Re: [PATCH v2 21/35] platform/x86/thinkpad: Use kmemdup rather than duplicating its implementation

From: Andy Shevchenko
Date: Thu Jul 25 2019 - 14:09:11 EST


On Wed, Jul 3, 2019 at 7:30 PM Fuqian Huang <huangfq.daxian@xxxxxxxxx> 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@xxxxxxxxx>
> ---
> 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