| 1 | // SPDX-License-Identifier: GPL-2.0-only |
|---|---|
| 2 | /* |
| 3 | * Stacktrace support for Hexagon |
| 4 | * |
| 5 | * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved. |
| 6 | */ |
| 7 | |
| 8 | #include <linux/sched.h> |
| 9 | #include <linux/sched/task_stack.h> |
| 10 | #include <linux/stacktrace.h> |
| 11 | #include <linux/thread_info.h> |
| 12 | #include <linux/module.h> |
| 13 | |
| 14 | struct stackframe { |
| 15 | unsigned long fp; |
| 16 | unsigned long rets; |
| 17 | }; |
| 18 | |
| 19 | /* |
| 20 | * Save stack-backtrace addresses into a stack_trace buffer. |
| 21 | */ |
| 22 | void save_stack_trace(struct stack_trace *trace) |
| 23 | { |
| 24 | unsigned long low, high; |
| 25 | unsigned long fp; |
| 26 | struct stackframe *frame; |
| 27 | int skip = trace->skip; |
| 28 | |
| 29 | low = (unsigned long)task_stack_page(current); |
| 30 | high = low + THREAD_SIZE; |
| 31 | fp = (unsigned long)__builtin_frame_address(0); |
| 32 | |
| 33 | while (fp >= low && fp <= (high - sizeof(*frame))) { |
| 34 | frame = (struct stackframe *)fp; |
| 35 | |
| 36 | if (skip) { |
| 37 | skip--; |
| 38 | } else { |
| 39 | trace->entries[trace->nr_entries++] = frame->rets; |
| 40 | if (trace->nr_entries >= trace->max_entries) |
| 41 | break; |
| 42 | } |
| 43 | |
| 44 | /* |
| 45 | * The next frame must be at a higher address than the |
| 46 | * current frame. |
| 47 | */ |
| 48 | low = fp + sizeof(*frame); |
| 49 | fp = frame->fp; |
| 50 | } |
| 51 | } |
| 52 | EXPORT_SYMBOL_GPL(save_stack_trace); |
| 53 |