linux-kernel - Re: [PATCH v10 2/3] ublk: move check for empty address field on command submission

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <87350zxgkk.fsf@metaspace.dk>
Date:   Fri, 04 Aug 2023 12:08:55 +0200
From:   "Andreas Hindborg (Samsung)" <nmi@...aspace.dk>
To:     Ming Lei <tom.leiming@...il.com>
Cc:     Ming Lei <ming.lei@...hat.com>,
        Christoph Hellwig <hch@...radead.org>, gost.dev@...sung.com,
        "open list:BLOCK LAYER" <linux-block@...r.kernel.org>,
        Hans Holmberg <Hans.Holmberg@....com>,
        Matias Bjorling <Matias.Bjorling@....com>,
        Minwoo Im <minwoo.im.dev@...il.com>,
        Jens Axboe <axboe@...nel.dk>,
        Johannes Thumshirn <jth@...nel.org>,
        Aravind Ramesh <Aravind.Ramesh@....com>,
        Damien Le Moal <dlemoal@...nel.org>,
        open list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v10 2/3] ublk: move check for empty address field on
 command submission


Ming Lei <tom.leiming@...il.com> writes:

> Hi Andreas,
>
> On Thu, Aug 03, 2023 at 04:07:00PM +0200, Andreas Hindborg (Samsung) wrote:
>> From: Andreas Hindborg <a.hindborg@...sung.com>
>> 
>> In preparation for zoned storage support, move the check for empty `addr`
>> field into the command handler case statement. Note that the check makes no
>> sense for `UBLK_IO_NEED_GET_DATA` because the `addr` field must always be
>> set for this command.
>> 
>> Signed-off-by: Andreas Hindborg <a.hindborg@...sung.com>
>> ---
>>  drivers/block/ublk_drv.c | 18 +++++++++++++-----
>>  1 file changed, 13 insertions(+), 5 deletions(-)
>> 
>> diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
>> index db3523e281a6..5a1ee17636ac 100644
>> --- a/drivers/block/ublk_drv.c
>> +++ b/drivers/block/ublk_drv.c
>> @@ -1419,11 +1419,6 @@ static int __ublk_ch_uring_cmd(struct io_uring_cmd *cmd,
>>  			^ (_IOC_NR(cmd_op) == UBLK_IO_NEED_GET_DATA))
>>  		goto out;
>>  
>> -	if (ublk_support_user_copy(ubq) && ub_cmd->addr) {
>> -		ret = -EINVAL;
>> -		goto out;
>> -	}
>> -
>>  	ret = ublk_check_cmd_op(cmd_op);
>>  	if (ret)
>>  		goto out;
>> @@ -1452,6 +1447,12 @@ static int __ublk_ch_uring_cmd(struct io_uring_cmd *cmd,
>>  				goto out;
>>  		}
>>  
>> +		/* User copy requires addr to be unset */
>> +		if (ublk_support_user_copy(ubq) && ub_cmd->addr) {
>> +			ret = -EINVAL;
>> +			goto out;
>> +		}
>> +
>
> Given you have to post v11 for fixing build issue, please convert the
> above two 'if' into one 'if else':
>
> 		if (!ublk_support_user_copy(ubq)) {
> 			/*
> 			 * FETCH_RQ has to provide IO buffer if NEED GET
> 			 * DATA is not enabled
> 			 */
> 			if (!ub_cmd->addr && !ublk_need_get_data(ubq))
> 				goto out;
> 		} else {
> 			if (ub_cmd->addr) {
> 				ret = -EINVAL;
> 				goto out;
> 			}
> 		}

Alright. I was debating with myself one over the other 😅

>
>>  		ublk_fill_io_cmd(io, cmd, ub_cmd->addr);
>>  		ublk_mark_io_ready(ub, ubq);
>>  		break;
>> @@ -1470,6 +1471,13 @@ static int __ublk_ch_uring_cmd(struct io_uring_cmd *cmd,
>>  						req_op(req) == REQ_OP_READ))
>>  				goto out;
>>  		}
>> +
>> +		/* User copy requires addr to be unset */
>> +		if (ublk_support_user_copy(ubq) && ub_cmd->addr) {
>> +			ret = -EINVAL;
>> +			goto out;
>> +		}
>> +
>
> Same with above.
>
> BTW, I have verified this patchset with ublk-zoned example in
> libublk-rs:
>
> https://github.com/ming1/libublk-rs/tree/zoned.v2
>
> cargo run --example zoned -- add -1 10240
> mkfs.btrfs -O zoned /dev/ublkb0
> mount & git clone linux-kernel &umount

Thanks!

BR Andreas