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