Line data    Source code

       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           0 : void __init dump_stack_set_arch_desc(const char *fmt, ...)
      31             : {
      32             :         va_list args;
      33             : 
      34           0 :         va_start(args, fmt);
      35           0 :         vsnprintf(dump_stack_arch_desc_str, sizeof(dump_stack_arch_desc_str),
      36             :                   fmt, args);
      37           0 :         va_end(args);
      38           0 : }
      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           1 : void dump_stack_print_info(const char *log_lvl)
      56             : {
      57           3 :         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           1 :         if (dump_stack_arch_desc_str[0] != '\0')
      66           0 :                 printk("%sHardware name: %s\n",
      67             :                        log_lvl, dump_stack_arch_desc_str);
      68             : 
      69           1 :         print_worker_info(log_lvl, current);
      70           1 :         print_stop_info(log_lvl, current);
      71           1 : }
      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             :  */
      80           0 : void show_regs_print_info(const char *log_lvl)
      81             : {
      82           0 :         dump_stack_print_info(log_lvl);
      83           0 : }
      84             : 
      85             : static void __dump_stack(const char *log_lvl)
      86             : {
      87           1 :         dump_stack_print_info(log_lvl);
      88           1 :         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             :  */
      97           1 : asmlinkage __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           1 :         printk_cpu_sync_get_irqsave(flags);
     106           1 :         __dump_stack(log_lvl);
     107           2 :         printk_cpu_sync_put_irqrestore(flags);
     108           1 : }
     109             : EXPORT_SYMBOL(dump_stack_lvl);
     110             : 
     111           1 : asmlinkage __visible void dump_stack(void)
     112             : {
     113           1 :         dump_stack_lvl(KERN_DEFAULT);
     114           1 : }
     115             : EXPORT_SYMBOL(dump_stack);