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 556763e5a500d71879d632867b75826551acd49c 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 microblaze 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: Michal Simek monstr@monstr.eu 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/microblaze/kernel/ftrace.c | 15 ++------------- 1 file changed, 2 insertions(+), 13 deletions(-)
--- a/arch/microblaze/kernel/ftrace.c +++ b/arch/microblaze/kernel/ftrace.c @@ -22,8 +22,7 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr) { unsigned long old; - int faulted, err; - struct ftrace_graph_ent trace; + int faulted; unsigned long return_hooker = (unsigned long) &return_to_handler;
@@ -63,18 +62,8 @@ void prepare_ftrace_return(unsigned long return; }
- err = ftrace_push_return_trace(old, self_addr, &trace.depth, 0, NULL); - if (err == -EBUSY) { + if (function_graph_enter(old, self_addr, 0, NULL)) *parent = old; - return; - } - - trace.func = self_addr; - /* Only trace if the calling function expects to */ - if (!ftrace_graph_entry(&trace)) { - current->curr_ret_stack--; - *parent = old; - } } #endif /* CONFIG_FUNCTION_GRAPH_TRACER */