From: Peter Zijlstra <peterz@infradead.org>
To: Andi Kleen <ak@linux.intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>,
syzbot <syzbot+84fe685c02cd112a2ac3@syzkaller.appspotmail.com>,
bp@alien8.de, hpa@zytor.com, inglorion@google.com,
linux-kernel@vger.kernel.org, mingo@redhat.com,
syzkaller-bugs@googlegroups.com, tglx@linutronix.de,
x86@kernel.org, Andy Lutomirski <luto@kernel.org>
Subject: Re: [syzbot] KASAN: stack-out-of-bounds Read in profile_pc
Date: Thu, 3 Jun 2021 15:30:10 +0200 [thread overview]
Message-ID: <YLjZYvXnuPnbXzOm@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <527ad07e-eec2-a211-03e7-afafe5196100@linux.intel.com>
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.
next prev parent reply other threads:[~2021-06-03 13:30 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-31 7:15 [syzbot] KASAN: stack-out-of-bounds Read in profile_pc syzbot
2021-06-02 23:00 ` Josh Poimboeuf
2021-06-02 23:35 ` Andi Kleen
2021-06-03 13:29 ` Josh Poimboeuf
2021-06-03 13:30 ` Peter Zijlstra [this message]
2021-06-03 13:39 ` Josh Poimboeuf
2021-06-03 13:52 ` Andi Kleen
2021-10-11 13:07 ` Lee Jones
2021-10-11 14:43 ` Steven Rostedt
2021-10-11 17:10 ` Dmitry Vyukov
2021-10-11 17:30 ` Josh Poimboeuf
2021-06-03 8:02 ` syzbot
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