arm/kernel/stacktrace.c

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