leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity
bc850d6b37
linux/arch/x86/kernel/traps_64.c
Arjan van de Ven bc850d6b37 x86: add the capability to print fuzzy backtraces 
For enhancing the 32 bit EBP based backtracer, I need the capability
for the backtracer to tell it's customer that an entry is either
reliable or unreliable, and the backtrace printing code then needs to
print the unreliable ones slightly different.

This patch adds the basic capability, the next patch will add a user
of this capability.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:33:07 +01:00

1130 lines
28 KiB
C
Raw Blame History

/*
* 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
*/
/*
* 'Traps.c' handles hardware traps and faults after we have saved some
* state in 'entry.S'.
*/
#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/kallsyms.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/nmi.h>
#include <linux/kprobes.h>
#include <linux/kexec.h>
#include <linux/unwind.h>
#include <linux/uaccess.h>
#include <linux/bug.h>
#include <linux/kdebug.h>
#include <linux/utsname.h>
#if defined(CONFIG_EDAC)
#include <linux/edac.h>
#endif
#include <asm/system.h>
#include <asm/io.h>
#include <asm/atomic.h>
#include <asm/debugreg.h>
#include <asm/desc.h>
#include <asm/i387.h>
#include <asm/processor.h>
#include <asm/unwind.h>
#include <asm/smp.h>
#include <asm/pgalloc.h>
#include <asm/pda.h>
#include <asm/proto.h>
#include <asm/nmi.h>
#include <asm/stacktrace.h>
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);
static inline void conditional_sti(struct pt_regs *regs)
{
if (regs->flags & X86_EFLAGS_IF)
local_irq_enable();
}
static inline void preempt_conditional_sti(struct pt_regs *regs)
{
preempt_disable();
if (regs->flags & X86_EFLAGS_IF)
local_irq_enable();
}
static inline void preempt_conditional_cli(struct pt_regs *regs)
{
if (regs->flags & X86_EFLAGS_IF)
local_irq_disable();
/* Make sure to not schedule here because we could be running
on an exception stack. */
preempt_enable_no_resched();
}
int kstack_depth_to_print = 12;
#ifdef CONFIG_KALLSYMS
void printk_address(unsigned long address, int reliable)
{
unsigned long offset = 0, symsize;
const char *symname;
char *modname;
char *delim = ":";
char namebuf[128];
char reliab[4] = "";;
symname = kallsyms_lookup(address, &symsize, &offset,
&modname, namebuf);
if (!symname) {
printk(" [<%016lx>]\n", address);
return;
}
if (!reliable)
strcpy(reliab, "? ");
if (!modname)
modname = delim = "";
printk(" [<%016lx>] %s%s%s%s%s+0x%lx/0x%lx\n",
address, reliab, delim, modname, delim, symname, offset, symsize);
}
#else
void printk_address(unsigned long address, int reliable)
{
printk(" [<%016lx>]\n", address);
}
#endif
static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
unsigned *usedp, char **idp)
{
static char ids[][8] = {
[DEBUG_STACK - 1] = "#DB",
[NMI_STACK - 1] = "NMI",
[DOUBLEFAULT_STACK - 1] = "#DF",
[STACKFAULT_STACK - 1] = "#SS",
[MCE_STACK - 1] = "#MC",
#if DEBUG_STKSZ > EXCEPTION_STKSZ
[N_EXCEPTION_STACKS ... N_EXCEPTION_STACKS + DEBUG_STKSZ / EXCEPTION_STKSZ - 2] = "#DB[?]"
#endif
};
unsigned k;
/*
* Iterate over all exception stacks, and figure out whether
* 'stack' is in one of them:
*/
for (k = 0; k < N_EXCEPTION_STACKS; k++) {
unsigned long end = per_cpu(orig_ist, cpu).ist[k];
/*
* Is 'stack' above this exception frame's end?
* If yes then skip to the next frame.
*/
if (stack >= end)
continue;
/*
* Is 'stack' above this exception frame's start address?
* If yes then we found the right frame.
*/
if (stack >= end - EXCEPTION_STKSZ) {
/*
* Make sure we only iterate through an exception
* stack once. If it comes up for the second time
* then there's something wrong going on - just
* break out and return NULL:
*/
if (*usedp & (1U << k))
break;
*usedp |= 1U << k;
*idp = ids[k];
return (unsigned long *)end;
}
/*
* If this is a debug stack, and if it has a larger size than
* the usual exception stacks, then 'stack' might still
* be within the lower portion of the debug stack:
*/
#if DEBUG_STKSZ > EXCEPTION_STKSZ
if (k == DEBUG_STACK - 1 && stack >= end - DEBUG_STKSZ) {
unsigned j = N_EXCEPTION_STACKS - 1;
/*
* Black magic. A large debug stack is composed of
* multiple exception stack entries, which we
* iterate through now. Dont look:
*/
do {
++j;
end -= EXCEPTION_STKSZ;
ids[j][4] = '1' + (j - N_EXCEPTION_STACKS);
} while (stack < end - EXCEPTION_STKSZ);
if (*usedp & (1U << j))
break;
*usedp |= 1U << j;
*idp = ids[j];
return (unsigned long *)end;
}
#endif
}
return NULL;
}
#define MSG(txt) ops->warning(data, txt)
/*
* x86-64 can have up to three kernel stacks:
* process stack
* interrupt stack
* severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
*/
static inline int valid_stack_ptr(struct thread_info *tinfo, void *p)
{
void *t = (void *)tinfo;
return p > t && p < t + THREAD_SIZE - 3;
}
void dump_trace(struct task_struct *tsk, struct pt_regs *regs,
unsigned long *stack, unsigned long bp,
const struct stacktrace_ops *ops, void *data)
{
const unsigned cpu = get_cpu();
unsigned long *irqstack_end = (unsigned long*)cpu_pda(cpu)->irqstackptr;
unsigned used = 0;
struct thread_info *tinfo;
if (!tsk)
tsk = current;
if (!stack) {
unsigned long dummy;
stack = &dummy;
if (tsk && tsk != current)
stack = (unsigned long *)tsk->thread.sp;
}
/*
* Print function call entries within a stack. 'cond' is the
* "end of stackframe" condition, that the 'stack++'
* iteration will eventually trigger.
*/
#define HANDLE_STACK(cond) \
do while (cond) { \
unsigned long addr = *stack++; \
/* Use unlocked access here because except for NMIs \
we should be already protected against module unloads */ \
if (__kernel_text_address(addr)) { \
/* \
* 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. \
*/ \
ops->address(data, addr, 1); \
} \
} while (0)
/*
* Print function call entries in all stacks, starting at the
* current stack address. If the stacks consist of nested
* exceptions
*/
for (;;) {
char *id;
unsigned long *estack_end;
estack_end = in_exception_stack(cpu, (unsigned long)stack,
&used, &id);
if (estack_end) {
if (ops->stack(data, id) < 0)
break;
HANDLE_STACK (stack < estack_end);
ops->stack(data, "<EOE>");
/*
* We link to the next stack via the
* second-to-last pointer (index -2 to end) in the
* exception stack:
*/
stack = (unsigned long *) estack_end[-2];
continue;
}
if (irqstack_end) {
unsigned long *irqstack;
irqstack = irqstack_end -
(IRQSTACKSIZE - 64) / sizeof(*irqstack);
if (stack >= irqstack && stack < irqstack_end) {
if (ops->stack(data, "IRQ") < 0)
break;
HANDLE_STACK (stack < irqstack_end);
/*
* We link to the next stack (which would be
* the process stack normally) the last
* pointer (index -1 to end) in the IRQ stack:
*/
stack = (unsigned long *) (irqstack_end[-1]);
irqstack_end = NULL;
ops->stack(data, "EOI");
continue;
}
}
break;
}
/*
* This handles the process stack:
*/
tinfo = task_thread_info(tsk);
HANDLE_STACK (valid_stack_ptr(tinfo, stack));
#undef HANDLE_STACK
put_cpu();
}
EXPORT_SYMBOL(dump_trace);
static void
print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
{
print_symbol(msg, symbol);
printk("\n");
}
static void print_trace_warning(void *data, char *msg)
{
printk("%s\n", msg);
}
static int print_trace_stack(void *data, char *name)
{
printk(" <%s> ", name);
return 0;
}
static void print_trace_address(void *data, unsigned long addr, int reliable)
{
touch_nmi_watchdog();
printk_address(addr, reliable);
}
static const struct stacktrace_ops print_trace_ops = {
.warning = print_trace_warning,
.warning_symbol = print_trace_warning_symbol,
.stack = print_trace_stack,
.address = print_trace_address,
};
void
show_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long *stack,
unsigned long bp)
{
printk("\nCall Trace:\n");
dump_trace(tsk, regs, stack, bp, &print_trace_ops, NULL);
printk("\n");
}
static void
_show_stack(struct task_struct *tsk, struct pt_regs *regs, unsigned long *sp,
unsigned long bp)
{
unsigned long *stack;
int i;
const int cpu = 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 (sp == NULL) {
if (tsk)
sp = (unsigned long *)tsk->thread.sp;
else
sp = (unsigned long *)&sp;
}
stack = sp;
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(tsk, regs, sp, bp);
}
void show_stack(struct task_struct *tsk, unsigned long * sp)
{
_show_stack(tsk, NULL, sp, 0);
}
/*
* The architecture-independent dump_stack generator
*/
void dump_stack(void)
{
unsigned long dummy;
unsigned long bp = 0;
printk("Pid: %d, comm: %.20s %s %s %.*s\n",
current->pid, current->comm, print_tainted(),
init_utsname()->release,
(int)strcspn(init_utsname()->version, " "),
init_utsname()->version);
show_trace(NULL, NULL, &dummy, bp);
}
EXPORT_SYMBOL(dump_stack);
void show_registers(struct pt_regs *regs)
{
int i;
int in_kernel = !user_mode(regs);
unsigned long sp;
const int cpu = smp_processor_id();
struct task_struct *cur = cpu_pda(cpu)->pcurrent;
sp = regs->sp;
printk("CPU %d ", cpu);
__show_regs(regs);
printk("Process %s (pid: %d, threadinfo %p, task %p)\n",
cur->comm, cur->pid, task_thread_info(cur), 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, regs, (unsigned long *)sp, regs->bp);
printk("\nCode: ");
if (regs->ip < PAGE_OFFSET)
goto bad;
for (i=0; i<20; i++) {
unsigned char c;
if (__get_user(c, &((unsigned char*)regs->ip)[i])) {
bad:
printk(" Bad RIP value.");
break;
}
printk("%02x ", c);
}
}
printk("\n");
}
int is_valid_bugaddr(unsigned long ip)
{
unsigned short ud2;
if (__copy_from_user(&ud2, (const void __user *) ip, sizeof(ud2)))
return 0;
return ud2 == 0x0b0f;
}
static raw_spinlock_t die_lock = __RAW_SPIN_LOCK_UNLOCKED;
static int die_owner = -1;
static unsigned int die_nest_count;
unsigned __kprobes long oops_begin(void)
{
int cpu;
unsigned long flags;
oops_enter();
/* racy, but better than risking deadlock. */
raw_local_irq_save(flags);
cpu = smp_processor_id();
if (!__raw_spin_trylock(&die_lock)) {
if (cpu == die_owner)
/* nested oops. should stop eventually */;
else
__raw_spin_lock(&die_lock);
}
die_nest_count++;
die_owner = cpu;
console_verbose();
bust_spinlocks(1);
return flags;
}
void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr)
{
die_owner = -1;
bust_spinlocks(0);
die_nest_count--;
if (!die_nest_count)
/* Nest count reaches zero, release the lock. */
__raw_spin_unlock(&die_lock);
raw_local_irq_restore(flags);
if (!regs) {
oops_exit();
return;
}
if (panic_on_oops)
panic("Fatal exception");
oops_exit();
do_exit(signr);
}
int __kprobes __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");
if (notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV) == NOTIFY_STOP)
return 1;
show_registers(regs);
add_taint(TAINT_DIE);
/* Executive summary in case the oops scrolled away */
printk(KERN_ALERT "RIP ");
printk_address(regs->ip, regs->bp);
printk(" RSP <%016lx>\n", regs->sp);
if (kexec_should_crash(current))
crash_kexec(regs);
return 0;
}
void die(const char * str, struct pt_regs * regs, long err)
{
unsigned long flags = oops_begin();
if (!user_mode(regs))
report_bug(regs->ip, regs);
if (__die(str, regs, err))
regs = NULL;
oops_end(flags, regs, SIGSEGV);
}
void __kprobes die_nmi(char *str, struct pt_regs *regs, int do_panic)
{
unsigned long flags = oops_begin();
/*
* We are in trouble anyway, lets at least try
* to get a message out.
*/
printk(str, smp_processor_id());
show_registers(regs);
if (kexec_should_crash(current))
crash_kexec(regs);
if (do_panic || panic_on_oops)
panic("Non maskable interrupt");
oops_end(flags, NULL, SIGBUS);
nmi_exit();
local_irq_enable();
do_exit(SIGBUS);
}
static void __kprobes do_trap(int trapnr, int signr, char *str,
struct pt_regs * regs, long error_code,
siginfo_t *info)
{
struct task_struct *tsk = current;
if (user_mode(regs)) {
/*
* We want error_code and trap_no set for userspace
* faults and kernelspace faults which result in
* die(), but not kernelspace faults which are fixed
* up. die() gives the process no chance to handle
* the signal and notice the kernel fault information,
* so that won't result in polluting the information
* about previously queued, but not yet delivered,
* faults. See also do_general_protection below.
*/
tsk->thread.error_code = error_code;
tsk->thread.trap_no = trapnr;
if (show_unhandled_signals && unhandled_signal(tsk, signr) &&
printk_ratelimit())
printk(KERN_INFO
"%s[%d] trap %s ip:%lx sp:%lx error:%lx\n",
tsk->comm, tsk->pid, str,
regs->ip, regs->sp, error_code);
if (info)
force_sig_info(signr, info, tsk);
else
force_sig(signr, tsk);
return;
}
if (!fixup_exception(regs)) {
tsk->thread.error_code = error_code;
tsk->thread.trap_no = trapnr;
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; \
conditional_sti(regs); \
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; \
trace_hardirqs_fixup(); \
if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
== NOTIFY_STOP) \
return; \
conditional_sti(regs); \
do_trap(trapnr, signr, str, regs, error_code, &info); \
}
DO_ERROR_INFO( 0, SIGFPE, "divide error", divide_error, FPE_INTDIV, regs->ip)
DO_ERROR( 4, SIGSEGV, "overflow", overflow)
DO_ERROR( 5, SIGSEGV, "bounds", bounds)
DO_ERROR_INFO( 6, SIGILL, "invalid opcode", invalid_op, ILL_ILLOPN, regs->ip)
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)
/* Runs on IST stack */
asmlinkage void do_stack_segment(struct pt_regs *regs, long error_code)
{
if (notify_die(DIE_TRAP, "stack segment", regs, error_code,
12, SIGBUS) == NOTIFY_STOP)
return;
preempt_conditional_sti(regs);
do_trap(12, SIGBUS, "stack segment", regs, error_code, NULL);
preempt_conditional_cli(regs);
}
asmlinkage void do_double_fault(struct pt_regs * regs, long error_code)
{
static const char str[] = "double fault";
struct task_struct *tsk = current;
/* Return not checked because double check cannot be ignored */
notify_die(DIE_TRAP, str, regs, error_code, 8, SIGSEGV);
tsk->thread.error_code = error_code;
tsk->thread.trap_no = 8;
/* This is always a kernel trap and never fixable (and thus must
never return). */
for (;;)
die(str, regs, error_code);
}
asmlinkage void __kprobes do_general_protection(struct pt_regs * regs,
long error_code)
{
struct task_struct *tsk = current;
conditional_sti(regs);
if (user_mode(regs)) {
tsk->thread.error_code = error_code;
tsk->thread.trap_no = 13;
if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) &&
printk_ratelimit())
printk(KERN_INFO
"%s[%d] general protection ip:%lx sp:%lx error:%lx\n",
tsk->comm, tsk->pid,
regs->ip, regs->sp, error_code);
force_sig(SIGSEGV, tsk);
return;
}
if (fixup_exception(regs))
return;
tsk->thread.error_code = error_code;
tsk->thread.trap_no = 13;
if (notify_die(DIE_GPF, "general protection fault", regs,
error_code, 13, SIGSEGV) == NOTIFY_STOP)
return;
die("general protection fault", regs, error_code);
}
static __kprobes void
mem_parity_error(unsigned char reason, struct pt_regs * regs)
{
printk(KERN_EMERG "Uhhuh. NMI received for unknown reason %02x.\n",
reason);
printk(KERN_EMERG "You have some hardware problem, likely on the PCI bus.\n");
#if defined(CONFIG_EDAC)
if(edac_handler_set()) {
edac_atomic_assert_error();
return;
}
#endif
if (panic_on_unrecovered_nmi)
panic("NMI: Not continuing");
printk(KERN_EMERG "Dazed and confused, but trying to continue\n");
/* Clear and disable the memory parity error line. */
reason = (reason & 0xf) | 4;
outb(reason, 0x61);
}
static __kprobes 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 __kprobes void
unknown_nmi_error(unsigned char reason, struct pt_regs * regs)
{
printk(KERN_EMERG "Uhhuh. NMI received for unknown reason %02x.\n",
reason);
printk(KERN_EMERG "Do you have a strange power saving mode enabled?\n");
if (panic_on_unrecovered_nmi)
panic("NMI: Not continuing");
printk(KERN_EMERG "Dazed and confused, but trying to continue\n");
}
/* Runs on IST stack. This code must keep interrupts off all the time.
Nested NMIs are prevented by the CPU. */
asmlinkage __kprobes void default_do_nmi(struct pt_regs *regs)
{
unsigned char reason = 0;
int cpu;
cpu = smp_processor_id();
/* Only the BSP gets external NMIs from the system. */
if (!cpu)
reason = get_nmi_reason();
if (!(reason & 0xc0)) {
if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT)
== NOTIFY_STOP)
return;
/*
* Ok, so this is none of the documented NMI sources,
* so it must be the NMI watchdog.
*/
if (nmi_watchdog_tick(regs,reason))
return;
if (!do_nmi_callback(regs,cpu))
unknown_nmi_error(reason, regs);
return;
}
if (notify_die(DIE_NMI, "nmi", regs, reason, 2, 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);
}
/* runs on IST stack. */
asmlinkage void __kprobes do_int3(struct pt_regs * regs, long error_code)
{
trace_hardirqs_fixup();
if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) == NOTIFY_STOP) {
return;
}
preempt_conditional_sti(regs);
do_trap(3, SIGTRAP, "int3", regs, error_code, NULL);
preempt_conditional_cli(regs);
}
/* 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 __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs)
{
struct pt_regs *regs = eregs;
/* Did already sync */
if (eregs == (struct pt_regs *)eregs->sp)
;
/* Exception from user space */
else if (user_mode(eregs))
regs = task_pt_regs(current);
/* Exception from kernel and interrupts are enabled. Move to
kernel process stack. */
else if (eregs->flags & X86_EFLAGS_IF)
regs = (struct pt_regs *)(eregs->sp -= sizeof(struct pt_regs));
if (eregs != regs)
*regs = *eregs;
return regs;
}
/* runs on IST stack. */
asmlinkage void __kprobes do_debug(struct pt_regs * regs,
unsigned long error_code)
{
unsigned long condition;
struct task_struct *tsk = current;
siginfo_t info;
trace_hardirqs_fixup();
get_debugreg(condition, 6);
/*
* The processor cleared BTF, so don't mark that we need it set.
*/
clear_tsk_thread_flag(tsk, TIF_DEBUGCTLMSR);
tsk->thread.debugctlmsr = 0;
if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
SIGTRAP) == NOTIFY_STOP)
return;
preempt_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;
/*
* Single-stepping through TF: make sure we ignore any events in
* kernel space (but re-enable TF when returning to user mode).
*/
if (condition & DR_STEP) {
if (!user_mode(regs))
goto clear_TF_reenable;
}
/* 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;
info.si_addr = user_mode(regs) ? (void __user *)regs->ip : NULL;
force_sig_info(SIGTRAP, &info, tsk);
clear_dr7:
set_debugreg(0UL, 7);
preempt_conditional_cli(regs);
return;
clear_TF_reenable:
set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
regs->flags &= ~X86_EFLAGS_TF;
preempt_conditional_cli(regs);
}
static int kernel_math_error(struct pt_regs *regs, const char *str, int trapnr)
{
if (fixup_exception(regs))
return 1;
notify_die(DIE_GPF, str, regs, 0, trapnr, SIGFPE);
/* Illegal floating point operation in the kernel */
current->thread.trap_no = trapnr;
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 *ip = (void __user *)(regs->ip);
struct task_struct * task;
siginfo_t info;
unsigned short cwd, swd;
conditional_sti(regs);
if (!user_mode(regs) &&
kernel_math_error(regs, "kernel x87 math error", 16))
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 = ip;
/*
* (~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 (swd & ~cwd & 0x3f) {
case 0x000:
default:
break;
case 0x001: /* Invalid Op */
/*
* swd & 0x240 == 0x040: Stack Underflow
* swd & 0x240 == 0x240: Stack Overflow
* User must clear the SF bit (0x40) if set
*/
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 *ip = (void __user *)(regs->ip);
struct task_struct * task;
siginfo_t info;
unsigned short mxcsr;
conditional_sti(regs);
if (!user_mode(regs) &&
kernel_math_error(regs, "kernel simd math error", 19))
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 = ip;
/*
* 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)
{
}
asmlinkage void __attribute__((weak)) mce_threshold_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);
task_thread_info(me)->status |= TS_USEDFPU;
me->fpu_counter++;
}
EXPORT_SYMBOL_GPL(math_state_restore);
void __init trap_init(void)
{
set_intr_gate(0,&divide_error);
set_intr_gate_ist(1,&debug,DEBUG_STACK);
set_intr_gate_ist(2,&nmi,NMI_STACK);
set_system_gate_ist(3,&int3,DEBUG_STACK); /* int3 can be called from all */
set_system_gate(4,&overflow); /* int4 can be called from all */
set_intr_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
/*
* Should be a barrier for any external CPU state.
*/
cpu_init();
}
static int __init oops_setup(char *s)
{
if (!s)
return -EINVAL;
if (!strcmp(s, "panic"))
panic_on_oops = 1;
return 0;
}
early_param("oops", oops_setup);
static int __init kstack_setup(char *s)
{
if (!s)
return -EINVAL;
kstack_depth_to_print = simple_strtoul(s,NULL,0);
return 0;
}
early_param("kstack", kstack_setup);
Reference in New Issue View Git Blame Copy Permalink