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Date: Tue, 2 Aug 2016 22:30:35 +0200
From: Oleg Nesterov <oleg@redhat.com>
To: Pratyush Anand <panand@redhat.com>,
        Ananth Mavinakayanahalli <ananth@linux.vnet.ibm.com>,
        Masami Hiramatsu <mhiramat@kernel.org>
Cc: linux-kernel@vger.kernel.org, srikar@linux.vnet.ibm.com,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Ingo Molnar <mingo@redhat.com>, Peter Zijlstra <peterz@infradead.org>
Subject: Re: [PATCH] uprobe: Add uprobe_pre/post_sstep_notifier to
 NOKPROBE_SYMBOL
Message-ID: <20160802203035.GA8335@redhat.com>
References: <66dfa2cb82fc306d42e51adf0f5d819b4695644e.1470120173.git.panand@redhat.com>
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On 08/02, Pratyush Anand wrote:
>
> uprobe_pre_sstep_notifier and uprobe_post_sstep_notifier are called from
> debug exception handler, so blacklist them for kprobing.

Let me add kprobes maintainers, I am a bit confused...

> @@ -1997,6 +1998,7 @@ int uprobe_pre_sstep_notifier(struct pt_regs *regs)
>  	set_thread_flag(TIF_UPROBE);
>  	return 1;
>  }
> +NOKPROBE_SYMBOL(uprobe_pre_sstep_notifier);
>
>  /*
>   * uprobe_post_sstep_notifier gets called in interrupt context as part of notifier
> @@ -2014,6 +2016,7 @@ int uprobe_post_sstep_notifier(struct pt_regs *regs)
>  	set_thread_flag(TIF_UPROBE);
>  	return 1;
>  }
> +NOKPROBE_SYMBOL(uprobe_post_sstep_notifier);

but if we need to blacklist uprobe_pre/post_sstep_notifier then we
also need to blacklist their caller, arch_uprobe_exception_notify() ?

and every .notifier_call used in register_die_notifier() ?

Oleg.