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)
  26 {
  27         struct stack_trace *trace = (struct stack_trace *)data;
  28         if (trace->skip > 0) {
  29                 trace->skip--;
  30                 return;
  31         }
  32         if (trace->nr_entries < trace->max_entries)
  33                 trace->entries[trace->nr_entries++] = addr;
  34 }
  35
  36 static void save_stack_address_nosched(void *data, unsigned long addr)
  37 {
  38         struct stack_trace *trace = (struct stack_trace *)data;
  39         if (in_sched_functions(addr))
  40                 return;
  41         if (trace->skip > 0) {
  42                 trace->skip--;
  43                 return;
  44         }
  45         if (trace->nr_entries < trace->max_entries)
  46                 trace->entries[trace->nr_entries++] = addr;
  47 }
  48
  49 static const struct stacktrace_ops save_stack_ops = {
  50         .warning = save_stack_warning,
  51         .warning_symbol = save_stack_warning_symbol,
  52         .stack = save_stack_stack,
  53         .address = save_stack_address,
  54 };
  55
  56 static const struct stacktrace_ops save_stack_ops_nosched = {
  57         .warning = save_stack_warning,
  58         .warning_symbol = save_stack_warning_symbol,
  59         .stack = save_stack_stack,
  60         .address = save_stack_address_nosched,
  61 };
  62
  63 /*
  64  * Save stack-backtrace addresses into a stack_trace buffer.
  65  */
  66 void save_stack_trace(struct stack_trace *trace)
  67 {
  68         dump_trace(current, NULL, NULL, &save_stack_ops, trace);
  69         if (trace->nr_entries < trace->max_entries)
  70                 trace->entries[trace->nr_entries++] = ULONG_MAX;
  71 }
  72 EXPORT_SYMBOL(save_stack_trace);
  73
  74 void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
  75 {
  76         dump_trace(tsk, NULL, NULL, &save_stack_ops_nosched, trace);
  77         if (trace->nr_entries < trace->max_entries)
  78                 trace->entries[trace->nr_entries++] = ULONG_MAX;
  79 }