/* * Stack dumping functions * *  Copyright IBM Corp. 1999, 2013 */ #include <linux/kallsyms.h>#include <linux/hardirq.h>#include <linux/kprobes.h>#include <linux/utsname.h>#include <linux/export.h>#include <linux/kdebug.h>#include <linux/ptrace.h>#include <linux/mm.h>#include <linux/module.h>#include <linux/sched.h>#include <linux/sched/debug.h>#include <linux/sched/task_stack.h>#include <asm/processor.h>#include <asm/debug.h>#include <asm/dis.h>#include <asm/ipl.h> /* * For dump_trace we have tree different stack to consider: *   - the panic stack which is used if the kernel stack has overflown *   - the asynchronous interrupt stack (cpu related) *   - the synchronous kernel stack (process related) * The stack trace can start at any of the three stacks and can potentially * touch all of them. The order is: panic stack, async stack, sync stack. */static unsigned long__dump_trace(dump_trace_func_t func, void *data, unsigned long sp,	     unsigned long low, unsigned long high){	struct stack_frame *sf;	struct pt_regs *regs; 	while (1) {		if (sp < low || sp > high - sizeof(*sf))			return sp;		sf = (struct stack_frame *) sp;		if (func(data, sf->gprs[8], 0))			return sp;		/* Follow the backchain. */		while (1) {			low = sp;			sp = sf->back_chain;			if (!sp)				break;			if (sp <= low || sp > high - sizeof(*sf))				return sp;			sf = (struct stack_frame *) sp;			if (func(data, sf->gprs[8], 1))				return sp;		}		/* Zero backchain detected, check for interrupt frame. */		sp = (unsigned long) (sf + 1);		if (sp <= low || sp > high - sizeof(*regs))			return sp;		regs = (struct pt_regs *) sp;		if (!user_mode(regs)) {			if (func(data, regs->psw.addr, 1))				return sp;		}		low = sp;		sp = regs->gprs[15];	}} void dump_trace(dump_trace_func_t func, void *data, struct task_struct *task,		unsigned long sp){	unsigned long frame_size; 	frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);#ifdef CONFIG_CHECK_STACK	sp = __dump_trace(func, data, sp,			  S390_lowcore.panic_stack + frame_size - 4096,			  S390_lowcore.panic_stack + frame_size);#endif	sp = __dump_trace(func, data, sp,			  S390_lowcore.async_stack + frame_size - ASYNC_SIZE,			  S390_lowcore.async_stack + frame_size);	task = task ?: current;	__dump_trace(func, data, sp,		     (unsigned long)task_stack_page(task),		     (unsigned long)task_stack_page(task) + THREAD_SIZE);}EXPORT_SYMBOL_GPL(dump_trace); static int show_address(void *data, unsigned long address, int reliable){	if (reliable)		printk(" [<%016lx>] %pSR \n", address, (void *)address);	else		printk("([<%016lx>] %pSR)\n", address, (void *)address);	return 0;} void show_stack(struct task_struct *task, unsigned long *stack){	unsigned long sp = (unsigned long) stack; 	if (!sp)		sp = task ? task->thread.ksp : current_stack_pointer();	printk("Call Trace:\n");	dump_trace(show_address, NULL, task, sp);	if (!task)		task = current;	debug_show_held_locks(task);} static void show_last_breaking_event(struct pt_regs *regs){	printk("Last Breaking-Event-Address:\n");	printk(" [<%016lx>] %pSR\n", regs->args[0], (void *)regs->args[0]);} void show_registers(struct pt_regs *regs){	struct psw_bits *psw = &psw_bits(regs->psw);	char *mode; 	mode = user_mode(regs) ? "User" : "Krnl";	printk("%s PSW : %p %p", mode, (void *)regs->psw.mask, (void *)regs->psw.addr);	if (!user_mode(regs))		pr_cont(" (%pSR)", (void *)regs->psw.addr);	pr_cont("\n");	printk("           R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "	       "P:%x AS:%x CC:%x PM:%x", psw->per, psw->dat, psw->io, psw->ext,	       psw->key, psw->mcheck, psw->wait, psw->pstate, psw->as, psw->cc, psw->pm);	pr_cont(" RI:%x EA:%x\n", psw->ri, psw->eaba);	printk("%s GPRS: %016lx %016lx %016lx %016lx\n", mode,	       regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);	printk("           %016lx %016lx %016lx %016lx\n",	       regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);	printk("           %016lx %016lx %016lx %016lx\n",	       regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);	printk("           %016lx %016lx %016lx %016lx\n",	       regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);	show_code(regs);} void show_regs(struct pt_regs *regs){	show_regs_print_info(KERN_DEFAULT);	show_registers(regs);	/* Show stack backtrace if pt_regs is from kernel mode */	if (!user_mode(regs))		show_stack(NULL, (unsigned long *) regs->gprs[15]);	show_last_breaking_event(regs);} static DEFINE_SPINLOCK(die_lock); void die(struct pt_regs *regs, const char *str){	static int die_counter; 	oops_enter();	lgr_info_log();	debug_stop_all();	console_verbose();	spin_lock_irq(&die_lock);	bust_spinlocks(1);	printk("%s: %04x ilc:%d [#%d] ", str, regs->int_code & 0xffff,	       regs->int_code >> 17, ++die_counter);#ifdef CONFIG_PREEMPT	pr_cont("PREEMPT ");#endif#ifdef CONFIG_SMP	pr_cont("SMP ");#endif	if (debug_pagealloc_enabled())		pr_cont("DEBUG_PAGEALLOC");	pr_cont("\n");	notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV);	print_modules();	show_regs(regs);	bust_spinlocks(0);	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);	spin_unlock_irq(&die_lock);	if (in_interrupt())		panic("Fatal exception in interrupt");	if (panic_on_oops)		panic("Fatal exception: panic_on_oops");	oops_exit();	do_exit(SIGSEGV);}