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/*
* BK Id: SCCS/s.traps.c 1.22 10/11/01 10:33:09 paulus
*/
/*
* linux/arch/ppc/kernel/traps.c
*
* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* Modified by Cort Dougan (cort@cs.nmt.edu)
* and Paul Mackerras (paulus@cs.anu.edu.au)
*/
/*
* This file handles the architecture-dependent parts of hardware exceptions
*/
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/ptrace.h>
#include <linux/slab.h>
#include <linux/user.h>
#include <linux/a.out.h>
#include <linux/interrupt.h>
#include <linux/config.h>
#include <linux/init.h>
#include <asm/pgtable.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/processor.h>
extern int fix_alignment(struct pt_regs *);
extern void bad_page_fault(struct pt_regs *, unsigned long, int sig);
#ifdef CONFIG_XMON
extern void xmon(struct pt_regs *regs);
extern int xmon_bpt(struct pt_regs *regs);
extern int xmon_sstep(struct pt_regs *regs);
extern int xmon_iabr_match(struct pt_regs *regs);
extern int xmon_dabr_match(struct pt_regs *regs);
extern void (*xmon_fault_handler)(struct pt_regs *regs);
#endif
#ifdef CONFIG_XMON
void (*debugger)(struct pt_regs *regs) = xmon;
int (*debugger_bpt)(struct pt_regs *regs) = xmon_bpt;
int (*debugger_sstep)(struct pt_regs *regs) = xmon_sstep;
int (*debugger_iabr_match)(struct pt_regs *regs) = xmon_iabr_match;
int (*debugger_dabr_match)(struct pt_regs *regs) = xmon_dabr_match;
void (*debugger_fault_handler)(struct pt_regs *regs);
#else
#ifdef CONFIG_KGDB
void (*debugger)(struct pt_regs *regs);
int (*debugger_bpt)(struct pt_regs *regs);
int (*debugger_sstep)(struct pt_regs *regs);
int (*debugger_iabr_match)(struct pt_regs *regs);
int (*debugger_dabr_match)(struct pt_regs *regs);
void (*debugger_fault_handler)(struct pt_regs *regs);
#endif
#endif
/*
* Trap & Exception support
*/
spinlock_t oops_lock = SPIN_LOCK_UNLOCKED;
void die(const char * str, struct pt_regs * fp, long err)
{
console_verbose();
spin_lock_irq(&oops_lock);
printk("Oops: %s, sig: %ld\n", str, err);
show_regs(fp);
spin_unlock_irq(&oops_lock);
/* do_exit() should take care of panic'ing from an interrupt
* context so we don't handle it here
*/
do_exit(err);
}
void
_exception(int signr, struct pt_regs *regs)
{
if (!user_mode(regs))
{
#if defined(CONFIG_XMON) || defined(CONFIG_KGDB)
debugger(regs);
#endif
die("Exception in kernel mode", regs, signr);
}
force_sig(signr, current);
}
void
MachineCheckException(struct pt_regs *regs)
{
#ifdef CONFIG_ALL_PPC
unsigned long fixup;
#endif /* CONFIG_ALL_PPC */
unsigned long msr = regs->msr;
if (user_mode(regs)) {
_exception(SIGSEGV, regs);
return;
}
#if defined(CONFIG_8xx) && defined(CONFIG_PCI)
/* the qspan pci read routines can cause machine checks -- Cort */
bad_page_fault(regs, regs->dar, SIGBUS);
return;
#endif
#if defined(CONFIG_XMON) || defined(CONFIG_KGDB)
if (debugger_fault_handler) {
debugger_fault_handler(regs);
return;
}
#endif
#ifdef CONFIG_ALL_PPC
/*
* I/O accesses can cause machine checks on powermacs.
* Check if the NIP corresponds to the address of a sync
* instruction for which there is an entry in the exception
* table.
* Note that the 601 only takes a machine check on TEA
* (transfer error ack) signal assertion, and does not
* set of the top 16 bits of SRR1.
* -- paulus.
*/
if (((msr & 0xffff0000) == 0 || (msr & (0x80000 | 0x40000)))
&& (fixup = search_exception_table(regs->nip)) != 0) {
/*
* Check that it's a sync instruction, or somewhere
* in the twi; isync; nop sequence that inb/inw/inl uses.
* As the address is in the exception table
* we should be able to read the instr there.
* For the debug message, we look at the preceding
* load or store.
*/
unsigned int *nip = (unsigned int *)regs->nip;
if (*nip == 0x60000000) /* nop */
nip -= 2;
else if (*nip == 0x4c00012c) /* isync */
--nip;
if (*nip == 0x7c0004ac || (*nip >> 26) == 3) {
/* sync or twi */
unsigned int rb;
--nip;
rb = (*nip >> 11) & 0x1f;
printk(KERN_DEBUG "%s bad port %lx at %p\n",
(*nip & 0x100)? "OUT to": "IN from",
regs->gpr[rb] - _IO_BASE, nip);
regs->nip = fixup;
return;
}
}
#endif /* CONFIG_ALL_PPC */
printk("Machine check in kernel mode.\n");
printk("Caused by (from SRR1=%lx): ", msr);
switch (msr & 0xF0000) {
case 0x80000:
printk("Machine check signal\n");
break;
case 0: /* for 601 */
case 0x40000:
printk("Transfer error ack signal\n");
break;
case 0x20000:
printk("Data parity error signal\n");
break;
case 0x10000:
printk("Address parity error signal\n");
break;
default:
printk("Unknown values in msr\n");
}
#if defined(CONFIG_XMON) || defined(CONFIG_KGDB)
debugger(regs);
#endif
die("machine check", regs, SIGBUS);
}
void
SMIException(struct pt_regs *regs)
{
#if defined(CONFIG_XMON) || defined(CONFIG_KGDB)
{
debugger(regs);
return;
}
#endif
show_regs(regs);
panic("System Management Interrupt");
}
void
UnknownException(struct pt_regs *regs)
{
printk("Bad trap at PC: %lx, SR: %lx, vector=%lx %s\n",
regs->nip, regs->msr, regs->trap, print_tainted());
_exception(SIGTRAP, regs);
}
void
InstructionBreakpoint(struct pt_regs *regs)
{
#if defined(CONFIG_XMON) || defined(CONFIG_KGDB)
if (debugger_iabr_match(regs))
return;
#endif
_exception(SIGTRAP, regs);
}
void
RunModeException(struct pt_regs *regs)
{
_exception(SIGTRAP, regs);
}
/* Illegal instruction emulation support. Originally written to
* provide the PVR to user applications using the mfspr rd, PVR.
* Return non-zero if we can't emulate, or EFAULT if the associated
* memory access caused an access fault. Return zero on success.
*
* There are a couple of ways to do this, either "decode" the instruction
* or directly match lots of bits. In this case, matching lots of
* bits is faster and easier.
*
*/
#define INST_MFSPR_PVR 0x7c1f42a6
#define INST_MFSPR_PVR_MASK 0xfc1fffff
static int
emulate_instruction(struct pt_regs *regs)
{
uint instword;
uint rd;
uint retval;
retval = EINVAL;
if (!user_mode(regs))
return retval;
if (get_user(instword, (uint *)(regs->nip)))
return -EFAULT;
/* Emulate the mfspr rD, PVR.
*/
if ((instword & INST_MFSPR_PVR_MASK) == INST_MFSPR_PVR) {
rd = (instword >> 21) & 0x1f;
regs->gpr[rd] = mfspr(PVR);
retval = 0;
}
if (retval == 0)
regs->nip += 4;
return(retval);
}
void
ProgramCheckException(struct pt_regs *regs)
{
#if defined(CONFIG_4xx)
unsigned int esr = mfspr(SPRN_ESR);
if (esr & ESR_PTR) {
#if defined(CONFIG_XMON) || defined(CONFIG_KGDB)
if (debugger_bpt(regs))
return;
#endif
_exception(SIGTRAP, regs);
} else {
_exception(SIGILL, regs);
}
#else
if (regs->msr & 0x100000) {
/* IEEE FP exception */
_exception(SIGFPE, regs);
} else if (regs->msr & 0x20000) {
/* trap exception */
#if defined(CONFIG_XMON) || defined(CONFIG_KGDB)
if (debugger_bpt(regs))
return;
#endif
_exception(SIGTRAP, regs);
} else {
/* Try to emulate it if we should. */
int errcode;
if ((errcode = emulate_instruction(regs))) {
if (errcode == -EFAULT)
_exception(SIGBUS, regs);
else
_exception(SIGILL, regs);
}
}
#endif
}
void
SingleStepException(struct pt_regs *regs)
{
regs->msr &= ~MSR_SE; /* Turn off 'trace' bit */
#if defined(CONFIG_XMON) || defined(CONFIG_KGDB)
if (debugger_sstep(regs))
return;
#endif
_exception(SIGTRAP, regs);
}
void
AlignmentException(struct pt_regs *regs)
{
int fixed;
fixed = fix_alignment(regs);
if (fixed == 1) {
regs->nip += 4; /* skip over emulated instruction */
return;
}
if (fixed == -EFAULT) {
/* fixed == -EFAULT means the operand address was bad */
if (user_mode(regs))
force_sig(SIGSEGV, current);
else
bad_page_fault(regs, regs->dar, SIGSEGV);
return;
}
_exception(SIGBUS, regs);
}
void
StackOverflow(struct pt_regs *regs)
{
printk(KERN_CRIT "Kernel stack overflow in process %p, r1=%lx\n",
current, regs->gpr[1]);
#if defined(CONFIG_XMON) || defined(CONFIG_KGDB)
debugger(regs);
#endif
show_regs(regs);
panic("kernel stack overflow");
}
void
trace_syscall(struct pt_regs *regs)
{
printk("Task: %p(%d), PC: %08lX/%08lX, Syscall: %3ld, Result: %s%ld %s\n",
current, current->pid, regs->nip, regs->link, regs->gpr[0],
regs->ccr&0x10000000?"Error=":"", regs->gpr[3], print_tainted());
}
#ifdef CONFIG_8xx
void
SoftwareEmulation(struct pt_regs *regs)
{
extern int do_mathemu(struct pt_regs *);
int errcode;
if (!user_mode(regs)) {
#if defined(CONFIG_XMON) || defined(CONFIG_KGDB)
debugger(regs);
#endif
die("Kernel Mode Software FPU Emulation", regs, SIGFPE);
}
#ifdef CONFIG_MATH_EMULATION
if ((errcode = do_mathemu(regs))) {
#else
if ((errcode = Soft_emulate_8xx(regs))) {
#endif
if (errcode > 0)
_exception(SIGFPE, regs);
else if (errcode == -EFAULT)
_exception(SIGSEGV, regs);
else
_exception(SIGILL, regs);
}
}
#endif
#if !defined(CONFIG_TAU_INT)
void
TAUException(struct pt_regs *regs)
{
printk("TAU trap at PC: %lx, SR: %lx, vector=%lx %s\n",
regs->nip, regs->msr, regs->trap, print_tainted());
}
#endif /* CONFIG_INT_TAU */
void __init trap_init(void)
{
}
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