From 761efe8a94cfcd0a3dd90f2008411550f3520b63 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Sun, 18 Nov 2018 18:44:04 -0500 Subject: [PATCH] function_graph: Remove the use of FTRACE_NOTRACE_DEPTH The curr_ret_stack is no longer set to a negative value when a function is not to be traced by the function graph tracer. Remove the usage of FTRACE_NOTRACE_DEPTH, as it is no longer needed. Reviewed-by: Joel Fernandes (Google) Signed-off-by: Steven Rostedt (VMware) --- include/linux/ftrace.h | 1 - kernel/trace/fgraph.c | 19 ------------------- kernel/trace/trace_functions_graph.c | 11 ----------- 3 files changed, 31 deletions(-) diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 10bd464..98625f10 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -790,7 +790,6 @@ unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx, */ #define __notrace_funcgraph notrace -#define FTRACE_NOTRACE_DEPTH 65536 #define FTRACE_RETFUNC_DEPTH 50 #define FTRACE_RETSTACK_ALLOC_SIZE 32 extern int register_ftrace_graph(trace_func_graph_ret_t retfunc, diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c index e852b69..de887a9 100644 --- a/kernel/trace/fgraph.c +++ b/kernel/trace/fgraph.c @@ -112,16 +112,6 @@ ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret, index = current->curr_ret_stack; - /* - * A negative index here means that it's just returned from a - * notrace'd function. Recover index to get an original - * return address. See ftrace_push_return_trace(). - * - * TODO: Need to check whether the stack gets corrupted. - */ - if (index < 0) - index += FTRACE_NOTRACE_DEPTH; - if (unlikely(index < 0 || index >= FTRACE_RETFUNC_DEPTH)) { ftrace_graph_stop(); WARN_ON(1); @@ -190,15 +180,6 @@ unsigned long ftrace_return_to_handler(unsigned long frame_pointer) */ barrier(); current->curr_ret_stack--; - /* - * The curr_ret_stack can be less than -1 only if it was - * filtered out and it's about to return from the function. - * Recover the index and continue to trace normal functions. - */ - if (current->curr_ret_stack < -1) { - current->curr_ret_stack += FTRACE_NOTRACE_DEPTH; - return ret; - } if (unlikely(!ret)) { ftrace_graph_stop(); diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index ecf543d..eaf9b16 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -115,9 +115,6 @@ unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx, if (ret != (unsigned long)return_to_handler) return ret; - if (index < -1) - index += FTRACE_NOTRACE_DEPTH; - if (index < 0) return ret; @@ -675,10 +672,6 @@ print_graph_entry_leaf(struct trace_iterator *iter, cpu_data = per_cpu_ptr(data->cpu_data, cpu); - /* If a graph tracer ignored set_graph_notrace */ - if (call->depth < -1) - call->depth += FTRACE_NOTRACE_DEPTH; - /* * Comments display at + 1 to depth. Since * this is a leaf function, keep the comments @@ -721,10 +714,6 @@ print_graph_entry_nested(struct trace_iterator *iter, struct fgraph_cpu_data *cpu_data; int cpu = iter->cpu; - /* If a graph tracer ignored set_graph_notrace */ - if (call->depth < -1) - call->depth += FTRACE_NOTRACE_DEPTH; - cpu_data = per_cpu_ptr(data->cpu_data, cpu); cpu_data->depth = call->depth; -- 2.7.4