On Tue, 7 May 2019 23:13:40 +0900 Masami Hiramatsu <mhiramat@xxxxxxxxxx> wrote: > On Mon, 6 May 2019 17:45:11 -0400 > Steven Rostedt <rostedt@xxxxxxxxxxx> wrote: > > > If we go with Peter's patch, I can make this code much more sane, and > > not have to worry about having ®s->sp be at the top of the stack. I > > could simply, just push everything in the order of pt_regs and call the > > handler. > > Hi Steve, I need to catch up with the origin of this series, but it seems > also good to optprobe which is doing similar trick on pt_regs. If we can > assume that int3 pt_regs can have a gap, optprobe can also make a gap, and > it can be also used for storing destination address. Sorry, I misunderstood. I see the issue ( https://lkml.org/lkml/2019/5/1/497 ) and solutions on the thread. If we really need to fix this trace-livepatch combination issue, it may be good to backport to stable trees. >From this viewpoint, Linus's suggestion (no pt_reg changes on x86-32) seems to have a point. BTW, even though I think Peter's patch (unifying pt_regs behavior) will also be good for us for more general reason (not only for fixing actual issue). Thank you, -- Masami Hiramatsu <mhiramat@xxxxxxxxxx>
