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Subject: Re: [syzbot] KASAN: stack-out-of-bounds Read in profile_pc
To:     Josh Poimboeuf <jpoimboe@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>
Cc:     syzbot <syzbot+84fe685c02cd112a2ac3@syzkaller.appspotmail.com>,
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        linux-kernel@vger.kernel.org, mingo@redhat.com,
        syzkaller-bugs@googlegroups.com, tglx@linutronix.de,
        x86@kernel.org, Andy Lutomirski <luto@kernel.org>,
        Steven Rostedt <rostedt@goodmis.org>
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From:   Andi Kleen <ak@linux.intel.com>
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Date:   Thu, 3 Jun 2021 06:52:19 -0700
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> True, ftrace does have function profiling (function_profile_enabled).
>
> Steve, is there a way to enable that on the kernel cmdline?

That's not really comparable. function profiling has a lot more 
overhead. Also there is various code which has ftrace instrumentation 
disabled.

I don't think why you want to kill the old profiler. It's rarely used, 
but when you need it usually works. It's always good to have simple fall 
backs. And it's not that it's a lot of difficult code.

-Andi