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Subject: Re: [Regression] Missing device nodes for ETR, ETF and STM after
 CONFIG_UEVENT_HELPER=n
From:   Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
To:     Geert Uytterhoeven <geert+renesas@glider.be>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Mathieu Poirier <mathieu.poirier@linaro.org>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Leo Yan <leo.yan@linaro.org>, linux-arm-msm@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
References: <cfe09a46-462f-633a-37c2-52f8bfc0ffb2@codeaurora.org>
Message-ID: <e3a01f7e-9662-415d-1e3d-df3734d3e305@codeaurora.org>
Date:   Fri, 26 Jul 2019 11:56:02 +0530
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On 7/26/2019 11:49 AM, Sai Prakash Ranjan wrote:
> Hi,
> 
> When trying to test my coresight patches, I found that etr,etf and stm 
> device nodes are missing from /dev.
> 
> Bisection gives this as the bad commit.
> 
> 1be01d4a57142ded23bdb9e0c8d9369e693b26cc is the first bad commit
> commit 1be01d4a57142ded23bdb9e0c8d9369e693b26cc
> Author: Geert Uytterhoeven <geert+renesas@glider.be>
> Date:   Thu Mar 14 12:13:50 2019 +0100
> 
>      driver: base: Disable CONFIG_UEVENT_HELPER by default
> 
>      Since commit 7934779a69f1184f ("Driver-Core: disable /sbin/hotplug by
>      default"), the help text for the /sbin/hotplug fork-bomb says
>      "This should not be used today [...] creates a high system load, or
>      [...] out-of-memory situations during bootup".  The rationale for this
>      was that no recent mainstream system used this anymore (in 2010!).
> 
>      A few years later, the complete uevent helper support was made 
> optional
>      in commit 86d56134f1b67d0c ("kobject: Make support for uevent_helper
>      optional.").  However, if was still left enabled by default, to 
> support
>      ancient userland.
> 
>      Time passed by, and nothing should use this anymore, so it can be
>      disabled by default.
> 
>      Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
>      Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> 
>   drivers/base/Kconfig | 1 -
>   1 file changed, 1 deletion(-)
> 
> 
FYI, I am testing on linux-next.

Thanks,
Sai

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