* [PATCH 4.19 106/139] parisc: function_graph: Simplify with function_graph_enter()
[not found] <20181204103649.950154335@linuxfoundation.org>
@ 2018-12-04 10:49 ` Greg Kroah-Hartman
0 siblings, 0 replies; only message in thread
From: Greg Kroah-Hartman @ 2018-12-04 10:49 UTC (permalink / raw)
To: linux-kernel
Cc: Greg Kroah-Hartman, stable, James E.J. Bottomley, Helge Deller,
linux-parisc, stable, Masami Hiramatsu, Steven Rostedt (VMware)
4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Steven Rostedt (VMware) <rostedt@goodmis.org>
commit a87532c78d291265efadc4b20a8c7a70cd59ea29 upstream.
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" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
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 <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/parisc/kernel/ftrace.c | 17 +++--------------
1 file changed, 3 insertions(+), 14 deletions(-)
--- a/arch/parisc/kernel/ftrace.c
+++ b/arch/parisc/kernel/ftrace.c
@@ -30,7 +30,6 @@ static void __hot prepare_ftrace_return(
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(
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 */
^ permalink raw reply [flat|nested] only message in thread