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Re: [PATCH][kprobes] support kretprobe-blacklist
- From: Masami Hiramatsu <mhiramat at redhat dot com>
- To: Christoph Hellwig <hch at infradead dot org>
- Cc: Masami Hiramatsu <mhiramat at redhat dot com>, Andrew Morton <akpm at linux-foundation dot org>, ananth at in dot ibm dot com, prasanna at in dot ibm dot com, anil dot s dot keshavamurthy at intel dot com, Jim Keniston <jkenisto at us dot ibm dot com>, davem at davemloft dot net, linux-kernel at vger dot kernel dot org, systemtap-ml <systemtap at sources dot redhat dot com>
- Date: Mon, 27 Aug 2007 11:49:21 -0400
- Subject: Re: [PATCH][kprobes] support kretprobe-blacklist
- References: <46C5FA48.2050308@redhat.com> <20070827133154.GA22322@infradead.org>
Hi Christoph,
Christoph Hellwig wrote:
> On Fri, Aug 17, 2007 at 03:43:04PM -0400, Masami Hiramatsu wrote:
>> This patch introduces architecture dependent kretprobe
>> blacklists to prohibit users from inserting return
>> probes on the function in which kprobes can be inserted
>> but kretprobes can not.
>
> I don't like this at all. If people want to shoot themselves into
> their own foot using kernel modules they have an unlimited number
> of ways to do this, and even more with kprobes, so there's no point
> in making it a little harder for some cases.
Would you mean that the kernel need not to check whether the probe
point is safe or not?
Actually, there are many ways to shoot themselves from kernel modules.
Even so, IMHO, it is benefit for people that the kernel rejects at least
those obviously (and known) dangerous operation.
--
Masami Hiramatsu
Software Engineer
Hitachi Computer Products (America) Inc.
Software Solutions Division
e-mail: mhiramat@redhat.com, masami.hiramatsu.pt@hitachi.com