Messages in this thread | | | Date | Thu, 3 Jun 2021 08:39:14 -0500 | From | Josh Poimboeuf <> | Subject | Re: [syzbot] KASAN: stack-out-of-bounds Read in profile_pc |
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On Thu, Jun 03, 2021 at 03:30:10PM +0200, Peter Zijlstra wrote: > On Wed, Jun 02, 2021 at 04:35:11PM -0700, Andi Kleen wrote: > > > > We could just use ORC to unwind to the next frame. Though, isn't > > > /proc/profile redundant, compared to all the more sophisticated options > > > nowadays? Is there still a distinct use case for it or can we just > > > remove it? > > > > It's still needed for some special cases. For example there is no other > > viable way to profile early boot without a VM > > > > I would just drop the hack to unwind, at least for the early boot profile > > use case locking profiling is usually not needed. > > Surely we can cook up something else there and delete this thing? ftrace > buffers are available really early, it shouldn't be hard to dump some > data in there during boot.
True, ftrace does have function profiling (function_profile_enabled).
Steve, is there a way to enable that on the kernel cmdline?
-- Josh
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