daeeafecf0
Calling a notifier three times in the debug handler does not make much sense,
because a debugger can figure out the various conditions by itself. Remove
the additional calls to DIE_DEBUG and DIE_DEBUGSTEP completely.
This matches what i386 does now.
This also makes sure interrupts are always still disabled when calling a
debugger, which prevents:
BUG: using smp_processor_id() in preemptible [00000001] code: tpopf/1470
caller is post_kprobe_handler+0x9/0x70
Call Trace:<ffffffff8024f10f>{smp_processor_id+191} <ffffffff80120e69>{post_kpro
be_handler+9}
<ffffffff80120f7a>{kprobe_exceptions_notify+58}
<ffffffff80144fc0>{notifier_call_chain+32} <ffffffff80110daf>{do_debug+335}
<ffffffff8010f513>{debug+127} <EOE>
on preemptible debug kernels with kprobes when single stepping in user space.
This was probably a bug even on non preempt kernels, this function was
supposed to be running with interrupts off according to a comment there.
Note to third part debugger maintainers: please double check your debugger can
still single step.
Cc: <prasanna@in.ibm.com>
Cc: <jbeulich@novell.com>
Cc: <kaos@sgi.com>
Cc: <jim.houston@ccur.com>
Cc: <jfv@bluesong.net>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
942 lines
24 KiB
C
942 lines
24 KiB
C
/*
|
|
* linux/arch/x86-64/traps.c
|
|
*
|
|
* Copyright (C) 1991, 1992 Linus Torvalds
|
|
* Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
|
|
*
|
|
* Pentium III FXSR, SSE support
|
|
* Gareth Hughes <gareth@valinux.com>, May 2000
|
|
*
|
|
* $Id: traps.c,v 1.36 2002/03/24 11:09:10 ak Exp $
|
|
*/
|
|
|
|
/*
|
|
* 'Traps.c' handles hardware traps and faults after we have saved some
|
|
* state in 'entry.S'.
|
|
*/
|
|
#include <linux/config.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/string.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/ptrace.h>
|
|
#include <linux/timer.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/init.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/module.h>
|
|
#include <linux/moduleparam.h>
|
|
#include <linux/nmi.h>
|
|
|
|
#include <asm/system.h>
|
|
#include <asm/uaccess.h>
|
|
#include <asm/io.h>
|
|
#include <asm/atomic.h>
|
|
#include <asm/debugreg.h>
|
|
#include <asm/desc.h>
|
|
#include <asm/i387.h>
|
|
#include <asm/kdebug.h>
|
|
#include <asm/processor.h>
|
|
|
|
#include <asm/smp.h>
|
|
#include <asm/pgalloc.h>
|
|
#include <asm/pda.h>
|
|
#include <asm/proto.h>
|
|
#include <asm/nmi.h>
|
|
|
|
#include <linux/irq.h>
|
|
|
|
|
|
extern struct gate_struct idt_table[256];
|
|
|
|
asmlinkage void divide_error(void);
|
|
asmlinkage void debug(void);
|
|
asmlinkage void nmi(void);
|
|
asmlinkage void int3(void);
|
|
asmlinkage void overflow(void);
|
|
asmlinkage void bounds(void);
|
|
asmlinkage void invalid_op(void);
|
|
asmlinkage void device_not_available(void);
|
|
asmlinkage void double_fault(void);
|
|
asmlinkage void coprocessor_segment_overrun(void);
|
|
asmlinkage void invalid_TSS(void);
|
|
asmlinkage void segment_not_present(void);
|
|
asmlinkage void stack_segment(void);
|
|
asmlinkage void general_protection(void);
|
|
asmlinkage void page_fault(void);
|
|
asmlinkage void coprocessor_error(void);
|
|
asmlinkage void simd_coprocessor_error(void);
|
|
asmlinkage void reserved(void);
|
|
asmlinkage void alignment_check(void);
|
|
asmlinkage void machine_check(void);
|
|
asmlinkage void spurious_interrupt_bug(void);
|
|
asmlinkage void call_debug(void);
|
|
|
|
struct notifier_block *die_chain;
|
|
static DEFINE_SPINLOCK(die_notifier_lock);
|
|
|
|
int register_die_notifier(struct notifier_block *nb)
|
|
{
|
|
int err = 0;
|
|
unsigned long flags;
|
|
spin_lock_irqsave(&die_notifier_lock, flags);
|
|
err = notifier_chain_register(&die_chain, nb);
|
|
spin_unlock_irqrestore(&die_notifier_lock, flags);
|
|
return err;
|
|
}
|
|
|
|
static inline void conditional_sti(struct pt_regs *regs)
|
|
{
|
|
if (regs->eflags & X86_EFLAGS_IF)
|
|
local_irq_enable();
|
|
}
|
|
|
|
static int kstack_depth_to_print = 10;
|
|
|
|
#ifdef CONFIG_KALLSYMS
|
|
#include <linux/kallsyms.h>
|
|
int printk_address(unsigned long address)
|
|
{
|
|
unsigned long offset = 0, symsize;
|
|
const char *symname;
|
|
char *modname;
|
|
char *delim = ":";
|
|
char namebuf[128];
|
|
|
|
symname = kallsyms_lookup(address, &symsize, &offset, &modname, namebuf);
|
|
if (!symname)
|
|
return printk("[<%016lx>]", address);
|
|
if (!modname)
|
|
modname = delim = "";
|
|
return printk("<%016lx>{%s%s%s%s%+ld}",
|
|
address,delim,modname,delim,symname,offset);
|
|
}
|
|
#else
|
|
int printk_address(unsigned long address)
|
|
{
|
|
return printk("[<%016lx>]", address);
|
|
}
|
|
#endif
|
|
|
|
unsigned long *in_exception_stack(int cpu, unsigned long stack)
|
|
{
|
|
int k;
|
|
for (k = 0; k < N_EXCEPTION_STACKS; k++) {
|
|
struct tss_struct *tss = &per_cpu(init_tss, cpu);
|
|
unsigned long start = tss->ist[k] - EXCEPTION_STKSZ;
|
|
|
|
if (stack >= start && stack < tss->ist[k])
|
|
return (unsigned long *)tss->ist[k];
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* x86-64 can have upto three kernel stacks:
|
|
* process stack
|
|
* interrupt stack
|
|
* severe exception (double fault, nmi, stack fault) hardware stack
|
|
* Check and process them in order.
|
|
*/
|
|
|
|
void show_trace(unsigned long *stack)
|
|
{
|
|
unsigned long addr;
|
|
unsigned long *irqstack, *irqstack_end, *estack_end;
|
|
const int cpu = safe_smp_processor_id();
|
|
int i;
|
|
|
|
printk("\nCall Trace:");
|
|
i = 0;
|
|
|
|
estack_end = in_exception_stack(cpu, (unsigned long)stack);
|
|
if (estack_end) {
|
|
while (stack < estack_end) {
|
|
addr = *stack++;
|
|
if (__kernel_text_address(addr)) {
|
|
i += printk_address(addr);
|
|
i += printk(" ");
|
|
if (i > 50) {
|
|
printk("\n");
|
|
i = 0;
|
|
}
|
|
}
|
|
}
|
|
i += printk(" <EOE> ");
|
|
i += 7;
|
|
stack = (unsigned long *) estack_end[-2];
|
|
}
|
|
|
|
irqstack_end = (unsigned long *) (cpu_pda[cpu].irqstackptr);
|
|
irqstack = (unsigned long *) (cpu_pda[cpu].irqstackptr - IRQSTACKSIZE + 64);
|
|
|
|
if (stack >= irqstack && stack < irqstack_end) {
|
|
printk("<IRQ> ");
|
|
while (stack < irqstack_end) {
|
|
addr = *stack++;
|
|
/*
|
|
* If the address is either in the text segment of the
|
|
* kernel, or in the region which contains vmalloc'ed
|
|
* memory, it *may* be the address of a calling
|
|
* routine; if so, print it so that someone tracing
|
|
* down the cause of the crash will be able to figure
|
|
* out the call path that was taken.
|
|
*/
|
|
if (__kernel_text_address(addr)) {
|
|
i += printk_address(addr);
|
|
i += printk(" ");
|
|
if (i > 50) {
|
|
printk("\n ");
|
|
i = 0;
|
|
}
|
|
}
|
|
}
|
|
stack = (unsigned long *) (irqstack_end[-1]);
|
|
printk(" <EOI> ");
|
|
i += 7;
|
|
}
|
|
|
|
while (((long) stack & (THREAD_SIZE-1)) != 0) {
|
|
addr = *stack++;
|
|
if (__kernel_text_address(addr)) {
|
|
i += printk_address(addr);
|
|
i += printk(" ");
|
|
if (i > 50) {
|
|
printk("\n ");
|
|
i = 0;
|
|
}
|
|
}
|
|
}
|
|
printk("\n");
|
|
}
|
|
|
|
void show_stack(struct task_struct *tsk, unsigned long * rsp)
|
|
{
|
|
unsigned long *stack;
|
|
int i;
|
|
const int cpu = safe_smp_processor_id();
|
|
unsigned long *irqstack_end = (unsigned long *) (cpu_pda[cpu].irqstackptr);
|
|
unsigned long *irqstack = (unsigned long *) (cpu_pda[cpu].irqstackptr - IRQSTACKSIZE);
|
|
|
|
// debugging aid: "show_stack(NULL, NULL);" prints the
|
|
// back trace for this cpu.
|
|
|
|
if (rsp == NULL) {
|
|
if (tsk)
|
|
rsp = (unsigned long *)tsk->thread.rsp;
|
|
else
|
|
rsp = (unsigned long *)&rsp;
|
|
}
|
|
|
|
stack = rsp;
|
|
for(i=0; i < kstack_depth_to_print; i++) {
|
|
if (stack >= irqstack && stack <= irqstack_end) {
|
|
if (stack == irqstack_end) {
|
|
stack = (unsigned long *) (irqstack_end[-1]);
|
|
printk(" <EOI> ");
|
|
}
|
|
} else {
|
|
if (((long) stack & (THREAD_SIZE-1)) == 0)
|
|
break;
|
|
}
|
|
if (i && ((i % 4) == 0))
|
|
printk("\n ");
|
|
printk("%016lx ", *stack++);
|
|
touch_nmi_watchdog();
|
|
}
|
|
show_trace((unsigned long *)rsp);
|
|
}
|
|
|
|
/*
|
|
* The architecture-independent dump_stack generator
|
|
*/
|
|
void dump_stack(void)
|
|
{
|
|
unsigned long dummy;
|
|
show_trace(&dummy);
|
|
}
|
|
|
|
EXPORT_SYMBOL(dump_stack);
|
|
|
|
void show_registers(struct pt_regs *regs)
|
|
{
|
|
int i;
|
|
int in_kernel = (regs->cs & 3) == 0;
|
|
unsigned long rsp;
|
|
const int cpu = safe_smp_processor_id();
|
|
struct task_struct *cur = cpu_pda[cpu].pcurrent;
|
|
|
|
rsp = regs->rsp;
|
|
|
|
printk("CPU %d ", cpu);
|
|
__show_regs(regs);
|
|
printk("Process %s (pid: %d, threadinfo %p, task %p)\n",
|
|
cur->comm, cur->pid, cur->thread_info, cur);
|
|
|
|
/*
|
|
* When in-kernel, we also print out the stack and code at the
|
|
* time of the fault..
|
|
*/
|
|
if (in_kernel) {
|
|
|
|
printk("Stack: ");
|
|
show_stack(NULL, (unsigned long*)rsp);
|
|
|
|
printk("\nCode: ");
|
|
if(regs->rip < PAGE_OFFSET)
|
|
goto bad;
|
|
|
|
for(i=0;i<20;i++)
|
|
{
|
|
unsigned char c;
|
|
if(__get_user(c, &((unsigned char*)regs->rip)[i])) {
|
|
bad:
|
|
printk(" Bad RIP value.");
|
|
break;
|
|
}
|
|
printk("%02x ", c);
|
|
}
|
|
}
|
|
printk("\n");
|
|
}
|
|
|
|
void handle_BUG(struct pt_regs *regs)
|
|
{
|
|
struct bug_frame f;
|
|
char tmp;
|
|
|
|
if (regs->cs & 3)
|
|
return;
|
|
if (__copy_from_user(&f, (struct bug_frame *) regs->rip,
|
|
sizeof(struct bug_frame)))
|
|
return;
|
|
if ((unsigned long)f.filename < __PAGE_OFFSET ||
|
|
f.ud2[0] != 0x0f || f.ud2[1] != 0x0b)
|
|
return;
|
|
if (__get_user(tmp, f.filename))
|
|
f.filename = "unmapped filename";
|
|
printk("----------- [cut here ] --------- [please bite here ] ---------\n");
|
|
printk(KERN_ALERT "Kernel BUG at %.50s:%d\n", f.filename, f.line);
|
|
}
|
|
|
|
void out_of_line_bug(void)
|
|
{
|
|
BUG();
|
|
}
|
|
|
|
static DEFINE_SPINLOCK(die_lock);
|
|
static int die_owner = -1;
|
|
|
|
void oops_begin(void)
|
|
{
|
|
int cpu = safe_smp_processor_id();
|
|
/* racy, but better than risking deadlock. */
|
|
local_irq_disable();
|
|
if (!spin_trylock(&die_lock)) {
|
|
if (cpu == die_owner)
|
|
/* nested oops. should stop eventually */;
|
|
else
|
|
spin_lock(&die_lock);
|
|
}
|
|
die_owner = cpu;
|
|
console_verbose();
|
|
bust_spinlocks(1);
|
|
}
|
|
|
|
void oops_end(void)
|
|
{
|
|
die_owner = -1;
|
|
bust_spinlocks(0);
|
|
spin_unlock(&die_lock);
|
|
if (panic_on_oops)
|
|
panic("Oops");
|
|
}
|
|
|
|
void __die(const char * str, struct pt_regs * regs, long err)
|
|
{
|
|
static int die_counter;
|
|
printk(KERN_EMERG "%s: %04lx [%u] ", str, err & 0xffff,++die_counter);
|
|
#ifdef CONFIG_PREEMPT
|
|
printk("PREEMPT ");
|
|
#endif
|
|
#ifdef CONFIG_SMP
|
|
printk("SMP ");
|
|
#endif
|
|
#ifdef CONFIG_DEBUG_PAGEALLOC
|
|
printk("DEBUG_PAGEALLOC");
|
|
#endif
|
|
printk("\n");
|
|
notify_die(DIE_OOPS, (char *)str, regs, err, 255, SIGSEGV);
|
|
show_registers(regs);
|
|
/* Executive summary in case the oops scrolled away */
|
|
printk(KERN_ALERT "RIP ");
|
|
printk_address(regs->rip);
|
|
printk(" RSP <%016lx>\n", regs->rsp);
|
|
}
|
|
|
|
void die(const char * str, struct pt_regs * regs, long err)
|
|
{
|
|
oops_begin();
|
|
handle_BUG(regs);
|
|
__die(str, regs, err);
|
|
oops_end();
|
|
do_exit(SIGSEGV);
|
|
}
|
|
static inline void die_if_kernel(const char * str, struct pt_regs * regs, long err)
|
|
{
|
|
if (!(regs->eflags & VM_MASK) && (regs->cs == __KERNEL_CS))
|
|
die(str, regs, err);
|
|
}
|
|
|
|
void die_nmi(char *str, struct pt_regs *regs)
|
|
{
|
|
oops_begin();
|
|
/*
|
|
* We are in trouble anyway, lets at least try
|
|
* to get a message out.
|
|
*/
|
|
printk(str, safe_smp_processor_id());
|
|
show_registers(regs);
|
|
if (panic_on_timeout || panic_on_oops)
|
|
panic("nmi watchdog");
|
|
printk("console shuts up ...\n");
|
|
oops_end();
|
|
do_exit(SIGSEGV);
|
|
}
|
|
|
|
static void do_trap(int trapnr, int signr, char *str,
|
|
struct pt_regs * regs, long error_code, siginfo_t *info)
|
|
{
|
|
conditional_sti(regs);
|
|
|
|
#ifdef CONFIG_CHECKING
|
|
{
|
|
unsigned long gs;
|
|
struct x8664_pda *pda = cpu_pda + safe_smp_processor_id();
|
|
rdmsrl(MSR_GS_BASE, gs);
|
|
if (gs != (unsigned long)pda) {
|
|
wrmsrl(MSR_GS_BASE, pda);
|
|
printk("%s: wrong gs %lx expected %p rip %lx\n", str, gs, pda,
|
|
regs->rip);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
if ((regs->cs & 3) != 0) {
|
|
struct task_struct *tsk = current;
|
|
|
|
if (exception_trace && unhandled_signal(tsk, signr))
|
|
printk(KERN_INFO
|
|
"%s[%d] trap %s rip:%lx rsp:%lx error:%lx\n",
|
|
tsk->comm, tsk->pid, str,
|
|
regs->rip,regs->rsp,error_code);
|
|
|
|
tsk->thread.error_code = error_code;
|
|
tsk->thread.trap_no = trapnr;
|
|
if (info)
|
|
force_sig_info(signr, info, tsk);
|
|
else
|
|
force_sig(signr, tsk);
|
|
return;
|
|
}
|
|
|
|
|
|
/* kernel trap */
|
|
{
|
|
const struct exception_table_entry *fixup;
|
|
fixup = search_exception_tables(regs->rip);
|
|
if (fixup) {
|
|
regs->rip = fixup->fixup;
|
|
} else
|
|
die(str, regs, error_code);
|
|
return;
|
|
}
|
|
}
|
|
|
|
#define DO_ERROR(trapnr, signr, str, name) \
|
|
asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
|
|
{ \
|
|
if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
|
|
== NOTIFY_STOP) \
|
|
return; \
|
|
do_trap(trapnr, signr, str, regs, error_code, NULL); \
|
|
}
|
|
|
|
#define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
|
|
asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
|
|
{ \
|
|
siginfo_t info; \
|
|
info.si_signo = signr; \
|
|
info.si_errno = 0; \
|
|
info.si_code = sicode; \
|
|
info.si_addr = (void __user *)siaddr; \
|
|
if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
|
|
== NOTIFY_STOP) \
|
|
return; \
|
|
do_trap(trapnr, signr, str, regs, error_code, &info); \
|
|
}
|
|
|
|
DO_ERROR_INFO( 0, SIGFPE, "divide error", divide_error, FPE_INTDIV, regs->rip)
|
|
DO_ERROR( 4, SIGSEGV, "overflow", overflow)
|
|
DO_ERROR( 5, SIGSEGV, "bounds", bounds)
|
|
DO_ERROR_INFO( 6, SIGILL, "invalid operand", invalid_op, ILL_ILLOPN, regs->rip)
|
|
DO_ERROR( 7, SIGSEGV, "device not available", device_not_available)
|
|
DO_ERROR( 9, SIGFPE, "coprocessor segment overrun", coprocessor_segment_overrun)
|
|
DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS)
|
|
DO_ERROR(11, SIGBUS, "segment not present", segment_not_present)
|
|
DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0)
|
|
DO_ERROR(18, SIGSEGV, "reserved", reserved)
|
|
DO_ERROR(12, SIGBUS, "stack segment", stack_segment)
|
|
DO_ERROR( 8, SIGSEGV, "double fault", double_fault)
|
|
|
|
asmlinkage void do_general_protection(struct pt_regs * regs, long error_code)
|
|
{
|
|
conditional_sti(regs);
|
|
|
|
#ifdef CONFIG_CHECKING
|
|
{
|
|
unsigned long gs;
|
|
struct x8664_pda *pda = cpu_pda + safe_smp_processor_id();
|
|
rdmsrl(MSR_GS_BASE, gs);
|
|
if (gs != (unsigned long)pda) {
|
|
wrmsrl(MSR_GS_BASE, pda);
|
|
oops_in_progress++;
|
|
printk("general protection handler: wrong gs %lx expected %p\n", gs, pda);
|
|
oops_in_progress--;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
if ((regs->cs & 3)!=0) {
|
|
struct task_struct *tsk = current;
|
|
|
|
if (exception_trace && unhandled_signal(tsk, SIGSEGV))
|
|
printk(KERN_INFO
|
|
"%s[%d] general protection rip:%lx rsp:%lx error:%lx\n",
|
|
tsk->comm, tsk->pid,
|
|
regs->rip,regs->rsp,error_code);
|
|
|
|
tsk->thread.error_code = error_code;
|
|
tsk->thread.trap_no = 13;
|
|
force_sig(SIGSEGV, tsk);
|
|
return;
|
|
}
|
|
|
|
/* kernel gp */
|
|
{
|
|
const struct exception_table_entry *fixup;
|
|
fixup = search_exception_tables(regs->rip);
|
|
if (fixup) {
|
|
regs->rip = fixup->fixup;
|
|
return;
|
|
}
|
|
if (notify_die(DIE_GPF, "general protection fault", regs,
|
|
error_code, 13, SIGSEGV) == NOTIFY_STOP)
|
|
return;
|
|
die("general protection fault", regs, error_code);
|
|
}
|
|
}
|
|
|
|
static void mem_parity_error(unsigned char reason, struct pt_regs * regs)
|
|
{
|
|
printk("Uhhuh. NMI received. Dazed and confused, but trying to continue\n");
|
|
printk("You probably have a hardware problem with your RAM chips\n");
|
|
|
|
/* Clear and disable the memory parity error line. */
|
|
reason = (reason & 0xf) | 4;
|
|
outb(reason, 0x61);
|
|
}
|
|
|
|
static void io_check_error(unsigned char reason, struct pt_regs * regs)
|
|
{
|
|
printk("NMI: IOCK error (debug interrupt?)\n");
|
|
show_registers(regs);
|
|
|
|
/* Re-enable the IOCK line, wait for a few seconds */
|
|
reason = (reason & 0xf) | 8;
|
|
outb(reason, 0x61);
|
|
mdelay(2000);
|
|
reason &= ~8;
|
|
outb(reason, 0x61);
|
|
}
|
|
|
|
static void unknown_nmi_error(unsigned char reason, struct pt_regs * regs)
|
|
{ printk("Uhhuh. NMI received for unknown reason %02x.\n", reason);
|
|
printk("Dazed and confused, but trying to continue\n");
|
|
printk("Do you have a strange power saving mode enabled?\n");
|
|
}
|
|
|
|
/* Runs on IST stack. This code must keep interrupts off all the time.
|
|
Nested NMIs are prevented by the CPU. */
|
|
asmlinkage void default_do_nmi(struct pt_regs *regs)
|
|
{
|
|
unsigned char reason = 0;
|
|
|
|
/* Only the BSP gets external NMIs from the system. */
|
|
if (!smp_processor_id())
|
|
reason = get_nmi_reason();
|
|
|
|
if (!(reason & 0xc0)) {
|
|
if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 0, SIGINT)
|
|
== NOTIFY_STOP)
|
|
return;
|
|
#ifdef CONFIG_X86_LOCAL_APIC
|
|
/*
|
|
* Ok, so this is none of the documented NMI sources,
|
|
* so it must be the NMI watchdog.
|
|
*/
|
|
if (nmi_watchdog > 0) {
|
|
nmi_watchdog_tick(regs,reason);
|
|
return;
|
|
}
|
|
#endif
|
|
unknown_nmi_error(reason, regs);
|
|
return;
|
|
}
|
|
if (notify_die(DIE_NMI, "nmi", regs, reason, 0, SIGINT) == NOTIFY_STOP)
|
|
return;
|
|
|
|
/* AK: following checks seem to be broken on modern chipsets. FIXME */
|
|
|
|
if (reason & 0x80)
|
|
mem_parity_error(reason, regs);
|
|
if (reason & 0x40)
|
|
io_check_error(reason, regs);
|
|
}
|
|
|
|
asmlinkage void do_int3(struct pt_regs * regs, long error_code)
|
|
{
|
|
if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) == NOTIFY_STOP) {
|
|
return;
|
|
}
|
|
do_trap(3, SIGTRAP, "int3", regs, error_code, NULL);
|
|
return;
|
|
}
|
|
|
|
/* Help handler running on IST stack to switch back to user stack
|
|
for scheduling or signal handling. The actual stack switch is done in
|
|
entry.S */
|
|
asmlinkage struct pt_regs *sync_regs(struct pt_regs *eregs)
|
|
{
|
|
struct pt_regs *regs = eregs;
|
|
/* Did already sync */
|
|
if (eregs == (struct pt_regs *)eregs->rsp)
|
|
;
|
|
/* Exception from user space */
|
|
else if (eregs->cs & 3)
|
|
regs = ((struct pt_regs *)current->thread.rsp0) - 1;
|
|
/* Exception from kernel and interrupts are enabled. Move to
|
|
kernel process stack. */
|
|
else if (eregs->eflags & X86_EFLAGS_IF)
|
|
regs = (struct pt_regs *)(eregs->rsp -= sizeof(struct pt_regs));
|
|
if (eregs != regs)
|
|
*regs = *eregs;
|
|
return regs;
|
|
}
|
|
|
|
/* runs on IST stack. */
|
|
asmlinkage void do_debug(struct pt_regs * regs, unsigned long error_code)
|
|
{
|
|
unsigned long condition;
|
|
struct task_struct *tsk = current;
|
|
siginfo_t info;
|
|
|
|
#ifdef CONFIG_CHECKING
|
|
{
|
|
/* RED-PEN interaction with debugger - could destroy gs */
|
|
unsigned long gs;
|
|
struct x8664_pda *pda = cpu_pda + safe_smp_processor_id();
|
|
rdmsrl(MSR_GS_BASE, gs);
|
|
if (gs != (unsigned long)pda) {
|
|
wrmsrl(MSR_GS_BASE, pda);
|
|
printk("debug handler: wrong gs %lx expected %p\n", gs, pda);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
asm("movq %%db6,%0" : "=r" (condition));
|
|
|
|
if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
|
|
SIGTRAP) == NOTIFY_STOP)
|
|
return;
|
|
|
|
conditional_sti(regs);
|
|
|
|
/* Mask out spurious debug traps due to lazy DR7 setting */
|
|
if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) {
|
|
if (!tsk->thread.debugreg7) {
|
|
goto clear_dr7;
|
|
}
|
|
}
|
|
|
|
tsk->thread.debugreg6 = condition;
|
|
|
|
/* Mask out spurious TF errors due to lazy TF clearing */
|
|
if (condition & DR_STEP) {
|
|
/*
|
|
* The TF error should be masked out only if the current
|
|
* process is not traced and if the TRAP flag has been set
|
|
* previously by a tracing process (condition detected by
|
|
* the PT_DTRACE flag); remember that the i386 TRAP flag
|
|
* can be modified by the process itself in user mode,
|
|
* allowing programs to debug themselves without the ptrace()
|
|
* interface.
|
|
*/
|
|
if ((regs->cs & 3) == 0)
|
|
goto clear_TF_reenable;
|
|
/*
|
|
* Was the TF flag set by a debugger? If so, clear it now,
|
|
* so that register information is correct.
|
|
*/
|
|
if (tsk->ptrace & PT_DTRACE) {
|
|
regs->eflags &= ~TF_MASK;
|
|
tsk->ptrace &= ~PT_DTRACE;
|
|
}
|
|
}
|
|
|
|
/* Ok, finally something we can handle */
|
|
tsk->thread.trap_no = 1;
|
|
tsk->thread.error_code = error_code;
|
|
info.si_signo = SIGTRAP;
|
|
info.si_errno = 0;
|
|
info.si_code = TRAP_BRKPT;
|
|
if ((regs->cs & 3) == 0)
|
|
goto clear_dr7;
|
|
|
|
info.si_addr = (void __user *)regs->rip;
|
|
force_sig_info(SIGTRAP, &info, tsk);
|
|
clear_dr7:
|
|
asm volatile("movq %0,%%db7"::"r"(0UL));
|
|
return;
|
|
|
|
clear_TF_reenable:
|
|
set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
|
|
regs->eflags &= ~TF_MASK;
|
|
}
|
|
|
|
static int kernel_math_error(struct pt_regs *regs, char *str)
|
|
{
|
|
const struct exception_table_entry *fixup;
|
|
fixup = search_exception_tables(regs->rip);
|
|
if (fixup) {
|
|
regs->rip = fixup->fixup;
|
|
return 1;
|
|
}
|
|
notify_die(DIE_GPF, str, regs, 0, 16, SIGFPE);
|
|
/* Illegal floating point operation in the kernel */
|
|
die(str, regs, 0);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Note that we play around with the 'TS' bit in an attempt to get
|
|
* the correct behaviour even in the presence of the asynchronous
|
|
* IRQ13 behaviour
|
|
*/
|
|
asmlinkage void do_coprocessor_error(struct pt_regs *regs)
|
|
{
|
|
void __user *rip = (void __user *)(regs->rip);
|
|
struct task_struct * task;
|
|
siginfo_t info;
|
|
unsigned short cwd, swd;
|
|
|
|
conditional_sti(regs);
|
|
if ((regs->cs & 3) == 0 &&
|
|
kernel_math_error(regs, "kernel x87 math error"))
|
|
return;
|
|
|
|
/*
|
|
* Save the info for the exception handler and clear the error.
|
|
*/
|
|
task = current;
|
|
save_init_fpu(task);
|
|
task->thread.trap_no = 16;
|
|
task->thread.error_code = 0;
|
|
info.si_signo = SIGFPE;
|
|
info.si_errno = 0;
|
|
info.si_code = __SI_FAULT;
|
|
info.si_addr = rip;
|
|
/*
|
|
* (~cwd & swd) will mask out exceptions that are not set to unmasked
|
|
* status. 0x3f is the exception bits in these regs, 0x200 is the
|
|
* C1 reg you need in case of a stack fault, 0x040 is the stack
|
|
* fault bit. We should only be taking one exception at a time,
|
|
* so if this combination doesn't produce any single exception,
|
|
* then we have a bad program that isn't synchronizing its FPU usage
|
|
* and it will suffer the consequences since we won't be able to
|
|
* fully reproduce the context of the exception
|
|
*/
|
|
cwd = get_fpu_cwd(task);
|
|
swd = get_fpu_swd(task);
|
|
switch (((~cwd) & swd & 0x3f) | (swd & 0x240)) {
|
|
case 0x000:
|
|
default:
|
|
break;
|
|
case 0x001: /* Invalid Op */
|
|
case 0x041: /* Stack Fault */
|
|
case 0x241: /* Stack Fault | Direction */
|
|
info.si_code = FPE_FLTINV;
|
|
break;
|
|
case 0x002: /* Denormalize */
|
|
case 0x010: /* Underflow */
|
|
info.si_code = FPE_FLTUND;
|
|
break;
|
|
case 0x004: /* Zero Divide */
|
|
info.si_code = FPE_FLTDIV;
|
|
break;
|
|
case 0x008: /* Overflow */
|
|
info.si_code = FPE_FLTOVF;
|
|
break;
|
|
case 0x020: /* Precision */
|
|
info.si_code = FPE_FLTRES;
|
|
break;
|
|
}
|
|
force_sig_info(SIGFPE, &info, task);
|
|
}
|
|
|
|
asmlinkage void bad_intr(void)
|
|
{
|
|
printk("bad interrupt");
|
|
}
|
|
|
|
asmlinkage void do_simd_coprocessor_error(struct pt_regs *regs)
|
|
{
|
|
void __user *rip = (void __user *)(regs->rip);
|
|
struct task_struct * task;
|
|
siginfo_t info;
|
|
unsigned short mxcsr;
|
|
|
|
conditional_sti(regs);
|
|
if ((regs->cs & 3) == 0 &&
|
|
kernel_math_error(regs, "kernel simd math error"))
|
|
return;
|
|
|
|
/*
|
|
* Save the info for the exception handler and clear the error.
|
|
*/
|
|
task = current;
|
|
save_init_fpu(task);
|
|
task->thread.trap_no = 19;
|
|
task->thread.error_code = 0;
|
|
info.si_signo = SIGFPE;
|
|
info.si_errno = 0;
|
|
info.si_code = __SI_FAULT;
|
|
info.si_addr = rip;
|
|
/*
|
|
* The SIMD FPU exceptions are handled a little differently, as there
|
|
* is only a single status/control register. Thus, to determine which
|
|
* unmasked exception was caught we must mask the exception mask bits
|
|
* at 0x1f80, and then use these to mask the exception bits at 0x3f.
|
|
*/
|
|
mxcsr = get_fpu_mxcsr(task);
|
|
switch (~((mxcsr & 0x1f80) >> 7) & (mxcsr & 0x3f)) {
|
|
case 0x000:
|
|
default:
|
|
break;
|
|
case 0x001: /* Invalid Op */
|
|
info.si_code = FPE_FLTINV;
|
|
break;
|
|
case 0x002: /* Denormalize */
|
|
case 0x010: /* Underflow */
|
|
info.si_code = FPE_FLTUND;
|
|
break;
|
|
case 0x004: /* Zero Divide */
|
|
info.si_code = FPE_FLTDIV;
|
|
break;
|
|
case 0x008: /* Overflow */
|
|
info.si_code = FPE_FLTOVF;
|
|
break;
|
|
case 0x020: /* Precision */
|
|
info.si_code = FPE_FLTRES;
|
|
break;
|
|
}
|
|
force_sig_info(SIGFPE, &info, task);
|
|
}
|
|
|
|
asmlinkage void do_spurious_interrupt_bug(struct pt_regs * regs)
|
|
{
|
|
}
|
|
|
|
asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void)
|
|
{
|
|
}
|
|
|
|
/*
|
|
* 'math_state_restore()' saves the current math information in the
|
|
* old math state array, and gets the new ones from the current task
|
|
*
|
|
* Careful.. There are problems with IBM-designed IRQ13 behaviour.
|
|
* Don't touch unless you *really* know how it works.
|
|
*/
|
|
asmlinkage void math_state_restore(void)
|
|
{
|
|
struct task_struct *me = current;
|
|
clts(); /* Allow maths ops (or we recurse) */
|
|
|
|
if (!used_math())
|
|
init_fpu(me);
|
|
restore_fpu_checking(&me->thread.i387.fxsave);
|
|
me->thread_info->status |= TS_USEDFPU;
|
|
}
|
|
|
|
void do_call_debug(struct pt_regs *regs)
|
|
{
|
|
notify_die(DIE_CALL, "debug call", regs, 0, 255, SIGINT);
|
|
}
|
|
|
|
void __init trap_init(void)
|
|
{
|
|
set_intr_gate(0,÷_error);
|
|
set_intr_gate_ist(1,&debug,DEBUG_STACK);
|
|
set_intr_gate_ist(2,&nmi,NMI_STACK);
|
|
set_system_gate(3,&int3);
|
|
set_system_gate(4,&overflow); /* int4-5 can be called from all */
|
|
set_system_gate(5,&bounds);
|
|
set_intr_gate(6,&invalid_op);
|
|
set_intr_gate(7,&device_not_available);
|
|
set_intr_gate_ist(8,&double_fault, DOUBLEFAULT_STACK);
|
|
set_intr_gate(9,&coprocessor_segment_overrun);
|
|
set_intr_gate(10,&invalid_TSS);
|
|
set_intr_gate(11,&segment_not_present);
|
|
set_intr_gate_ist(12,&stack_segment,STACKFAULT_STACK);
|
|
set_intr_gate(13,&general_protection);
|
|
set_intr_gate(14,&page_fault);
|
|
set_intr_gate(15,&spurious_interrupt_bug);
|
|
set_intr_gate(16,&coprocessor_error);
|
|
set_intr_gate(17,&alignment_check);
|
|
#ifdef CONFIG_X86_MCE
|
|
set_intr_gate_ist(18,&machine_check, MCE_STACK);
|
|
#endif
|
|
set_intr_gate(19,&simd_coprocessor_error);
|
|
|
|
#ifdef CONFIG_IA32_EMULATION
|
|
set_system_gate(IA32_SYSCALL_VECTOR, ia32_syscall);
|
|
#endif
|
|
|
|
set_intr_gate(KDB_VECTOR, call_debug);
|
|
|
|
/*
|
|
* Should be a barrier for any external CPU state.
|
|
*/
|
|
cpu_init();
|
|
}
|
|
|
|
|
|
/* Actual parsing is done early in setup.c. */
|
|
static int __init oops_dummy(char *s)
|
|
{
|
|
panic_on_oops = 1;
|
|
return -1;
|
|
}
|
|
__setup("oops=", oops_dummy);
|
|
|
|
static int __init kstack_setup(char *s)
|
|
{
|
|
kstack_depth_to_print = simple_strtoul(s,NULL,0);
|
|
return 0;
|
|
}
|
|
__setup("kstack=", kstack_setup);
|
|
|