* [PATCH 4.19 103/139] powerpc/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, Paul Mackerras, Masami Hiramatsu,
Steven Rostedt (VMware), linuxppc-dev, stable
4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Steven Rostedt (VMware) <rostedt@goodmis.org>
commit fe60522ec60082a1dd735691b82c64f65d4ad15e 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 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")
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/powerpc/kernel/trace/ftrace.c | 15 ++-------------
1 file changed, 2 insertions(+), 13 deletions(-)
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -697,7 +697,6 @@ int ftrace_disable_ftrace_graph_caller(v
*/
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()))
@@ -708,18 +707,8 @@ unsigned long prepare_ftrace_return(unsi
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;
}
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