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From: Naresh Kamboju <naresh.kamboju@linaro.org>
To: Christoph Hellwig <hch@lst.de>
Cc: Qian Cai <cai@lca.pw>, Jens Axboe <axboe@kernel.dk>,
	dm-devel@redhat.com, open list <linux-kernel@vger.kernel.org>,
	linux-m68k@lists.linux-m68k.org, linux-xtensa@linux-xtensa.org,
	drbd-dev@lists.linbit.com,
	linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
	linux-bcache@vger.kernel.org, linux-raid@vger.kernel.org,
	linux-nvdimm@lists.01.org, linux-nvme@lists.infradead.org,
	linux-s390@vger.kernel.org,
	Andrey Ryabinin <aryabinin@virtuozzo.com>,
	Alexander Potapenko <glider@google.com>,
	Dmitry Vyukov <dvyukov@google.com>,
	kasan-dev@googlegroups.com
Subject: Re: [PATCH 18/20] block: refator submit_bio_noacct
Date: Thu, 2 Jul 2020 21:22:46 +0530
Message-ID: <CA+G9fYv6DfJB=DeQFVptAuaVv1Ng-BK0fRHgFZ=DNzymu8LVvw@mail.gmail.com> (raw)
In-Reply-To: <20200702151453.GA1799@lst.de>

On Thu, 2 Jul 2020 at 20:45, Christoph Hellwig <hch@lst.de> wrote:
>
> On Thu, Jul 02, 2020 at 10:10:10AM -0400, Qian Cai wrote:
> > On Mon, Jun 29, 2020 at 09:39:45PM +0200, Christoph Hellwig wrote:
> > > Split out a __submit_bio_noacct helper for the actual de-recursion
> > > algorithm, and simplify the loop by using a continue when we can't
> > > enter the queue for a bio.
> > >
> > > Signed-off-by: Christoph Hellwig <hch@lst.de>
> >
> > Reverting this commit and its dependencies,
> >
> > 5a6c35f9af41 block: remove direct_make_request
> > ff93ea0ce763 block: shortcut __submit_bio_noacct for blk-mq drivers
> >
> > fixed the stack-out-of-bounds during boot,
> >
> > https://lore.kernel.org/linux-block/000000000000bcdeaa05a97280e4@google.com/
>
> Yikes.  bio_alloc_bioset pokes into bio_list[1] in a totally
> undocumented way.  But even with that the problem should only show
> up with "block: shortcut __submit_bio_noacct for blk-mq drivers".
>
> Can you try this patch?

Applied your patch on top of linux-next 20200702 and tested on
arm64 and x86_64 devices and the reported BUG fixed.

Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>

>
> diff --git a/block/blk-core.c b/block/blk-core.c
> index bf882b8d84450c..9f1bf8658b611a 100644
> --- a/block/blk-core.c
> +++ b/block/blk-core.c
> @@ -1155,11 +1155,10 @@ static blk_qc_t __submit_bio_noacct(struct bio *bio)
>  static blk_qc_t __submit_bio_noacct_mq(struct bio *bio)
>  {
>         struct gendisk *disk = bio->bi_disk;
> -       struct bio_list bio_list;
> +       struct bio_list bio_list[2] = { };
>         blk_qc_t ret = BLK_QC_T_NONE;
>
> -       bio_list_init(&bio_list);
> -       current->bio_list = &bio_list;
> +       current->bio_list = bio_list;
>
>         do {
>                 WARN_ON_ONCE(bio->bi_disk != disk);
> @@ -1174,7 +1173,7 @@ static blk_qc_t __submit_bio_noacct_mq(struct bio *bio)
>                 }
>
>                 ret = blk_mq_submit_bio(bio);
> -       } while ((bio = bio_list_pop(&bio_list)));
> +       } while ((bio = bio_list_pop(&bio_list[0])));
>
>         current->bio_list = NULL;
>         return ret;

ref:
https://lkft.validation.linaro.org/scheduler/job/1538359#L288
https://lkft.validation.linaro.org/scheduler/job/1538360#L572


- Naresh

  reply index

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-29 19:39 rename ->make_request_fn and move it to the block_device_operations Christoph Hellwig
2020-06-29 19:39 ` [PATCH 01/20] nfblock: stop using ->queuedata Christoph Hellwig
2020-06-29 21:47   ` Geert Uytterhoeven
2020-06-29 19:39 ` [PATCH 02/20] simdisk: " Christoph Hellwig
2020-06-29 19:39 ` [PATCH 03/20] drbd: " Christoph Hellwig
2020-06-29 19:39 ` [PATCH 04/20] null_blk: stop using ->queuedata for bio mode Christoph Hellwig
2020-06-29 19:39 ` [PATCH 05/20] ps3vram: stop using ->queuedata Christoph Hellwig
2020-06-29 19:39 ` [PATCH 06/20] rsxx: " Christoph Hellwig
2020-06-29 19:39 ` [PATCH 07/20] umem: " Christoph Hellwig
2020-06-29 19:39 ` [PATCH 08/20] zram: " Christoph Hellwig
2020-06-29 19:39 ` [PATCH 09/20] bcache: stop setting ->queuedata Christoph Hellwig
2020-06-29 19:39 ` [PATCH 10/20] dm: stop using ->queuedata Christoph Hellwig
2020-06-29 19:39 ` [PATCH 11/20] fs: remove a weird comment in submit_bh_wbc Christoph Hellwig
2020-06-30 13:54   ` Jens Axboe
2020-06-29 19:39 ` [PATCH 12/20] block: remove the request_queue argument from blk_queue_split Christoph Hellwig
2020-06-29 19:39 ` [PATCH 13/20] block: tidy up a warning in bio_check_ro Christoph Hellwig
2020-06-29 19:39 ` [PATCH 14/20] block: remove the NULL queue check in generic_make_request_checks Christoph Hellwig
2020-06-29 19:39 ` [PATCH 15/20] block: remove the nr_sectors variable " Christoph Hellwig
2020-06-29 19:39 ` [PATCH 16/20] block: move ->make_request_fn to struct block_device_operations Christoph Hellwig
2020-06-29 19:39 ` [PATCH 17/20] block: rename generic_make_request to submit_bio_noacct Christoph Hellwig
2020-06-29 19:39 ` [PATCH 18/20] block: refator submit_bio_noacct Christoph Hellwig
2020-07-02 14:10   ` Qian Cai
2020-07-02 15:14     ` Christoph Hellwig
2020-07-02 15:52       ` Naresh Kamboju [this message]
2020-07-02 15:15     ` Naresh Kamboju
2020-06-29 19:39 ` [PATCH 19/20] block: shortcut __submit_bio_noacct for blk-mq drivers Christoph Hellwig
2020-06-29 19:39 ` [PATCH 20/20] block: remove direct_make_request Christoph Hellwig
2020-06-30 13:57 ` rename ->make_request_fn and move it to the block_device_operations Jens Axboe
2020-06-30 15:43   ` Jens Axboe
2020-06-30 18:19     ` Christoph Hellwig
2020-06-30 18:21       ` Jens Axboe
2020-07-01  8:59 rename ->make_request_fn and move it to the block_device_operations v2 Christoph Hellwig
2020-07-01  8:59 ` [PATCH 18/20] block: refator submit_bio_noacct Christoph Hellwig

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