diff --git a/include/linux/sched.h b/include/linux/sched.h index a51c13c2b1a0..d6183a55e8eb 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1116,6 +1116,7 @@ struct task_struct { #ifdef CONFIG_FUNCTION_GRAPH_TRACER /* Index of current stored address in ret_stack: */ int curr_ret_stack; + int curr_ret_depth; /* Stack of return addresses for return function tracing: */ struct ftrace_ret_stack *ret_stack; diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index f536f601bd46..48513954713c 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -6814,6 +6814,7 @@ static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) atomic_set(&t->tracing_graph_pause, 0); atomic_set(&t->trace_overrun, 0); t->curr_ret_stack = -1; + t->curr_ret_depth = -1; /* Make sure the tasks see the -1 first: */ smp_wmb(); t->ret_stack = ret_stack_list[start++]; @@ -7038,6 +7039,7 @@ graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack) void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { t->curr_ret_stack = -1; + t->curr_ret_depth = -1; /* * The idle task has no parent, it either has its own * stack or no stack at all. @@ -7068,6 +7070,7 @@ void ftrace_graph_init_task(struct task_struct *t) /* Make sure we do not use the parent ret_stack */ t->ret_stack = NULL; t->curr_ret_stack = -1; + t->curr_ret_depth = -1; if (ftrace_graph_active) { struct ftrace_ret_stack *ret_stack; diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index 88ca787a1cdc..02d4081a7f5a 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -119,7 +119,7 @@ print_graph_duration(struct trace_array *tr, unsigned long long duration, /* Add a function return address to the trace stack on thread info.*/ static int -ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth, +ftrace_push_return_trace(unsigned long ret, unsigned long func, unsigned long frame_pointer, unsigned long *retp) { unsigned long long calltime; @@ -177,8 +177,6 @@ ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth, #ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR current->ret_stack[index].retp = retp; #endif - *depth = current->curr_ret_stack; - return 0; } @@ -188,14 +186,20 @@ int function_graph_enter(unsigned long ret, unsigned long func, struct ftrace_graph_ent trace; trace.func = func; - trace.depth = current->curr_ret_stack + 1; + trace.depth = ++current->curr_ret_depth; /* Only trace if the calling function expects to */ if (!ftrace_graph_entry(&trace)) - return -EBUSY; + goto out; - return ftrace_push_return_trace(ret, func, &trace.depth, - frame_pointer, retp); + if (ftrace_push_return_trace(ret, func, + frame_pointer, retp)) + goto out; + + return 0; + out: + current->curr_ret_depth--; + return -EBUSY; } /* Retrieve a function return address to the trace stack on thread info.*/ @@ -257,7 +261,7 @@ ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret, trace->func = current->ret_stack[index].func; trace->calltime = current->ret_stack[index].calltime; trace->overrun = atomic_read(¤t->trace_overrun); - trace->depth = index; + trace->depth = current->curr_ret_depth; } /* @@ -273,6 +277,7 @@ unsigned long ftrace_return_to_handler(unsigned long frame_pointer) trace.rettime = trace_clock_local(); barrier(); current->curr_ret_stack--; + current->curr_ret_depth--; /* * The curr_ret_stack can be less than -1 only if it was * filtered out and it's about to return from the function.