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[2001:8b0:df16::2]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-431606c64b8sm23559035e9.38.2024.10.18.03.31.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 18 Oct 2024 03:31:26 -0700 (PDT) Date: Fri, 18 Oct 2024 11:31:24 +0100 From: Phillip Potter To: Jens Axboe Cc: linux-kernel@vger.kernel.org, Jordy Zomer , Josh Poimboeuf Subject: Re: [PATCH] cdrom: Avoid barrier_nospec() in cdrom_ioctl_media_changed() Message-ID: References: <1d86f4d9d8fba68e5ca64cdeac2451b95a8bf872.1729202937.git.jpoimboe@kernel.org> <172921605188.361223.17436309372879358744.b4-ty@kernel.dk> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <172921605188.361223.17436309372879358744.b4-ty@kernel.dk> On Thu, Oct 17, 2024 at 07:47:31PM -0600, Jens Axboe wrote: > > On Thu, 17 Oct 2024 15:09:02 -0700, Josh Poimboeuf wrote: > > The barrier_nospec() after the array bounds check is overkill and > > painfully slow for arches which implement it. > > > > Furthermore, most arches don't implement it, so they remain exposed to > > Spectre v1 (which can affect pretty much any CPU with branch > > prediction). > > > > [...] > > Applied, thanks! > > [1/1] cdrom: Avoid barrier_nospec() in cdrom_ioctl_media_changed() > commit: b0bf1afde7c34698cf61422fa8ee60e690dc25c3 > > Best regards, > -- > Jens Axboe > > > Sorry for lack of reply, this conversation took place in the early hours for my timezone and thus I was unconscious :-) Change sounds good to me for the aforementioned reasons. Regards, Phil