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/sched/debug.h>
  14 #include <linux/stacktrace.h>
  15 #include <linux/thread_info.h>
  16 #include <linux/module.h>
  17 #include <asm/unwinder.h>
  18 #include <asm/ptrace.h>
  19 #include <asm/stacktrace.h>
  20
  21 static int save_stack_stack(void *data, char *name)
  22 {
  23         return 0;
  24 }
  25
  26 /*
  27  * Save stack-backtrace addresses into a stack_trace buffer.
  28  */
  29 static void save_stack_address(void *data, unsigned long addr, int reliable)
  30 {
  31         struct stack_trace *trace = data;
  32
  33         if (!reliable)
  34                 return;
  35
  36         if (trace->skip > 0) {
  37                 trace->skip--;
  38                 return;
  39         }
  40
  41         if (trace->nr_entries < trace->max_entries)
  42                 trace->entries[trace->nr_entries++] = addr;
  43 }
  44
  45 static const struct stacktrace_ops save_stack_ops = {
  46         .stack = save_stack_stack,
  47         .address = save_stack_address,
  48 };
  49
  50 void save_stack_trace(struct stack_trace *trace)
  51 {
  52         unsigned long *sp = (unsigned long *)current_stack_pointer;
  53
  54         unwind_stack(current, NULL, sp,  &save_stack_ops, trace);
  55         if (trace->nr_entries < trace->max_entries)
  56                 trace->entries[trace->nr_entries++] = ULONG_MAX;
  57 }
  58 EXPORT_SYMBOL_GPL(save_stack_trace);
  59
  60 static void
  61 save_stack_address_nosched(void *data, unsigned long addr, int reliable)
  62 {
  63         struct stack_trace *trace = (struct stack_trace *)data;
  64
  65         if (!reliable)
  66                 return;
  67
  68         if (in_sched_functions(addr))
  69                 return;
  70
  71         if (trace->skip > 0) {
  72                 trace->skip--;
  73                 return;
  74         }
  75
  76         if (trace->nr_entries < trace->max_entries)
  77                 trace->entries[trace->nr_entries++] = addr;
  78 }
  79
  80 static const struct stacktrace_ops save_stack_ops_nosched = {
  81         .stack = save_stack_stack,
  82         .address = save_stack_address_nosched,
  83 };
  84
  85 void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
  86 {
  87         unsigned long *sp = (unsigned long *)tsk->thread.sp;
  88
  89         unwind_stack(current, NULL, sp,  &save_stack_ops_nosched, trace);
  90         if (trace->nr_entries < trace->max_entries)
  91                 trace->entries[trace->nr_entries++] = ULONG_MAX;
  92 }
  93 EXPORT_SYMBOL_GPL(save_stack_trace_tsk);