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Date:   Thu, 27 Aug 2020 11:02:20 +0200
From:   peterz@infradead.org
To:     Masami Hiramatsu <mhiramat@kernel.org>
Cc:     "Eddy_Wu@trendmicro.com" <Eddy_Wu@trendmicro.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "x86@kernel.org" <x86@kernel.org>,
        "David S. Miller" <davem@davemloft.net>
Subject: Re: x86/kprobes: kretprobe fails to triggered if kprobe at function
 entry is not optimized (trigger by int3 breakpoint)
Message-ID: <20200827090220.GH1362448@hirez.programming.kicks-ass.net>
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On Tue, Aug 25, 2020 at 10:15:55PM +0900, Masami Hiramatsu wrote:

> Yeah, kretprobe already provided the per-instance data (as far as
> I know, only systemtap depends on it). We need to provide it for
> such users.

Well, systemtap is out of tree, we don't _need_ to provide anything for
them. Furthermore, the function-graph tracer's ret_stack, which you said
you wanted to integrate with, also doesn't provide this.

Ditching it makes things simpler in that all kretprobe_instance's will
be the same and we no longer need per kretprobe storage of them.

Anyway, let me try and preserve them for now...