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kernel_optimize_test/arch/x86_64/kernel/traps.c
Jan Beulich c33bd9aac0 [PATCH] i386/x86-64: fall back to old-style call trace if no unwinding 
If no unwinding is possible at all for a certain exception instance,
fall back to the old style call trace instead of not showing any trace
at all.

Also, allow setting the stack trace mode at the command line.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 10:48:18 -07:00

1074 lines
27 KiB
C
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/*
* 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
*/
/*
* '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 <linux/kprobes.h>
#include <linux/kexec.h>
#include <linux/unwind.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/unwind.h>
#include <asm/smp.h>
#include <asm/pgalloc.h>
#include <asm/pda.h>
#include <asm/proto.h>
#include <asm/nmi.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);
ATOMIC_NOTIFIER_HEAD(die_chain);
int register_die_notifier(struct notifier_block *nb)
{
vmalloc_sync_all();
return atomic_notifier_chain_register(&die_chain, nb);
}
EXPORT_SYMBOL(register_die_notifier);
int unregister_die_notifier(struct notifier_block *nb)
{
return atomic_notifier_chain_unregister(&die_chain, nb);
}
EXPORT_SYMBOL(unregister_die_notifier);
static inline void conditional_sti(struct pt_regs *regs)
{
if (regs->eflags & X86_EFLAGS_IF)
local_irq_enable();
}
static inline void preempt_conditional_sti(struct pt_regs *regs)
{
preempt_disable();
if (regs->eflags & X86_EFLAGS_IF)
local_irq_enable();
}
static inline void preempt_conditional_cli(struct pt_regs *regs)
{
if (regs->eflags & 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();
}
static int kstack_depth_to_print = 10;
static int call_trace = 1;
#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
static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
unsigned *usedp, const 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;
for (k = 0; k < N_EXCEPTION_STACKS; k++) {
unsigned long end;
switch (k + 1) {
#if DEBUG_STKSZ > EXCEPTION_STKSZ
case DEBUG_STACK:
end = cpu_pda(cpu)->debugstack + DEBUG_STKSZ;
break;
#endif
default:
end = per_cpu(init_tss, cpu).ist[k];
break;
}
if (stack >= end)
continue;
if (stack >= end - EXCEPTION_STKSZ) {
if (*usedp & (1U << k))
break;
*usedp |= 1U << k;
*idp = ids[k];
return (unsigned long *)end;
}
#if DEBUG_STKSZ > EXCEPTION_STKSZ
if (k == DEBUG_STACK - 1 && stack >= end - DEBUG_STKSZ) {
unsigned j = N_EXCEPTION_STACKS - 1;
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;
}
static int show_trace_unwind(struct unwind_frame_info *info, void *context)
{
int i = 11, n = 0;
while (unwind(info) == 0 && UNW_PC(info)) {
++n;
if (i > 50) {
printk("\n ");
i = 7;
} else
i += printk(" ");
i += printk_address(UNW_PC(info));
if (arch_unw_user_mode(info))
break;
}
printk("\n");
return n;
}
/*
* x86-64 can have upto three kernel stacks:
* process stack
* interrupt stack
* severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
*/
void show_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long * stack)
{
const unsigned cpu = safe_smp_processor_id();
unsigned long *irqstack_end = (unsigned long *)cpu_pda(cpu)->irqstackptr;
int i = 11;
unsigned used = 0;
printk("\nCall Trace:");
if (!tsk)
tsk = current;
if (call_trace >= 0) {
int unw_ret = 0;
struct unwind_frame_info info;
if (regs) {
if (unwind_init_frame_info(&info, tsk, regs) == 0)
unw_ret = show_trace_unwind(&info, NULL);
} else if (tsk == current)
unw_ret = unwind_init_running(&info, show_trace_unwind, NULL);
else {
if (unwind_init_blocked(&info, tsk) == 0)
unw_ret = show_trace_unwind(&info, NULL);
}
if (unw_ret > 0) {
if (call_trace > 0)
return;
printk("Legacy call trace:");
i = 18;
}
}
#define HANDLE_STACK(cond) \
do while (cond) { \
unsigned long addr = *stack++; \
if (kernel_text_address(addr)) { \
if (i > 50) { \
printk("\n "); \
i = 0; \
} \
else \
i += printk(" "); \
/* \
* 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. \
*/ \
i += printk_address(addr); \
} \
} while (0)
for(; ; ) {
const char *id;
unsigned long *estack_end;
estack_end = in_exception_stack(cpu, (unsigned long)stack,
&used, &id);
if (estack_end) {
i += printk(" <%s>", id);
HANDLE_STACK (stack < estack_end);
i += printk(" <EOE>");
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) {
i += printk(" <IRQ>");
HANDLE_STACK (stack < irqstack_end);
stack = (unsigned long *) (irqstack_end[-1]);
irqstack_end = NULL;
i += printk(" <EOI>");
continue;
}
}
break;
}
HANDLE_STACK (((long) stack & (THREAD_SIZE-1)) != 0);
#undef HANDLE_STACK
printk("\n");
}
static void _show_stack(struct task_struct *tsk, struct pt_regs *regs, 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(tsk, regs, rsp);
}
void show_stack(struct task_struct *tsk, unsigned long * rsp)
{
_show_stack(tsk, NULL, rsp);
}
/*
* The architecture-independent dump_stack generator
*/
void dump_stack(void)
{
unsigned long dummy;
show_trace(NULL, NULL, &dummy);
}
EXPORT_SYMBOL(dump_stack);
void show_registers(struct pt_regs *regs)
{
int i;
int in_kernel = !user_mode(regs);
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, 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*)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;
long len;
const char *prefix = "";
if (user_mode(regs))
return;
if (__copy_from_user(&f, (const void __user *) regs->rip,
sizeof(struct bug_frame)))
return;
if (f.filename >= 0 ||
f.ud2[0] != 0x0f || f.ud2[1] != 0x0b)
return;
len = __strnlen_user((char *)(long)f.filename, PATH_MAX) - 1;
if (len < 0 || len >= PATH_MAX)
f.filename = (int)(long)"unmapped filename";
else if (len > 50) {
f.filename += len - 50;
prefix = "...";
}
printk("----------- [cut here ] --------- [please bite here ] ---------\n");
printk(KERN_ALERT "Kernel BUG at %s%.50s:%d\n", prefix, (char *)(long)f.filename, f.line);
}
#ifdef CONFIG_BUG
void out_of_line_bug(void)
{
BUG();
}
#endif
static DEFINE_SPINLOCK(die_lock);
static int die_owner = -1;
static unsigned int die_nest_count;
unsigned __kprobes long oops_begin(void)
{
int cpu = safe_smp_processor_id();
unsigned long flags;
/* racy, but better than risking deadlock. */
local_irq_save(flags);
if (!spin_trylock(&die_lock)) {
if (cpu == die_owner)
/* nested oops. should stop eventually */;
else
spin_lock(&die_lock);
}
die_nest_count++;
die_owner = cpu;
console_verbose();
bust_spinlocks(1);
return flags;
}
void __kprobes oops_end(unsigned long flags)
{
die_owner = -1;
bust_spinlocks(0);
die_nest_count--;
if (die_nest_count)
/* We still own the lock */
local_irq_restore(flags);
else
/* Nest count reaches zero, release the lock. */
spin_unlock_irqrestore(&die_lock, flags);
if (panic_on_oops)
panic("Oops");
}
void __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");
notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, 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);
if (kexec_should_crash(current))
crash_kexec(regs);
}
void die(const char * str, struct pt_regs * regs, long err)
{
unsigned long flags = oops_begin();
handle_BUG(regs);
__die(str, regs, err);
oops_end(flags);
do_exit(SIGSEGV);
}
void __kprobes die_nmi(char *str, struct pt_regs *regs)
{
unsigned long flags = 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 (kexec_should_crash(current))
crash_kexec(regs);
if (panic_on_timeout || panic_on_oops)
panic("nmi watchdog");
printk("console shuts up ...\n");
oops_end(flags);
nmi_exit();
local_irq_enable();
do_exit(SIGSEGV);
}
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;
tsk->thread.error_code = error_code;
tsk->thread.trap_no = trapnr;
if (user_mode(regs)) {
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);
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; \
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; \
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->rip)
DO_ERROR( 4, SIGSEGV, "overflow", overflow)
DO_ERROR( 5, SIGSEGV, "bounds", bounds)
DO_ERROR_INFO( 6, SIGILL, "invalid opcode", 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)
/* 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);
tsk->thread.error_code = error_code;
tsk->thread.trap_no = 13;
if (user_mode(regs)) {
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);
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 __kprobes 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 __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("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 __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;
#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, 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)
{
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->rsp)
;
/* 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->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 __kprobes do_debug(struct pt_regs * regs,
unsigned long error_code)
{
unsigned long condition;
struct task_struct *tsk = current;
siginfo_t info;
get_debugreg(condition, 6);
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;
/* 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 (!user_mode(regs))
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;
info.si_addr = user_mode(regs) ? (void __user *)regs->rip : 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->eflags &= ~TF_MASK;
preempt_conditional_cli(regs);
}
static int kernel_math_error(struct pt_regs *regs, const char *str, int trapnr)
{
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, 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 *rip = (void __user *)(regs->rip);
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 = 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 (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 *rip = (void __user *)(regs->rip);
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 = 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)
{
}
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;
}
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();
}
/* 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 1;
}
__setup("kstack=", kstack_setup);
static int __init call_trace_setup(char *s)
{
if (strcmp(s, "old") == 0)
call_trace = -1;
else if (strcmp(s, "both") == 0)
call_trace = 0;
else if (strcmp(s, "new") == 0)
call_trace = 1;
return 1;
}
__setup("call_trace=", call_trace_setup);
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