16  * Unwind the current stack frame and store the new register values in the
47 static int frame_pointer_check(struct stackframe *frame)  in frame_pointer_check()  argument
50 	unsigned long fp = frame->fp;  in frame_pointer_check()
51 	unsigned long pc = frame->pc;  in frame_pointer_check()
63 	low = frame->sp;  in frame_pointer_check()
66 	/* check current frame pointer is within bounds */  in frame_pointer_check()
78 int notrace unwind_frame(struct stackframe *frame)  in unwind_frame()  argument
80 	unsigned long fp = frame->fp;  in unwind_frame()
82 	if (frame_pointer_check(frame))  in unwind_frame()
89 	if (frame->ex_frame) {  in unwind_frame()
90 		struct pt_regs *regs = (struct pt_regs *)frame->sp;  in unwind_frame()
96 		 * when frame->ex_frame is a false positive.  in unwind_frame()
98 		if ((unsigned long)&regs[1] > ALIGN(frame->sp, THREAD_SIZE))  in unwind_frame()
101 		frame->pc = regs->ARM_pc;  in unwind_frame()
102 		frame->ex_frame = false;  in unwind_frame()
106 	/* restore the registers from the stack frame */  in unwind_frame()
108 	frame->sp = frame->fp;  in unwind_frame()
109 	frame->fp = READ_ONCE_NOCHECK(*(unsigned long *)(fp));  in unwind_frame()
110 	frame->pc = READ_ONCE_NOCHECK(*(unsigned long *)(fp + 4));  in unwind_frame()
112 	frame->fp = READ_ONCE_NOCHECK(*(unsigned long *)(fp - 12));  in unwind_frame()
113 	frame->sp = READ_ONCE_NOCHECK(*(unsigned long *)(fp - 8));  in unwind_frame()
114 	frame->pc = READ_ONCE_NOCHECK(*(unsigned long *)(fp - 4));  in unwind_frame()
117 	if (is_kretprobe_trampoline(frame->pc))  in unwind_frame()
118 		frame->pc = kretprobe_find_ret_addr(frame->tsk,  in unwind_frame()
119 					(void *)frame->fp, &frame->kr_cur);  in unwind_frame()
122 	if (in_entry_text(frame->pc))  in unwind_frame()
123 		frame->ex_frame = true;  in unwind_frame()
129 void notrace walk_stackframe(struct stackframe *frame,  in walk_stackframe()  argument
135 		if (!fn(data, frame->pc))  in walk_stackframe()
137 		ret = unwind_frame(frame);  in walk_stackframe()
145 static void start_stack_trace(struct stackframe *frame, struct task_struct *task,  in start_stack_trace()  argument
149 	frame->fp = fp;  in start_stack_trace()
150 	frame->sp = sp;  in start_stack_trace()
151 	frame->lr = lr;  in start_stack_trace()
152 	frame->pc = pc;  in start_stack_trace()
154 	frame->kr_cur = NULL;  in start_stack_trace()
155 	frame->tsk = task;  in start_stack_trace()
158 	frame->ex_frame = in_entry_text(frame->pc);  in start_stack_trace()
165 	struct stackframe frame;  in arch_stack_walk()  local
168 		start_stack_trace(&frame, NULL, regs->ARM_fp, regs->ARM_sp,  in arch_stack_walk()
179 		start_stack_trace(&frame, task, thread_saved_fp(task),  in arch_stack_walk()
185 		start_stack_trace(&frame, task,  in arch_stack_walk()
191 		if (unwind_frame(&frame))  in arch_stack_walk()
195 	walk_stackframe(&frame, consume_entry, cookie);  in arch_stack_walk()