From: Raslan Darawsheh <rasland@mellanox.com>
To: Bing Zhao <bingz@mellanox.com>,
Slava Ovsiienko <viacheslavo@mellanox.com>
Cc: Ori Kam <orika@mellanox.com>, Matan Azrad <matan@mellanox.com>,
"dev@dpdk.org" <dev@dpdk.org>,
"stable@dpdk.org" <stable@dpdk.org>,
Dekel Peled <dekelp@mellanox.com>
Subject: Re: [dpdk-stable] [PATCH] net/mlx5: fix left shift extension of doorbell bitmap
Date: Sun, 17 May 2020 09:18:41 +0000 [thread overview]
Message-ID: <AM0PR05MB6707A7199AEA718257597865C2BB0@AM0PR05MB6707.eurprd05.prod.outlook.com> (raw)
In-Reply-To: <1589530438-437604-1-git-send-email-bingz@mellanox.com>
Hi,
> -----Original Message-----
> From: Bing Zhao <bingz@mellanox.com>
> Sent: Friday, May 15, 2020 11:14 AM
> To: Slava Ovsiienko <viacheslavo@mellanox.com>; Raslan Darawsheh
> <rasland@mellanox.com>
> Cc: Ori Kam <orika@mellanox.com>; Matan Azrad <matan@mellanox.com>;
> dev@dpdk.org; stable@dpdk.org; Dekel Peled <dekelp@mellanox.com>
> Subject: [PATCH] net/mlx5: fix left shift extension of doorbell bitmap
>
> The doorbell record is organized with page and bitmap. When some new
> doorbell needs to be associated with a queue, the bit will be set
> in the bitmap to indicate the corresponding doorbell occupied. A
> counter is used to record the number of doorbell occupied to speed
> up the searching.
> If the number reachs the maximal value of a pre-defined number of a
> page, a new page will be allocated. If not, then the bitmap will be
> checked to find a free one.
> The LSHIFT and OR (AND NOT) operations are used to update the bitmap
> of a page. But 1 will be treated as a signed integer when compiling.
> When the shift number is 31, the shifted value will be considered as
> negative. Then a wrong extension will be done when setting it to a
> 64-bits variable. All the upper 32-bits will be set to 1 by such
> extension.
> Then a wrong offset value will be calculated because of this. The
> next 64 bits will be also treated as the bitmap and get corrupted
> through the bit set operation.
> The immediate value 1 needs to be used as 64 bits width explicitly.
>
> Fixes: 21cae8580fd0 ("net/mlx5: allocate door-bells via DevX")
> Cc: dekelp@mellanox.com
> Cc: stable@dpdk.org
>
> Signed-off-by: Bing Zhao <bingz@mellanox.com>
> Acked-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
> ---
> drivers/net/mlx5/mlx5.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/mlx5/mlx5.c b/drivers/net/mlx5/mlx5.c
> index 1445809..ab4adec 100644
> --- a/drivers/net/mlx5/mlx5.c
> +++ b/drivers/net/mlx5/mlx5.c
> @@ -2174,7 +2174,7 @@ struct mlx5_flow_id_pool *
> /* Find the first clear bit. */
> MLX5_ASSERT(i < MLX5_DBR_BITMAP_SIZE);
> j = rte_bsf64(~page->dbr_bitmap[i]);
> - page->dbr_bitmap[i] |= (1 << j);
> + page->dbr_bitmap[i] |= (UINT64_C(1) << j);
> page->dbr_count++;
> *dbr_page = page;
> return (((i * 64) + j) * sizeof(uint64_t));
> @@ -2219,7 +2219,7 @@ struct mlx5_flow_id_pool *
> int i = offset / 64;
> int j = offset % 64;
>
> - page->dbr_bitmap[i] &= ~(1 << j);
> + page->dbr_bitmap[i] &= ~(UINT64_C(1) << j);
> }
> return ret;
> }
> --
> 1.8.3.1
Commit title changed to:
net/mlx5: fix left shift extension of doorbell bitmap
Patch applied to next-net-mlx,
Kindest regards
Raslan Darawsheh
next prev parent reply other threads:[~2020-05-17 9:18 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-15 8:13 Bing Zhao
2020-05-17 5:45 ` Matan Azrad
2020-05-17 9:18 ` Raslan Darawsheh [this message]
2020-05-17 9:54 ` Raslan Darawsheh
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=AM0PR05MB6707A7199AEA718257597865C2BB0@AM0PR05MB6707.eurprd05.prod.outlook.com \
--to=rasland@mellanox.com \
--cc=bingz@mellanox.com \
--cc=dekelp@mellanox.com \
--cc=dev@dpdk.org \
--cc=matan@mellanox.com \
--cc=orika@mellanox.com \
--cc=stable@dpdk.org \
--cc=viacheslavo@mellanox.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).