NetBSD-5.0.2/sys/arch/arm/arm/undefined.c
/* $NetBSD: undefined.c,v 1.34 2008/05/21 14:12:06 ad Exp $ */
/*
* Copyright (c) 2001 Ben Harris.
* Copyright (c) 1995 Mark Brinicombe.
* Copyright (c) 1995 Brini.
* All rights reserved.
*
* This code is derived from software written for Brini by Mark Brinicombe
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Brini.
* 4. The name of the company nor the name of the author may be used to
* endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY BRINI ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL BRINI OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* RiscBSD kernel project
*
* undefined.c
*
* Fault handler
*
* Created : 06/01/95
*/
#define FAST_FPE
#include "opt_ddb.h"
#include "opt_kgdb.h"
#include <sys/param.h>
#ifdef KGDB
#include <sys/kgdb.h>
#endif
__KERNEL_RCSID(0, "$NetBSD: undefined.c,v 1.34 2008/05/21 14:12:06 ad Exp $");
#include <sys/malloc.h>
#include <sys/queue.h>
#include <sys/signal.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/user.h>
#include <sys/syslog.h>
#include <sys/vmmeter.h>
#ifdef FAST_FPE
#include <sys/acct.h>
#endif
#include <sys/userret.h>
#include <uvm/uvm_extern.h>
#include <machine/cpu.h>
#include <machine/frame.h>
#include <arm/undefined.h>
#include <machine/trap.h>
#include <arch/arm/arm/disassem.h>
#ifdef DDB
#include <ddb/db_output.h>
#include <machine/db_machdep.h>
#endif
#ifdef acorn26
#include <machine/machdep.h>
#endif
static int gdb_trapper(u_int, u_int, struct trapframe *, int);
LIST_HEAD(, undefined_handler) undefined_handlers[NUM_UNKNOWN_HANDLERS];
void *
install_coproc_handler(int coproc, undef_handler_t handler)
{
struct undefined_handler *uh;
KASSERT(coproc >= 0 && coproc < NUM_UNKNOWN_HANDLERS);
KASSERT(handler != NULL); /* Used to be legal. */
/* XXX: M_TEMP??? */
MALLOC(uh, struct undefined_handler *, sizeof(*uh), M_TEMP, M_WAITOK);
uh->uh_handler = handler;
install_coproc_handler_static(coproc, uh);
return uh;
}
void
install_coproc_handler_static(int coproc, struct undefined_handler *uh)
{
LIST_INSERT_HEAD(&undefined_handlers[coproc], uh, uh_link);
}
void
remove_coproc_handler(void *cookie)
{
struct undefined_handler *uh = cookie;
LIST_REMOVE(uh, uh_link);
FREE(uh, M_TEMP);
}
static int
gdb_trapper(u_int addr, u_int insn, struct trapframe *frame, int code)
{
struct lwp *l;
l = curlwp;
#ifdef THUMB_CODE
if (frame->tf_spsr & PSR_T_bit) {
if (insn == GDB_THUMB_BREAKPOINT)
goto bkpt;
}
else
#endif
{
if (insn == GDB_BREAKPOINT || insn == GDB5_BREAKPOINT) {
#ifdef THUMB_CODE
bkpt:
#endif
if (code == FAULT_USER) {
ksiginfo_t ksi;
KSI_INIT_TRAP(&ksi);
ksi.ksi_signo = SIGTRAP;
ksi.ksi_code = TRAP_BRKPT;
ksi.ksi_addr = (u_int32_t *)addr;
ksi.ksi_trap = 0;
trapsignal(l, &ksi);
return 0;
}
#ifdef KGDB
return !kgdb_trap(T_BREAKPOINT, frame);
#endif
}
}
return 1;
}
static struct undefined_handler gdb_uh;
#ifdef THUMB_CODE
static struct undefined_handler gdb_uh_thumb;
#endif
void
undefined_init()
{
int loop;
/* Not actually necessary -- the initialiser is just NULL */
for (loop = 0; loop < NUM_UNKNOWN_HANDLERS; ++loop)
LIST_INIT(&undefined_handlers[loop]);
/* Install handler for GDB breakpoints */
gdb_uh.uh_handler = gdb_trapper;
install_coproc_handler_static(CORE_UNKNOWN_HANDLER, &gdb_uh);
#ifdef THUMB_CODE
gdb_uh_thumb.uh_handler = gdb_trapper;
install_coproc_handler_static(THUMB_UNKNOWN_HANDLER, &gdb_uh_thumb);
#endif
}
void
undefinedinstruction(trapframe_t *frame)
{
struct lwp *l;
u_int fault_pc;
int fault_instruction;
int fault_code;
int coprocessor;
int user;
struct undefined_handler *uh;
#ifdef VERBOSE_ARM32
int s;
#endif
/* Enable interrupts if they were enabled before the exception. */
#ifdef acorn26
if ((frame->tf_r15 & R15_IRQ_DISABLE) == 0)
int_on();
#else
if (!(frame->tf_spsr & I32_bit))
enable_interrupts(I32_bit);
#endif
#ifndef acorn26
#ifdef THUMB_CODE
if (frame->tf_spsr & PSR_T_bit)
frame->tf_pc -= THUMB_INSN_SIZE;
else
#endif
{
frame->tf_pc -= INSN_SIZE;
}
#endif
#ifdef __PROG26
fault_pc = frame->tf_r15 & R15_PC;
#else
fault_pc = frame->tf_pc;
#endif
/* Get the current lwp/proc structure or lwp0/proc0 if there is none. */
l = curlwp;
#ifdef __PROG26
if ((frame->tf_r15 & R15_MODE) == R15_MODE_USR) {
#else
if ((frame->tf_spsr & PSR_MODE) == PSR_USR32_MODE) {
#endif
user = 1;
LWP_CACHE_CREDS(l, l->l_proc);
} else
user = 0;
#ifdef THUMB_CODE
if (frame->tf_spsr & PSR_T_bit) {
fault_instruction = fusword((void *)(fault_pc & ~1));
}
else
#endif
{
/*
* Make sure the program counter is correctly aligned so we
* don't take an alignment fault trying to read the opcode.
*/
if (__predict_false((fault_pc & 3) != 0)) {
ksiginfo_t ksi;
/* Give the user an illegal instruction signal. */
KSI_INIT_TRAP(&ksi);
ksi.ksi_signo = SIGILL;
ksi.ksi_code = ILL_ILLOPC;
ksi.ksi_addr = (u_int32_t *)(intptr_t) fault_pc;
trapsignal(l, &ksi);
userret(l);
return;
}
/*
* Should use fuword() here .. but in the interests of
* squeezing every bit of speed we will just use
* ReadWord(). We know the instruction can be read
* as was just executed so this will never fail unless
* the kernel is screwed up in which case it does
* not really matter does it ?
*/
fault_instruction = *(u_int32_t *)fault_pc;
}
/* Update vmmeter statistics */
uvmexp.traps++;
#ifdef THUMB_CODE
if (frame->tf_spsr & PSR_T_bit) {
coprocessor = THUMB_UNKNOWN_HANDLER;
}
else
#endif
{
/* Check for coprocessor instruction */
/*
* According to the datasheets you only need to look at
* bit 27 of the instruction to tell the difference
* between and undefined instruction and a coprocessor
* instruction following an undefined instruction trap.
*
* ARMv5 adds undefined instructions in the NV space,
* even when bit 27 is set.
*/
if ((fault_instruction & (1 << 27)) != 0
&& (fault_instruction & 0xf0000000) != 0xf0000000)
coprocessor = (fault_instruction >> 8) & 0x0f;
else
coprocessor = CORE_UNKNOWN_HANDLER;
}
if (user) {
/*
* Modify the fault_code to reflect the USR/SVC state at
* time of fault.
*/
fault_code = FAULT_USER;
l->l_addr->u_pcb.pcb_tf = frame;
} else
fault_code = 0;
/* OK this is were we do something about the instruction. */
LIST_FOREACH(uh, &undefined_handlers[coprocessor], uh_link)
if (uh->uh_handler(fault_pc, fault_instruction, frame,
fault_code) == 0)
break;
if (uh == NULL) {
/* Fault has not been handled */
ksiginfo_t ksi;
#ifdef VERBOSE_ARM32
s = spltty();
if ((fault_instruction & 0x0f000010) == 0x0e000000) {
printf("CDP\n");
disassemble(fault_pc);
} else if ((fault_instruction & 0x0e000000) == 0x0c000000) {
printf("LDC/STC\n");
disassemble(fault_pc);
} else if ((fault_instruction & 0x0f000010) == 0x0e000010) {
printf("MRC/MCR\n");
disassemble(fault_pc);
} else if ((fault_instruction & ~INSN_COND_MASK)
!= (KERNEL_BREAKPOINT & ~INSN_COND_MASK)) {
printf("Undefined instruction\n");
disassemble(fault_pc);
}
splx(s);
#endif
if ((fault_code & FAULT_USER) == 0) {
#ifdef DDB
db_printf("Undefined instruction in kernel\n");
kdb_trap(T_FAULT, frame);
#else
panic("undefined instruction in kernel");
#endif
}
KSI_INIT_TRAP(&ksi);
ksi.ksi_signo = SIGILL;
ksi.ksi_code = ILL_ILLOPC;
ksi.ksi_addr = (u_int32_t *)fault_pc;
ksi.ksi_trap = fault_instruction;
trapsignal(l, &ksi);
}
if ((fault_code & FAULT_USER) == 0)
return;
#ifdef FAST_FPE
/* Optimised exit code */
{
/*
* Check for reschedule request, at the moment there is only
* 1 ast so this code should always be run
*/
if (curcpu()->ci_want_resched) {
/*
* We are being preempted.
*/
preempt();
}
/* Invoke MI userret code */
mi_userret(l);
}
#else
userret(l);
#endif
}