* [for-next][PATCH 09/18] powerpc/function_graph: Simplify with function_graph_entry()
[not found] <20181122002801.501220343@goodmis.org>
@ 2018-11-22 0:28 ` Steven Rostedt
2018-11-23 7:30 ` Sasha Levin
0 siblings, 1 reply; 2+ messages in thread
From: Steven Rostedt @ 2018-11-22 0:28 UTC (permalink / raw)
To: linux-kernel
Cc: linux-arch, Peter Zijlstra, Frederic Weisbecker, linuxppc-dev,
stable, Thomas Gleixner, Masami Hiramatsu, Andy Lutomirski,
Josh Poimboeuf, Joel Fernandes, Paul Mackerras, Andrew Morton,
Linus Torvalds, Ingo Molnar
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
The function_graph_entry() 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 powerpc 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: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: stable@kernel.org
Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
arch/powerpc/kernel/trace/ftrace.c | 15 ++-------------
1 file changed, 2 insertions(+), 13 deletions(-)
diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index 4bf051d3e21e..b65c8a34ad6e 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -950,7 +950,6 @@ int ftrace_disable_ftrace_graph_caller(void)
*/
unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip)
{
- struct ftrace_graph_ent trace;
unsigned long return_hooker;
if (unlikely(ftrace_graph_is_dead()))
@@ -961,18 +960,8 @@ unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip)
return_hooker = ppc_function_entry(return_to_handler);
- trace.func = ip;
- trace.depth = current->curr_ret_stack + 1;
-
- /* Only trace if the calling function expects to */
- if (!ftrace_graph_entry(&trace))
- goto out;
-
- if (ftrace_push_return_trace(parent, ip, &trace.depth, 0,
- NULL) == -EBUSY)
- goto out;
-
- parent = return_hooker;
+ if (!function_graph_enter(parent, ip, 0, NULL))
+ parent = return_hooker;
out:
return parent;
}
--
2.19.1
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