On Tue, 22 Nov 2022 19:29:58 +0800
Hanjun Guo <guohanjun@xxxxxxxxxx> wrote:
> The ACPI buffer memory (buffer.pointer) returned by acpi_evaluate_object()
> is not used after the call of _RST method, so it leads to memory leak.
>
> For the calling of ACPI _RST method, we don't need to pass a buffer
> for acpi_evaluate_object(), we can just pass NULL and remove the ACPI
> buffer memory in vfio_platform_acpi_call_reset(), then we don't need to
> free the memory and no memory leak.
>
> Fixes: d30daa33ec1d ("vfio: platform: call _RST method when using ACPI")
> Signed-off-by: Hanjun Guo <guohanjun@xxxxxxxxxx>
> ---
> drivers/vfio/platform/vfio_platform_common.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
> index 55dc4f4..1a0a238 100644
> --- a/drivers/vfio/platform/vfio_platform_common.c
> +++ b/drivers/vfio/platform/vfio_platform_common.c
> @@ -72,12 +72,11 @@ static int vfio_platform_acpi_call_reset(struct vfio_platform_device *vdev,
> const char **extra_dbg)
> {
> #ifdef CONFIG_ACPI
> - struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
> struct device *dev = vdev->device;
> acpi_handle handle = ACPI_HANDLE(dev);
> acpi_status acpi_ret;
>
> - acpi_ret = acpi_evaluate_object(handle, "_RST", NULL, &buffer);
> + acpi_ret = acpi_evaluate_object(handle, "_RST", NULL, NULL);
> if (ACPI_FAILURE(acpi_ret)) {
> if (extra_dbg)
> *extra_dbg = acpi_format_exception(acpi_ret);
An identical change was already posted and accepted into the vfio next
branch, see:
https://lore.kernel.org/all/20221018152825.891032-1-rafaelmendsr@xxxxxxxxx/
In linux-next as:
e67e070632a6 ("vfio: platform: Do not pass return buffer to ACPI _RST method")
Thanks,
Alex
