linux-kernel - [DEBUG PATCH 0/2] debug explicit GFP_NO{FS,IO} usage from the scope context

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: <20170106141845.24362-1-mhocko@kernel.org>
Date:   Fri,  6 Jan 2017 15:18:43 +0100
From:   Michal Hocko <mhocko@...nel.org>
To:     <linux-mm@...ck.org>, <linux-fsdevel@...r.kernel.org>
Cc:     Andrew Morton <akpm@...ux-foundation.org>,
        Dave Chinner <david@...morbit.com>, djwong@...nel.org,
        "Theodore Ts'o" <tytso@....edu>, Chris Mason <clm@...com>,
        David Sterba <dsterba@...e.cz>, Jan Kara <jack@...e.cz>,
        ceph-devel@...r.kernel.org, cluster-devel@...hat.com,
        linux-nfs@...r.kernel.org, logfs@...fs.org,
        linux-xfs@...r.kernel.org, linux-ext4@...r.kernel.org,
        linux-btrfs@...r.kernel.org, linux-mtd@...ts.infradead.org,
        reiserfs-devel@...r.kernel.org,
        linux-ntfs-dev@...ts.sourceforge.net,
        linux-f2fs-devel@...ts.sourceforge.net,
        linux-afs@...ts.infradead.org, LKML <linux-kernel@...r.kernel.org>
Subject: [DEBUG PATCH 0/2] debug explicit GFP_NO{FS,IO} usage from the scope context

These two patches should help to identify explicit GFP_NO{FS,IO} usage
from withing a scope context and reduce such a usage as a result. Such
a usage can be changed to the full GFP_KERNEL because all the calls
from within the NO{FS,IO} scope will drop the __GFP_FS resp. __GFP_IO
automatically and if the function is called outside of the scope then
we do not need to restrict it to NOFS/NOIO as long as all the reclaim
recursion unsafe contexts are marked properly. This means that each such
a reported allocation site has to be checked before converted.

The debugging has to be enabled explicitly by a kernel command line
parameter and then it reports the stack trace of the allocation and
also the function which has started the current scope.

These two patches are _not_ intended to be merged and they are only
aimed at debugging.