From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
To: Eric Blake <eblake@redhat.com>, Alberto Garcia <berto@igalia.com>,
qemu-block@nongnu.org
Cc: kwolf@redhat.com, fam@euphon.net, integration@gluster.org,
sheepdog@lists.wpkg.org, pavel.dovgaluk@ispras.ru,
dillaman@redhat.com, qemu-devel@nongnu.org, sw@weilnetz.de,
pl@kamp.de, ronniesahlberg@gmail.com, mreitz@redhat.com,
den@openvz.org, stefanha@redhat.com, namei.unix@gmail.com,
pbonzini@redhat.com, jsnow@redhat.com, ari@tuxera.com
Subject: Re: [PATCH v3 05/17] block/io: support int64_t bytes in bdrv_co_do_pwrite_zeroes()
Date: Tue, 23 Jun 2020 13:20:11 +0300 [thread overview]
Message-ID: <58dd9502-9356-3fa1-e37d-b9ce8b646b3b@virtuozzo.com> (raw)
In-Reply-To: <7b5f7192-9a03-da06-1583-039b671c1e81@redhat.com>
11.05.2020 21:34, Eric Blake wrote:
> On 5/11/20 12:17 PM, Alberto Garcia wrote:
>> On Thu 30 Apr 2020 01:10:21 PM CEST, Vladimir Sementsov-Ogievskiy wrote:
>>> compute 'int tail' via % 'int alignment' - safe
>>
>> tail = (offset + bytes) % alignment;
>>
>> both are int64_t, no chance of overflow here?
>
> Good question - I know several places check that offset+bytes does not overflow, but did not specifically audit if this one does. Adding an assert() in this function may be easier than trying to prove all callers pass in safe values.
>
Hm, it's preexisting, as int64_t + int may overflow as well. Strange, but I don't see overflow check neither in blk_check_byte_request nor in bdrv_check_byte_request. Only discard, which recently dropped call of bdrv_check_byte_request() has this check.
I can add a patch for overflow check in blk_check_byte_request and bdrv_check_byte_request.. But what about alignment? There may be requests, for which bytes + offset doesn't overflow, but do overflow after aligning up. Refactor bdrv_pad_request() to return an error if we can't pad request due to overflow?
--
Best regards,
Vladimir
next prev parent reply other threads:[~2020-06-23 10:21 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-30 11:10 [PATCH v3 00/17] 64bit block-layer Vladimir Sementsov-Ogievskiy
2020-04-30 11:10 ` [PATCH v3 01/17] block/throttle-groups: throttle_group_co_io_limits_intercept(): 64bit bytes Vladimir Sementsov-Ogievskiy
2020-05-11 15:28 ` Alberto Garcia
2020-04-30 11:10 ` [PATCH v3 02/17] block: use int64_t as bytes type in tracked requests Vladimir Sementsov-Ogievskiy
2020-05-11 15:32 ` Alberto Garcia
2020-05-22 19:09 ` Eric Blake
2020-04-30 11:10 ` [PATCH v3 03/17] block/io: use int64_t bytes parameter in bdrv_check_byte_request() Vladimir Sementsov-Ogievskiy
2020-05-11 15:57 ` Alberto Garcia
2020-04-30 11:10 ` [PATCH v3 04/17] block/io: use int64_t bytes in driver wrappers Vladimir Sementsov-Ogievskiy
2020-05-11 16:30 ` Alberto Garcia
2020-04-30 11:10 ` [PATCH v3 05/17] block/io: support int64_t bytes in bdrv_co_do_pwrite_zeroes() Vladimir Sementsov-Ogievskiy
2020-05-08 18:20 ` Eric Blake
2020-05-11 17:17 ` Alberto Garcia
2020-05-11 18:34 ` Eric Blake
2020-06-23 10:20 ` Vladimir Sementsov-Ogievskiy [this message]
2020-06-23 16:37 ` Eric Blake
2020-04-30 11:10 ` [PATCH v3 06/17] block/io: support int64_t bytes in bdrv_aligned_pwritev() Vladimir Sementsov-Ogievskiy
2020-05-08 20:38 ` Eric Blake
2020-06-18 14:29 ` Alberto Garcia
2020-04-30 11:10 ` [PATCH v3 07/17] block/io: support int64_t bytes in bdrv_co_do_copy_on_readv() Vladimir Sementsov-Ogievskiy
2020-05-21 22:29 ` Eric Blake
2020-05-22 6:30 ` Vladimir Sementsov-Ogievskiy
2020-04-30 11:10 ` [PATCH v3 08/17] block/io: support int64_t bytes in bdrv_aligned_preadv() Vladimir Sementsov-Ogievskiy
2020-05-22 15:14 ` Eric Blake
2020-06-18 14:35 ` Alberto Garcia
2020-06-18 14:47 ` Eric Blake
2020-04-30 11:10 ` [PATCH v3 09/17] block/io: support int64_t bytes in bdrv_co_p{read, write}v_part() Vladimir Sementsov-Ogievskiy
2020-05-22 19:34 ` [PATCH v3 09/17] block/io: support int64_t bytes in bdrv_co_p{read,write}v_part() Eric Blake
2020-04-30 11:10 ` [PATCH v3 10/17] block/io: support int64_t bytes in read/write wrappers Vladimir Sementsov-Ogievskiy
2020-04-30 11:10 ` [PATCH v3 11/17] block/io: use int64_t bytes in copy_range Vladimir Sementsov-Ogievskiy
2020-04-30 11:10 ` [PATCH v3 12/17] block/block-backend: convert blk io path to use int64_t parameters Vladimir Sementsov-Ogievskiy
2020-06-23 22:11 ` Eric Blake
2020-04-30 11:10 ` [PATCH v3 13/17] block: use int64_t instead of uint64_t in driver read handlers Vladimir Sementsov-Ogievskiy
2020-04-30 11:10 ` [PATCH v3 14/17] block: use int64_t instead of uint64_t in driver write handlers Vladimir Sementsov-Ogievskiy
2020-04-30 11:10 ` [PATCH v3 15/17] block: use int64_t instead of uint64_t in copy_range driver handlers Vladimir Sementsov-Ogievskiy
2020-04-30 11:10 ` [PATCH v3 16/17] block: use int64_t instead of int in driver write_zeroes handlers Vladimir Sementsov-Ogievskiy
2020-04-30 11:10 ` [PATCH v3 17/17] block: use int64_t instead of int in driver discard handlers Vladimir Sementsov-Ogievskiy
2020-05-06 6:40 ` Vladimir Sementsov-Ogievskiy
2020-04-30 20:51 ` [PATCH v3 00/17] 64bit block-layer no-reply
2020-05-06 6:39 ` Vladimir Sementsov-Ogievskiy
2020-04-30 20:57 ` no-reply
2020-12-01 16:07 ` Vladimir Sementsov-Ogievskiy
2020-12-01 16:56 ` Vladimir Sementsov-Ogievskiy
2020-12-01 21:50 ` Eric Blake
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