linux-kernel - Re: [PATCH v4 0/3] vfs: Define new syscall umask2 [formerly getumask]

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Message-ID: <20160413205315.GM11600@redhat.com>
Date:	Wed, 13 Apr 2016 21:53:15 +0100
From:	"Richard W.M. Jones" <rjones@...hat.com>
To:	Florian Weimer <fw@...eb.enyo.de>
Cc:	"H. Peter Anvin" <hpa@...or.com>, linux-kernel@...r.kernel.org,
	tglx@...utronix.de, mingo@...hat.com, akpm@...ux-foundation.org,
	luto@...nel.org, viro@...iv.linux.org.uk,
	mathieu.desnoyers@...icios.com, zab@...hat.com,
	paulmck@...ux.vnet.ibm.com, aarcange@...hat.com,
	josh@...htriplett.org, xemul@...allels.com, sfr@...b.auug.org.au,
	milosz@...in.com, rostedt@...dmis.org, arnd@...db.de,
	ebiederm@...ssion.com, gorcunov@...nvz.org,
	iulia.manda21@...il.com, dave.hansen@...ux.intel.com,
	mguzik@...hat.com, adobriyan@...il.com, dave@...olabs.net,
	linux-api@...r.kernel.org, gorcunov@...il.com, walters@...bum.org
Subject: Re: [PATCH v4 0/3] vfs: Define new syscall umask2 [formerly getumask]


On Wed, Apr 13, 2016 at 10:45:05PM +0200, Florian Weimer wrote:
> * H. Peter Anvin:
> 
> > I have to say I'm skeptic to the need for umask2() as opposed to
> > getumask().
> 
> I find the extension with a set-the-thread umask somewhat unlikely.
> How would a potential per-thread umask interact with CLONE_FS?
> Have a per-thread umask that, when active, overrides the global
> one, similar to what uselocale provides?  That seems rather messy,
> and I'm not aware of any precedent.

The flags parameter is for extensions we can't envisage now ...

... although since umask has been around since Unix V6 in 1978, we
might be waiting a long time.

Rich.

-- 
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