linux-kernel - Re: [PATCH v2 1/1] pinctrl: ocelot: fix system hang on level based interrupts

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] [thread-next>] [day] [month] [year] [list]

Message-ID: <CACRpkdbCVFEgP3ZchLtM8KgDVVbCiK7ZgGha=iVfTBveRstDkA@mail.gmail.com>
Date: Sat, 12 Oct 2024 22:04:30 +0200
From: Linus Walleij <linus.walleij@...aro.org>
To: Sergey Matsievskiy <matsievskiysv@...il.com>
Cc: alexandre.belloni@...tlin.com, quentin.schulz@...tlin.com, 
	lars.povlsen@...rochip.com, horatiu.vultur@...rochip.com, 
	andriy.shevchenko@...ux.intel.com, linux-gpio@...r.kernel.org, 
	linux-kernel@...r.kernel.org, linux-mips@...r.kernel.org, 
	UNGLinuxDriver@...rochip.com
Subject: Re: [PATCH v2 1/1] pinctrl: ocelot: fix system hang on level based interrupts

On Sat, Oct 12, 2024 at 12:58 PM Sergey Matsievskiy
<matsievskiysv@...il.com> wrote:

> The current implementation only calls chained_irq_enter() and
> chained_irq_exit() if it detects pending interrupts.
>
> ```
> for (i = 0; i < info->stride; i++) {
>         uregmap_read(info->map, id_reg + 4 * i, &reg);
>         if (!reg)
>                 continue;
>
>         chained_irq_enter(parent_chip, desc);
> ```
>
> However, in case of GPIO pin configured in level mode and the parent
> controller configured in edge mode, GPIO interrupt might be lowered by the
> hardware. In the result, if the interrupt is short enough, the parent
> interrupt is still pending while the GPIO interrupt is cleared;
> chained_irq_enter() never gets called and the system hangs trying to
> service the parent interrupt.
>
> Moving chained_irq_enter() and chained_irq_exit() outside the for loop
> ensures that they are called even when GPIO interrupt is lowered by the
> hardware.
>
> The similar code with chained_irq_enter() / chained_irq_exit() functions
> wrapping interrupt checking loop may be found in many other drivers:
> ```
> grep -r -A 10 chained_irq_enter drivers/pinctrl
> ```
>
> Signed-off-by: Sergey Matsievskiy <matsievskiysv@...il.com>
> Reviewed-by: Alexandre Belloni <alexandre.belloni@...tlin.com>

Patch applied and tagged for stable!

Yours,
Linus Walleij