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Date:   Fri, 6 Nov 2020 11:05:17 +0100 (CET)
From:   Miroslav Benes <mbenes@suse.cz>
To:     Steven Rostedt <rostedt@goodmis.org>
cc:     linux-kernel@vger.kernel.org,
        Masami Hiramatsu <mhiramat@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@kernel.org>,
        Josh Poimboeuf <jpoimboe@redhat.com>,
        Jiri Kosina <jikos@kernel.org>, Petr Mladek <pmladek@suse.com>,
        Joe Lawrence <joe.lawrence@redhat.com>,
        live-patching@vger.kernel.org
Subject: Re: [PATCH 06/11 v3] livepatch/ftrace: Add recursion protection to
 the ftrace callback
In-Reply-To: <20201106023547.122802424@goodmis.org>
Message-ID: <alpine.LSU.2.21.2011061105030.10425@pobox.suse.cz>
References: <20201106023235.367190737@goodmis.org> <20201106023547.122802424@goodmis.org>
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On Thu, 5 Nov 2020, Steven Rostedt wrote:

> From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
> 
> If a ftrace callback does not supply its own recursion protection and
> does not set the RECURSION_SAFE flag in its ftrace_ops, then ftrace will
> make a helper trampoline to do so before calling the callback instead of
> just calling the callback directly.
> 
> The default for ftrace_ops is going to change. It will expect that handlers
> provide their own recursion protection, unless its ftrace_ops states
> otherwise.
> 
> Link: https://lkml.kernel.org/r/20201028115613.291169246@goodmis.org
> 
> Cc: Masami Hiramatsu <mhiramat@kernel.org>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Josh Poimboeuf <jpoimboe@redhat.com>
> Cc: Jiri Kosina <jikos@kernel.org>
> Cc: Miroslav Benes <mbenes@suse.cz>
> Cc: Joe Lawrence <joe.lawrence@redhat.com>
> Cc: live-patching@vger.kernel.org
> Reviewed-by: Petr Mladek <pmladek@suse.com>
> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Acked-by: Miroslav Benes <mbenes@suse.cz>

M