4.19-stable review patch. If anyone has any objections, please let me know.
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From: Steven Rostedt (VMware) rostedt@goodmis.org
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@andestech.com Cc: Alan Kao alankao@andestech.com Cc: stable@kernel.org Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback") Reviewed-by: Palmer Dabbelt palmer@sifive.com 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/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