| Date | Thu, 27 Aug 2009 17:25:41 +0200 | From | Frederic Weisbecker <> | Subject | Re: [GIT PULL] tracing/kprobes: Add dynamic tracepoints + instruction decoder |
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On Thu, Aug 27, 2009 at 11:00:38AM -0400, Masami Hiramatsu wrote: > Frederic Weisbecker wrote: > > Ingo, > > > > This is the kprobes tracing pile of patches. I've tested it > > successfully by setting some kprobes through debugfs by hand. > > > > It brings no known regressions. > > > > However, the stress test provided by Masami have revealed some > > unstable points. Some symbols are unsafe to probe and raise > > probing recursion. > > > > I've added a tiny patch in the series that helps identifying the > > kprobe that has raised such situation. > > For example it has learned me today that it's unsafe to trace > > ret_from_exception() (obviously: it's on the int 3 handler path). > > Thank you, Frederic. > > I'm currently fixing those problems on x86-64 (on kvm). > I'll also check it on x86-32, and fix it. > > Thanks
Cool. Don't hesitate to interate through small patches that fix these sites.
So that I can continue to test it over time and report you what I find, may be I can try to fix some of them too.
I haven't fixed ret_from_exception because I wasn't sure about the right thing to do: putting it in the kprobes section or blacklist its name. It's a bit more delicate to put assembly code into sections so... :)
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