arch/sh/kernel/stacktrace.c

   1 /*
   2  * arch/sh/kernel/stacktrace.c
   3  *
   4  * Stack trace management functions
   5  *
   6  *  Copyright (C) 2006 - 2008  Paul Mundt
   7  *
   8  * This file is subject to the terms and conditions of the GNU General Public
   9  * License.  See the file "COPYING" in the main directory of this archive
  10  * for more details.
  11  */
  12 #include <linux/sched.h>
  13 #include <linux/stacktrace.h>
  14 #include <linux/thread_info.h>
  15 #include <linux/module.h>
  16 #include <asm/unwinder.h>
  17 #include <asm/ptrace.h>
  18 #include <asm/stacktrace.h>
  19
  20 static int save_stack_stack(void *data, char *name)
  21 {
  22         return 0;
  23 }
  24
  25 /*
  26  * Save stack-backtrace addresses into a stack_trace buffer.
  27  */
  28 static void save_stack_address(void *data, unsigned long addr, int reliable)
  29 {
  30         struct stack_trace *trace = data;
  31
  32         if (!reliable)
  33                 return;
  34
  35         if (trace->skip > 0) {
  36                 trace->skip--;
  37                 return;
  38         }
  39
  40         if (trace->nr_entries < trace->max_entries)
  41                 trace->entries[trace->nr_entries++] = addr;
  42 }
  43
  44 static const struct stacktrace_ops save_stack_ops = {
  45         .stack = save_stack_stack,
  46         .address = save_stack_address,
  47 };
  48
  49 void save_stack_trace(struct stack_trace *trace)
  50 {
  51         unsigned long *sp = (unsigned long *)current_stack_pointer;
  52
  53         unwind_stack(current, NULL, sp,  &save_stack_ops, trace);
  54         if (trace->nr_entries < trace->max_entries)
  55                 trace->entries[trace->nr_entries++] = ULONG_MAX;
  56 }
  57 EXPORT_SYMBOL_GPL(save_stack_trace);
  58
  59 static void
  60 save_stack_address_nosched(void *data, unsigned long addr, int reliable)
  61 {
  62         struct stack_trace *trace = (struct stack_trace *)data;
  63
  64         if (!reliable)
  65                 return;
  66
  67         if (in_sched_functions(addr))
  68                 return;
  69
  70         if (trace->skip > 0) {
  71                 trace->skip--;
  72                 return;
  73         }
  74
  75         if (trace->nr_entries < trace->max_entries)
  76                 trace->entries[trace->nr_entries++] = addr;
  77 }
  78
  79 static const struct stacktrace_ops save_stack_ops_nosched = {
  80         .stack = save_stack_stack,
  81         .address = save_stack_address_nosched,
  82 };
  83
  84 void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
  85 {
  86         unsigned long *sp = (unsigned long *)tsk->thread.sp;
  87
  88         unwind_stack(current, NULL, sp,  &save_stack_ops_nosched, trace);
  89         if (trace->nr_entries < trace->max_entries)
  90                 trace->entries[trace->nr_entries++] = ULONG_MAX;
  91 }
  92 EXPORT_SYMBOL_GPL(save_stack_trace_tsk);