[PATCH v2 11/13] powerpc/ftrace: directly call of function graph tracer by ftrace caller

Steven Rostedt rostedt at goodmis.org
Tue Feb 15 06:03:04 AEDT 2022


On Mon, 14 Feb 2022 22:54:23 +0530
"Naveen N. Rao" <naveen.n.rao at linux.vnet.ibm.com> wrote:

> For x86, commit 0c0593b45c9b4e ("x86/ftrace: Make function graph use 
> ftrace directly") also adds recursion check before the call to 
> function_graph_enter() in prepare_ftrace_return(). Do we need that on
> powerpc as well?

Yes. The function_graph_enter() does not provide any recursion protection,
so if it were to call something that gets function graph traced, it will
crash the machine.

-- Steve


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