Messages in this thread | | | Date | Wed, 29 May 2019 15:47:40 +0900 | From | Masami Hiramatsu <> | Subject | Re: [RFC][PATCH 00/14 v2] function_graph: Rewrite to allow multiple users |
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On Wed, 22 May 2019 10:40:27 -0400 Steven Rostedt <rostedt@goodmis.org> wrote:
> On Wed, 22 May 2019 23:19:55 +0900 > Masami Hiramatsu <mhiramat@kernel.org> wrote: > > > > void *fgraph_reserve_data(int size_in_bytes) > > > > > > Allows the entry function to reserve up to 4 words of data on > > > the shadow stack. On success, a pointer to the contents is returned. > > > This may be only called once per entry function. > > > > > > void *fgraph_retrieve_data(void) > > > > > > Allows the return function to retrieve the reserved data that was > > > allocated by the entry function. > > > > Nice! this seems good for kretprobe too. I'll review and try to port > > kretprobe on this framework. > > If you rather pull from my git repo and not download all the patches, > they are currently available in my ftrace/fgraph-multi branch.
Hi Steve,
I found that these interfaces seem tightly coupled with fgraph_ops. But that cause a problem when I'm using it from kretprobe.
kretprobe has 2 handlers, entry handler and return handler, and both need pt_regs. But fgraph_ops's entryfunc and retfunc do not pass the pt_regs. That is the biggest issue for me on these APIs. Can we expand fgraph_ops with regs parameter?
Thank you,
-- Masami Hiramatsu <mhiramat@kernel.org>
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