4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
commit e949b6db51dc172a35c962bc4414ca148315fe21 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 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 <greentime@xxxxxxxxxxxxx>
Cc: Alan Kao <alankao@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxx
Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Reviewed-by: Palmer Dabbelt <palmer@xxxxxxxxxx>
Reviewed-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/riscv/kernel/ftrace.c | 14 ++------------
1 file changed, 2 insertions(+), 12 deletions(-)
--- a/arch/riscv/kernel/ftrace.c
+++ b/arch/riscv/kernel/ftrace.c
@@ -132,7 +132,6 @@ void prepare_ftrace_return(unsigned long
{
unsigned long return_hooker = (unsigned long)&return_to_handler;
unsigned long old;
- struct ftrace_graph_ent trace;
int err;
if (unlikely(atomic_read(¤t->tracing_graph_pause)))
@@ -144,17 +143,8 @@ void prepare_ftrace_return(unsigned long
*/
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
