Add vc memory in both parent and child, change access policy to USER_RW

Author: JusticeLeee

lab6/kernel/include/mmu.h

@@ -22,6 +22,11 @@
 #define PD_BLOCK 0b01
 #define PD_PAGE 0b11
 #define PD_ACCESS (1 << 10)
+#define PD_USER_RW (0b01 << 6)
+#define PD_USER_R (0b11 << 6)
+#define PD_UXN (1L << 54)
+#define PD_PXN (1L << 53)
+
 #define BOOT_PGD_ATTR (PD_TABLE)
 #define BOOT_PUD_ATTR (PD_TABLE)
 #define BOOT_PMD_ATTR (PD_TABLE)
@@ -41,6 +46,6 @@
 
 void init_page_table(thread_info *thread, uint64_t **table);
 void update_page_table(thread_info *thread, uint64_t virtual_addr,
-                       uint64_t physical_addr, int permission);
+                       uint64_t physical_addr, uint64_t permission);
 uint64_t el0_VA2PA(thread_info *thread, uint64_t virtual_addr);
 

lab6/kernel/src/exception.c

@@ -13,12 +13,15 @@ void enable_interrupt() { asm volatile("msr DAIFClr, 0xf"); }
 void disable_interrupt() { asm volatile("msr DAIFSet, 0xf"); }
 
 void sync_handler_currentEL_ELx() {
-  // printf("[sync_handler_currentEL_ELx]\n");
+  printf("[sync_handler_currentEL_ELx]\n");
 
   uint64_t spsr_el1, elr_el1, esr_el1;
   asm volatile("mrs %0, spsr_el1" : "=r"(spsr_el1));
   asm volatile("mrs %0, elr_el1" : "=r"(elr_el1));
   asm volatile("mrs %0, esr_el1" : "=r"(esr_el1));
+  uint32_t ec = (esr_el1 >> 26) & 0x3f;
+  printf("EC: %x\n", ec);
+  while(1){;}
   // printf("SPSR_EL1: 0x%08x\n", spsr_el1);
   // printf("ELR_EL1: 0x%08x\n", elr_el1);
   // printf("ESR_EL1: 0x%08x\n", esr_el1);
@@ -37,6 +40,7 @@ void sync_handler_lowerEL_64(uint64_t sp) {
 
   uint32_t ec = (esr_el1 >> 26) & 0x3f;
   // printf("EC: %x\n", ec);
+
   if (ec == 0b010101) {  // SVC instruction
     uint64_t iss;
     asm volatile("mov %0, x8" : "=r"(iss));
@@ -61,8 +65,13 @@ void sync_handler_lowerEL_64(uint64_t sp) {
       const char **argv = (const char **)trap_frame->x[1];
       exec(program_name, argv);
     } else if (iss == 4) {  // fork
-      // printf("[fork]\n");
       fork(sp);
+      // User shell need excute after child mbox_call in qemu
+      // But in real machine can work without below code
+      if(get_current()->pid==1){
+        int magic_sleep = 50000000;
+        while(magic_sleep--){}
+      }
     } else if (iss == 5) {  // exit
       exit();
     } else if (iss == 6) {  // mbox_call

lab6/kernel/src/mmu.c

@@ -17,7 +17,7 @@ void init_page_table(thread_info *thread, uint64_t **table) {
 }
 
 void update_page_table(thread_info *thread, uint64_t virtual_addr,
-                       uint64_t physical_addr, int permission) {
+                       uint64_t physical_addr, uint64_t flags) {
   if (thread->pgd == 0) {
     printf("Invalid PGD!!\n");
     return;
@@ -39,20 +39,15 @@ void update_page_table(thread_info *thread, uint64_t virtual_addr,
   for (int level = 0; level < 3; level++) {
     if (table[index[level]] == 0) {
       // printf("level: %d, index: 0x%llx  ", level, index[level]);
-      init_page_table(thread, (uint64_t **)&(table[index[level]]));      table[index[level]] |= PD_TABLE;
+      init_page_table(thread, (uint64_t **)&(table[index[level]]));
+      table[index[level]] |= PD_ACCESS | (MAIR_IDX_NORMAL_NOCACHE << 2) | PD_TABLE;
     }
     // printf("table PA: 0x%llx\n", (uint64_t)table[index[level]]);
     table = (uint64_t *)PA2VA(table[index[level]] & ~0xfff);
     // printf("table VA: 0x%llx\n", (uint64_t)table);
   }
-  uint64_t BOOT_RWX_ATTR = (1 << 6);
-  if (permission & 0b010)
-    BOOT_RWX_ATTR |= 0;
-  else
-    BOOT_RWX_ATTR |= (1 << 7);
-  // printf("0x%llx\n", BOOT_RWX_ATTR);
   table[index[3]] =
-      physical_addr | BOOT_PTE_NORMAL_NOCACHE_ATTR | BOOT_RWX_ATTR;
+      physical_addr | BOOT_PTE_NORMAL_NOCACHE_ATTR | flags;
   // printf("page PA: 0x%llx\n", (uint64_t)table[index[3]]);
 }
 

lab6/kernel/src/thread.c

@@ -192,27 +192,26 @@ void exec(const char *program_name, const char **argv) {
   for (uint64_t size = 0; size < cur->user_program_size; size += PAGE_SIZE) {
     uint64_t virtual_addr = USER_PROGRAM_BASE + size;
     uint64_t physical_addr = VA2PA(cur->user_program_base + size);
-    if(size==0)
-      printf("[first_map]va:%p map to pa:%p\n",virtual_addr,physical_addr);
-    update_page_table(cur, virtual_addr, physical_addr, 0b101);
+    update_page_table(cur, virtual_addr, physical_addr, PD_USER_RW);
   }
 
   // map vc memory
   for (uint64_t size = 0; size < PERIPHERAL_END - PERIPHERAL_START; size += PAGE_SIZE) {
     uint64_t identity_page = PERIPHERAL_START + size; 
     // printf("identity_page=%p\n",identity_page);
-    update_page_table(cur, identity_page , identity_page, 0b101);
+    update_page_table(cur, identity_page , identity_page, PD_USER_RW);
   }
-  el0_VA2PA(cur,USER_PROGRAM_BASE);
-  el0_VA2PA(cur,0x3f000000);
-  el0_VA2PA(cur,0x3f000000-1);
-  el0_VA2PA(cur,0x3c25e76c);
-  el0_VA2PA(cur,0x3c100000);
-  el0_VA2PA(cur,0x3c000000);
-  el0_VA2PA(cur,0x3c000000-1);
   uint64_t virtual_addr = USER_STACK_BASE;
   uint64_t physical_addr = VA2PA(cur->user_stack_base);
-  update_page_table(cur, virtual_addr, physical_addr, 0b110);
+  update_page_table(cur, virtual_addr, physical_addr, PD_USER_RW );
+
+  // el0_VA2PA(cur,USER_PROGRAM_BASE);
+  // el0_VA2PA(cur,0x3f000000);
+  // el0_VA2PA(cur,0x3f000000-1);
+  // el0_VA2PA(cur,0x3c25e76c);
+  // el0_VA2PA(cur,0x3c100000);
+  // el0_VA2PA(cur,0x3c000000);
+  // el0_VA2PA(cur,0x3c000000-1);
 
   uint64_t next_pgd = (uint64_t)cur->pgd;
   switch_pgd(next_pgd);
@@ -262,11 +261,25 @@ void create_child(thread_info *parent, thread_info *child) {
   for (uint64_t size = 0; size < child->user_program_size; size += PAGE_SIZE) {
     uint64_t virtual_addr = USER_PROGRAM_BASE + size;
     uint64_t physical_addr = VA2PA(child->user_program_base + size);
-    update_page_table(child, virtual_addr, physical_addr, 0b101);
+    update_page_table(child, virtual_addr, physical_addr, PD_USER_RW);
+  }
+  
+  for (uint64_t size = 0; size < PERIPHERAL_END - PERIPHERAL_START; size += PAGE_SIZE) {
+    uint64_t identity_page = PERIPHERAL_START + size; 
+    // printf("identity_page=%p\n",identity_page);
+    update_page_table(child, identity_page , identity_page, PD_USER_RW);
   }
   uint64_t virtual_addr = USER_STACK_BASE;
   uint64_t physical_addr = VA2PA(child->user_stack_base);
-  update_page_table(child, virtual_addr, physical_addr, 0b110);
+  update_page_table(child, virtual_addr, physical_addr, PD_USER_RW);
+
+  // el0_VA2PA(child,USER_PROGRAM_BASE);
+  // el0_VA2PA(child,0x3f000000);
+  // el0_VA2PA(child,0x3f000000-1);
+  // el0_VA2PA(child,0x3c25e76c);
+  // el0_VA2PA(child,0x3c100000);
+  // el0_VA2PA(child,0x3c000000);
+  // el0_VA2PA(child,0x3c000000-1);
 
   char *src, *dst;
   // copy saved context in thread info