From 4f670845ff9ab6c48bcb5f7bf4d4ef6dc3c3064b Mon Sep 17 00:00:00 2001 From: manuel Date: Tue, 27 Mar 2012 11:51:08 +0200 Subject: reorganize file structure to match the upstream requirements --- pintos-progos/userprog/exception.c | 174 ------------------------------------- 1 file changed, 174 deletions(-) delete mode 100644 pintos-progos/userprog/exception.c (limited to 'pintos-progos/userprog/exception.c') diff --git a/pintos-progos/userprog/exception.c b/pintos-progos/userprog/exception.c deleted file mode 100644 index 17620ad..0000000 --- a/pintos-progos/userprog/exception.c +++ /dev/null @@ -1,174 +0,0 @@ -#include "userprog/exception.h" -#include -#include -#include "userprog/gdt.h" -#include "threads/interrupt.h" -#include "threads/thread.h" -#include "threads/vaddr.h" - -/* Number of page faults processed. */ -static long long page_fault_cnt; - -static void kill (struct intr_frame *); -static void page_fault (struct intr_frame *); - -/* Registers handlers for interrupts that can be caused by user - programs. - - In a real Unix-like OS, most of these interrupts would be - 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 - implement virtual memory. - - Refer to [IA32-v3a] section 5.15 "Exception and Interrupt - Reference" for a description of each of these exceptions. */ -void -exception_init (void) -{ - /* These exceptions can be raised explicitly by a user program, - e.g. via the INT, INT3, INTO, and BOUND instructions. Thus, - we set DPL==3, meaning that user programs are allowed to - invoke them via these instructions. */ - intr_register_int (3, 3, INTR_ON, kill, "#BP Breakpoint Exception"); - intr_register_int (4, 3, INTR_ON, kill, "#OF Overflow Exception"); - intr_register_int (5, 3, INTR_ON, kill, - "#BR BOUND Range Exceeded Exception"); - - /* These exceptions have DPL==0, preventing user processes from - invoking them via the INT instruction. They can still be - caused indirectly, e.g. #DE can be caused by dividing by - 0. */ - intr_register_int (0, 0, INTR_ON, kill, "#DE Divide Error"); - intr_register_int (1, 0, INTR_ON, kill, "#DB Debug Exception"); - intr_register_int (6, 0, INTR_ON, kill, "#UD Invalid Opcode Exception"); - intr_register_int (7, 0, INTR_ON, kill, - "#NM Device Not Available Exception"); - intr_register_int (11, 0, INTR_ON, kill, "#NP Segment Not Present"); - intr_register_int (12, 0, INTR_ON, kill, "#SS Stack Fault Exception"); - intr_register_int (13, 0, INTR_ON, kill, "#GP General Protection Exception"); - intr_register_int (16, 0, INTR_ON, kill, "#MF x87 FPU Floating-Point Error"); - intr_register_int (19, 0, INTR_ON, kill, - "#XF SIMD Floating-Point Exception"); - - /* Most exceptions can be handled with interrupts turned on. - We need to disable interrupts for page faults because the - fault address is stored in CR2 and needs to be preserved. */ - intr_register_int (14, 0, INTR_OFF, page_fault, "#PF Page-Fault Exception"); -} - -/* Prints exception statistics. */ -void -exception_print_stats (void) -{ - printf ("Exception: %lld page faults\n", page_fault_cnt); -} - -/* Handler for an exception (probably) caused by a user process. */ -static void -kill (struct intr_frame *f) -{ - /* This interrupt is one (probably) caused by a user process. - For example, the process might have tried to access unmapped - virtual memory (a page fault). For now, we simply kill the - user process. Later, we'll want to handle page faults in - the kernel. Real Unix-like operating systems pass most - exceptions back to the process via signals, but we don't - implement them. */ - - /* The interrupt frame's code segment value tells us where the - exception originated. */ - switch (f->cs) - { - case SEL_UCSEG: - /* User's code segment, so it's a user exception, as we - expected. Kill the user process. */ - printf ("%s: dying due to interrupt %#04x (%s).\n", - thread_name (), f->vec_no, intr_name (f->vec_no)); - intr_dump_frame (f); - thread_exit (); - - case SEL_KCSEG: - /* Kernel's code segment, which indicates a kernel bug. - Kernel code shouldn't throw exceptions. (Page faults - may cause kernel exceptions--but they shouldn't arrive - here.) Panic the kernel to make the point. */ - intr_dump_frame (f); - PANIC ("Kernel bug - unexpected interrupt in kernel"); - - default: - /* Some other code segment? Shouldn't happen. Panic the - kernel. */ - printf ("Interrupt %#04x (%s) in unknown segment %04x\n", - f->vec_no, intr_name (f->vec_no), f->cs); - thread_exit (); - } -} - -/* Page fault handler. This is a skeleton that must be filled in - to implement virtual memory. Some solutions to project 2 may - also require modifying this code. - - At entry, the address that faulted is in CR2 (Control Register - 2) and information about the fault, formatted as described in - the PF_* macros in exception.h, is in F's error_code member. The - example code here shows how to parse that information. You - can find more information about both of these in the - description of "Interrupt 14--Page Fault Exception (#PF)" in - [IA32-v3a] section 5.15 "Exception and Interrupt Reference". */ -static void -page_fault (struct intr_frame *f) -{ - bool not_present; /* True: not-present page, false: writing r/o page. */ - bool write; /* True: access was write, false: access was read. */ - bool user; /* True: access by user, false: access by kernel. */ - void *fault_addr; /* Fault address. */ - - /* Obtain faulting address, the virtual address that was - accessed to cause the fault. It may point to code or to - data. It is not necessarily the address of the instruction - that caused the fault (that's f->eip). - See [IA32-v2a] "MOV--Move to/from Control Registers" and - [IA32-v3a] 5.15 "Interrupt 14--Page Fault Exception - (#PF)". */ - asm ("movl %%cr2, %0" : "=r" (fault_addr)); - - /* Turn interrupts back on (they were only off so that we could - be assured of reading CR2 before it changed). */ - intr_enable (); - - /* Count page faults. */ - page_fault_cnt++; - - /* 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, adapt the rest of the function - body, adding code that brings in the page to - which fault_addr refers. */ - if (is_user_vaddr(fault_addr)) { - if (! user) { - /* syscall exception; set eax and eip */ - f->eip = (void*)f->eax; - f->eax = 0xFFFFFFFF; - return; - } else { - /* user process access violation */ - thread_exit(); - } - } else { - printf ("Page fault at %p: %s error %s page in %s context.\n", - fault_addr, - not_present ? "not present" : "rights violation", - write ? "writing" : "reading", - user ? "user" : "kernel"); - kill (f); - } -} - -- cgit v1.2.3