minix/kernel/arch/i386/exception.c

199 lines
5.6 KiB
C
Executable file

/* This file contains a simple exception handler. Exceptions in user
* processes are converted to signals. Exceptions in a kernel task cause
* a panic.
*/
#include "../../kernel.h"
#include "proto.h"
#include <signal.h>
#include <stdio.h>
#include <string.h>
#include <minix/sysutil.h>
#include "../../proc.h"
extern int vm_copy_in_progress;
extern struct proc *vm_copy_from, *vm_copy_to;
extern u32_t vm_copy_from_v, vm_copy_to_v;
extern u32_t vm_copy_from_p, vm_copy_to_p, vm_copy_cr3;
u32_t pagefault_cr2, pagefault_count = 0;
void pagefault(struct proc *pr, int trap_errno)
{
int s;
vir_bytes ph;
u32_t pte;
if(pagefault_count != 1)
minix_panic("recursive pagefault", pagefault_count);
/* Don't schedule this process until pagefault is handled. */
if(RTS_ISSET(pr, PAGEFAULT))
minix_panic("PAGEFAULT set", pr->p_endpoint);
RTS_LOCK_SET(pr, PAGEFAULT);
if(pr->p_endpoint <= INIT_PROC_NR && !(pr->p_misc_flags & MF_FULLVM)) {
/* Page fault we can't / don't want to
* handle.
*/
kprintf("pagefault for process %d ('%s'), pc = 0x%x\n",
pr->p_endpoint, pr->p_name, pr->p_reg.pc);
proc_stacktrace(pr);
minix_panic("page fault in system process", pr->p_endpoint);
return;
}
/* Save pagefault details, suspend process,
* add process to pagefault chain,
* and tell VM there is a pagefault to be
* handled.
*/
pr->p_pagefault.pf_virtual = pagefault_cr2;
pr->p_pagefault.pf_flags = trap_errno;
pr->p_nextpagefault = pagefaults;
pagefaults = pr;
lock_notify(HARDWARE, VM_PROC_NR);
pagefault_count = 0;
#if 0
kprintf("pagefault for process %d ('%s'), pc = 0x%x\n",
pr->p_endpoint, pr->p_name, pr->p_reg.pc);
proc_stacktrace(pr);
#endif
return;
}
/*===========================================================================*
* exception *
*===========================================================================*/
PUBLIC void exception(vec_nr, trap_errno, old_eip, old_cs, old_eflags)
unsigned vec_nr;
u32_t trap_errno;
u32_t old_eip;
U16_t old_cs;
u32_t old_eflags;
{
/* An exception or unexpected interrupt has occurred. */
struct ex_s {
char *msg;
int signum;
int minprocessor;
};
static struct ex_s ex_data[] = {
{ "Divide error", SIGFPE, 86 },
{ "Debug exception", SIGTRAP, 86 },
{ "Nonmaskable interrupt", SIGBUS, 86 },
{ "Breakpoint", SIGEMT, 86 },
{ "Overflow", SIGFPE, 86 },
{ "Bounds check", SIGFPE, 186 },
{ "Invalid opcode", SIGILL, 186 },
{ "Coprocessor not available", SIGFPE, 186 },
{ "Double fault", SIGBUS, 286 },
{ "Copressor segment overrun", SIGSEGV, 286 },
{ "Invalid TSS", SIGSEGV, 286 },
{ "Segment not present", SIGSEGV, 286 },
{ "Stack exception", SIGSEGV, 286 }, /* STACK_FAULT already used */
{ "General protection", SIGSEGV, 286 },
{ "Page fault", SIGSEGV, 386 }, /* not close */
{ NIL_PTR, SIGILL, 0 }, /* probably software trap */
{ "Coprocessor error", SIGFPE, 386 },
};
register struct ex_s *ep;
struct proc *saved_proc;
/* Save proc_ptr, because it may be changed by debug statements. */
saved_proc = proc_ptr;
ep = &ex_data[vec_nr];
if (vec_nr == 2) { /* spurious NMI on some machines */
kprintf("got spurious NMI\n");
return;
}
/* If an exception occurs while running a process, the k_reenter variable
* will be zero. Exceptions in interrupt handlers or system traps will make
* k_reenter larger than zero.
*/
if (k_reenter == 0 && ! iskernelp(saved_proc)) {
{
switch(vec_nr) {
case PAGE_FAULT_VECTOR:
pagefault(saved_proc, trap_errno);
return;
}
kprintf(
"exception for process %d, endpoint %d ('%s'), pc = 0x%x:0x%x, sp = 0x%x:0x%x\n",
proc_nr(saved_proc), saved_proc->p_endpoint,
saved_proc->p_name,
saved_proc->p_reg.cs, saved_proc->p_reg.pc,
saved_proc->p_reg.ss, saved_proc->p_reg.sp);
kprintf(
"vec_nr= %d, trap_errno= 0x%lx, eip= 0x%lx, cs= 0x%x, eflags= 0x%lx\n",
vec_nr, (unsigned long)trap_errno,
(unsigned long)old_eip, old_cs,
(unsigned long)old_eflags);
proc_stacktrace(saved_proc);
}
kprintf("kernel: cause_sig %d for %d\n",
ep->signum, saved_proc->p_endpoint);
cause_sig(proc_nr(saved_proc), ep->signum);
return;
}
/* Exception in system code. This is not supposed to happen. */
if (ep->msg == NIL_PTR || machine.processor < ep->minprocessor)
kprintf("\nIntel-reserved exception %d\n", vec_nr);
else
kprintf("\n%s\n", ep->msg);
kprintf("k_reenter = %d ", k_reenter);
kprintf("process %d (%s), ", proc_nr(saved_proc), saved_proc->p_name);
kprintf("pc = %u:0x%x\n", (unsigned) saved_proc->p_reg.cs,
(unsigned) saved_proc->p_reg.pc);
kprintf(
"vec_nr= %d, trap_errno= 0x%lx, eip= 0x%lx, cs= 0x%x, eflags= 0x%lx\n",
vec_nr, (unsigned long)trap_errno,
(unsigned long)old_eip, old_cs, (unsigned long)old_eflags);
proc_stacktrace(saved_proc);
minix_panic("exception in a kernel task", saved_proc->p_endpoint);
}
/*===========================================================================*
* stacktrace *
*===========================================================================*/
PUBLIC void proc_stacktrace(struct proc *proc)
{
reg_t bp, v_bp, v_pc, v_hbp;
v_bp = proc->p_reg.fp;
kprintf("%s / %d pc 0x%lx stack ",
proc->p_name, proc->p_endpoint, proc->p_reg.pc);
while(v_bp) {
if(data_copy(proc->p_endpoint, v_bp,
SYSTEM, (vir_bytes) &v_hbp, sizeof(v_hbp)) != OK) {
kprintf("(v_bp 0x%lx ?)", v_bp);
break;
}
if(data_copy(proc->p_endpoint, v_bp + sizeof(v_pc),
SYSTEM, (vir_bytes) &v_pc, sizeof(v_pc)) != OK) {
kprintf("(v_pc 0x%lx ?)", v_pc);
break;
}
kprintf("0x%lx ", (unsigned long) v_pc);
if(v_hbp != 0 && v_hbp <= v_bp) {
kprintf("(hbp %lx ?)", v_hbp);
break;
}
v_bp = v_hbp;
}
kprintf("\n");
}