arch/sh/kernel/stacktrace.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * arch/sh/kernel/stacktrace.c
   4  *
   5  * Stack trace management functions
   6  *
   7  *  Copyright (C) 2006 - 2008  Paul Mundt
   8  */
   9 #include <linux/sched.h>
  10 #include <linux/sched/debug.h>
  11 #include <linux/stacktrace.h>
  12 #include <linux/thread_info.h>
  13 #include <linux/module.h>
  14 #include <asm/unwinder.h>
  15 #include <asm/ptrace.h>
  16 #include <asm/stacktrace.h>
  17
  18 /*
  19  * Save stack-backtrace addresses into a stack_trace buffer.
  20  */
  21 static void save_stack_address(void *data, unsigned long addr, int reliable)
  22 {
  23         struct stack_trace *trace = data;
  24
  25         if (!reliable)
  26                 return;
  27
  28         if (trace->skip > 0) {
  29                 trace->skip--;
  30                 return;
  31         }
  32
  33         if (trace->nr_entries < trace->max_entries)
  34                 trace->entries[trace->nr_entries++] = addr;
  35 }
  36
  37 static const struct stacktrace_ops save_stack_ops = {
  38         .address = save_stack_address,
  39 };
  40
  41 void save_stack_trace(struct stack_trace *trace)
  42 {
  43         unsigned long *sp = (unsigned long *)current_stack_pointer;
  44
  45         unwind_stack(current, NULL, sp,  &save_stack_ops, trace);
  46 }
  47 EXPORT_SYMBOL_GPL(save_stack_trace);
  48
  49 static void
  50 save_stack_address_nosched(void *data, unsigned long addr, int reliable)
  51 {
  52         struct stack_trace *trace = (struct stack_trace *)data;
  53
  54         if (!reliable)
  55                 return;
  56
  57         if (in_sched_functions(addr))
  58                 return;
  59
  60         if (trace->skip > 0) {
  61                 trace->skip--;
  62                 return;
  63         }
  64
  65         if (trace->nr_entries < trace->max_entries)
  66                 trace->entries[trace->nr_entries++] = addr;
  67 }
  68
  69 static const struct stacktrace_ops save_stack_ops_nosched = {
  70         .address = save_stack_address_nosched,
  71 };
  72
  73 void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
  74 {
  75         unsigned long *sp = (unsigned long *)tsk->thread.sp;
  76
  77         unwind_stack(current, NULL, sp,  &save_stack_ops_nosched, trace);
  78 }
  79 EXPORT_SYMBOL_GPL(save_stack_trace_tsk);