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From: Christoph Hellwig <hch@lst.de>
To: Jens Axboe <axboe@kernel.dk>
Cc: linux-arch@vger.kernel.org, linux-api@vger.kernel.org,
	linux-kernel@vger.kernel.org, io-uring@vger.kernel.org
Subject: io_uring vs in_compat_syscall()
Date: Mon, 20 Jul 2020 08:10:46 +0200	[thread overview]
Message-ID: <20200720061046.GA10678@lst.de> (raw)

Hi Jens,

I just found a (so far theoretical) issue with the io_uring submission
offloading to workqueues or threads.  We have lots of places using
in_compat_syscall() to check if a syscall needs compat treatmenet.
While the biggest users is iocttl(), we also have a fair amount of
places using in_compat_task() in read and write methods, and these
will not do the wrong thing when used with io_uring under certain
conditions.  I'm not sure how to best fix this, except for making sure
in_compat_syscall() returns true one way or another for these cases.

             reply	other threads:[~2020-07-20  6:10 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-20  6:10 Christoph Hellwig [this message]
2020-07-20 16:36 ` io_uring vs in_compat_syscall() Jens Axboe
2020-07-20 16:58   ` Andy Lutomirski
2020-07-20 17:02     ` Jens Axboe
2020-07-20 17:28       ` Andy Lutomirski
2020-07-21  7:07         ` Christoph Hellwig
2020-07-21 14:31           ` Andy Lutomirski
2020-07-21 14:34             ` Christoph Hellwig
2020-07-21 17:25               ` Andy Lutomirski
2020-07-22  6:30                 ` Christoph Hellwig
2020-07-22  8:39                   ` David Laight

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