linux-kernel - Re: [PATCH 3/5] perf_counter: rework ioctl()s

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1242109650.11251.313.camel@twins>
Date:	Tue, 12 May 2009 08:27:30 +0200
From:	Peter Zijlstra <a.p.zijlstra@...llo.nl>
To:	Paul Mackerras <paulus@...ba.org>
Cc:	Arnd Bergmann <arnd@...db.de>, Ingo Molnar <mingo@...e.hu>,
	Corey Ashford <cjashfor@...ux.vnet.ibm.com>,
	linux-kernel@...r.kernel.org, Thomas Gleixner <tglx@...utronix.de>
Subject: Re: [PATCH 3/5] perf_counter: rework ioctl()s

On Tue, 2009-05-12 at 16:22 +1000, Paul Mackerras wrote:
> Peter Zijlstra writes:
> 
> > Hmm, are you saying that the 3rd argument to unlocked_ioctl is actually
> > (void __user *) instead of unsigned long?
> 
> He's saying (correctly) that using _IOR or _IOW implies that the ioctl
> is going to read or write the memory location pointed to by the 3rd
> argument to unlocked_ioctl.  If the 3rd argument is just a number, not
> an address, I believe you should use _IO.

Oh, somewhat confusing all this. Would be good to spell out these things
somewhere. Documentation/ioctl/ seems less than helpful.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/