refactor: full rewrite of signal feature

[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 610c1cb978fd0dd1031a4d5825b6cbbacc8fbb36..f527e12c3dcc0f81c292c3761c78c125943faa80 100644 (file)
--- a/lunaix-os/kernel/asm/x86/pfault.c
+++ b/lunaix-os/kernel/asm/x86/pfault.c
@@ -11,6 +11,19 @@
 
 #include <klibc/string.h>
 
+static u32_t
+get_ptattr(struct mm_region* vmr)
+{
+    u32_t vmr_attr = vmr->attr;
+    u32_t ptattr = PG_PRESENT | PG_ALLOW_USER;
+
+    if ((vmr_attr & PROT_WRITE)) {
+        ptattr |= PG_WRITE;
+    }
+
+    return ptattr & 0xfff;
+}
+
 static void
 kprintf(const char* fmt, ...)
 {
@@ -28,7 +41,8 @@ __print_panic_msg(const char* msg, const isr_param* param);
 void
 intr_routine_page_fault(const isr_param* param)
 {
-    uintptr_t ptr = cpu_rcr2();
+    uint32_t errcode = param->execp->err_code;
+    ptr_t ptr = cpu_rcr2();
     if (!ptr) {
         goto segv_term;
     }
@@ -39,14 +53,11 @@ intr_routine_page_fault(const isr_param* param)
     }
 
     if (!SEL_RPL(param->execp->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。
+        // TODO if kernel pfault
     }
 
-    struct mm_region* hit_region = region_get(&__current->mm.regions, ptr);
+    vm_regions_t* vmr = (vm_regions_t*)&__current->mm.regions;
+    struct mm_region* hit_region = region_get(vmr, ptr);
 
     if (!hit_region) {
         // 当你凝视深渊时……
@@ -55,13 +66,23 @@ intr_routine_page_fault(const isr_param* param)
 
     volatile x86_pte_t* pte = &PTE_MOUNTED(VMS_SELF, ptr >> 12);
     if (PG_IS_PRESENT(*pte)) {
+        if (((errcode ^ mapping.flags) & PG_ALLOW_USER)) {
+            // invalid access
+            kprintf(KDEBUG "invalid user access. (%p->%p, attr:0x%x)\n",
+                    mapping.va,
+                    mapping.pa,
+                    mapping.flags);
+            goto segv_term;
+        }
         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));
+            cpu_invplg((ptr_t)pte);
+
+            ptr_t pa = (ptr_t)vmm_dup_page(__current->pid, PG_ENTRY_ADDR(*pte));
+
             pmm_free_page(__current->pid, *pte & ~0xFFF);
             *pte = (*pte & 0xFFF & ~PG_DIRTY) | pa | PG_WRITE;
+
             goto resolved;
         }
         // impossible cases or accessing privileged page
@@ -72,14 +93,15 @@ intr_routine_page_fault(const isr_param* param)
     //   -> 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);
+            cpu_invplg((ptr_t)pte);
+
+            ptr_t pa = pmm_alloc_page(__current->pid, 0);
             if (!pa) {
                 goto oom;
             }
 
-            *pte = *pte | pa | PG_PRESENT;
-            memset(PG_ALIGN(ptr), 0, PG_SIZE);
+            *pte = *pte | pa | get_ptattr(hit_region);
+            memset((void*)PG_ALIGN(ptr), 0, PG_SIZE);
             goto resolved;
         }
         // permission denied on anon page (e.g., write on readonly page)
@@ -92,23 +114,23 @@ intr_routine_page_fault(const isr_param* param)
 
         ptr = PG_ALIGN(ptr);
 
-        u32_t offset = (ptr - hit_region->start) + hit_region->foff;
-        uintptr_t pa = pmm_alloc_page(__current->pid, 0);
+        u32_t mseg_off = (ptr - hit_region->start);
+        u32_t mfile_off = mseg_off + hit_region->foff;
+        ptr_t pa = pmm_alloc_page(__current->pid, 0);
 
         if (!pa) {
             goto oom;
         }
 
-        cpu_invplg(pte);
-        *pte = (*pte & 0xFFF) | pa | PG_PRESENT;
+        cpu_invplg((ptr_t)pte);
+        *pte = (*pte & 0xFFF) | pa | get_ptattr(hit_region);
 
-        memset(ptr, 0, PG_SIZE);
+        memset((void*)ptr, 0, PG_SIZE);
 
         int errno = 0;
-        if (hit_region->init_page) {
-            errno = hit_region->init_page(hit_region, ptr, offset);
-        } else {
-            errno = file->ops->read_page(file->inode, ptr, PG_SIZE, offset);
+        if (mseg_off < hit_region->flen) {
+            errno =
+              file->ops->read_page(file->inode, (void*)ptr, PG_SIZE, mfile_off);
         }
 
         if (errno < 0) {
@@ -128,13 +150,17 @@ intr_routine_page_fault(const isr_param* param)
 
 oom:
     kprintf(KERROR "out of memory\n");
+
 segv_term:
-    kprintf(KERROR "(pid: %d) Segmentation fault on %p (%p:%p)\n",
+    kprintf(KERROR "(pid: %d) Segmentation fault on %p (%p:%p,e=0x%x)\n",
             __current->pid,
             ptr,
             param->execp->cs,
-            param->execp->eip);
-    __SIGSET(__current->sig_pending, _SIGSEGV);
+            param->execp->eip,
+            param->execp->err_code);
+
+    sigset_add(__current->sigctx.sig_pending, _SIGSEGV);
+
     schedule();
     // should not reach
     while (1)
@@ -143,16 +169,4 @@ segv_term:
 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