-#include "exception.h"
+#include "userprog/exception.h"
#include <inttypes.h>
-#include "lib.h"
-#include "gdt.h"
-#include "interrupt.h"
-#include "thread.h"
+#include <stdio.h>
+#include "userprog/gdt.h"
+#include "threads/interrupt.h"
+#include "threads/thread.h"
static void kill (struct intr_frame *);
static void page_fault (struct intr_frame *);
programs.
In a real Unix-like OS, most of these interrupts would be
- passed along to the user process in the form of signals, but
- we don't implement signals. Instead, we'll make them simply
- kill the user process.
+ passed along to the user process in the form of signals, as
+ described in [SV-386] 3-24 and 3-25, but we don't implement
+ signals. Instead, we'll make them simply kill the user
+ process.
Page faults are an exception. Here they are treated the same
way as other exceptions, but this will need to change to
case SEL_UCSEG:
/* User's code segment, so it's a user exception, as we
expected. Kill the user process. */
- printk ("%s: dying due to interrupt %#04x (%s).\n",
+ printf ("%s: dying due to interrupt %#04x (%s).\n",
thread_name (thread_current ()),
f->vec_no, intr_name (f->vec_no));
intr_dump_frame (f);
default:
/* Some other code segment? Shouldn't happen. Panic the
kernel. */
- printk ("Interrupt %#04x (%s) in unknown segment %04x\n",
+ printf ("Interrupt %#04x (%s) in unknown segment %04x\n",
f->vec_no, intr_name (f->vec_no), f->cs);
thread_exit ();
}
bool not_present, write, user;
uint32_t fault_addr;
- /* Determine cause. */
- not_present = (f->error_code & PF_P) == 0;
- write = (f->error_code & PF_W) != 0;
- user = (f->error_code & PF_U) != 0;
-
- /* Obtain faulting address.
+ /* Obtain faulting address, then turn interrupts back on.
+ (Interrupts were only off so that we could be assured of
+ reading CR2 before it changed.)
- (The faulting address is not necesarily the address of the
+ The faulting address is not necesarily the address of the
instruction that caused the fault--that's in F's eip
member. Rather, it's the linear address that was accessed
to cause the fault, which is probably an address of data,
- not code.) */
+ not code. */
asm ("movl %%cr2, %0" : "=r" (fault_addr));
+ intr_enable ();
+
+ /* Determine cause. */
+ not_present = (f->error_code & PF_P) == 0;
+ write = (f->error_code & PF_W) != 0;
+ user = (f->error_code & PF_U) != 0;
/* To implement virtual memory, delete the rest of the function
body, and replace it with code that brings in the page to
which fault_addr refers. */
- printk ("Page fault on address %08"PRIx32": %s %s page in %s context.\n",
+ printf ("Page fault at %08"PRIx32": %s error %s page in %s context.\n",
fault_addr,
not_present ? "not present" : "rights violation",
write ? "writing" : "reading",