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 a87532c78d291265efadc4b20a8c7a70cd59ea29 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 parisc 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: "James E.J. Bottomley" jejb@parisc-linux.org Cc: Helge Deller deller@gmx.de Cc: linux-parisc@vger.kernel.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/parisc/kernel/ftrace.c | 17 +++-------------- 1 file changed, 3 insertions(+), 14 deletions(-)
--- a/arch/parisc/kernel/ftrace.c +++ b/arch/parisc/kernel/ftrace.c @@ -30,7 +30,6 @@ static void __hot prepare_ftrace_return( unsigned long self_addr) { unsigned long old; - struct ftrace_graph_ent trace; extern int parisc_return_to_handler;
if (unlikely(ftrace_graph_is_dead())) @@ -41,19 +40,9 @@ static void __hot prepare_ftrace_return(
old = *parent;
- trace.func = self_addr; - trace.depth = current->curr_ret_stack + 1; - - /* Only trace if the calling function expects to */ - if (!ftrace_graph_entry(&trace)) - return; - - if (ftrace_push_return_trace(old, self_addr, &trace.depth, - 0, NULL) == -EBUSY) - return; - - /* activate parisc_return_to_handler() as return point */ - *parent = (unsigned long) &parisc_return_to_handler; + if (!function_graph_enter(old, self_addr, 0, NULL)) + /* activate parisc_return_to_handler() as return point */ + *parent = (unsigned long) &parisc_return_to_handler; } #endif /* CONFIG_FUNCTION_GRAPH_TRACER */