From mboxrd@z Thu Jan  1 00:00:00 1970
From: Geert Uytterhoeven <geert@linux-m68k.org>
Subject: Re: [RFC 0/4] clk/driver: platform: Fix kfree() of const memory on
 setting driver_override
Date: Mon, 18 Feb 2019 11:40:12 +0100
Message-ID: <CAMuHMdWXy_0zL8FZWapPj4+cXRd0wHy9buLhf0D0txpAHPkK7Q@mail.gmail.com>
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Cc: Russell King <linux@armlinux.org.uk>,
        Mark Brown <broonie@kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        linux-spi <linux-spi@vger.kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Sylwester Nawrocki <s.nawrocki@samsung.com>,
        Tomasz Figa <tomasz.figa@gmail.com>,
        Chanwoo Choi <cw00.choi@samsung.com>,
        Michael Turquette <mturquette@baylibre.com>,
        Stephen Boyd <sboyd@kernel.org>, Kukjin Kim <kgene@kernel.org>,
        Andy Gross <andy.gross@linaro.org>,
        David Brown <david.brown@linaro.org>,
        Srinivas Kandagatla <srinivas.kandagatla@linaro.org>,
        linux-samsung-soc@vger.kernel.org,
        linux-clk <linux-clk@vger.kernel.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        linux-arm-msm@vger.ke
To: Krzysztof Kozlowski <krzk@kernel.org>
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Hi Krzysztof,

On Mon, Feb 18, 2019 at 11:27 AM Krzysztof Kozlowski <krzk@kernel.org> wrote:
> The problem
> ===========
> Several device types (platform, amba, spi etc.) provide a driver_override
> field.  On sysfs store or during device removal, they kfree() the
> existing value.
>
> However the users are unaware of this and set the driver_override like:
>
>         pdev->driver_override = "exynos5-subcmu";
>
> which obviously leads to error.

IMHO driver_override is not meant to be set by a driver, only from userspace,
for binding the device to vfio (is there another use case?).

>   clk: samsung: exynos5: Fix kfree() of const memory on setting
>     driver_override
>   slimbus: ngd: Fix kfree() of const memory on setting driver_override

I see all users set override immediately after allocating a platform device.
Can't they just allocate a platform device using the override name instead?
What am I missing?

Thanks!

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds