1 #include <linux/sched.h>
2 #include <linux/ftrace.h>
3 #include <asm/ptrace.h>
4 #include <asm/bitops.h>
5 #include <asm/stacktrace.h>
6 #include <asm/unwind.h>
8 unsigned long unwind_get_return_address(struct unwind_state *state)
12 if (unwind_done(state))
15 addr = READ_ONCE_NOCHECK(*state->sp);
17 return ftrace_graph_ret_addr(state->task, &state->graph_idx,
20 EXPORT_SYMBOL_GPL(unwind_get_return_address);
22 bool unwind_next_frame(struct unwind_state *state)
24 struct stack_info *info = &state->stack_info;
26 if (unwind_done(state))
30 for (state->sp++; state->sp < info->end; state->sp++) {
31 unsigned long addr = READ_ONCE_NOCHECK(*state->sp);
33 if (__kernel_text_address(addr))
37 state->sp = info->next_sp;
39 } while (!get_stack_info(state->sp, state->task, info,
44 EXPORT_SYMBOL_GPL(unwind_next_frame);
46 void __unwind_start(struct unwind_state *state, struct task_struct *task,
47 struct pt_regs *regs, unsigned long *first_frame)
49 memset(state, 0, sizeof(*state));
52 state->sp = first_frame;
54 get_stack_info(first_frame, state->task, &state->stack_info,
58 * The caller can provide the address of the first frame directly
59 * (first_frame) or indirectly (regs->sp) to indicate which stack frame
60 * to start unwinding at. Skip ahead until we reach it.
62 if (!unwind_done(state) &&
63 (!on_stack(&state->stack_info, first_frame, sizeof(long)) ||
64 !__kernel_text_address(*first_frame)))
65 unwind_next_frame(state);
67 EXPORT_SYMBOL_GPL(__unwind_start);