[PATCH 19/30] platform/x86: Use kmemdup rather than duplicating its implementation

[PATCH 19/30] platform/x86: Use kmemdup rather than duplicating its implementation

[Fuqian Huang]

kmemdup is introduced to duplicate a region of memory in a neat way.
Rather than kmalloc/kzalloc + memset, 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 + memset.

Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
---
 drivers/platform/x86/asus-wmi.c      |  3 +--
 drivers/platform/x86/thinkpad_acpi.c | 17 +++++++----------
 2 files changed, 8 insertions(+), 12 deletions(-)

diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
index 9b18a184e0aa..472b317ad814 100644
--- a/drivers/platform/x86/asus-wmi.c
+++ b/drivers/platform/x86/asus-wmi.c
@@ -260,12 +260,11 @@ static int asus_wmi_evaluate_method_agfn(const struct acpi_buffer args)
 	 * Copy to dma capable address otherwise memory corruption occurs as
 	 * bios has to be able to access it.
 	 */
-	input.pointer = kzalloc(args.length, GFP_DMA | GFP_KERNEL);
+	input.pointer = kmemdup(args.pointer, args.length, GFP_DMA | GFP_KERNEL);
 	input.length = args.length;
 	if (!input.pointer)
 		return -ENOMEM;
 	phys_addr = virt_to_phys(input.pointer);
-	memcpy(input.pointer, args.pointer, args.length);
 
 	status = asus_wmi_evaluate_method(ASUS_WMI_METHODID_AGFN,
 					phys_addr, 0, &retval);
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

Re: [PATCH 19/30] platform/x86: Use kmemdup rather than duplicating its implementation

[Andy Shevchenko]

On Wed, Jul 3, 2019 at 4:19 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 + memset, 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 + memset.
>

Please, split on driver basis and use correct prefix.

> Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
> ---
>  drivers/platform/x86/asus-wmi.c      |  3 +--
>  drivers/platform/x86/thinkpad_acpi.c | 17 +++++++----------
>  2 files changed, 8 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
> index 9b18a184e0aa..472b317ad814 100644
> --- a/drivers/platform/x86/asus-wmi.c
> +++ b/drivers/platform/x86/asus-wmi.c
> @@ -260,12 +260,11 @@ static int asus_wmi_evaluate_method_agfn(const struct acpi_buffer args)
>          * Copy to dma capable address otherwise memory corruption occurs as
>          * bios has to be able to access it.
>          */
> -       input.pointer = kzalloc(args.length, GFP_DMA | GFP_KERNEL);
> +       input.pointer = kmemdup(args.pointer, args.length, GFP_DMA | GFP_KERNEL);
>         input.length = args.length;
>         if (!input.pointer)
>                 return -ENOMEM;
>         phys_addr = virt_to_phys(input.pointer);
> -       memcpy(input.pointer, args.pointer, args.length);
>
>         status = asus_wmi_evaluate_method(ASUS_WMI_METHODID_AGFN,
>                                         phys_addr, 0, &retval);
> 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