x86/kernel/unwind_frame.c

14 unsigned long unwind_get_return_address(struct unwind_state *state)
16 	if (unwind_done(state))
19 	return __kernel_text_address(state->ip) ? state->ip : 0;
23 unsigned long *unwind_get_return_address_ptr(struct unwind_state *state)
25 	if (unwind_done(state))
28 	return state->regs ? &state->regs->ip : state->bp + 1;
31 static void unwind_dump(struct unwind_state *state)
45 			state->stack_info.type, state->stack_info.next_sp,
46 			state->stack_mask, state->graph_idx);
48 	for (sp = PTR_ALIGN(state->orig_sp, sizeof(long)); sp;
50 		if (get_stack_info(sp, state->task, &stack_info, &visit_mask))
80 static inline unsigned long *last_frame(struct unwind_state *state)
82 	return (unsigned long *)task_pt_regs(state->task) - 2;
85 static bool is_last_frame(struct unwind_state *state)
87 	return state->bp == last_frame(state);
96 static inline unsigned long *last_aligned_frame(struct unwind_state *state)
98 	return last_frame(state) - GCC_REALIGN_WORDS;
101 static bool is_last_aligned_frame(struct unwind_state *state)
103 	unsigned long *last_bp = last_frame(state);
104 	unsigned long *aligned_bp = last_aligned_frame(state);
129 	return (state->bp == aligned_bp && *(aligned_bp + 1) == *(last_bp + 1));
132 static bool is_last_ftrace_frame(struct unwind_state *state)
134 	unsigned long *last_bp = last_frame(state);
149 	return (state->bp == last_ftrace_bp &&
150 		*state->bp == *(state->bp + 2) &&
151 		*(state->bp + 1) == *(state->bp + 4));
154 static bool is_last_task_frame(struct unwind_state *state)
156 	return is_last_frame(state) || is_last_aligned_frame(state) ||
157 	       is_last_ftrace_frame(state);
196 static bool update_stack_state(struct unwind_state *state,
199 	struct stack_info *info = &state->stack_info;
205 	if (state->regs)
206 		prev_frame_end = (void *)state->regs + sizeof(*state->regs);
208 		prev_frame_end = (void *)state->bp + FRAME_HEADER_SIZE;
215 		state->got_irq = true;
229 		if (get_stack_info(info->next_sp, state->task, info,
230 				   &state->stack_mask))
234 	if (state->orig_sp && state->stack_info.type == prev_type &&
238 	/* Move state to the next frame: */
240 		state->regs = regs;
241 		state->bp = NULL;
243 		state->bp = next_bp;
244 		state->regs = NULL;
248 	if (state->regs && user_mode(state->regs))
249 		state->ip = 0;
251 		addr_p = unwind_get_return_address_ptr(state);
252 		addr = READ_ONCE_TASK_STACK(state->task, *addr_p);
253 		state->ip = unwind_recover_ret_addr(state, addr, addr_p);
257 	if (!state->orig_sp)
258 		state->orig_sp = frame;
264 bool unwind_next_frame(struct unwind_state *state)
269 	if (unwind_done(state))
273 	if (state->regs && user_mode(state->regs))
276 	if (is_last_task_frame(state)) {
277 		regs = task_pt_regs(state->task);
298 		state->regs = regs;
299 		state->bp = NULL;
300 		state->ip = 0;
305 	if (state->next_bp) {
306 		next_bp = state->next_bp;
307 		state->next_bp = NULL;
308 	} else if (state->regs) {
309 		next_bp = (unsigned long *)state->regs->bp;
311 		next_bp = (unsigned long *)READ_ONCE_TASK_STACK(state->task, *state->bp);
315 	if (!update_stack_state(state, next_bp))
321 	state->error = true;
330 	if (state->task != current)
337 	if (state->got_irq && in_entry_code(state->ip))
339 	if (state->regs &&
340 	    state->regs->sp >= (unsigned long)last_aligned_frame(state) &&
341 	    state->regs->sp < (unsigned long)task_pt_regs(state->task))
351 	if (state->task != current)
354 	if (state->regs) {
357 			state->regs, state->task->comm,
358 			state->task->pid, next_bp);
359 		unwind_dump(state);
363 			state->bp, state->task->comm,
364 			state->task->pid, next_bp);
365 		unwind_dump(state);
368 	state->stack_info.type = STACK_TYPE_UNKNOWN;
373 void __unwind_start(struct unwind_state *state, struct task_struct *task,
378 	memset(state, 0, sizeof(*state));
379 	state->task = task;
380 	state->got_irq = (regs);
384 		state->stack_info.type = STACK_TYPE_UNKNOWN;
400 		state->next_bp = bp;
405 	get_stack_info(bp, state->task, &state->stack_info,
406 		       &state->stack_mask);
407 	update_stack_state(state, bp);
414 	while (!unwind_done(state) &&
415 	       (!on_stack(&state->stack_info, first_frame, sizeof(long)) ||
416 			(state->next_bp == NULL && state->bp < first_frame)))
417 		unwind_next_frame(state);