Start work on an initrd driver and attempt to debug pg fault on msg send

Makefile

@@ -30,7 +30,7 @@ debug: os.iso kernel/kernel.elf
 	@$(GDB)
 	#gdbgui -g i386-elf-gdb --project $(CWD)
 
-os.iso: kernel/kernel.elf init vfs devfs initrd vga_drv pci
+os.iso: kernel/kernel.elf init vfs devfs initrd vga_drv initrd_drv pci
 	@cp kernel/kernel.elf sysroot/boot
 	@cd initrd; tar -f ../sysroot/boot/initrd.tar -c *
 	@grub-mkrescue -o $@ sysroot >/dev/null 2>/dev/null
@@ -58,6 +58,10 @@ vga_drv: crts libc
 	@cd $@ && make
 	@cp $@/$@ initrd/$@
 
+initrd_drv: crts libc
+	@cd $@ && make
+	@cp $@/$@ initrd/$@
+
 kernel/kernel.elf: $(OBJ) $(ASM_OBJ) $(S_ASM_OBJ) sysroot/usr/lib/libc.a
 	@$(CC) -z max-page-size=4096 -Xlinker -n -T kernel/cpu/$(PLAT)/linker.ld -o $@ $(CFLAGS) -nostdlib $^ -lgcc
 

devfs/main.c

@@ -77,6 +77,7 @@ char devfs_puts(vfs_message* vfs_msg) {
   msg.size=vfs_msg->data;
   msg.msg=data;
   mailbox_send_msg(&msg);
+  free(data);
   return 0;
 }
 
@@ -92,18 +93,36 @@ char devfs_gets(vfs_message* vfs_msg) {
 }
 
 char* devfs_gets_finish(vfs_message* vfs_msg) {
+  char str[256];
+  int_to_ascii(vfs_msg->data,str);
+  serial_print("gets_finish: Driver wants ");
+  serial_print(str);
+  serial_print(" bytes of gets data\n");
   if (vfs_msg->flags) {
     return NULL;
   }
   char* gets_data=malloc(sizeof(vfs_msg->data));
   Message msg;
   msg.msg=gets_data;
-  mailbox_get_msg(devfs_drv_box,&msg,vfs_msg->data);
-  while (msg.from==0 && msg.size==0) {
-    yield();
-    mailbox_get_msg(devfs_drv_box,&msg,sizeof(vfs_message));
-  }
+  int_to_ascii(vfs_msg->data,str);
+  serial_print("gets_finish: Driver now wants ");
+  serial_print(str);
+  serial_print(" bytes of gets data\n");
+  mailbox_get_msg(devfs_drv_box,&msg,(uint32_t)vfs_msg->data);
+  // while (msg.from==0 && msg.size==0) {
+  //   serial_print("Yielding to wait for data msg\n");
+  //   yield();
+  //   mailbox_get_msg(devfs_drv_box,&msg,(uint32_t)vfs_msg->data);
+  // }
+  int_to_ascii(vfs_msg->data,str);
+  serial_print("gets_finish: Again, driver now wants ");
+  serial_print(str);
+  serial_print(" bytes of gets data\n");
   vfs_msg->flags=0;
+  int_to_ascii(vfs_msg->data,str);
+  serial_print("gets_finish: Sending ");
+  serial_print(str);
+  serial_print(" bytes of gets data\n");
   return gets_data;
 }
 
@@ -127,8 +146,18 @@ char devfs_mount(vfs_message* vfs_msg) {
 }
 
 void process_vfs_msg(vfs_message* vfs_msg, uint32_t from) {
-  if (vfs_msg->in_progress&2) {
+  char str[256];
+  int_to_ascii(vfs_msg->data,str);
+  serial_print("vfs_msg->data=");
+  serial_print(str);
+  serial_print("\n");
+  if (from!=vfs_box) {
     if (vfs_msg->flags) {
+      serial_print("vfs_msg->flags=");
+      char str[256];
+      int_to_ascii(vfs_msg->flags,str);
+      serial_print(str);
+      serial_print("\n");
       if (vfs_msg->type==VFS_OPEN) {
         free((void*)vfs_msg->data);
       }
@@ -148,7 +177,13 @@ void process_vfs_msg(vfs_message* vfs_msg, uint32_t from) {
         vfs_msg->flags=0;
         break;
         case VFS_GETS:
+        int_to_ascii(vfs_msg->data,str);
+        serial_print("process_vfs_msg: Driver sending ");
+        serial_print(str);
+        serial_print(" bytes of gets data\n");
+        serial_print("GETS_FINISH\n");
         gets_data=devfs_gets_finish(vfs_msg);
+        serial_print("GETS_FINISH DONE\n");
         break;
         case VFS_MOUNT:
         vfs_msg->flags=0;
@@ -163,27 +198,42 @@ void process_vfs_msg(vfs_message* vfs_msg, uint32_t from) {
       msg.msg=vfs_msg;
       mailbox_send_msg(&msg);
       if (gets_data) {
+        serial_print("Gets data\n");
+        char str[256];
+        int_to_ascii(vfs_msg->data,str);
+        serial_print("Sending ");
+        serial_print(str);
+        serial_print(" bytes of gets data\n");
         msg.size=vfs_msg->data;
         msg.msg=gets_data;
         mailbox_send_msg(&msg);
+        free(gets_data);
+      } else {
+        serial_print("No gets data\n");
       }
     }
   } else {
     char send_msg;
-    vfs_msg->in_progress=vfs_msg->in_progress|2;
     switch (vfs_msg->type) {
       case VFS_OPEN:
+      serial_print("OPEN\n");
       send_msg=devfs_open(vfs_msg);
+      serial_print("OPEN DONE\n");
       break;
       case VFS_PUTS:
+      serial_print("PUTS\n");
       send_msg=devfs_puts(vfs_msg);
+      serial_print("PUTS DONE\n");
       break;
       case VFS_GETS:
+      serial_print("GETS\n");
       send_msg=devfs_gets(vfs_msg);
+      serial_print("GETS DONE\n");
       break;
       case VFS_MOUNT:
-      serial_print("Mount\n");
+      serial_print("MOUNT\n");
       send_msg=devfs_mount(vfs_msg);
+      serial_print("MOUNT DONE\n");
       break;
       default:
       vfs_msg->flags=1;
@@ -223,6 +273,7 @@ int main() {
     } else {
       vfs_message* vfs_msg=(vfs_message*)msg.msg;
       process_vfs_msg(vfs_msg,msg.from);
+      free(msg.msg);
     }
     mailbox_get_msg(devfs_drv_box,&msg,sizeof(vfs_message));
     if (msg.from==0) {
@@ -230,10 +281,13 @@ int main() {
     } else {
       vfs_message* vfs_msg=(vfs_message*)msg.msg;
       process_vfs_msg(vfs_msg,msg.from);
+      free(msg.msg);
     }
     msg.msg=malloc(sizeof(devfs_message));
     mailbox_get_msg(devfs_reg_box,&msg,sizeof(devfs_message));
-    if (msg.from!=0) {
+    if (msg.from==0) {
+      free(msg.msg);
+    } else {
       devfs_message* devfs_msg=(devfs_message*)msg.msg;
       if (num_devs==max_devs) {
         max_devs+=32;
@@ -246,8 +300,8 @@ int main() {
       dev_mboxes[num_devs]=devfs_msg->mbox;
       dev_types[num_devs]=devfs_msg->dev_type;
       num_devs++;
-    }
       free(msg.msg);
+    }
     yield();
   }
 }

init/main.c

@@ -59,6 +59,11 @@ char load_task(uint32_t datapos,char* initrd) {
   int pos=0;
   elf_header header;
   pos=datapos;
+  char str[256];
+  int_to_ascii(pos,str);
+  serial_print("POS:");
+  serial_print(str);
+  serial_print("\n");
   char* hdr_ptr=(char*)&header;
   for (size_t i=0;i<sizeof(elf_header);i++) {
     hdr_ptr[i]=initrd[pos];
@@ -92,6 +97,35 @@ char load_task(uint32_t datapos,char* initrd) {
   return 1;
 }
 
+char load_task_devfs(uint32_t datapos) {
+  serial_print("load_task_devfs\n");
+  FILE* initrd=fopen("/dev/initrd","r");
+  elf_header header;
+  fseek(initrd,datapos,SEEK_SET);
+  fread(&header,sizeof(elf_header),1,initrd);
+  if (header.magic!=ELF_MAGIC) {
+    serial_print("Bad magic number\n");
+    return 0;
+  } else {
+    void* cr3=new_address_space();
+    for (int i=0;i<header.pheader_ent_nm;i++) {
+      elf_pheader pheader;
+      fseek(initrd,(header.prog_hdr)+(header.pheader_ent_sz*i)+datapos,SEEK_SET);
+      fread(&pheader,sizeof(elf_pheader),1,initrd);
+      char* ptr=alloc_memory(((pheader.memsz)/4096)+1);
+      memset(ptr,0,pheader.memsz);
+      if (pheader.filesz>0) {
+        fseek(initrd,pheader.offset+datapos,SEEK_SET);
+        fread(ptr,sizeof(char),pheader.memsz,initrd);
+      }
+      copy_data(cr3,ptr,pheader.memsz,(void*)pheader.vaddr);
+    }
+    createTaskCr3((void*)header.entry,cr3);
+  }
+  return 1;
+}
+
+
 int main() {
   long size=initrd_sz();
   char* initrd=malloc(size);
@@ -103,10 +137,15 @@ int main() {
   datapos=find_loc("devfs",initrd);
   load_task(datapos,initrd);
   yieldToPID(3);
-  datapos=find_loc("vga_drv",initrd);
+  datapos=find_loc("initrd_drv",initrd);
   load_task(datapos,initrd);
   yieldToPID(4);
   mount("","devfs","/dev/");
+  datapos=find_loc("vga_drv",initrd);
+  serial_print("Making vga task\n");
+  load_task_devfs(datapos);
+  serial_print("Made vga task\n");
+  yieldToPID(5);
   FILE* file;
   do {
     file=fopen("/dev/vga","w");

initrd_drv/Makefile

@@ -0,0 +1,13 @@
+C_SOURCES = $(wildcard *.c)
+OBJ = $(C_SOURCES:.c=.o )
+CFLAGS =  -Wall -g
+CC = i386-myos-gcc
+
+initrd_drv: $(OBJ) ../libc/*
+	@$(CC)  -o $@ $(CFLAGS) $(OBJ)
+
+%.o: %.c
+	@$(CC) $(CFLAGS) -c $< -o $@
+
+clean:
+	@rm -rf *.o initrd_drv

initrd_drv/main.c

@@ -0,0 +1,147 @@
+#include <tasking.h>
+#include <stdlib.h>
+#include <mailboxes.h>
+#include <ipc/vfs.h>
+#include <memory.h>
+#include <grub/text_fb_info.h>
+#include <vfs.h>
+#include <ipc/devfs.h>
+#include <string.h>
+#include <dbg.h>
+#include <initrd.h>
+
+#define VFS_PID 2
+#define DEVFS_PID 3
+
+uint32_t box;
+char* initrd;
+long size;
+
+void initrd_puts(vfs_message* vfs_msg) {
+  char* data=malloc(sizeof(char)*vfs_msg->data);
+  Message msg;
+  msg.msg=data;
+  mailbox_get_msg(box,&msg,vfs_msg->data);
+  while (msg.from==0 && msg.size==0) {
+    yield();
+    mailbox_get_msg(box,&msg,sizeof(vfs_message));
+  }
+  if (msg.from==0) {
+    serial_print("Could not recieve fputs data from the VFS\n");
+    vfs_msg->flags=2;
+    return;
+  }
+  free(data);
+  vfs_msg->flags=2;
+  return;
+}
+
+char* initrd_gets(vfs_message* vfs_msg) {
+  char str[256];
+  serial_print("File pos initrd:");
+  int_to_ascii(vfs_msg->pos,str);
+  serial_print(str);
+  serial_print("\n");
+  long max_data=size-vfs_msg->pos;
+  serial_print("max_data=");
+  int_to_ascii(max_data,str);
+  serial_print(str);
+  serial_print("\n");
+  serial_print("Amount requested:");
+  int_to_ascii(vfs_msg->data,str);
+  serial_print(str);
+  serial_print("\n");
+  if (vfs_msg->data>max_data) {
+    serial_print("OVER\n");
+    vfs_msg->flags=2;
+    return NULL;
+  }
+  char* data=malloc(sizeof(char)*vfs_msg->data);
+  for (long i=0;i<vfs_msg->data;i++) {
+    data[i]=(uint8_t)initrd[i+vfs_msg->pos];
+    // if (i<sizeof(vfs_message)) {
+    //   serial_print("data[");
+    //   char str[256];
+    //   int_to_ascii(i,str);
+    //   serial_print(str);
+    //   serial_print("]=");
+    //   hex_to_ascii((uint8_t)data[i],str);
+    //   serial_print(str);
+    //   serial_print("\n");
+    // }
+  }
+  vfs_msg->flags=0;
+  return data;
+}
+
+void process_vfs_msg(vfs_message* vfs_msg, uint32_t from) {
+  char* gets_data;
+  switch (vfs_msg->type) {
+    case VFS_PUTS:
+    initrd_puts(vfs_msg);
+    break;
+    case VFS_GETS:
+    gets_data=initrd_gets(vfs_msg);
+    break;
+    break;
+    default:
+    vfs_msg->flags=1;
+  }
+  Message msg;
+  msg.to=from;
+  msg.from=box;
+  msg.size=sizeof(vfs_message);
+  msg.msg=vfs_msg;
+  serial_print("Sending message with flags of ");
+  char str[256];
+  int_to_ascii(vfs_msg->flags,str);
+  serial_print(str);
+  serial_print("\n");
+  mailbox_send_msg(&msg);
+  if (gets_data) {
+    serial_print("Amount sending:");
+    char str[256];
+    int_to_ascii(vfs_msg->data,str);
+    serial_print(str);
+    serial_print("\n");
+    msg.size=vfs_msg->data;
+    msg.msg=gets_data;
+    mailbox_send_msg(&msg);
+    free(gets_data);
+  }
+}
+
+
+int main() {
+  size=initrd_sz();
+  initrd=malloc(size);
+  initrd_get(initrd);
+  box=mailbox_new(16,"initrd");
+  devfs_message* msg_data=malloc(sizeof(devfs_message));
+  msg_data->msg_type=DEVFS_REGISTER;
+  msg_data->dev_type=DEV_GLOBAL;
+  msg_data->mbox=box;
+  strcpy(&msg_data->name[0],"initrd");
+  Message msg;
+  msg.from=box;
+  msg.to=mailbox_find_by_name("devfs_register");
+  msg.size=sizeof(devfs_message);
+  msg.msg=msg_data;
+  mailbox_send_msg(&msg);
+  free(msg_data);
+  yieldToPID(DEVFS_PID);
+  for (;;) {
+    Message msg;
+    msg.msg=malloc(sizeof(vfs_message));
+    mailbox_get_msg(box,&msg,sizeof(vfs_message));
+    if (msg.from==0) {
+      free(msg.msg);
+    } else {
+      vfs_message* vfs_msg=(vfs_message*)msg.msg;
+      process_vfs_msg(vfs_msg,msg.from);
+      free(vfs_msg);
+      yieldToPID(VFS_PID);
+    }
+    yield();
+  }
+}

kernel/cpu/i386/cpu_init.c

@@ -9,8 +9,8 @@ void cpu_init(struct multiboot_boot_header_tag* tags) {
   gdt_init();
   isr_install();
   asm volatile("sti");
+  serial_init();
   pmem_init(tags);
   paging_init();
   tasking_init();
-  serial_init();
 }

kernel/cpu/i386/isr.c

@@ -132,8 +132,12 @@ __attribute__((unused)) static char *exception_messages[] = {
 };
 
 void isr_handler(registers_t r) {
+  if (r.int_no!=80 && r.int_no!=14) {
+    vga_write_string(exception_messages[r.int_no]);
+  }
   switch (r.int_no) {
     case 14: {
+      serial_write_string("PAGE FAULT\n");
       uint32_t addr;
       asm("movl %%cr2,%0": "=r"(addr));
       vga_write_string("In PID ");

kernel/cpu/i386/mailboxes.c

@@ -40,17 +40,15 @@ void kernel_mailbox_send_msg(Message* user_msg) {
   }
   Mailbox mailbox=mailboxes[user_msg->to];
   uint32_t num_pages=(user_msg->size/4096)+1;
+  serial_printf("Storing data in pmem\n");
   void* phys_addr=pmem_alloc(num_pages);
   void* virt_addr=find_free_pages(num_pages);
-  // char* msg_data=kmalloc(user_msg->size);
   map_pages(virt_addr,phys_addr,num_pages,0,1);
-  // if (msg_data==NULL) {
-  //   serial_print("Cannot allocate kernel msg data!\n");
-  //   vga_write_string("Cannot allocate kernel msg data!\n");
-  //   for(;;);
-  // }
+  serial_printf("Mapped into vmem\n");
+  serial_printf("memcpy(%x,%x,%d)\n",virt_addr,user_msg->msg,user_msg->size);
   memcpy(virt_addr,user_msg->msg,user_msg->size);
   unmap_pages(virt_addr,num_pages);
+  serial_printf("Stored data in pmem\n");
   mailbox.msg_store[mailbox.wr].msg=phys_addr;
   mailbox.msg_store[mailbox.wr].from=user_msg->from;
   mailbox.msg_store[mailbox.wr].to=user_msg->to;
@@ -89,12 +87,16 @@ void kernel_mailbox_get_msg(uint32_t box, Message* recv_msg, uint32_t buffer_sz)
     mailboxes[box]=mailbox;
     return;
   }
+  if (buffer_sz>mailbox.msg_store[mailbox.rd].size) {
+    serial_printf("Warning: buffer sized for message %d big, but got message sized %d.\n",buffer_sz,mailbox.msg_store[mailbox.rd].size);
+  }
   Message msg=mailbox.msg_store[mailbox.rd];
   uint32_t num_pages=(msg.size/4096)+1;
   void* virt_addr=find_free_pages(num_pages);
   map_pages(virt_addr,msg.msg,num_pages,0,1);
   memcpy(recv_msg->msg,virt_addr,mailbox.msg_store[mailbox.rd].size);
   unmap_pages(virt_addr,num_pages);
+  pmem_free(((uint32_t)msg.msg)>>12,num_pages);
   // kfree(mailbox.msg_store[mailbox.rd].msg);
   mailbox.msg_store[mailbox.rd].from=0;
   uint32_t orig_rd=mailbox.rd;

kernel/cpu/i386/paging.c

@@ -176,6 +176,28 @@ void unmap_pages(void* start_virt,uint32_t num_pages) {
   }
 }
 
+char make_protector(int page) {
+  int table=page>>10;
+  if (is_page_present(page)) return 0;
+  page=page&0x3FF;
+  smap_page_tables[table+1]=(smap[table]&0xFFFFFC00)|0x3;
+  uint32_t page_val=smap[(1024+(1024*table))+page];
+  page_val=page_val&(~0x6);
+  page_val=page_val|0x800;
+  smap[(1024+(1024*table))+page]=page_val;
+  return 1;
+}
+
+char is_in_protector(uint32_t* addr) {
+  int page=((uint32_t)addr)>>12;
+  if (is_page_present(page)) return 0;
+  int table=page>>10;
+  page=page&0x3FF;
+  smap_page_tables[table+1]=(smap[table]&0xFFFFFC00)|0x3;
+  return smap[(1024+(1024*table))+page]&0x800;
+  return 1;
+}
+
 void paging_init() {
   for (uint32_t i=0;i<NUM_KERN_DIRS*1024;i++) {
     kern_page_tables[i]=(i<<12)|0x3;

kernel/cpu/i386/paging.h

@@ -17,5 +17,7 @@ void load_address_space(uint32_t cr3);
 void* virt_to_phys(void* virt_addr);
 void* find_free_pages(int num_pages);
 void load_smap(uint32_t cr3);
+char make_protector(int page);
+char is_in_protector(uint32_t* addr);
 
 #endif

kernel/cpu/i386/tasking.c

@@ -72,7 +72,10 @@ Task* tasking_createTaskCr3KmodeParam(void* eip,void* cr3,char kmode,char param1
       kstacks[top_idx-5]=0;
       kstacks[top_idx-4]=0;
       kstacks[top_idx-3]=(uint32_t)task_init;
-      uint32_t* user_stack=(uint32_t*)(((uint32_t)alloc_pages(1))+0x1000);
+      uint32_t* user_stack=(uint32_t*)(((uint32_t)alloc_pages(2))+0x2000);
+      int buffer_pg_num=(((uint32_t)user_stack)-0x2000)>>12;
+      make_protector(buffer_pg_num);
+      // uint32_t* user_stack=(uint32_t*)(((uint32_t)alloc_pages(1))+0x1000);
       user_stack-=2;
       user_stack[0]=param1;
       user_stack[1]=param2;

sysroot/usr/include/ipc/vfs.h

@@ -13,17 +13,17 @@ typedef enum {
 } vfs_message_type;
 
 typedef struct {
+  char flags;
   vfs_message_type type;
   uint8_t id;
   char mode[10];
   uint32_t fd;
-  char path[4096];
   uint32_t pos;
-  char flags;
   int data;
   char in_progress;
   uint32_t orig_mbox;
   void* fs_data;
-} vfs_message;
+  char path[4096];
+} __attribute__((packed)) vfs_message;
 
 #endif