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From: Linus Walleij <linus.walleij@linaro.org>
To: "Pali Rohár" <pali@kernel.org>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Rob Herring <robh@kernel.org>, Marc Zyngier <maz@kernel.org>,
	linux-pci <linux-pci@vger.kernel.org>,
	linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: pci-ftpci100: race condition in masking/unmasking interrupts
Date: Tue, 7 Sep 2021 13:22:37 +0200	[thread overview]
Message-ID: <CACRpkdYe-Y-1YstovrJd7b8iNCDeX312mB4gLGcG1y6dE6di=A@mail.gmail.com> (raw)
In-Reply-To: <20210818114743.kksb7tydqjkww67h@pali>

On Wed, Aug 18, 2021 at 1:47 PM Pali Rohár <pali@kernel.org> wrote:

> I do not see any entry in MAINTAINERS file for pci-ftpci100.c driver, so
> I'm not sure to whom should I address this issue...

It's me.

> During pci-aardvark review, Marc pointed one issue which is currently
> available also in pci-ftpci100.c driver.
>
> When masking or unmasking interrupts there is read-modify-write sequence
> for FARADAY_PCI_CTRL2 register without any locking and is not atomic:
>
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/pci/controller/pci-ftpci100.c?h=v5.13#n270
>
> So there is race condition when masking/unmasking more interrupts at the
> same time.

I thought those operations were called in atomic context.
How did you fix it?

Yours,
Linus Walleij

  reply	other threads:[~2021-09-07 11:22 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-18 11:47 pci-ftpci100: race condition in masking/unmasking interrupts Pali Rohár
2021-09-07 11:22 ` Linus Walleij [this message]
2021-09-07 12:20   ` Pali Rohár
2021-09-07 16:53   ` Marc Zyngier

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