x86_64: split out dumpstack code from traps_64.c

CFLAGS_tsc.o		:= $(nostackp)

obj-y			:= process_$(BITS).o signal_$(BITS).o entry_$(BITS).o

obj-y			+= traps_$(BITS).o irq_$(BITS).o

obj-y			+= traps_$(BITS).o irq_$(BITS).o dumpstack_$(BITS).o

obj-y			+= time_$(BITS).o ioport.o ldt.o

obj-y			+= setup.o i8259.o irqinit_$(BITS).o setup_percpu.o

obj-$(CONFIG_X86_VISWS)	+= visws_quirks.o

obj-$(CONFIG_X86_32)	+= probe_roms_32.o

obj-$(CONFIG_X86_32)	+= sys_i386_32.o i386_ksyms_32.o dumpstack_32.o

obj-$(CONFIG_X86_32)	+= sys_i386_32.o i386_ksyms_32.o

obj-$(CONFIG_X86_64)	+= sys_x86_64.o x8664_ksyms_64.o

obj-$(CONFIG_X86_64)	+= syscall_64.o vsyscall_64.o

obj-y			+= bootflag.o e820.o

/*

 *  Copyright (C) 1991, 1992  Linus Torvalds

 *  Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs

 */

#include <linux/kallsyms.h>

#include <linux/kprobes.h>

#include <linux/uaccess.h>

#include <linux/utsname.h>

#include <linux/hardirq.h>

#include <linux/kdebug.h>

#include <linux/module.h>

#include <linux/ptrace.h>

#include <linux/kexec.h>

#include <linux/bug.h>

#include <linux/nmi.h>

#include <asm/stacktrace.h>

int panic_on_unrecovered_nmi;

int kstack_depth_to_print = 12;

static unsigned int code_bytes = 64;

static int die_counter;

void printk_address(unsigned long address, int reliable)

{

	printk(" [<%016lx>] %s%pS\n",

			address, reliable ?	"" : "? ", (void *) address);

}

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;

}

/*

 * 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, unsigned int size, void *end)

{

	void *t = tinfo;

	if (end) {

		if (p < end && p >= (end-THREAD_SIZE))

			return 1;

		else

			return 0;

	}

	return p > t && p < t + THREAD_SIZE - size;

}

/* The form of the top of the frame on the stack */

struct stack_frame {

	struct stack_frame *next_frame;

	unsigned long return_address;

};

static inline unsigned long

print_context_stack(struct thread_info *tinfo,

		unsigned long *stack, unsigned long bp,

		const struct stacktrace_ops *ops, void *data,

		unsigned long *end)

{

	struct stack_frame *frame = (struct stack_frame *)bp;

	while (valid_stack_ptr(tinfo, stack, sizeof(*stack), end)) {

		unsigned long addr;

		addr = *stack;

		if (__kernel_text_address(addr)) {

			if ((unsigned long) stack == bp + 8) {

				ops->address(data, addr, 1);

				frame = frame->next_frame;

				bp = (unsigned long) frame;

			} else {

				ops->address(data, addr, bp == 0);

			}

		}

		stack++;

	}

	return bp;

}

void dump_trace(struct task_struct *task, 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 (!task)

		task = current;

	if (!stack) {

		unsigned long dummy;

		stack = &dummy;

		if (task && task != current)

			stack = (unsigned long *)task->thread.sp;

	}

#ifdef CONFIG_FRAME_POINTER

	if (!bp) {

		if (task == current) {

			/* Grab bp right from our regs */

			asm("movq %%rbp, %0" : "=r" (bp) : );

		} else {

			/* bp is the last reg pushed by switch_to */

			bp = *(unsigned long *) task->thread.sp;

		}

	}

#endif

	/*

	 * Print function call entries in all stacks, starting at the

	 * current stack address. If the stacks consist of nested

	 * exceptions

	 */

	tinfo = task_thread_info(task);

	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;

			bp = print_context_stack(tinfo, stack, bp, ops,

							data, 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;

				bp = print_context_stack(tinfo, stack, bp,

						ops, data, 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:

	 */

	bp = print_context_stack(tinfo, stack, bp, ops, data, NULL);

	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,

};

static void

show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,

		unsigned long *stack, unsigned long bp, char *log_lvl)

{

	printk("Call Trace:\n");

	dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl);

}

void show_trace(struct task_struct *task, struct pt_regs *regs,

		unsigned long *stack, unsigned long bp)

{

	show_trace_log_lvl(task, regs, stack, bp, "");

}

static void

show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,

		unsigned long *sp, unsigned long bp, char *log_lvl)

{

	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 (task)

			sp = (unsigned long *)task->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();

	}

	printk("\n");

	show_trace_log_lvl(task, regs, sp, bp, log_lvl);

}

void show_stack(struct task_struct *task, unsigned long *sp)

{

	show_stack_log_lvl(task, NULL, sp, 0, "");

}

/*

 * The architecture-independent dump_stack generator

 */

void dump_stack(void)

{

	unsigned long bp = 0;

	unsigned long stack;

#ifdef CONFIG_FRAME_POINTER

	if (!bp)

		asm("movq %%rbp, %0" : "=r" (bp) : );

#endif

	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, &stack, bp);

}

EXPORT_SYMBOL(dump_stack);

void show_registers(struct pt_regs *regs)

{

	int i;

	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, 1);

	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 (!user_mode(regs)) {

		unsigned int code_prologue = code_bytes * 43 / 64;

		unsigned int code_len = code_bytes;

		unsigned char c;

		u8 *ip;

		printk("Stack: ");

		show_stack_log_lvl(NULL, regs, (unsigned long *)sp,

				regs->bp, "");

		printk(KERN_EMERG "Code: ");

		ip = (u8 *)regs->ip - code_prologue;

		if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) {

			/* try starting at RIP */

			ip = (u8 *)regs->ip;

			code_len = code_len - code_prologue + 1;

		}

		for (i = 0; i < code_len; i++, ip++) {

			if (ip < (u8 *)PAGE_OFFSET ||

					probe_kernel_address(ip, c)) {

				printk(" Bad RIP value.");

				break;

			}

			if (ip == (u8 *)regs->ip)

				printk("<%02x> ", c);

			else

				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 (in_interrupt())

		panic("Fatal exception in interrupt");

	if (panic_on_oops)

		panic("Fatal exception");

	oops_exit();

	do_exit(signr);

}

int __kprobes __die(const char *str, struct pt_regs *regs, long err)

{

	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, 1);

	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);

}

notrace __kprobes void

die_nmi(char *str, struct pt_regs *regs, int do_panic)

{

	unsigned long flags;

	if (notify_die(DIE_NMIWATCHDOG, str, regs, 0, 2, SIGINT) == NOTIFY_STOP)

		return;

	flags = oops_begin();

	/*

	 * We are in trouble anyway, lets at least try

	 * to get a message out.

	 */

	printk(KERN_EMERG "%s", str);

	printk(" on CPU%d, ip %08lx, registers:\n",

		smp_processor_id(), regs->ip);

	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 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);

static int __init code_bytes_setup(char *s)

{

	code_bytes = simple_strtoul(s, NULL, 0);

	if (code_bytes > 8192)

		code_bytes = 8192;

	return 1;

}

__setup("code_bytes=", code_bytes_setup);