minix/kernel/arch/earm/exception.c
Lionel Sambuc b1c4ba4ab6 ARM updates
Due to the ABI we are using we have to use the earm architecture
moniker for the build system to behave correctly. This involves
then some headers to move around.

There is also a few related Makefile updates as well as minor
source code corrections.
2013-01-17 10:03:58 +01:00

225 lines
5.7 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)
{
int in_physcopy = 0, in_memset = 0;
reg_t pagefault_addr, pagefault_status;
message m_pagefault;
int err;
pagefault_addr = read_dfar();
pagefault_status = read_dfsr();
#if 0
printf("kernel: pagefault in pr %d, addr 0x%lx, his ttbr 0x%lx, actual ttbr 0x%lx\n",
pr->p_endpoint, pagefault_addr, pr->p_seg.p_ttbr, read_ttbr0());
#endif
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 0
printf("pf caught! addr 0x%lx\n", pagefault_addr);
#endif
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];
/*
* 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 occured 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);
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)
{
}