/*
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* Stack trace utility for OpenRISC
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*
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* Copyright (C) 2017 Stafford Horne <shorne@gmail.com>
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*
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* This file is licensed under the terms of the GNU General Public License
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* version 2. This program is licensed "as is" without any warranty of any
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* kind, whether express or implied.
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*
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* Losely based on work from sh and powerpc.
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*/
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#include <linux/export.h>
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#include <linux/sched.h>
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#include <linux/sched/debug.h>
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#include <linux/sched/task_stack.h>
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#include <linux/stacktrace.h>
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#include <asm/processor.h>
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#include <asm/unwinder.h>
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/*
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* Save stack-backtrace addresses into a stack_trace buffer.
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*/
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static void
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save_stack_address(void *data, unsigned long addr, int reliable)
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{
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struct stack_trace *trace = data;
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if (!reliable)
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return;
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if (trace->skip > 0) {
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trace->skip--;
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return;
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}
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if (trace->nr_entries < trace->max_entries)
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trace->entries[trace->nr_entries++] = addr;
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}
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void save_stack_trace(struct stack_trace *trace)
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{
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unwind_stack(trace, (unsigned long *) &trace, save_stack_address);
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}
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EXPORT_SYMBOL_GPL(save_stack_trace);
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static void
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save_stack_address_nosched(void *data, unsigned long addr, int reliable)
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{
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struct stack_trace *trace = (struct stack_trace *)data;
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if (!reliable)
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return;
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if (in_sched_functions(addr))
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return;
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if (trace->skip > 0) {
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trace->skip--;
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return;
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}
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if (trace->nr_entries < trace->max_entries)
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trace->entries[trace->nr_entries++] = addr;
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}
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void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
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{
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unsigned long *sp = NULL;
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if (!try_get_task_stack(tsk))
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return;
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if (tsk == current)
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sp = (unsigned long *) &sp;
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else {
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unsigned long ksp;
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/* Locate stack from kernel context */
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ksp = task_thread_info(tsk)->ksp;
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ksp += STACK_FRAME_OVERHEAD; /* redzone */
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ksp += sizeof(struct pt_regs);
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sp = (unsigned long *) ksp;
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}
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unwind_stack(trace, sp, save_stack_address_nosched);
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put_task_stack(tsk);
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}
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EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
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void
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save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
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{
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unwind_stack(trace, (unsigned long *) regs->sp,
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save_stack_address_nosched);
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}
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EXPORT_SYMBOL_GPL(save_stack_trace_regs);
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