From 07f7175b43827640d1e69c9eded89aa089a234b4 Mon Sep 17 00:00:00 2001 From: Steven Rostedt (VMware) Date: Sun, 18 Nov 2018 17:14:10 -0500 Subject: x86/function_graph: Simplify with function_graph_enter() The function_graph_enter() function does the work of calling the function graph hook function and the management of the shadow stack, simplifying the work done in the architecture dependent prepare_ftrace_return(). Have x86 use the new code, and remove the shadow stack management as well as having to set up the trace structure. This is needed to prepare for a fix of a design bug on how the curr_ret_stack is used. Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: "H. Peter Anvin" Cc: x86@kernel.org Cc: stable@kernel.org Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback") Reviewed-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- arch/x86/kernel/ftrace.c | 15 +-------------- 1 file changed, 1 insertion(+), 14 deletions(-) diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index 01ebcb6f263e..7ee8067cbf45 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -994,7 +994,6 @@ void prepare_ftrace_return(unsigned long self_addr, unsigned long *parent, { unsigned long old; int faulted; - struct ftrace_graph_ent trace; unsigned long return_hooker = (unsigned long) &return_to_handler; @@ -1046,19 +1045,7 @@ void prepare_ftrace_return(unsigned long self_addr, unsigned long *parent, return; } - trace.func = self_addr; - trace.depth = current->curr_ret_stack + 1; - - /* Only trace if the calling function expects to */ - if (!ftrace_graph_entry(&trace)) { + if (function_graph_enter(old, self_addr, frame_pointer, parent)) *parent = old; - return; - } - - if (ftrace_push_return_trace(old, self_addr, &trace.depth, - frame_pointer, parent) == -EBUSY) { - *parent = old; - return; - } } #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ -- cgit v1.2.3-55-g7522