From b0e21a61d3196762b61f43ae994ffd255f646774 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Mon, 19 Nov 2018 20:54:08 -0500 Subject: function_graph: Have profiler use new helper ftrace_graph_get_ret_stack() The ret_stack processing is going to change, and that is going to break anything that is accessing the ret_stack directly. One user is the function graph profiler. By using the ftrace_graph_get_ret_stack() helper function, the profiler can access the ret_stack entry without relying on the implementation details of the stack itself. Reviewed-by: Joel Fernandes (Google) Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/fgraph.c | 11 +++++++++++ kernel/trace/ftrace.c | 21 +++++++++++---------- 2 files changed, 22 insertions(+), 10 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c index 90fcefcaff2a..a3704ec8b599 100644 --- a/kernel/trace/fgraph.c +++ b/kernel/trace/fgraph.c @@ -232,6 +232,17 @@ unsigned long ftrace_return_to_handler(unsigned long frame_pointer) return ret; } +struct ftrace_ret_stack * +ftrace_graph_get_ret_stack(struct task_struct *task, int idx) +{ + idx = current->curr_ret_stack - idx; + + if (idx >= 0 && idx <= task->curr_ret_stack) + return ¤t->ret_stack[idx]; + + return NULL; +} + /** * ftrace_graph_ret_addr - convert a potentially modified stack return address * to its original value diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index d06fe588e650..8ef9fc226037 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -792,7 +792,7 @@ void ftrace_graph_graph_time_control(bool enable) static int profile_graph_entry(struct ftrace_graph_ent *trace) { - int index = current->curr_ret_stack; + struct ftrace_ret_stack *ret_stack; function_profile_call(trace->func, 0, NULL, NULL); @@ -800,14 +800,16 @@ static int profile_graph_entry(struct ftrace_graph_ent *trace) if (!current->ret_stack) return 0; - if (index >= 0 && index < FTRACE_RETFUNC_DEPTH) - current->ret_stack[index].subtime = 0; + ret_stack = ftrace_graph_get_ret_stack(current, 0); + if (ret_stack) + ret_stack->subtime = 0; return 1; } static void profile_graph_return(struct ftrace_graph_ret *trace) { + struct ftrace_ret_stack *ret_stack; struct ftrace_profile_stat *stat; unsigned long long calltime; struct ftrace_profile *rec; @@ -825,16 +827,15 @@ static void profile_graph_return(struct ftrace_graph_ret *trace) calltime = trace->rettime - trace->calltime; if (!fgraph_graph_time) { - int index; - - index = current->curr_ret_stack; /* Append this call time to the parent time to subtract */ - if (index) - current->ret_stack[index - 1].subtime += calltime; + ret_stack = ftrace_graph_get_ret_stack(current, 1); + if (ret_stack) + ret_stack->subtime += calltime; - if (current->ret_stack[index].subtime < calltime) - calltime -= current->ret_stack[index].subtime; + ret_stack = ftrace_graph_get_ret_stack(current, 0); + if (ret_stack && ret_stack->subtime < calltime) + calltime -= ret_stack->subtime; else calltime = 0; } -- cgit v1.2.3