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FAILED: patch "[PATCH] riscv/function_graph: Simplify with function_graph_enter()" failed to apply to 4.4-stable tree

PATCH [email protected] 1 participant 1 message Dec 3, 2018

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The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

Quoted 1 line

From e949b6db51dc172a35c962bc4414ca148315fe21 Mon Sep 17 00:00:00 2001

From: "Steven Rostedt (VMware)" <[email protected]>
Date: Sun, 18 Nov 2018 17:31:44 -0500
Subject: [PATCH] riscv/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 riscv 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 Greentime Hu <[email protected]>
Cc Alan Kao <[email protected]>
Cc [email protected]
Fixes 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Reviewed-by Palmer Dabbelt <[email protected]>
Reviewed-by Masami Hiramatsu <[email protected]>
Signed-off-by Steven Rostedt (VMware) <[email protected]>
arch/riscv/kernel/ftrace.c +2 -12
index 1157b6b52d25..c433f6d3dd64 100644
@@ -132,7 +132,6 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
 {
 	unsigned long return_hooker = (unsigned long)&return_to_handler;
 	unsigned long old;
-	struct ftrace_graph_ent trace;
 	int err;
 
 	if (unlikely(atomic_read(&current->tracing_graph_pause)))

@@ -144,17 +143,8 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
 	 */
 	old = *parent;
 
-	trace.func = self_addr;
-	trace.depth = current->curr_ret_stack + 1;
-
-	if (!ftrace_graph_entry(&trace))
-		return;
-
-	err = ftrace_push_return_trace(old, self_addr, &trace.depth,
-				       frame_pointer, parent);
-	if (err == -EBUSY)
-		return;
-	*parent = return_hooker;
+	if (function_graph_enter(old, self_addr, frame_pointer, parent))
+		*parent = return_hooker;
 }
 
 #ifdef CONFIG_DYNAMIC_FTRACE