param* param)
         goto segv_term;
     }
 
-    if (!SEL_RPL(param->cs)) {
+    if (!SEL_RPL(param->execp->cs)) {
         // 如果是内核页错误……
         if (do_kernel(&mapping)) {
             return;
         }
-        goto segv_term;
+        // 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) {
-        // Into the void...
+        // 当你凝视深渊时……
         goto segv_term;
     }
 
-    x86_pte_t* pte = &PTE_MOUNTED(PD_REFERENCED, ptr >> 12);
-    if ((*pte & PG_PRESENT)) {
+    volatile x86_pte_t* pte = &PTE_MOUNTED(VMS_SELF, ptr >> 12);
+    if (PG_IS_PRESENT(*pte)) {
         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;
+            *pte = (*pte & 0xFFF & ~PG_DIRTY) | pa | PG_WRITE;
             goto resolved;
         }
         // impossible cases or accessing privileged page
         goto segv_term;
     }
 
-    if (!(*pte)) {
-        // Invalid location
+    // an anonymous page and not present
+    //   -> a new page need to be alloc
+    if ((hit_region->attr & REGION_ANON)) {
+        if (!PG_IS_PRESENT(*pte)) {
+            cpu_invplg(pte);
+            uintptr_t pa = pmm_alloc_page(__current->pid, 0);
+            if (!pa) {
+                goto oom;
+            }
+
+            *pte = *pte | pa | PG_PRESENT;
+            memset(PG_ALIGN(ptr), 0, PG_SIZE);
+            goto resolved;
+        }
+        // permission denied on anon page (e.g., write on readonly page)
         goto segv_term;
     }
 
-    uintptr_t loc = *pte & ~0xfff;
+    // if mfile is set (Non-anonymous), then it is a mem map
+    if (hit_region->mfile && !PG_IS_PRESENT(*pte)) {
+        struct v_file* file = hit_region->mfile;
 
-    // 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);
+        ptr = PG_ALIGN(ptr);
+
+        u32_t mseg_off = (ptr - hit_region->start);
+        u32_t mfile_off = mseg_off + hit_region->foff;
         uintptr_t pa = pmm_alloc_page(__current->pid, 0);
-        *pte = *pte | pa | PG_PRESENT;
+
+        if (!pa) {
+            goto oom;
+        }
+
+        cpu_invplg(pte);
+        *pte = (*pte & 0xFFF) | pa | PG_PRESENT;
+
+        memset(ptr, 0, PG_SIZE);
+
+        int errno = 0;
+        if (mseg_off < hit_region->flen) {
+            errno = file->ops->read_page(file->inode, ptr, PG_SIZE, mfile_off);
+        }
+
+        if (errno < 0) {
+            kprintf(KERROR "fail to populate page (%d)\n", errno);
+            goto segv_term;
+        }
+
+        *pte &= ~PG_DIRTY;
+
         goto resolved;
     }
 
-    // page not present, bring it from disk or somewhere else
+    // page not present, might be a chance to introduce swap file?
     __print_panic_msg("WIP page fault route", param);
     while (1)
         ;
 
+oom:
+    kprintf(KERROR "out of memory\n");
 segv_term:
     kprintf(KERROR "(pid: %d) Segmentation fault on %p (%p:%p)\n",
             __current->pid,
             ptr,
-            param->cs,
-            param->eip);
-    signal_send(__current->pid, _SIGSEGV);
+            param->execp->cs,
+            param->execp->eip);
+    __SIGSET(__current->sig_pending, _SIGSEGV);
     schedule();
     // should not reach
     while (1)
@@ -108,14 +148,8 @@ int
 do_kernel(v_mapping* mapping)
 {
     uintptr_t addr = mapping->va;
-    if (addr >= KHEAP_START && addr < PROC_START) {
-        // This is kernel heap page
-        uintptr_t pa = pmm_alloc_page(KERNEL_PID, 0);
-        *mapping->pte = (*mapping->pte & 0xfff) | pa | PG_PRESENT;
-        cpu_invplg(mapping->pte);
-        cpu_invplg(addr);
-        goto done;
-    }
+
+    // TODO
 
     return 0;
 done: