From:   Alexander Shishkin <alexander.shishkin@linux.intel.com>
To:     Leon Romanovsky <leon@kernel.org>
Cc:     Bjorn Helgaas <bhelgaas@google.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
        Marc Zyngier <maz@kernel.org>, darwi@linutronix.de,
        elena.reshetova@intel.com, kirill.shutemov@linux.intel.com,
        Mika Westerberg <mika.westerberg@linux.intel.com>,
        stable@vger.kernel.org, alexander.shishkin@linux.intel.com
Subject: Re: [PATCH 1/2] PCI/MSI: Cache the MSIX table size
In-Reply-To: <Y8/WPAqZACAHcmf+@unreal>
References: <20230119170633.40944-1-alexander.shishkin@linux.intel.com>
 <20230119170633.40944-2-alexander.shishkin@linux.intel.com>
 <Y8z7FPcuDXDBi+1U@unreal> <87v8kwp2t6.fsf@ubik.fi.intel.com>
 <Y8/Kyzh+stow83lQ@unreal> <87pmb4p0ik.fsf@ubik.fi.intel.com>
 <Y8/WPAqZACAHcmf+@unreal>
Date:   Tue, 24 Jan 2023 17:28:27 +0200
Message-ID: <87mt68ostg.fsf@ubik.fi.intel.com>
MIME-Version: 1.0
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Leon Romanovsky <leon@kernel.org> writes:

> On Tue, Jan 24, 2023 at 02:42:11PM +0200, Alexander Shishkin wrote:
>> Leon Romanovsky <leon@kernel.org> writes:
>> 
>> A malicious device is what the fuzzing is aiming to simulate. The fact
>> of fuzzing process itself didn't seem relevant to the patch, so I didn't
>> include it, going instead for the problem statement and proposed
>> solution. Will the commit message benefit from mentioning fuzzing?
>
> No, for most if not all kernel developers, the fuzzing means some sort of
> random user-space input. PCI devices are trusted in the kernel.

Right, it's a different kind of fuzzing. Apologies, I should have made
it clear.

>> > Do you see "gazillion bugs" for devices which don't change their MSI-X
>> > table size under the hood, which is main kernel assumption?
>> 
>> Not so far.
>
> So please share them with us.

We do, as soon as we find them. This patch is one such instance.

>> > If yes, you should fix these bugs.
>> 
>> That's absolutely the intention.
>
> So let's fix the bugs and not hide them.

Yes, that's what this patch aims to achieve.

Thanks,
--
Alex