x86_64: split out dumpstack code from traps_64.c

The dumpstack code is logically quite independent from the
hardware traps. Split it out into its own file.

Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 0 insertions, 545 deletions

diff --git a/arch/x86/kernel/traps_64.c b/arch/x86/kernel/traps_64.c
index 729157e..1cd61dd 100644
--- a/arch/x86/kernel/traps_64.c
+++ b/arch/x86/kernel/traps_64.c
@@ -54,11 +54,7 @@
 
 #include <mach_traps.h>
 
-int panic_on_unrecovered_nmi;
-int kstack_depth_to_print = 12;
-static unsigned int code_bytes = 64;
 static int ignore_nmis;
-static int die_counter;
 
 static inline void conditional_sti(struct pt_regs *regs)
 {
@@ -82,518 +78,6 @@ static inline void preempt_conditional_cli(struct pt_regs *regs)
 	dec_preempt_count();
 }
 
-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 (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 void __kprobes
 do_trap(int trapnr, int signr, char *str, struct pt_regs *regs,
 	long error_code, siginfo_t *info)
@@ -1178,32 +662,3 @@ void __init trap_init(void)
 	 */
 	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);
-
-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);