// 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 = panic_on_this_cpu();	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);