2019-08-20 03:04:17

by Dexuan Cui

Subject: [PATCH] Input: hyperv-keyboard: Use in-place iterator API in the channel callback

Simplify the ring buffer handling with the in-place API.

Also avoid the dynamic allocation and the memory leak in the channel
callback function.

Signed-off-by: Dexuan Cui <[email protected]>
---

Hi Dmitry, can this patch go through Sasha's hyperv tree:
https://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux.git

This is a purely Hyper-V specific change.

drivers/input/serio/hyperv-keyboard.c | 35 ++++++-----------------------------
1 file changed, 6 insertions(+), 29 deletions(-)

diff --git a/drivers/input/serio/hyperv-keyboard.c b/drivers/input/serio/hyperv-keyboard.c
index 88ae7c2..e486a8a 100644
--- a/drivers/input/serio/hyperv-keyboard.c
+++ b/drivers/input/serio/hyperv-keyboard.c
@@ -237,40 +237,17 @@ static void hv_kbd_handle_received_packet(struct hv_device *hv_dev,

static void hv_kbd_on_channel_callback(void *context)
{
+ struct vmpacket_descriptor *desc;
struct hv_device *hv_dev = context;
- void *buffer;
- int bufferlen = 0x100; /* Start with sensible size */
u32 bytes_recvd;
u64 req_id;
- int error;

- buffer = kmalloc(bufferlen, GFP_ATOMIC);
- if (!buffer)
- return;
-
- while (1) {
- error = vmbus_recvpacket_raw(hv_dev->channel, buffer, bufferlen,
- &bytes_recvd, &req_id);
- switch (error) {
- case 0:
- if (bytes_recvd == 0) {
- kfree(buffer);
- return;
- }
-
- hv_kbd_handle_received_packet(hv_dev, buffer,
- bytes_recvd, req_id);
- break;
+ foreach_vmbus_pkt(desc, hv_dev->channel) {
+ bytes_recvd = desc->len8 * 8;
+ req_id = desc->trans_id;

- case -ENOBUFS:
- kfree(buffer);
- /* Handle large packet */
- bufferlen = bytes_recvd;
- buffer = kmalloc(bytes_recvd, GFP_ATOMIC);
- if (!buffer)
- return;
- break;
- }
+ hv_kbd_handle_received_packet(hv_dev, desc, bytes_recvd,
+ req_id);
}
}

--
1.8.3.1

2019-08-20 03:20:26

by Dmitry Torokhov

Subject: Re: [PATCH] Input: hyperv-keyboard: Use in-place iterator API in the channel callback

On Tue, Aug 20, 2019 at 03:01:23AM +0000, Dexuan Cui wrote:
> Simplify the ring buffer handling with the in-place API.
>
> Also avoid the dynamic allocation and the memory leak in the channel
> callback function.
>
> Signed-off-by: Dexuan Cui <[email protected]>
> ---
>
> Hi Dmitry, can this patch go through Sasha's hyperv tree:
> https://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux.git
>
> This is a purely Hyper-V specific change.

Sure, no problem.

Acked-by: Dmitry Torokhov <[email protected]>

>
> drivers/input/serio/hyperv-keyboard.c | 35 ++++++-----------------------------
> 1 file changed, 6 insertions(+), 29 deletions(-)
>
> diff --git a/drivers/input/serio/hyperv-keyboard.c b/drivers/input/serio/hyperv-keyboard.c
> index 88ae7c2..e486a8a 100644
> --- a/drivers/input/serio/hyperv-keyboard.c
> +++ b/drivers/input/serio/hyperv-keyboard.c
> @@ -237,40 +237,17 @@ static void hv_kbd_handle_received_packet(struct hv_device *hv_dev,
>
> static void hv_kbd_on_channel_callback(void *context)
> {
> + struct vmpacket_descriptor *desc;
> struct hv_device *hv_dev = context;
> - void *buffer;
> - int bufferlen = 0x100; /* Start with sensible size */
> u32 bytes_recvd;
> u64 req_id;
> - int error;
>
> - buffer = kmalloc(bufferlen, GFP_ATOMIC);
> - if (!buffer)
> - return;
> -
> - while (1) {
> - error = vmbus_recvpacket_raw(hv_dev->channel, buffer, bufferlen,
> - &bytes_recvd, &req_id);
> - switch (error) {
> - case 0:
> - if (bytes_recvd == 0) {
> - kfree(buffer);
> - return;
> - }
> -
> - hv_kbd_handle_received_packet(hv_dev, buffer,
> - bytes_recvd, req_id);
> - break;
> + foreach_vmbus_pkt(desc, hv_dev->channel) {
> + bytes_recvd = desc->len8 * 8;
> + req_id = desc->trans_id;
>
> - case -ENOBUFS:
> - kfree(buffer);
> - /* Handle large packet */
> - bufferlen = bytes_recvd;
> - buffer = kmalloc(bytes_recvd, GFP_ATOMIC);
> - if (!buffer)
> - return;
> - break;
> - }
> + hv_kbd_handle_received_packet(hv_dev, desc, bytes_recvd,
> + req_id);
> }
> }
>
> --
> 1.8.3.1
>

--
Dmitry

2019-08-20 15:30:42

by Sasha Levin

Subject: Re: [PATCH] Input: hyperv-keyboard: Use in-place iterator API in the channel callback

On Mon, Aug 19, 2019 at 08:18:05PM -0700, [email protected] wrote:
>On Tue, Aug 20, 2019 at 03:01:23AM +0000, Dexuan Cui wrote:
>> Simplify the ring buffer handling with the in-place API.
>>
>> Also avoid the dynamic allocation and the memory leak in the channel
>> callback function.
>>
>> Signed-off-by: Dexuan Cui <[email protected]>
>> ---
>>
>> Hi Dmitry, can this patch go through Sasha's hyperv tree:
>> https://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux.git
>>
>> This is a purely Hyper-V specific change.
>
>Sure, no problem.
>
>Acked-by: Dmitry Torokhov <[email protected]>

Queued up for hyperv-fixes, thank you.

--
Thanks,
Sasha