From a87532c78d291265efadc4b20a8c7a70cd59ea29 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Sun, 18 Nov 2018 17:27:43 -0500 Subject: [PATCH] parisc: 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 parisc 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: "James E.J. Bottomley" Cc: Helge Deller Cc: linux-parisc@vger.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/parisc/kernel/ftrace.c | 17 +++-------------- 1 file changed, 3 insertions(+), 14 deletions(-) diff --git a/arch/parisc/kernel/ftrace.c b/arch/parisc/kernel/ftrace.c index 6fa8535d3cce..e46a4157a894 100644 --- a/arch/parisc/kernel/ftrace.c +++ b/arch/parisc/kernel/ftrace.c @@ -30,7 +30,6 @@ static void __hot prepare_ftrace_return(unsigned long *parent, unsigned long self_addr) { unsigned long old; - struct ftrace_graph_ent trace; extern int parisc_return_to_handler; if (unlikely(ftrace_graph_is_dead())) @@ -41,19 +40,9 @@ static void __hot prepare_ftrace_return(unsigned long *parent, old = *parent; - trace.func = self_addr; - trace.depth = current->curr_ret_stack + 1; - - /* Only trace if the calling function expects to */ - if (!ftrace_graph_entry(&trace)) - return; - - if (ftrace_push_return_trace(old, self_addr, &trace.depth, - 0, NULL) == -EBUSY) - return; - - /* activate parisc_return_to_handler() as return point */ - *parent = (unsigned long) &parisc_return_to_handler; + if (!function_graph_enter(old, self_addr, 0, NULL)) + /* activate parisc_return_to_handler() as return point */ + *parent = (unsigned long) &parisc_return_to_handler; } #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ -- 2.30.2