1 // SPDX-License-Identifier: GPL-2.0
11 unsigned long unwind_get_return_address(struct unwind_state *state)  in unwind_get_return_address()  argument
14 	if (unwind_done(state))  in unwind_get_return_address()
16 	else if (state->type)  in unwind_get_return_address()
17 		return state->pc;  in unwind_get_return_address()
18 	else if (state->first)  in unwind_get_return_address()
19 		return state->pc;  in unwind_get_return_address()
21 	return *(unsigned long *)(state->sp);  in unwind_get_return_address()
26 static bool unwind_by_guess(struct unwind_state *state)  in unwind_by_guess()  argument
28 	struct stack_info *info = &state->stack_info;  in unwind_by_guess()
31 	for (state->sp += sizeof(unsigned long);  in unwind_by_guess()
32 	     state->sp < info->end;  in unwind_by_guess()
33 	     state->sp += sizeof(unsigned long)) {  in unwind_by_guess()
34 		addr = *(unsigned long *)(state->sp);  in unwind_by_guess()
42 static bool unwind_by_prologue(struct unwind_state *state)  in unwind_by_prologue()  argument
44 	struct stack_info *info = &state->stack_info;  in unwind_by_prologue()
46 	long frame_ra = -1;  in unwind_by_prologue()
48 	unsigned long size, offset, pc = state->pc;  in unwind_by_prologue()
50 	if (state->sp >= info->end || state->sp < info->begin)  in unwind_by_prologue()
56 	ip = (union loongarch_instruction *)(pc - offset);  in unwind_by_prologue()
61 			frame_size = (1 << 12) - ip->reg2i12_format.immediate;  in unwind_by_prologue()
69 		if (state->first)  in unwind_by_prologue()
77 			frame_ra = ip->reg2i12_format.immediate;  in unwind_by_prologue()
86 		if (state->first) {  in unwind_by_prologue()
87 			state->sp = state->sp + frame_size;  in unwind_by_prologue()
93 	if (state->first)  in unwind_by_prologue()
94 		state->first = false;  in unwind_by_prologue()
96 	state->pc = *(unsigned long *)(state->sp + frame_ra);  in unwind_by_prologue()
97 	state->sp = state->sp + frame_size;  in unwind_by_prologue()
98 	return !!__kernel_text_address(state->pc);  in unwind_by_prologue()
101 	state->first = false;  in unwind_by_prologue()
102 	if (state->pc == state->ra)  in unwind_by_prologue()
105 	state->pc = state->ra;  in unwind_by_prologue()
107 	return !!__kernel_text_address(state->ra);  in unwind_by_prologue()
110 void unwind_start(struct unwind_state *state, struct task_struct *task,  in unwind_start()  argument
113 	memset(state, 0, sizeof(*state));  in unwind_start()
115 	if (regs &&  __kernel_text_address(regs->csr_era)) {  in unwind_start()
116 		state->pc = regs->csr_era;  in unwind_start()
117 		state->sp = regs->regs[3];  in unwind_start()
118 		state->ra = regs->regs[1];  in unwind_start()
119 		state->type = UNWINDER_PROLOGUE;  in unwind_start()
122 	state->task = task;  in unwind_start()
123 	state->first = true;  in unwind_start()
125 	get_stack_info(state->sp, state->task, &state->stack_info);  in unwind_start()
127 	if (!unwind_done(state) && !__kernel_text_address(state->pc))  in unwind_start()
128 		unwind_next_frame(state);  in unwind_start()
132 bool unwind_next_frame(struct unwind_state *state)  in unwind_next_frame()  argument
134 	struct stack_info *info = &state->stack_info;  in unwind_next_frame()
138 	if (unwind_done(state))  in unwind_next_frame()
142 		switch (state->type) {  in unwind_next_frame()
144 			state->first = false;  in unwind_next_frame()
145 			if (unwind_by_guess(state))  in unwind_next_frame()
150 			if (unwind_by_prologue(state))  in unwind_next_frame()
153 			if (info->type == STACK_TYPE_IRQ &&  in unwind_next_frame()
154 				info->end == state->sp) {  in unwind_next_frame()
155 				regs = (struct pt_regs *)info->next_sp;  in unwind_next_frame()
156 				pc = regs->csr_era;  in unwind_next_frame()
161 				state->pc = pc;  in unwind_next_frame()
162 				state->sp = regs->regs[3];  in unwind_next_frame()
163 				state->ra = regs->regs[1];  in unwind_next_frame()
164 				state->first = true;  in unwind_next_frame()
165 				get_stack_info(state->sp, state->task, info);  in unwind_next_frame()
171 		state->sp = info->next_sp;  in unwind_next_frame()
173 	} while (!get_stack_info(state->sp, state->task, info));  in unwind_next_frame()