arch/x86/kernel/stacktrace.c

   1 /*
   2  * Stack trace management functions
   3  *
   4  *  Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
   5  */
   6 #include <linux/sched.h>
   7 #include <linux/stacktrace.h>
   8 #include <linux/module.h>
   9 #include <asm/stacktrace.h>
  10
  11 static void save_stack_warning(void *data, char *msg)
  12 {
  13 }
  14
  15 static void
  16 save_stack_warning_symbol(void *data, char *msg, unsigned long symbol)
  17 {
  18 }
  19
  20 static int save_stack_stack(void *data, char *name)
  21 {
  22         return -1;
  23 }
  24
  25 static void save_stack_address(void *data, unsigned long addr, int reliable)
  26 {
  27         struct stack_trace *trace = data;
  28         if (!reliable)
  29                 return;
  30         if (trace->skip > 0) {
  31                 trace->skip--;
  32                 return;
  33         }
  34         if (trace->nr_entries < trace->max_entries)
  35                 trace->entries[trace->nr_entries++] = addr;
  36 }
  37
  38 static void
  39 save_stack_address_nosched(void *data, unsigned long addr, int reliable)
  40 {
  41         struct stack_trace *trace = (struct stack_trace *)data;
  42         if (!reliable)
  43                 return;
  44         if (in_sched_functions(addr))
  45                 return;
  46         if (trace->skip > 0) {
  47                 trace->skip--;
  48                 return;
  49         }
  50         if (trace->nr_entries < trace->max_entries)
  51                 trace->entries[trace->nr_entries++] = addr;
  52 }
  53
  54 static const struct stacktrace_ops save_stack_ops = {
  55         .warning = save_stack_warning,
  56         .warning_symbol = save_stack_warning_symbol,
  57         .stack = save_stack_stack,
  58         .address = save_stack_address,
  59 };
  60
  61 static const struct stacktrace_ops save_stack_ops_nosched = {
  62         .warning = save_stack_warning,
  63         .warning_symbol = save_stack_warning_symbol,
  64         .stack = save_stack_stack,
  65         .address = save_stack_address_nosched,
  66 };
  67
  68 /*
  69  * Save stack-backtrace addresses into a stack_trace buffer.
  70  */
  71 void save_stack_trace(struct stack_trace *trace)
  72 {
  73         dump_trace(current, NULL, NULL, 0, &save_stack_ops, trace);
  74         if (trace->nr_entries < trace->max_entries)
  75                 trace->entries[trace->nr_entries++] = ULONG_MAX;
  76 }
  77 EXPORT_SYMBOL_GPL(save_stack_trace);
  78
  79 void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
  80 {
  81         dump_trace(tsk, NULL, NULL, 0, &save_stack_ops_nosched, trace);
  82         if (trace->nr_entries < trace->max_entries)
  83                 trace->entries[trace->nr_entries++] = ULONG_MAX;
  84 }
  85 EXPORT_SYMBOL_GPL(save_stack_trace_tsk);