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FAILED: patch "[PATCH] parisc: 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 a87532c78d291265efadc4b20a8c7a70cd59ea29 Mon Sep 17 00:00:00 2001

From: "Steven Rostedt (VMware)" <[email protected]>
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" <[email protected]>
Cc Helge Deller <[email protected]>
Fixes 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
arch/parisc/kernel/ftrace.c +3 -14
index 6fa8535d3cce..e46a4157a894 100644
@@ -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 */