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Date: Mon, 27 Nov 2017 23:25:28 +0100
From: Jiri Olsa <jolsa@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Milind Chabbi <chabbi.milind@gmail.com>, Jiri Olsa <jolsa@kernel.org>,
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Subject: Re: [PATCH 4/6] hw_breakpoint: Factor out
 __modify_user_hw_breakpoint function
Message-ID: <20171127222528.GA14335@krava>
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On Mon, Nov 27, 2017 at 11:01:28PM +0100, Peter Zijlstra wrote:
> On Mon, Nov 27, 2017 at 01:50:30PM -0800, Milind Chabbi wrote:
> > The possible checks is infinite
> 
> struct perf_event_attr is very much a finite data type.
> 
> Something as simple as:
> 
> 	struct perf_event_attr tmp1 = new_attr, tmp2 = event->attr;
> 
> 	tmp1.bp_type = tmp2.bp_type;
> 	tmp1.bp_addr = tmp2.bp_addr;
> 	tmp1.bp_len  = tmp2.bp_len;
> 
> 	if (memcmp(&tmp1, &tmp2, sizeof(tmp1)))
> 		return -EINVAL;
> 
> would actually do the checks __modify_user_hw_breakpoint() needs to do.

I see.. will post new version

thanks,
jirka