From: Jens Axboe <axboe@kernel.dk>
To: Eugene Syromiatnikov <esyr@redhat.com>,
linux-fsdevel@vger.kernel.org, io-uring@vger.kernel.org,
Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-kernel@vger.kernel.org, Jeff Moyer <jmoyer@redhat.com>,
"Dmitry V. Levin" <ldv@altlinux.org>
Subject: Re: [PATCH] io_uring: fix compat for IORING_REGISTER_FILES_UPDATE
Date: Wed, 15 Jan 2020 09:41:58 -0700 [thread overview]
Message-ID: <cce5ac48-641d-3051-d22c-dab7aaa5704c@kernel.dk> (raw)
In-Reply-To: <20200115163538.GA13732@asgard.redhat.com>
On 1/15/20 9:35 AM, Eugene Syromiatnikov wrote:
> fds field of struct io_uring_files_update is problematic with regards
> to compat user space, as pointer size is different in 32-bit, 32-on-64-bit,
> and 64-bit user space. In order to avoid custom handling of compat in
> the syscall implementation, make fds __u64 and use u64_to_user_ptr in
> order to retrieve it. Also, align the field naturally and check that
> no garbage is passed there.
Good point, it's an s32 pointer so won't align nicely. But how about
just having it be:
struct io_uring_files_update {
__u32 offset;
__u32 resv;
__s32 *fds;
};
which should align nicely on both 32 and 64-bit?
--
Jens Axboe
next prev parent reply other threads:[~2020-01-15 16:42 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-15 16:35 [PATCH] io_uring: fix compat for IORING_REGISTER_FILES_UPDATE Eugene Syromiatnikov
2020-01-15 16:41 ` Jens Axboe [this message]
2020-01-15 16:50 ` Eugene Syromiatnikov
2020-01-15 16:53 ` Jens Axboe
2020-01-15 16:59 ` Eugene Syromiatnikov
2020-01-20 23:51 ` Dmitry V. Levin
2020-01-20 23:54 ` Jens Axboe
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