Messages in this thread | | | Date | Fri, 20 May 2022 09:53:30 -0600 | Subject | Re: [PATCH v4 0/3] random: convert to using iters, for Al Viro | From | Jens Axboe <> |
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On 5/20/22 9:47 AM, Al Viro wrote: > On Fri, May 20, 2022 at 09:34:46AM -0600, Jens Axboe wrote: > >> I'm very sure, otherwise we're just accepting that we're breaking real >> world applications. > > "Breaking" as in "it used to work with earlier kernels, doesn't work with > recent ones"? Details, please...
Yes, as in exactly that. This is what drove this addition of ->read_iter() for urandom. See commit:
ommit 36e2c7421f02a22f71c9283e55fdb672a9eb58e7 Author: Christoph Hellwig <hch@lst.de> Date: Thu Sep 3 16:22:34 2020 +0200
fs: don't allow splice read/write without explicit ops
related to the set_fs() changes, and now go look for any commit that has:
Fixes: 36e2c7421f02 ("fs: don't allow splice read/write without explicit ops")
in it and see that this isn't an isolated incident at all.
tldr - splice from /dev/urandom used to work, and I recently got a report internally on an application that broke on upgrade from 5.6 to 5.12 exactly because it now just just -EINVAL's instead.
-- Jens Axboe
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