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> 7 8 unsigned long unwind_get_return_address(struct unwind_state *state) 9 { 10 if (unwind_done(state)) 11 return 0; 12 13 return ftrace_graph_ret_addr(state->task, &state->graph_idx, 14 *state->sp, state->sp); 15 } 16 EXPORT_SYMBOL_GPL(unwind_get_return_address); 17 18 bool unwind_next_frame(struct unwind_state *state) 19 { 20 struct stack_info *info = &state->stack_info; 21 22 if (unwind_done(state)) 23 return false; 24 25 do { 26 for (state->sp++; state->sp < info->end; state->sp++) 27 if (__kernel_text_address(*state->sp)) 28 return true; 29 30 state->sp = info->next_sp; 31 32 } while (!get_stack_info(state->sp, state->task, info, 33 &state->stack_mask)); 34 35 return false; 36 } 37 EXPORT_SYMBOL_GPL(unwind_next_frame); 38 39 void __unwind_start(struct unwind_state *state, struct task_struct *task, 40 struct pt_regs *regs, unsigned long *first_frame) 41 { 42 memset(state, 0, sizeof(*state)); 43 44 state->task = task; 45 state->sp = first_frame; 46 47 get_stack_info(first_frame, state->task, &state->stack_info, 48 &state->stack_mask); 49 50 /* 51 * The caller can provide the address of the first frame directly 52 * (first_frame) or indirectly (regs->sp) to indicate which stack frame 53 * to start unwinding at. Skip ahead until we reach it. 54 */ 55 if (!unwind_done(state) && 56 (!on_stack(&state->stack_info, first_frame, sizeof(long)) || 57 !__kernel_text_address(*first_frame))) 58 unwind_next_frame(state); 59 } 60 EXPORT_SYMBOL_GPL(__unwind_start); 61