[linux-2.6-block.git] / lib / dump_stack.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Provide a default dump_stack() function for architectures
 * which don't implement their own.
 */

#include <linux/kernel.h>
#include <linux/buildid.h>
#include <linux/export.h>
#include <linux/sched.h>
#include <linux/sched/debug.h>
#include <linux/smp.h>
#include <linux/atomic.h>
#include <linux/kexec.h>
#include <linux/utsname.h>
#include <linux/stop_machine.h>

static char dump_stack_arch_desc_str[128];

/**
 * dump_stack_set_arch_desc - set arch-specific str to show with task dumps
 * @fmt: printf-style format string
 * @...: arguments for the format string
 *
 * The configured string will be printed right after utsname during task
 * dumps.  Usually used to add arch-specific system identifiers.  If an
 * arch wants to make use of such an ID string, it should initialize this
 * as soon as possible during boot.
 */
void __init dump_stack_set_arch_desc(const char *fmt, ...)
{
	va_list args;

	va_start(args, fmt);
	vsnprintf(dump_stack_arch_desc_str, sizeof(dump_stack_arch_desc_str),
		  fmt, args);
	va_end(args);
}

#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID)
#define BUILD_ID_FMT " %20phN"
#define BUILD_ID_VAL vmlinux_build_id
#else
#define BUILD_ID_FMT "%s"
#define BUILD_ID_VAL ""
#endif

/**
 * dump_stack_print_info - print generic debug info for dump_stack()
 * @log_lvl: log level
 *
 * Arch-specific dump_stack() implementations can use this function to
 * print out the same debug information as the generic dump_stack().
 */
void dump_stack_print_info(const char *log_lvl)
{
	printk("%sCPU: %d UID: %u PID: %d Comm: %.20s %s%s %s %.*s %s " BUILD_ID_FMT "\n",
	       log_lvl, raw_smp_processor_id(),
	       __kuid_val(current_real_cred()->euid),
	       current->pid, current->comm,
	       kexec_crash_loaded() ? "Kdump: loaded " : "",
	       print_tainted(),
	       init_utsname()->release,
	       (int)strcspn(init_utsname()->version, " "),
	       init_utsname()->version, preempt_model_str(), BUILD_ID_VAL);

	if (get_taint())
		printk("%s%s\n", log_lvl, print_tainted_verbose());

	if (dump_stack_arch_desc_str[0] != '\0')
		printk("%sHardware name: %s\n",
		       log_lvl, dump_stack_arch_desc_str);

	print_worker_info(log_lvl, current);
	print_stop_info(log_lvl, current);
	print_scx_info(log_lvl, current);
}

/**
 * show_regs_print_info - print generic debug info for show_regs()
 * @log_lvl: log level
 *
 * show_regs() implementations can use this function to print out generic
 * debug information.
 */
void show_regs_print_info(const char *log_lvl)
{
	dump_stack_print_info(log_lvl);
}

static void __dump_stack(const char *log_lvl)
{
	dump_stack_print_info(log_lvl);
	show_stack(NULL, NULL, log_lvl);
}

/**
 * dump_stack_lvl - dump the current task information and its stack trace
 * @log_lvl: log level
 *
 * Architectures can override this implementation by implementing its own.
 */
asmlinkage __visible void dump_stack_lvl(const char *log_lvl)
{
	bool in_panic = this_cpu_in_panic();
	unsigned long flags;

	/*
	 * Permit this cpu to perform nested stack dumps while serialising
	 * against other CPUs, unless this CPU is in panic.
	 *
	 * When in panic, non-panic CPUs are not permitted to store new
	 * printk messages so there is no need to synchronize the output.
	 * This avoids potential deadlock in panic() if another CPU is
	 * holding and unable to release the printk_cpu_sync.
	 */
	if (!in_panic)
		printk_cpu_sync_get_irqsave(flags);

	__dump_stack(log_lvl);

	if (!in_panic)
		printk_cpu_sync_put_irqrestore(flags);
}
EXPORT_SYMBOL(dump_stack_lvl);

asmlinkage __visible void dump_stack(void)
{
	dump_stack_lvl(KERN_DEFAULT);
}
EXPORT_SYMBOL(dump_stack);
Commit	Line	Data
	1	// SPDX-License-Identifier: GPL-2.0
	2	/*
	3	* Provide a default dump_stack() function for architectures
	4	* which don't implement their own.
	5	*/
	6
	7	#include <linux/kernel.h>
	8	#include <linux/buildid.h>
	9	#include <linux/export.h>
	10	#include <linux/sched.h>
	11	#include <linux/sched/debug.h>
	12	#include <linux/smp.h>
	13	#include <linux/atomic.h>
	14	#include <linux/kexec.h>
	15	#include <linux/utsname.h>
	16	#include <linux/stop_machine.h>
	17
	18	static char dump_stack_arch_desc_str[128];
	19
	20	/**
	21	* dump_stack_set_arch_desc - set arch-specific str to show with task dumps
	22	* @fmt: printf-style format string
	23	* @...: arguments for the format string
	24	*
	25	* The configured string will be printed right after utsname during task
	26	* dumps. Usually used to add arch-specific system identifiers. If an
	27	* arch wants to make use of such an ID string, it should initialize this
	28	* as soon as possible during boot.
	29	*/
	30	void __init dump_stack_set_arch_desc(const char *fmt, ...)
	31	{
	32	va_list args;
	33
	34	va_start(args, fmt);
	35	vsnprintf(dump_stack_arch_desc_str, sizeof(dump_stack_arch_desc_str),
	36	fmt, args);
	37	va_end(args);
	38	}
	39
	40	#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID)
	41	#define BUILD_ID_FMT " %20phN"
	42	#define BUILD_ID_VAL vmlinux_build_id
	43	#else
	44	#define BUILD_ID_FMT "%s"
	45	#define BUILD_ID_VAL ""
	46	#endif
	47
	48	/**
	49	* dump_stack_print_info - print generic debug info for dump_stack()
	50	* @log_lvl: log level
	51	*
	52	* Arch-specific dump_stack() implementations can use this function to
	53	* print out the same debug information as the generic dump_stack().
	54	*/
	55	void dump_stack_print_info(const char *log_lvl)
	56	{
	57	printk("%sCPU: %d UID: %u PID: %d Comm: %.20s %s%s %s %.*s %s " BUILD_ID_FMT "\n",
	58	log_lvl, raw_smp_processor_id(),
	59	__kuid_val(current_real_cred()->euid),
	60	current->pid, current->comm,
	61	kexec_crash_loaded() ? "Kdump: loaded " : "",
	62	print_tainted(),
	63	init_utsname()->release,
	64	(int)strcspn(init_utsname()->version, " "),
	65	init_utsname()->version, preempt_model_str(), BUILD_ID_VAL);
	66
	67	if (get_taint())
	68	printk("%s%s\n", log_lvl, print_tainted_verbose());
	69
	70	if (dump_stack_arch_desc_str[0] != '\0')
	71	printk("%sHardware name: %s\n",
	72	log_lvl, dump_stack_arch_desc_str);
	73
	74	print_worker_info(log_lvl, current);
	75	print_stop_info(log_lvl, current);
	76	print_scx_info(log_lvl, current);
	77	}
	78
	79	/**
	80	* show_regs_print_info - print generic debug info for show_regs()
	81	* @log_lvl: log level
	82	*
	83	* show_regs() implementations can use this function to print out generic
	84	* debug information.
	85	*/
	86	void show_regs_print_info(const char *log_lvl)
	87	{
	88	dump_stack_print_info(log_lvl);
	89	}
	90
	91	static void __dump_stack(const char *log_lvl)
	92	{
	93	dump_stack_print_info(log_lvl);
	94	show_stack(NULL, NULL, log_lvl);
	95	}
	96
	97	/**
	98	* dump_stack_lvl - dump the current task information and its stack trace
	99	* @log_lvl: log level
	100	*
	101	* Architectures can override this implementation by implementing its own.
	102	*/
	103	asmlinkage __visible void dump_stack_lvl(const char *log_lvl)
	104	{
	105	bool in_panic = this_cpu_in_panic();
	106	unsigned long flags;
	107
	108	/*
	109	* Permit this cpu to perform nested stack dumps while serialising
	110	* against other CPUs, unless this CPU is in panic.
	111	*
	112	* When in panic, non-panic CPUs are not permitted to store new
	113	* printk messages so there is no need to synchronize the output.
	114	* This avoids potential deadlock in panic() if another CPU is
	115	* holding and unable to release the printk_cpu_sync.
	116	*/
	117	if (!in_panic)
	118	printk_cpu_sync_get_irqsave(flags);
	119
	120	__dump_stack(log_lvl);
	121
	122	if (!in_panic)
	123	printk_cpu_sync_put_irqrestore(flags);
	124	}
	125	EXPORT_SYMBOL(dump_stack_lvl);
	126
	127	asmlinkage __visible void dump_stack(void)
	128	{
	129	dump_stack_lvl(KERN_DEFAULT);
	130	}
	131	EXPORT_SYMBOL(dump_stack);