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From:   Andy Shevchenko <andy.shevchenko@gmail.com>
Date:   Thu, 25 Jul 2019 20:43:59 +0300
Message-ID: <CAHp75Vefj9dBFHYn84ZHMteWgGEAq5bvAuvgbO8XRZcn_UdXHA@mail.gmail.com>
Subject: Re: [PATCH v2 21/35] platform/x86/thinkpad: Use kmemdup rather than
 duplicating its implementation
To:     Fuqian Huang <huangfq.daxian@gmail.com>
Cc:     Henrique de Moraes Holschuh <ibm-acpi@hmh.eng.br>,
        Darren Hart <dvhart@infradead.org>,
        Andy Shevchenko <andy@infradead.org>,
        Thinkpad-acpi devel ML <ibm-acpi-devel@lists.sourceforge.net>,
        Platform Driver <platform-driver-x86@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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On Wed, Jul 3, 2019 at 7:30 PM Fuqian Huang <huangfq.daxian@gmail.com> wrote:
>
> kmemdup is introduced to duplicate a region of memory in a neat way.
> Rather than kmalloc/kzalloc + memcpy, which the programmer needs to
> write the size twice (sometimes lead to mistakes), kmemdup improves
> readability, leads to smaller code and also reduce the chances of mistakes.
> Suggestion to use kmemdup rather than using kmalloc/kzalloc + memcpy.
>

Pushed to my review and testing queue, thanks!

> Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
> ---
> Changes in v2:
>   - Fix a typo in commit message (memset -> memcpy)
>
>  drivers/platform/x86/thinkpad_acpi.c | 17 +++++++----------
>  1 file changed, 7 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
> index 7bde4640ef34..d379bdf98a0f 100644
> --- a/drivers/platform/x86/thinkpad_acpi.c
> +++ b/drivers/platform/x86/thinkpad_acpi.c
> @@ -3647,22 +3647,19 @@ static int __init hotkey_init(struct ibm_init_struct *iibm)
>                 goto err_exit;
>
>         /* Set up key map */
> -       hotkey_keycode_map = kmalloc(TPACPI_HOTKEY_MAP_SIZE,
> -                                       GFP_KERNEL);
> -       if (!hotkey_keycode_map) {
> -               pr_err("failed to allocate memory for key map\n");
> -               res = -ENOMEM;
> -               goto err_exit;
> -       }
> -
>         keymap_id = tpacpi_check_quirks(tpacpi_keymap_qtable,
>                                         ARRAY_SIZE(tpacpi_keymap_qtable));
>         BUG_ON(keymap_id >= ARRAY_SIZE(tpacpi_keymaps));
>         dbg_printk(TPACPI_DBG_INIT | TPACPI_DBG_HKEY,
>                    "using keymap number %lu\n", keymap_id);
>
> -       memcpy(hotkey_keycode_map, &tpacpi_keymaps[keymap_id],
> -               TPACPI_HOTKEY_MAP_SIZE);
> +       hotkey_keycode_map = kmemdup(&tpacpi_keymaps[keymap_id],
> +                       TPACPI_HOTKEY_MAP_SIZE, GFP_KERNEL);
> +       if (!hotkey_keycode_map) {
> +               pr_err("failed to allocate memory for key map\n");
> +               res = -ENOMEM;
> +               goto err_exit;
> +       }
>
>         input_set_capability(tpacpi_inputdev, EV_MSC, MSC_SCAN);
>         tpacpi_inputdev->keycodesize = TPACPI_HOTKEY_MAP_TYPESIZE;
> --
> 2.11.0
>


-- 
With Best Regards,
Andy Shevchenko