linux-kernel - Re: [PATCH 2/8] PM: suspend_block: Add driver to access suspend blockers from user-space

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: <201004290105.15707.rjw@sisk.pl>
Date:	Thu, 29 Apr 2010 01:05:15 +0200
From:	"Rafael J. Wysocki" <rjw@...k.pl>
To:	Arve Hjønnevåg <arve@...roid.com>
Cc:	linux-pm@...ts.linux-foundation.org, linux-kernel@...r.kernel.org,
	Alan Stern <stern@...land.harvard.edu>,
	Tejun Heo <tj@...nel.org>, Oleg Nesterov <oleg@...hat.com>,
	Randy Dunlap <rdunlap@...otime.net>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Ryusuke Konishi <konishi.ryusuke@....ntt.co.jp>,
	Jim Collar <jim.collar@...are.net>,
	"Greg Kroah-Hartman" <gregkh@...e.de>, Avi Kivity <avi@...hat.com>,
	Len Brown <len.brown@...el.com>, Pavel Machek <pavel@....cz>,
	Magnus Damm <damm@...l.co.jp>,
	Cornelia Huck <cornelia.huck@...ibm.com>,
	Nigel Cunningham <nigel@...onice.net>,
	linux-doc@...r.kernel.org
Subject: Re: [PATCH 2/8] PM: suspend_block: Add driver to access suspend blockers from user-space

On Thursday 29 April 2010, Arve Hjønnevåg wrote:
> 2010/4/28 Rafael J. Wysocki <rjw@...k.pl>:
> > On Wednesday 28 April 2010, Arve Hjønnevåg wrote:
> >> Add a misc device, "suspend_blocker", that allows user-space processes
> >> to block auto suspend. The device has ioctls to create a suspend_blocker,
> >> and to block and unblock suspend. To delete the suspend_blocker, close
> >> the device.
> >>
> >> Signed-off-by: Arve Hjønnevåg <arve@...roid.com>
> > ...
> >> +
> >> +#include <linux/fs.h>
> >> +#include <linux/miscdevice.h>
> >> +#include <linux/module.h>
> >> +#include <linux/uaccess.h>
> >> +#include <linux/slab.h>
> >> +#include <linux/suspend_blocker.h>
> >> +#include <linux/suspend_block_dev.h>
> >> +
> >> +enum {
> >> +     DEBUG_FAILURE   = BIT(0),
> >> +};
> >> +static int debug_mask = DEBUG_FAILURE;
> >
> > What's the exact purpose of this?
> 
> To show errors returned to user space. I can turn it off by default if you want.

Not necessarily, but why is it a mask?  It looks like a 0/1 thing would be
sufficient.

BTW, I'd put parens around (debug_mask & DEBUG_FAILURE) for clarity.

Rafael
--
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/