linux/arch/microblaze/kernel/exceptions.c
Edgar E. Iglesias 15ec090833 microblaze: Raise SIGFPE/FPE_INTDIV for div by zero
It fixes the signal nr raised for divizion by zero from
SIGILL to SIGFPE, in accordance to POSIX and other archs.

This came up due to a failed test in the GCC testsuite.

Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
2011-10-14 12:24:31 +02:00

160 lines
4.2 KiB
C

/*
* HW exception handling
*
* Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
* Copyright (C) 2008 PetaLogix
*
* This file is subject to the terms and conditions of the GNU General
* Public License. See the file COPYING in the main directory of this
* archive for more details.
*/
/*
* This file handles the architecture-dependent parts of hardware exceptions
*/
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/kallsyms.h>
#include <linux/module.h>
#include <asm/exceptions.h>
#include <asm/entry.h> /* For KM CPU var */
#include <linux/uaccess.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <asm/current.h>
#include <asm/cacheflush.h>
#define MICROBLAZE_ILL_OPCODE_EXCEPTION 0x02
#define MICROBLAZE_IBUS_EXCEPTION 0x03
#define MICROBLAZE_DBUS_EXCEPTION 0x04
#define MICROBLAZE_DIV_ZERO_EXCEPTION 0x05
#define MICROBLAZE_FPU_EXCEPTION 0x06
#define MICROBLAZE_PRIVILEGED_EXCEPTION 0x07
static DEFINE_SPINLOCK(die_lock);
void die(const char *str, struct pt_regs *fp, long err)
{
console_verbose();
spin_lock_irq(&die_lock);
printk(KERN_WARNING "Oops: %s, sig: %ld\n", str, err);
show_regs(fp);
spin_unlock_irq(&die_lock);
/* do_exit() should take care of panic'ing from an interrupt
* context so we don't handle it here
*/
do_exit(err);
}
/* for user application debugging */
asmlinkage void sw_exception(struct pt_regs *regs)
{
_exception(SIGTRAP, regs, TRAP_BRKPT, regs->r16);
flush_dcache_range(regs->r16, regs->r16 + 0x4);
flush_icache_range(regs->r16, regs->r16 + 0x4);
}
void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
{
siginfo_t info;
if (kernel_mode(regs)) {
die("Exception in kernel mode", regs, signr);
}
info.si_signo = signr;
info.si_errno = 0;
info.si_code = code;
info.si_addr = (void __user *) addr;
force_sig_info(signr, &info, current);
}
asmlinkage void full_exception(struct pt_regs *regs, unsigned int type,
int fsr, int addr)
{
#ifdef CONFIG_MMU
addr = regs->pc;
#endif
#if 0
printk(KERN_WARNING "Exception %02x in %s mode, FSR=%08x PC=%08x " \
"ESR=%08x\n",
type, user_mode(regs) ? "user" : "kernel", fsr,
(unsigned int) regs->pc, (unsigned int) regs->esr);
#endif
switch (type & 0x1F) {
case MICROBLAZE_ILL_OPCODE_EXCEPTION:
if (user_mode(regs)) {
pr_debug("Illegal opcode exception in user mode\n");
_exception(SIGILL, regs, ILL_ILLOPC, addr);
return;
}
printk(KERN_WARNING "Illegal opcode exception " \
"in kernel mode.\n");
die("opcode exception", regs, SIGBUS);
break;
case MICROBLAZE_IBUS_EXCEPTION:
if (user_mode(regs)) {
pr_debug("Instruction bus error exception in user mode\n");
_exception(SIGBUS, regs, BUS_ADRERR, addr);
return;
}
printk(KERN_WARNING "Instruction bus error exception " \
"in kernel mode.\n");
die("bus exception", regs, SIGBUS);
break;
case MICROBLAZE_DBUS_EXCEPTION:
if (user_mode(regs)) {
pr_debug("Data bus error exception in user mode\n");
_exception(SIGBUS, regs, BUS_ADRERR, addr);
return;
}
printk(KERN_WARNING "Data bus error exception " \
"in kernel mode.\n");
die("bus exception", regs, SIGBUS);
break;
case MICROBLAZE_DIV_ZERO_EXCEPTION:
if (user_mode(regs)) {
pr_debug("Divide by zero exception in user mode\n");
_exception(SIGFPE, regs, FPE_INTDIV, addr);
return;
}
printk(KERN_WARNING "Divide by zero exception " \
"in kernel mode.\n");
die("Divide by zero exception", regs, SIGBUS);
break;
case MICROBLAZE_FPU_EXCEPTION:
pr_debug("FPU exception\n");
/* IEEE FP exception */
/* I removed fsr variable and use code var for storing fsr */
if (fsr & FSR_IO)
fsr = FPE_FLTINV;
else if (fsr & FSR_OF)
fsr = FPE_FLTOVF;
else if (fsr & FSR_UF)
fsr = FPE_FLTUND;
else if (fsr & FSR_DZ)
fsr = FPE_FLTDIV;
else if (fsr & FSR_DO)
fsr = FPE_FLTRES;
_exception(SIGFPE, regs, fsr, addr);
break;
#ifdef CONFIG_MMU
case MICROBLAZE_PRIVILEGED_EXCEPTION:
pr_debug("Privileged exception\n");
_exception(SIGILL, regs, ILL_PRVOPC, addr);
break;
#endif
default:
/* FIXME what to do in unexpected exception */
printk(KERN_WARNING "Unexpected exception %02x "
"PC=%08x in %s mode\n", type, (unsigned int) addr,
kernel_mode(regs) ? "kernel" : "user");
}
return;
}