LXR linux/lib/dump

   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
  18static 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 */
  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_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 */
  55void dump_stack_print_info(const char *log_lvl)
  56{
  57        printk("%sCPU: %d PID: %d Comm: %.20s %s%s %s %.*s" BUILD_ID_FMT "\n",
  58               log_lvl, raw_smp_processor_id(), current->pid, current->comm,
  59               kexec_crash_loaded() ? "Kdump: loaded " : "",
  60               print_tainted(),
  61               init_utsname()->release,
  62               (int)strcspn(init_utsname()->version, " "),
  63               init_utsname()->version, BUILD_ID_VAL);
  64
  65        if (dump_stack_arch_desc_str[0] != '\0')
  66                printk("%sHardware name: %s\n",
  67                       log_lvl, dump_stack_arch_desc_str);
  68
  69        print_worker_info(log_lvl, current);
  70        print_stop_info(log_lvl, current);
  71}
  72
  73/**
  74 * show_regs_print_info - print generic debug info for show_regs()
  75 * @log_lvl: log level
  76 *
  77 * show_regs() implementations can use this function to print out generic
  78 * debug information.
  79 */
  80void show_regs_print_info(const char *log_lvl)
  81{
  82        dump_stack_print_info(log_lvl);
  83}
  84
  85static void __dump_stack(const char *log_lvl)
  86{
  87        dump_stack_print_info(log_lvl);
  88        show_stack(NULL, NULL, log_lvl);
  89}
  90
  91/**
  92 * dump_stack_lvl - dump the current task information and its stack trace
  93 * @log_lvl: log level
  94 *
  95 * Architectures can override this implementation by implementing its own.
  96 */
  97asmlinkage __visible void dump_stack_lvl(const char *log_lvl)
  98{
  99        unsigned long flags;
 100
 101        /*
 102         * Permit this cpu to perform nested stack dumps while serialising
 103         * against other CPUs
 104         */
 105        printk_cpu_lock_irqsave(flags);
 106        __dump_stack(log_lvl);
 107        printk_cpu_unlock_irqrestore(flags);
 108}
 109EXPORT_SYMBOL(dump_stack_lvl);
 110
 111asmlinkage __visible void dump_stack(void)
 112{
 113        dump_stack_lvl(KERN_DEFAULT);
 114}
 115EXPORT_SYMBOL(dump_stack);
 116