LXR linux/arch/openrisc/kernel/stacktrace.c

   1/*
   2 * Stack trace utility for OpenRISC
   3 *
   4 * Copyright (C) 2017 Stafford Horne <shorne@gmail.com>
   5 *
   6 * This file is licensed under the terms of the GNU General Public License
   7 * version 2.  This program is licensed "as is" without any warranty of any
   8 * kind, whether express or implied.
   9 *
  10 * Losely based on work from sh and powerpc.
  11 */
  12
  13#include <linux/export.h>
  14#include <linux/sched.h>
  15#include <linux/sched/debug.h>
  16#include <linux/stacktrace.h>
  17
  18#include <asm/processor.h>
  19#include <asm/unwinder.h>
  20
  21/*
  22 * Save stack-backtrace addresses into a stack_trace buffer.
  23 */
  24static void
  25save_stack_address(void *data, unsigned long addr, int reliable)
  26{
  27        struct stack_trace *trace = data;
  28
  29        if (!reliable)
  30                return;
  31
  32        if (trace->skip > 0) {
  33                trace->skip--;
  34                return;
  35        }
  36
  37        if (trace->nr_entries < trace->max_entries)
  38                trace->entries[trace->nr_entries++] = addr;
  39}
  40
  41void save_stack_trace(struct stack_trace *trace)
  42{
  43        unwind_stack(trace, (unsigned long *) &trace, save_stack_address);
  44}
  45EXPORT_SYMBOL_GPL(save_stack_trace);
  46
  47static void
  48save_stack_address_nosched(void *data, unsigned long addr, int reliable)
  49{
  50        struct stack_trace *trace = (struct stack_trace *)data;
  51
  52        if (!reliable)
  53                return;
  54
  55        if (in_sched_functions(addr))
  56                return;
  57
  58        if (trace->skip > 0) {
  59                trace->skip--;
  60                return;
  61        }
  62
  63        if (trace->nr_entries < trace->max_entries)
  64                trace->entries[trace->nr_entries++] = addr;
  65}
  66
  67void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
  68{
  69        unsigned long *sp = NULL;
  70
  71        if (tsk == current)
  72                sp = (unsigned long *) &sp;
  73        else
  74                sp = (unsigned long *) KSTK_ESP(tsk);
  75
  76        unwind_stack(trace, sp, save_stack_address_nosched);
  77}
  78EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
  79
  80void
  81save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
  82{
  83        unwind_stack(trace, (unsigned long *) regs->sp,
  84                     save_stack_address_nosched);
  85}
  86EXPORT_SYMBOL_GPL(save_stack_trace_regs);
  87