1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2022 Loongson Technology Corporation Limited
5 #include <linux/kernel.h>
6 #include <linux/ftrace.h>
8 #include <asm/unwind.h>
10 unsigned long unwind_get_return_address(struct unwind_state *state)
12 if (unwind_done(state))
14 else if (state->first)
17 return *(unsigned long *)(state->sp);
19 EXPORT_SYMBOL_GPL(unwind_get_return_address);
21 void unwind_start(struct unwind_state *state, struct task_struct *task,
24 memset(state, 0, sizeof(*state));
27 state->sp = regs->regs[3];
28 state->pc = regs->csr_era;
34 get_stack_info(state->sp, state->task, &state->stack_info);
36 if (!unwind_done(state) && !__kernel_text_address(state->pc))
37 unwind_next_frame(state);
39 EXPORT_SYMBOL_GPL(unwind_start);
41 bool unwind_next_frame(struct unwind_state *state)
43 struct stack_info *info = &state->stack_info;
46 if (unwind_done(state))
53 for (state->sp += sizeof(unsigned long);
54 state->sp < info->end;
55 state->sp += sizeof(unsigned long)) {
56 addr = *(unsigned long *)(state->sp);
57 state->pc = ftrace_graph_ret_addr(state->task, &state->graph_idx,
58 addr, (unsigned long *)(state->sp - GRAPH_FAKE_OFFSET));
59 if (__kernel_text_address(addr))
63 state->sp = info->next_sp;
65 } while (!get_stack_info(state->sp, state->task, info));
69 EXPORT_SYMBOL_GPL(unwind_next_frame);