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)
10 unsigned long addr = READ_ONCE_NOCHECK(*state->sp);
12 if (unwind_done(state))
15 return ftrace_graph_ret_addr(state->task, &state->graph_idx,
18 EXPORT_SYMBOL_GPL(unwind_get_return_address);
20 bool unwind_next_frame(struct unwind_state *state)
22 struct stack_info *info = &state->stack_info;
24 if (unwind_done(state))
28 unsigned long addr = READ_ONCE_NOCHECK(*state->sp);
30 for (state->sp++; state->sp < info->end; state->sp++)
31 if (__kernel_text_address(addr))
34 state->sp = info->next_sp;
36 } while (!get_stack_info(state->sp, state->task, info,
41 EXPORT_SYMBOL_GPL(unwind_next_frame);
43 void __unwind_start(struct unwind_state *state, struct task_struct *task,
44 struct pt_regs *regs, unsigned long *first_frame)
46 memset(state, 0, sizeof(*state));
49 state->sp = first_frame;
51 get_stack_info(first_frame, state->task, &state->stack_info,
55 * The caller can provide the address of the first frame directly
56 * (first_frame) or indirectly (regs->sp) to indicate which stack frame
57 * to start unwinding at. Skip ahead until we reach it.
59 if (!unwind_done(state) &&
60 (!on_stack(&state->stack_info, first_frame, sizeof(long)) ||
61 !__kernel_text_address(*first_frame)))
62 unwind_next_frame(state);
64 EXPORT_SYMBOL_GPL(__unwind_start);