Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933725AbbLOUee (ORCPT ); Tue, 15 Dec 2015 15:34:34 -0500 Received: from mail-wm0-f49.google.com ([74.125.82.49]:34910 "EHLO mail-wm0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932286AbbLOUec convert rfc822-to-8bit (ORCPT ); Tue, 15 Dec 2015 15:34:32 -0500 Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (1.0) Subject: Re: [PATCH] staging: lustre: fix address space mismatches From: Okash Khawaja X-Mailer: iPhone Mail (11A501) In-Reply-To: <20151215184803.GB16129@kroah.com> Date: Tue, 15 Dec 2015 20:34:34 +0000 Cc: "oleg.drokin@intel.com" , "andreas.dilger@intel.com" , "devel@driverdev.osuosl.org" , "linux-kernel@vger.kernel.org" , "lustre-devel@lists.lustre.org" Content-Transfer-Encoding: 8BIT Message-Id: <5612F531-9472-4E61-976D-44D116EF3C1F@gmail.com> References: <20151215165045.GA5213@bytefire-computer> <20151215184803.GB16129@kroah.com> To: Greg KH Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2800 Lines: 62 > On 15 Dec 2015, at 18:48, Greg KH wrote: > >> On Tue, Dec 15, 2015 at 04:50:45PM +0000, Okash Khawaja wrote: >> This patch fixes address space warnings from sparse. Function >> lprocfs_write_helper() accepts user space buffer but was being >> passed kernel space buffer by these functions: >> >> contention_seconds_store() >> lockless_truncate_store() >> >> Since these functions are used to implement show and store functions of >> lustre_attr object and since lustre_attr object is used to implement object >> inheritance through use of `container_of`, the address space warnings >> show up at multiple places inside driver's code base. >> >> This patch creates a user space version of lustre_attr object lustre_attr_u. >> Keeping function names and signatures same - other than the __user attribute - >> ensures that object inheritance continues to work as it was, but address >> space discrepency is removed. That removes a whole bunch of address >> space warnings. >> >> Signed-off-by: Okash Khawaja >> --- >> drivers/staging/lustre/lustre/include/lprocfs_status.h | 16 ++++++++++++++++ >> drivers/staging/lustre/lustre/osc/lproc_osc.c | 12 ++++++------ >> 2 files changed, 22 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/staging/lustre/lustre/include/lprocfs_status.h b/drivers/staging/lustre/lustre/include/lprocfs_status.h >> index f18c0c7..df6d9d5 100644 >> --- a/drivers/staging/lustre/lustre/include/lprocfs_status.h >> +++ b/drivers/staging/lustre/lustre/include/lprocfs_status.h >> @@ -698,6 +698,22 @@ static struct lustre_attr lustre_attr_##name = __ATTR(name, mode, show, store) >> #define LUSTRE_RO_ATTR(name) LUSTRE_ATTR(name, 0444, name##_show, NULL) >> #define LUSTRE_RW_ATTR(name) LUSTRE_ATTR(name, 0644, name##_show, name##_store) >> >> +struct lustre_attr_u { >> + struct attribute attr; >> + ssize_t (*show)(struct kobject *kobj, struct attribute *attr, >> + char *buf); >> + ssize_t (*store)(struct kobject *kobj, struct attribute *attr, >> + const char __user *buf, size_t len); > > sysfs files do not have __user pointers, something is really wrong here > if that's the solution :( > > See the other comments in the mailing list archives for how messed up > the __user and kernel pointers are in lustre, and how I'd not recommend > anyone trying to fix them, unless you are a lustre developer and can > test all of your changes... > > sorry, > > greg k-h I see. Thanks for getting back promptly. Okash -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/