| 1 | |
| 2 | * Stack trace utility for OpenRISC
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| 3 | *
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| 4 | * Copyright (C) 2017 Stafford Horne <[email protected]>
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| 5 | *
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| 6 | * This file is licensed under the terms of the GNU General Public License
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| 7 | * version 2. This program is licensed "as is" without any warranty of any
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| 8 | * kind, whether express or implied.
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| 9 | *
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| 10 | * Losely based on work from sh and powerpc.
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| 11 |
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| 12 |
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| 13 | #include <linux/export.h>
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| 14 | #include <linux/sched.h>
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| 15 | #include <linux/sched/debug.h>
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| 16 | #include <linux/sched/task_stack.h>
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| 17 | #include <linux/stacktrace.h>
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| 18 |
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| 19 | #include <asm/processor.h>
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| 20 | #include <asm/unwinder.h>
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| 21 |
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| 22 | |
| 23 | * Save stack-backtrace addresses into a stack_trace buffer.
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| 24 |
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| 25 | static void
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| 26 | save_stack_address(void *data, unsigned long addr, int reliable)
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| 27 | {
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| 28 | struct stack_trace *trace = data;
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| 29 |
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| 30 | if (!reliable)
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| 31 | return;
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| 32 |
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| 33 | if (trace->skip > 0) {
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| 34 | trace->skip--;
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| 35 | return;
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| 36 | }
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| 37 |
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| 38 | if (trace->nr_entries < trace->max_entries)
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| 39 | trace->entries[trace->nr_entries++] = addr;
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| 40 | }
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| 41 |
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| 42 | void save_stack_trace(struct stack_trace *trace)
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| 43 | {
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| 44 | unwind_stack(trace, (unsigned long *) &trace, save_stack_address);
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| 45 | }
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| 46 | EXPORT_SYMBOL_GPL(save_stack_trace);
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| 47 |
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| 48 | static void
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| 49 | save_stack_address_nosched(void *data, unsigned long addr, int reliable)
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| 50 | {
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| 51 | struct stack_trace *trace = (struct stack_trace *)data;
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| 52 |
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| 53 | if (!reliable)
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| 54 | return;
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| 55 |
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| 56 | if (in_sched_functions(addr))
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| 57 | return;
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| 58 |
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| 59 | if (trace->skip > 0) {
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| 60 | trace->skip--;
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| 61 | return;
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| 62 | }
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| 63 |
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| 64 | if (trace->nr_entries < trace->max_entries)
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| 65 | trace->entries[trace->nr_entries++] = addr;
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| 66 | }
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| 67 |
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| 68 | void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
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| 69 | {
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| 70 | unsigned long *sp = NULL;
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| 71 |
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| 72 | if (!try_get_task_stack(tsk))
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| 73 | return;
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| 74 |
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| 75 | if (tsk == current)
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| 76 | sp = (unsigned long *) &sp;
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| 77 | else {
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| 78 | unsigned long ksp;
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| 79 |
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| 80 |
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| 81 | ksp = task_thread_info(tsk)->ksp;
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| 82 | ksp += STACK_FRAME_OVERHEAD;
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| 83 | ksp += sizeof(struct pt_regs);
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| 84 |
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| 85 | sp = (unsigned long *) ksp;
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| 86 | }
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| 87 |
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| 88 | unwind_stack(trace, sp, save_stack_address_nosched);
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| 89 |
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| 90 | put_task_stack(tsk);
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| 91 | }
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| 92 | EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
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| 93 |
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| 94 | void
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| 95 | save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
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| 96 | {
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| 97 | unwind_stack(trace, (unsigned long *) regs->sp,
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| 98 | save_stack_address_nosched);
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| 99 | }
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| 100 | EXPORT_SYMBOL_GPL(save_stack_trace_regs);
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