233 lines
6.1 KiB
C
233 lines
6.1 KiB
C
|
/* 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/kernel.h"
|
||
|
#include "arch_proto.h"
|
||
|
#include <signal.h>
|
||
|
#include <string.h>
|
||
|
#include <assert.h>
|
||
|
#include "kernel/proc.h"
|
||
|
#include "kernel/proto.h"
|
||
|
#include <machine/vm.h>
|
||
|
|
||
|
struct ex_s {
|
||
|
char *msg;
|
||
|
int signum;
|
||
|
};
|
||
|
|
||
|
static struct ex_s ex_data[] = {
|
||
|
{ "Reset", 0},
|
||
|
{ "Undefined instruction", SIGILL},
|
||
|
{ "Supervisor call", 0},
|
||
|
{ "Prefetch Abort", SIGILL},
|
||
|
{ "Data Abort", SIGSEGV},
|
||
|
{ "Hypervisor call", 0},
|
||
|
{ "Interrupt", 0},
|
||
|
{ "Fast Interrupt", 0},
|
||
|
};
|
||
|
|
||
|
static void inkernel_disaster(struct proc *saved_proc,
|
||
|
reg_t *saved_lr, struct ex_s *ep, int is_nested);
|
||
|
|
||
|
extern int catch_pagefaults;
|
||
|
|
||
|
static void proc_stacktrace_execute(struct proc *whichproc, reg_t v_bp, reg_t pc);
|
||
|
|
||
|
static void pagefault( struct proc *pr,
|
||
|
reg_t *saved_lr,
|
||
|
int is_nested,
|
||
|
u32_t pagefault_addr,
|
||
|
u32_t pagefault_status)
|
||
|
{
|
||
|
int in_physcopy = 0, in_memset = 0;
|
||
|
|
||
|
message m_pagefault;
|
||
|
int err;
|
||
|
|
||
|
in_physcopy = (*saved_lr > (vir_bytes) phys_copy) &&
|
||
|
(*saved_lr < (vir_bytes) phys_copy_fault);
|
||
|
|
||
|
in_memset = (*saved_lr > (vir_bytes) phys_memset) &&
|
||
|
(*saved_lr < (vir_bytes) memset_fault);
|
||
|
|
||
|
if((is_nested || iskernelp(pr)) &&
|
||
|
catch_pagefaults && (in_physcopy || in_memset)) {
|
||
|
if (is_nested) {
|
||
|
if(in_physcopy) {
|
||
|
assert(!in_memset);
|
||
|
*saved_lr = (reg_t) phys_copy_fault_in_kernel;
|
||
|
} else {
|
||
|
*saved_lr = (reg_t) memset_fault_in_kernel;
|
||
|
}
|
||
|
}
|
||
|
else {
|
||
|
pr->p_reg.pc = (reg_t) phys_copy_fault;
|
||
|
pr->p_reg.retreg = pagefault_addr;
|
||
|
}
|
||
|
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
if(is_nested) {
|
||
|
printf("pagefault in kernel at pc 0x%lx address 0x%lx\n",
|
||
|
*saved_lr, pagefault_addr);
|
||
|
inkernel_disaster(pr, saved_lr, NULL, is_nested);
|
||
|
}
|
||
|
|
||
|
/* VM can't handle page faults. */
|
||
|
if(pr->p_endpoint == VM_PROC_NR) {
|
||
|
/* Page fault we can't / don't want to
|
||
|
* handle.
|
||
|
*/
|
||
|
printf("pagefault for VM on CPU %d, "
|
||
|
"pc = 0x%x, addr = 0x%x, flags = 0x%x, is_nested %d\n",
|
||
|
cpuid, pr->p_reg.pc, pagefault_addr, pagefault_status,
|
||
|
is_nested);
|
||
|
proc_stacktrace(pr);
|
||
|
printf("pc of pagefault: 0x%lx\n", pr->p_reg.pc);
|
||
|
panic("pagefault in VM");
|
||
|
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
/* Don't schedule this process until pagefault is handled. */
|
||
|
RTS_SET(pr, RTS_PAGEFAULT);
|
||
|
|
||
|
/* tell Vm about the pagefault */
|
||
|
m_pagefault.m_source = pr->p_endpoint;
|
||
|
m_pagefault.m_type = VM_PAGEFAULT;
|
||
|
m_pagefault.VPF_ADDR = pagefault_addr;
|
||
|
m_pagefault.VPF_FLAGS = pagefault_status;
|
||
|
|
||
|
if ((err = mini_send(pr, VM_PROC_NR,
|
||
|
&m_pagefault, FROM_KERNEL))) {
|
||
|
panic("WARNING: pagefault: mini_send returned %d\n", err);
|
||
|
}
|
||
|
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
static void inkernel_disaster(struct proc *saved_proc,
|
||
|
reg_t *saved_lr, struct ex_s *ep,
|
||
|
int is_nested)
|
||
|
{
|
||
|
#if USE_SYSDEBUG
|
||
|
if(ep)
|
||
|
printf("\n%s\n", ep->msg);
|
||
|
|
||
|
printf("cpu %d is_nested = %d ", cpuid, is_nested);
|
||
|
|
||
|
if (saved_proc) {
|
||
|
printf("scheduled was: process %d (%s), ", saved_proc->p_endpoint, saved_proc->p_name);
|
||
|
printf("pc = 0x%x\n", (unsigned) saved_proc->p_reg.pc);
|
||
|
proc_stacktrace(saved_proc);
|
||
|
|
||
|
panic("Unhandled kernel exception");
|
||
|
}
|
||
|
|
||
|
/* in an early stage of boot process we don't have processes yet */
|
||
|
panic("exception in kernel while booting, no saved_proc yet");
|
||
|
|
||
|
#endif /* USE_SYSDEBUG */
|
||
|
}
|
||
|
|
||
|
void exception_handler(int is_nested, reg_t *saved_lr, int vector)
|
||
|
{
|
||
|
/* An exception or unexpected interrupt has occurred. */
|
||
|
struct ex_s *ep;
|
||
|
struct proc *saved_proc;
|
||
|
|
||
|
saved_proc = get_cpulocal_var(proc_ptr);
|
||
|
|
||
|
ep = &ex_data[vector];
|
||
|
|
||
|
assert((vir_bytes) saved_lr >= kinfo.vir_kern_start);
|
||
|
|
||
|
/*
|
||
|
* handle special cases for nested problems as they might be tricky or filter
|
||
|
* them out quickly if the traps are not nested
|
||
|
*/
|
||
|
if (is_nested) {
|
||
|
/*
|
||
|
* if a problem occurred while copying a message from userspace because
|
||
|
* of a wrong pointer supplied by userland, handle it the only way we
|
||
|
* can handle it ...
|
||
|
*/
|
||
|
if (((void*)*saved_lr >= (void*)copy_msg_to_user &&
|
||
|
(void*)*saved_lr <= (void*)__copy_msg_to_user_end) ||
|
||
|
((void*)*saved_lr >= (void*)copy_msg_from_user &&
|
||
|
(void*)*saved_lr <= (void*)__copy_msg_from_user_end)) {
|
||
|
switch(vector) {
|
||
|
/* these error are expected */
|
||
|
case DATA_ABORT_VECTOR:
|
||
|
*saved_lr = (reg_t) __user_copy_msg_pointer_failure;
|
||
|
return;
|
||
|
default:
|
||
|
panic("Copy involving a user pointer failed unexpectedly!");
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
if (vector == DATA_ABORT_VECTOR) {
|
||
|
pagefault(saved_proc, saved_lr, is_nested, read_dfar(), read_dfsr());
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
if (!is_nested && vector == PREFETCH_ABORT_VECTOR) {
|
||
|
reg_t ifar = read_ifar(), ifsr = read_ifsr();
|
||
|
|
||
|
/* The saved_lr is the instruction we're going to execute after
|
||
|
* the fault is handled; IFAR is the address that pagefaulted
|
||
|
* while fetching the instruction. As far as we know the two
|
||
|
* should be the same, if not this assumption will lead to very
|
||
|
* hard to debug problems (instruction executing being off by one)
|
||
|
* and this assumption needs re-examining, hence the assert.
|
||
|
*/
|
||
|
assert(*saved_lr == ifar);
|
||
|
pagefault(saved_proc, saved_lr, is_nested, ifar, ifsr);
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
/* If an exception occurs while running a process, the is_nested variable
|
||
|
* will be zero. Exceptions in interrupt handlers or system traps will make
|
||
|
* is_nested non-zero.
|
||
|
*/
|
||
|
if (is_nested == 0 && ! iskernelp(saved_proc)) {
|
||
|
cause_sig(proc_nr(saved_proc), ep->signum);
|
||
|
return;
|
||
|
}
|
||
|
|
||
|
/* Exception in system code. This is not supposed to happen. */
|
||
|
inkernel_disaster(saved_proc, saved_lr, ep, is_nested);
|
||
|
|
||
|
panic("return from inkernel_disaster");
|
||
|
}
|
||
|
|
||
|
#if USE_SYSDEBUG
|
||
|
/*===========================================================================*
|
||
|
* proc_stacktrace_execute *
|
||
|
*===========================================================================*/
|
||
|
static void proc_stacktrace_execute(struct proc *whichproc, reg_t v_bp, reg_t pc)
|
||
|
{
|
||
|
printf("%-8.8s %6d 0x%lx \n",
|
||
|
whichproc->p_name, whichproc->p_endpoint, pc);
|
||
|
}
|
||
|
#endif
|
||
|
|
||
|
void proc_stacktrace(struct proc *whichproc)
|
||
|
{
|
||
|
#if USE_SYSDEBUG
|
||
|
proc_stacktrace_execute(whichproc, whichproc->p_reg.fp, whichproc->p_reg.pc);
|
||
|
#endif /* USE_SYSDEBUG */
|
||
|
}
|
||
|
|
||
|
void enable_fpu_exception(void)
|
||
|
{
|
||
|
}
|
||
|
|
||
|
void disable_fpu_exception(void)
|
||
|
{
|
||
|
}
|