Re: [PATCH 5.10 000/657] 5.10.20-rc4 review

[Naresh Kamboju]

On Fri, 5 Mar 2021 at 02:45, Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> On Thu, Mar 4, 2021 at 9:56 AM Naresh Kamboju <naresh.kamboju@xxxxxxxxxx> wrote:
> >
> > On Thu, 4 Mar 2021 at 01:34, Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
> > >
> > > Upstream has:
> > >
> > > e71a8d5cf4b4 tty: fix up iterate_tty_read() EOVERFLOW handling
> > > ddc5fda74561 tty: fix up hung_up_tty_read() conversion
> >
> > I have applied these two patches and the reported problem did not solve.
>
> Hmm. Upstream has:
>
> *  3342ff2698e9 ("tty: protect tty_write from odd low-level tty disciplines")
> *  a9cbbb80e3e7 ("tty: avoid using vfs_iocb_iter_write() for
> redirected console writes")
> *  17749851eb9c ("tty: fix up hung_up_tty_write() conversion")
> G  e71a8d5cf4b4 ("tty: fix up iterate_tty_read() EOVERFLOW handling")
> G  ddc5fda74561 ("tty: fix up hung_up_tty_read() conversion")
>  * c7135bbe5af2 ("tty: fix up hung_up_tty_write() conversion")
>   d7fe75cbc23c ("tty: teach the n_tty ICANON case about the new
> "cookie continuations" too")
>   15ea8ae8e03f ("tty: teach n_tty line discipline about the new
> "cookie continuations"")
>   64a69892afad ("tty: clean up legacy leftovers from n_tty line discipline")
> *  9bb48c82aced ("tty: implement write_iter")
> *  dd78b0c483e3 ("tty: implement read_iter")
> *  3b830a9c34d5 ("tty: convert tty_ldisc_ops 'read()' function to take
> a kernel pointer")
>
> Where those ones marked with '*' seem to be in v5.10.y, and the one
> prefixed with 'G' are the ones Guenter mentioned.
>
> (We seem to have the "tty: fix up hung_up_tty_write() conversion"
> commit twice. I'm not sure how that happened, but whatever).
>
> But that still leaves three commits that don't seem to be in 5.10.y:
>
>   d7fe75cbc23c ("tty: teach the n_tty ICANON case about the new
> "cookie continuations" too")
>   15ea8ae8e03f ("tty: teach n_tty line discipline about the new
> "cookie continuations"")
>   64a69892afad ("tty: clean up legacy leftovers from n_tty line discipline")
>
> and they might fix what are otherwise short reads. Which is allowed by
> POSIX, afaik, but ..
>
> Do those three commits fix your test-case?

Yes.
As per your suggestion I've added these three patches and tested
and the reported test case PASS now [1].

This means I have five extra patches on top of the stable v5.10.20 tag.

$ git log --oneline
8c1c1de499af tty: teach the n_tty ICANON case about the new "cookie
continuations" too
02aada164879 tty: teach n_tty line discipline about the new "cookie
continuations"
fb0df6b17897 tty: clean up legacy leftovers from n_tty line discipline
429f7fc84d6a tty: fix up iterate_tty_read() EOVERFLOW handling
d0d54bca80a8 tty: fix up hung_up_tty_read() conversion
83be32b6c9e5 (tag: v5.10.20, origin/linux-5.10.y) Linux 5.10.20

[1] https://lkft.validation.linaro.org/scheduler/job/2344990#L1207

- Naresh