linux/arch/sh/kernel/traps.c
Paul Mundt 1e1030dccb sh: nmi_debug support.
This implements support for NMI debugging that was shamelessly copied
from the avr32 port. A bit of special magic is needed in the interrupt
exception path given that the NMI exception handler is stubbed in to the
regular exception handling table despite being reported in INTEVT. So we
mangle the lookup and kick off an EXPEVT-style exception dispatch from
the INTEVT path for exceptions that do_IRQ() has no chance of handling.
As a result, we also drop the evt2irq() conversion from the do_IRQ() path
and just do it in assembly.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-09-01 17:38:32 +09:00

115 lines
2.1 KiB
C

#include <linux/bug.h>
#include <linux/io.h>
#include <linux/types.h>
#include <linux/kdebug.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/uaccess.h>
#include <linux/hardirq.h>
#include <asm/unwinder.h>
#include <asm/system.h>
#ifdef CONFIG_BUG
void handle_BUG(struct pt_regs *regs)
{
const struct bug_entry *bug;
unsigned long bugaddr = regs->pc;
enum bug_trap_type tt;
if (!is_valid_bugaddr(bugaddr))
goto invalid;
bug = find_bug(bugaddr);
/* Switch unwinders when unwind_stack() is called */
if (bug->flags & BUGFLAG_UNWINDER)
unwinder_faulted = 1;
tt = report_bug(bugaddr, regs);
if (tt == BUG_TRAP_TYPE_WARN) {
regs->pc += instruction_size(bugaddr);
return;
}
invalid:
die("Kernel BUG", regs, TRAPA_BUG_OPCODE & 0xff);
}
int is_valid_bugaddr(unsigned long addr)
{
insn_size_t opcode;
if (addr < PAGE_OFFSET)
return 0;
if (probe_kernel_address((insn_size_t *)addr, opcode))
return 0;
if (opcode == TRAPA_BUG_OPCODE)
return 1;
return 0;
}
#endif
/*
* Generic trap handler.
*/
BUILD_TRAP_HANDLER(debug)
{
TRAP_HANDLER_DECL;
/* Rewind */
regs->pc -= instruction_size(ctrl_inw(regs->pc - 4));
if (notify_die(DIE_TRAP, "debug trap", regs, 0, vec & 0xff,
SIGTRAP) == NOTIFY_STOP)
return;
force_sig(SIGTRAP, current);
}
/*
* Special handler for BUG() traps.
*/
BUILD_TRAP_HANDLER(bug)
{
TRAP_HANDLER_DECL;
/* Rewind */
regs->pc -= instruction_size(ctrl_inw(regs->pc - 4));
if (notify_die(DIE_TRAP, "bug trap", regs, 0, TRAPA_BUG_OPCODE & 0xff,
SIGTRAP) == NOTIFY_STOP)
return;
#ifdef CONFIG_BUG
if (__kernel_text_address(instruction_pointer(regs))) {
insn_size_t insn = *(insn_size_t *)instruction_pointer(regs);
if (insn == TRAPA_BUG_OPCODE)
handle_BUG(regs);
return;
}
#endif
force_sig(SIGTRAP, current);
}
BUILD_TRAP_HANDLER(nmi)
{
TRAP_HANDLER_DECL;
nmi_enter();
switch (notify_die(DIE_NMI, "NMI", regs, 0, vec & 0xff, SIGINT)) {
case NOTIFY_OK:
case NOTIFY_STOP:
break;
case NOTIFY_BAD:
die("Fatal Non-Maskable Interrupt", regs, SIGINT);
default:
printk(KERN_ALERT "Got NMI, but nobody cared. Ignoring...\n");
break;
}
nmi_exit();
}