forked from mirrors/linux
		
	dump_stack related stuff should belong to lib/dump_stack.c thus move them there. Also conditionally compile lib/dump_stack.c since dump_stack code does not make sense if printk is disabled. Link: http://lkml.kernel.org/r/20180213072834.GA24784@dhcp-128-65.nay.redhat.com To: Steven Rostedt <rostedt@goodmis.org> Cc: linux-kernel@vger.kernel.org Cc: akpm@linux-foundation.org Cc: Andi Kleen <ak@linux.intel.com> Signed-off-by: Dave Young <dyoung@redhat.com> Suggested-by: Steven Rostedt <rostedt@goodmis.org> Suggested-by: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
		
			
				
	
	
		
			126 lines
		
	
	
	
		
			3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			126 lines
		
	
	
	
		
			3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0
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/*
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 * Provide a default dump_stack() function for architectures
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 * which don't implement their own.
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 */
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#include <linux/kernel.h>
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#include <linux/export.h>
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#include <linux/sched.h>
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#include <linux/sched/debug.h>
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#include <linux/smp.h>
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#include <linux/atomic.h>
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#include <linux/kexec.h>
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#include <linux/utsname.h>
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static char dump_stack_arch_desc_str[128];
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/**
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 * dump_stack_set_arch_desc - set arch-specific str to show with task dumps
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 * @fmt: printf-style format string
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 * @...: arguments for the format string
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 *
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 * The configured string will be printed right after utsname during task
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 * dumps.  Usually used to add arch-specific system identifiers.  If an
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 * arch wants to make use of such an ID string, it should initialize this
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 * as soon as possible during boot.
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 */
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void __init dump_stack_set_arch_desc(const char *fmt, ...)
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{
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	va_list args;
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	va_start(args, fmt);
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	vsnprintf(dump_stack_arch_desc_str, sizeof(dump_stack_arch_desc_str),
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		  fmt, args);
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	va_end(args);
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}
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/**
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 * dump_stack_print_info - print generic debug info for dump_stack()
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 * @log_lvl: log level
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 *
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 * Arch-specific dump_stack() implementations can use this function to
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 * print out the same debug information as the generic dump_stack().
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 */
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void dump_stack_print_info(const char *log_lvl)
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{
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	printk("%sCPU: %d PID: %d Comm: %.20s %s%s %s %.*s\n",
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	       log_lvl, raw_smp_processor_id(), current->pid, current->comm,
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	       kexec_crash_loaded() ? "Kdump: loaded " : "",
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	       print_tainted(),
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	       init_utsname()->release,
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	       (int)strcspn(init_utsname()->version, " "),
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	       init_utsname()->version);
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	if (dump_stack_arch_desc_str[0] != '\0')
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		printk("%sHardware name: %s\n",
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		       log_lvl, dump_stack_arch_desc_str);
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	print_worker_info(log_lvl, current);
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}
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/**
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 * show_regs_print_info - print generic debug info for show_regs()
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 * @log_lvl: log level
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 *
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 * show_regs() implementations can use this function to print out generic
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 * debug information.
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 */
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void show_regs_print_info(const char *log_lvl)
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{
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	dump_stack_print_info(log_lvl);
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}
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static void __dump_stack(void)
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{
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	dump_stack_print_info(KERN_DEFAULT);
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	show_stack(NULL, NULL);
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}
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/**
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 * dump_stack - dump the current task information and its stack trace
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 *
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 * Architectures can override this implementation by implementing its own.
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 */
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#ifdef CONFIG_SMP
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static atomic_t dump_lock = ATOMIC_INIT(-1);
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asmlinkage __visible void dump_stack(void)
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{
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	unsigned long flags;
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	int was_locked;
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	int old;
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	int cpu;
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	/*
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	 * Permit this cpu to perform nested stack dumps while serialising
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	 * against other CPUs
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	 */
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retry:
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	local_irq_save(flags);
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	cpu = smp_processor_id();
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	old = atomic_cmpxchg(&dump_lock, -1, cpu);
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	if (old == -1) {
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		was_locked = 0;
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	} else if (old == cpu) {
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		was_locked = 1;
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	} else {
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		local_irq_restore(flags);
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		cpu_relax();
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		goto retry;
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	}
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	__dump_stack();
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	if (!was_locked)
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		atomic_set(&dump_lock, -1);
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	local_irq_restore(flags);
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}
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#else
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asmlinkage __visible void dump_stack(void)
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{
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	__dump_stack();
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}
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#endif
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EXPORT_SYMBOL(dump_stack);
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