1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Stack trace management functions
4  *
5  * Copyright (C) 2022 Loongson Technology Corporation Limited
6  */
7 #include <linux/sched.h>
8 #include <linux/stacktrace.h>
9 
10 #include <asm/stacktrace.h>
11 #include <asm/unwind.h>
12 
13 void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie,
14 		     struct task_struct *task, struct pt_regs *regs)
15 {
16 	unsigned long addr;
17 	struct pt_regs dummyregs;
18 	struct unwind_state state;
19 
20 	regs = &dummyregs;
21 
22 	if (task == current) {
23 		regs->regs[3] = (unsigned long)__builtin_frame_address(0);
24 		regs->csr_era = (unsigned long)__builtin_return_address(0);
25 	} else {
26 		regs->regs[3] = thread_saved_fp(task);
27 		regs->csr_era = thread_saved_ra(task);
28 	}
29 
30 	regs->regs[1] = 0;
31 	for (unwind_start(&state, task, regs);
32 	      !unwind_done(&state); unwind_next_frame(&state)) {
33 		addr = unwind_get_return_address(&state);
34 		if (!addr || !consume_entry(cookie, addr))
35 			break;
36 	}
37 }
38