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

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Date:	Thu, 14 Apr 2016 10:15:47 +0100
From:	"Richard W.M. Jones" <rjones@...hat.com>
To:	Stephen Rothwell <sfr@...b.auug.org.au>
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,
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	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]

On Thu, Apr 14, 2016 at 09:09:38AM +1000, Stephen Rothwell wrote:
> 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?

This would be very useful, although I think being able to read umask
is also useful.

---

FWIW I am currently developing a patch to add umask to
/proc/PID/status.  Will post it shortly once I've tested it properly.

Rich.

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