linux-kernel - Re: [PATCH v2 1/3] scsi: ufs: core: Remove redundant host

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] [day] [month] [year] [list]

Message-ID: <b43d5e01-cafe-4133-9873-68897439bf5f@acm.org>
Date: Wed, 23 Oct 2024 12:44:22 -0700
From: Bart Van Assche <bvanassche@....org>
To: Avri Altman <Avri.Altman@....com>,
 "Martin K . Petersen" <martin.petersen@...cle.com>
Cc: "linux-scsi@...r.kernel.org" <linux-scsi@...r.kernel.org>,
 "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2 1/3] scsi: ufs: core: Remove redundant host_lock calls
 around UTMRLDBR.

On 10/22/24 11:47 PM, Avri Altman wrote:
>> On 10/22/24 12:43 AM, Avri Altman wrote:
>>>        for_each_set_bit(tag, &issued, hba->nutmrs) {
>>>                struct request *req = hba->tmf_rqs[tag];
>>>                struct completion *c = req->end_io_data;
>>
>> Would it be sufficient to hold the SCSI host lock around the
>> hba->outstanding_tasks read only? I don't think that the
>> for_each_set_bit() loop needs to be protected with the SCSI host lock.
 >
> That may cause concurrent access to tmf_rqs?

Right, the host_lock serializes hba->tmf_rqs[] accesses. Without having
analyzed whether or not removing locking from around the hba->tmf_rqs[]
accesses, let's keep this locking.

> So better withdraw from changing ufshcd_tmc_handler() and just leave
> the whole function as it is?
That sounds good to me.

Thanks,

Bart.