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

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Message-ID: <20160414090938.44c56c78@canb.auug.org.au>
Date:	Thu, 14 Apr 2016 09:09:38 +1000
From:	Stephen Rothwell <sfr@...b.auug.org.au>
To:	"Richard W.M. Jones" <rjones@...hat.com>
Cc:	linux-kernel@...r.kernel.org, tglx@...utronix.de, mingo@...hat.com,
	hpa@...or.com, akpm@...ux-foundation.org, luto@...nel.org,
	viro@...iv.linux.org.uk, mathieu.desnoyers@...icios.com,
	zab@...hat.com, emunson@...mai.com, paulmck@...ux.vnet.ibm.com,
	aarcange@...hat.com, josh@...htriplett.org, xemul@...allels.com,
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	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, fw@...eb.enyo.de,
	walters@...bum.org
Subject: Re: [PATCH v4 0/3] vfs: Define new syscall umask2 [formerly
 getumask]

Hi Richard,

On Wed, 13 Apr 2016 20:05:33 +0100 "Richard W.M. Jones" <rjones@...hat.com> wrote:
>
> It's not possible to read the process umask without also modifying it,
> which is what umask(2) does.  A library cannot read umask safely,
> especially if the main program might be multithreaded.

I was wondering if you really need to read the umask, or would just a
"ignore umask" flag to open{,at} do what you want?

-- 
Cheers,
Stephen Rothwell