linux-kernel - Re: [PATCH 0/9] mm: Hardened usercopy

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Message-ID: <CA+55aFzv4kQitzhWgxRAi5XXM30f70d4dbTGkr7t=fZSh4r3Ow@mail.gmail.com>
Date:	Fri, 8 Jul 2016 09:19:04 -0700
From:	Linus Torvalds <torvalds@...ux-foundation.org>
To:	Ingo Molnar <mingo@...nel.org>
Cc:	Kees Cook <keescook@...omium.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Rik van Riel <riel@...hat.com>,
	Casey Schaufler <casey@...aufler-ca.com>,
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	Thomas Gleixner <tglx@...utronix.de>,
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	Peter Zijlstra <a.p.zijlstra@...llo.nl>
Subject: Re: [PATCH 0/9] mm: Hardened usercopy

On Fri, Jul 8, 2016 at 1:46 AM, Ingo Molnar <mingo@...nel.org> wrote:
>
> Could you please try to find some syscall workload that does many small user
> copies and thus excercises this code path aggressively?

Any stat()-heavy path will hit cp_new_stat() very heavily. Think the
usual kind of "traverse the whole tree looking for something". "git
diff" will do it, just checking that everything is up-to-date.

That said, other things tend to dominate.

                 Linus