From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Date: Mon, 21 Sep 2020 04:28:15 +0000 Subject: Re: [PATCH 1/9] kernel: add a PF_FORCE_COMPAT flag Message-Id: <20200921042815.GA16281@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit List-Id: References: <20200918124533.3487701-1-hch@lst.de> <20200918124533.3487701-2-hch@lst.de> <20200920151510.GS32101@casper.infradead.org> <20200920180742.GN3421308@ZenIV.linux.org.uk> In-Reply-To: To: Andy Lutomirski Cc: Al Viro , Matthew Wilcox , Christoph Hellwig , Andrew Morton , Jens Axboe , Arnd Bergmann , David Howells , linux-arm-kernel , X86 ML , LKML , "open list:MIPS" , Parisc List , linuxppc-dev , linux-s390 , sparclinux , linux-block , Linux SCSI List , Linux FS Devel , linux-aio , io-uring@vger.kernel.org, linux-arch , Linux-MM , Network Development , keyrings@vger.kernel.org, LSM List On Sun, Sep 20, 2020 at 12:14:49PM -0700, Andy Lutomirski wrote: > I wonder if this is really quite cast in stone. We could also have > FMODE_SHITTY_COMPAT and set that when a file like this is *opened* in > compat mode. Then that particular struct file would be read and > written using the compat data format. The change would be > user-visible, but the user that would see it would be very strange > indeed. > > I don't have a strong opinion as to whether that is better or worse > than denying io_uring access to these things, but at least it moves > the special case out of io_uring. open could have happened through an io_uring thread a well, so I don't see how this would do anything but move the problem to a different place. > > --Andy ---end quoted text---