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1// SPDX-License-Identifier: GPL-2.02/*3 * Provide a default dump_stack() function for architectures4 * 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 18static char dump_stack_arch_desc_str[128];19 20/**21 * dump_stack_set_arch_desc - set arch-specific str to show with task dumps22 * @fmt: printf-style format string23 * @...: arguments for the format string24 *25 * The configured string will be printed right after utsname during task26 * dumps. Usually used to add arch-specific system identifiers. If an27 * arch wants to make use of such an ID string, it should initialize this28 * as soon as possible during boot.29 */30void __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_id43#else44#define BUILD_ID_FMT "%s"45#define BUILD_ID_VAL ""46#endif47 48/**49 * dump_stack_print_info - print generic debug info for dump_stack()50 * @log_lvl: log level51 *52 * Arch-specific dump_stack() implementations can use this function to53 * print out the same debug information as the generic dump_stack().54 */55void dump_stack_print_info(const char *log_lvl)56{57 printk("%sCPU: %d UID: %u PID: %d Comm: %.20s %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, 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 level82 *83 * show_regs() implementations can use this function to print out generic84 * debug information.85 */86void show_regs_print_info(const char *log_lvl)87{88 dump_stack_print_info(log_lvl);89}90 91static 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 trace99 * @log_lvl: log level100 *101 * Architectures can override this implementation by implementing its own.102 */103asmlinkage __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 serialising110 * against other CPUs, unless this CPU is in panic.111 *112 * When in panic, non-panic CPUs are not permitted to store new113 * printk messages so there is no need to synchronize the output.114 * This avoids potential deadlock in panic() if another CPU is115 * 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}125EXPORT_SYMBOL(dump_stack_lvl);126 127asmlinkage __visible void dump_stack(void)128{129 dump_stack_lvl(KERN_DEFAULT);130}131EXPORT_SYMBOL(dump_stack);132