linux-kernel - Re: [PATCH v4 02/21] thermal/drivers/sun8i: convert to use devm_request*_irq

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]

Date:   Tue, 11 Jul 2023 19:57:26 +0200
From:   Jernej Škrabec <jernej.skrabec@...il.com>
To:     Vasily Khoruzhick <anarsoul@...il.com>,
        Yangtao Li <tiny.windzz@...il.com>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Daniel Lezcano <daniel.lezcano@...aro.org>,
        Amit Kucheria <amitk@...nel.org>,
        Zhang Rui <rui.zhang@...el.com>, Chen-Yu Tsai <wens@...e.org>,
        Samuel Holland <samuel@...lland.org>,
        Yangtao Li <frank.li@...o.com>
Cc:     Yangtao Li <frank.li@...o.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Krzysztof Kozlowski <krzk@...nel.org>,
        Uwe Kleine-König 
        <u.kleine-koenig@...gutronix.de>,
        Jonathan Cameron <Jonathan.Cameron@...wei.com>,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@...labora.com>,
        linux-pm@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-sunxi@...ts.linux.dev, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v4 02/21] thermal/drivers/sun8i: convert to use
 devm_request*_irq_probe()

Dne ponedeljek, 10. julij 2023 ob 11:59:06 CEST je Yangtao Li napisal(a):
> There are more than 700 calls to devm_request_threaded_irq method and
> more than 1000 calls to devm_request_irq method. Most drivers only
> request one interrupt resource, and these error messages are basically
> the same. If error messages are printed everywhere, more than 2000 lines
> of code can be saved by removing the msg in the driver.
> 
> And tglx point out that:
> 
>   If we actually look at the call sites of
>   devm_request_threaded_irq() then the vast majority of them print more or
>   less lousy error messages. A quick grep/sed/awk/sort/uniq revealed
> 
>      519 messages total (there are probably more)
> 
>      352 unique messages
> 
>      323 unique messages after lower casing
> 
>          Those 323 are mostly just variants of the same patterns with
>          slight modifications in formatting and information provided.
> 
>      186 of these messages do not deliver any useful information,
>          e.g. "no irq", "
> 
>      The most useful one of all is: "could request wakeup irq: %d"
> 
>   So there is certainly an argument to be made that this particular
>   function should print a well formatted and informative error message.
> 
>   It's not a general allocator like kmalloc(). It's specialized and in the
>   vast majority of cases failing to request the interrupt causes the
>   device probe to fail. So having proper and consistent information why
>   the device cannot be used _is_ useful.
> 
> So convert to use devm_request*_irq_probe() API, which ensure that all
> error handling branches print error information.
> 
> In this way, when this function fails, the upper-layer functions can
> directly return an error code without missing debugging information.
> Otherwise, the error message will be printed redundantly or missing.
> 
> Cc: Thomas Gleixner <tglx@...utronix.de>
> Cc: Krzysztof Kozlowski <krzk@...nel.org>
> Cc: "Uwe Kleine-König" <u.kleine-koenig@...gutronix.de>
> Cc: Jonathan Cameron <Jonathan.Cameron@...wei.com>
> Cc: AngeloGioacchino Del Regno  <angelogioacchino.delregno@...labora.com>
> Signed-off-by: Yangtao Li <frank.li@...o.com>
> ---

Acked-by: Jernej Skrabec <jernej.skrabec@...il.com>

Best regards,
Jernej

>  drivers/thermal/sun8i_thermal.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/thermal/sun8i_thermal.c b/drivers/thermal/sun8i_thermal.c
> index 195f3c5d0b38..a952804ff993 100644
> --- a/drivers/thermal/sun8i_thermal.c
> +++ b/drivers/thermal/sun8i_thermal.c
> @@ -512,9 +512,9 @@ static int sun8i_ths_probe(struct platform_device *pdev)
>  	 * registered yet, we deffer the registration of the interrupt to
>  	 * the end.
>  	 */
> -	ret = devm_request_threaded_irq(dev, irq, NULL,
> -					sun8i_irq_thread,
> -					IRQF_ONESHOT, "ths", tmdev);
> +	ret = devm_request_threaded_irq_probe(dev, irq, NULL,
> +					      sun8i_irq_thread,
> +					      IRQF_ONESHOT, "ths", tmdev, NULL);
>  	if (ret)
>  		return ret;
>  
>