From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 13 Jul 2007 00:44:08 -0700 From: Andrew Morton Subject: Re: [PATCH] do not limit locked memory when RLIMIT_MEMLOCK is RLIM_INFINITY Message-Id: <20070713004408.b7162501.akpm@linux-foundation.org> In-Reply-To: <4692D9E0.1000308@oracle.com> References: <4692D9E0.1000308@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Herbert van den Bergh Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Dave McCracken , Chris Mason List-ID: On Mon, 09 Jul 2007 17:59:12 -0700 Herbert van den Bergh wrote: > > [resending, since my previous message had tabs converted to spaces] > > This patch fixes a bug in mm/mlock.c on 32-bit architectures that prevents > a user from locking more than 4GB of shared memory, or allocating more > than 4GB of shared memory in hugepages, when rlim[RLIMIT_MEMLOCK] is > set to RLIM_INFINITY. > > Signed-off-by: Herbert van den Bergh > Acked-by: Chris Mason > > --- linux-2.6.22/mm/mlock.c.orig 2007-07-09 10:19:31.000000000 -0700 > +++ linux-2.6.22/mm/mlock.c 2007-07-09 10:19:19.000000000 -0700 > @@ -244,9 +244,12 @@ int user_shm_lock(size_t size, struct us > > locked = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; > lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur; > + if (lock_limit == RLIM_INFINITY) > + allowed = 1; > lock_limit >>= PAGE_SHIFT; > spin_lock(&shmlock_user_lock); > - if (locked + user->locked_shm > lock_limit && !capable(CAP_IPC_LOCK)) > + if (!allowed && > + locked + user->locked_shm > lock_limit && !capable(CAP_IPC_LOCK)) > goto out; > get_uid(user); > user->locked_shm += locked; OK. Seems like a nasty bug if one happens to want to do that. Should we backport this into 2.6.22.x? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org