Hi
On Wed, Mar 19, 2014 at 4:45 AM, Petri Gynther <pgynther@xxxxxxxxxx> wrote:
> UHID_CREATE2:
> HID report descriptor data (rd_data) is an array in struct uhid_create2_req,
> instead of a pointer. Enables use from languages that don't support pointers,
> e.g. Python.
..and this also makes the x32-COMPAT crap obsolete.
>
> UHID_INPUT2:
> Data array is the last field of struct uhid_input2_req. Enables userspace to
> write only the required bytes to kernel (ev.type + ev.u.input2.size + the part
> of the data array that matters), instead of the entire struct uhid_input2_req.
We should have swapped these fields right from the beginning. We
explicitly support truncated input, but I only ever tested that with
output, not input.. Thanks for fixing that!
> Signed-off-by: Petri Gynther <pgynther@xxxxxxxxxx>
> ---
> Documentation/hid/uhid.txt | 11 +++++++
> drivers/hid/uhid.c | 80 ++++++++++++++++++++++++++++++++++++++++++++++
> include/uapi/linux/uhid.h | 23 +++++++++++++
> 3 files changed, 114 insertions(+)
>
> diff --git a/Documentation/hid/uhid.txt b/Documentation/hid/uhid.txt
> index dc35a2b..ee65936 100644
> --- a/Documentation/hid/uhid.txt
> +++ b/Documentation/hid/uhid.txt
> @@ -93,6 +93,11 @@ the request was handled successfully.
> event to the kernel. The payload is of type struct uhid_create_req and
> contains information about your device. You can start I/O now.
>
> + UHID_CREATE2:
> + Same as UHID_CREATE, but the HID report descriptor data (rd_data) is an array
> + inside struct uhid_create2_req, instead of a pointer to a separate array.
> + Enables use from languages that don't support pointers, e.g. Python.
> +
> UHID_DESTROY:
> This destroys the internal HID device. No further I/O will be accepted. There
> may still be pending messages that you can receive with read() but no further
> @@ -105,6 +110,12 @@ the request was handled successfully.
> contains a data-payload. This is the raw data that you read from your device.
> The kernel will parse the HID reports and react on it.
>
> + UHID_INPUT2:
> + Same as UHID_INPUT, but the data array is the last field of uhid_input2_req.
> + Enables userspace to write only the required bytes to kernel (ev.type +
> + ev.u.input2.size + the part of the data array that matters), instead of
> + the entire struct uhid_input2_req.
> +
> UHID_FEATURE_ANSWER:
> If you receive a UHID_FEATURE request you must answer with this request. You
> must copy the "id" field from the request into the answer. Set the "err" field
> diff --git a/drivers/hid/uhid.c b/drivers/hid/uhid.c
> index cedc6da..c5ee173 100644
> --- a/drivers/hid/uhid.c
> +++ b/drivers/hid/uhid.c
> @@ -407,6 +407,69 @@ err_free:
> return ret;
> }
>
> +static int uhid_dev_create2(struct uhid_device *uhid,
> + const struct uhid_event *ev)
> +{
> + struct hid_device *hid;
> + int ret;
> +
> + if (uhid->running)
> + return -EALREADY;
> +
> + uhid->rd_size = ev->u.create2.rd_size;
> + if (uhid->rd_size <= 0 || uhid->rd_size > HID_MAX_DESCRIPTOR_SIZE)
> + return -EINVAL;
> +
> + uhid->rd_data = kmalloc(uhid->rd_size, GFP_KERNEL);
> + if (!uhid->rd_data)
> + return -ENOMEM;
> +
> + memcpy(uhid->rd_data, ev->u.create2.rd_data, uhid->rd_size);
Why don't we just use uhid_dev_create() and do this:
if (ev->type == UHID_CREATE) {
...copy_from_user()...
} else if (ev->type == UHID_CREATE2) {
memcpy(...);
}
This way we can avoid copying this whole function.
> +
> + hid = hid_allocate_device();
> + if (IS_ERR(hid)) {
> + ret = PTR_ERR(hid);
> + goto err_free;
> + }
> +
> + strncpy(hid->name, ev->u.create2.name, 127);
> + hid->name[127] = 0;
> + strncpy(hid->phys, ev->u.create2.phys, 63);
> + hid->phys[63] = 0;
> + strncpy(hid->uniq, ev->u.create2.uniq, 63);
> + hid->uniq[63] = 0;
> +
> + hid->ll_driver = &uhid_hid_driver;
> + hid->hid_get_raw_report = uhid_hid_get_raw;
> + hid->hid_output_raw_report = uhid_hid_output_raw;
> + hid->bus = ev->u.create2.bus;
> + hid->vendor = ev->u.create2.vendor;
> + hid->product = ev->u.create2.product;
> + hid->version = ev->u.create2.version;
> + hid->country = ev->u.create2.country;
> + hid->driver_data = uhid;
> + hid->dev.parent = uhid_misc.this_device;
> +
> + uhid->hid = hid;
> + uhid->running = true;
> +
> + ret = hid_add_device(hid);
> + if (ret) {
> + hid_err(hid, "Cannot register HID device\n");
> + goto err_hid;
> + }
> +
> + return 0;
> +
> +err_hid:
> + hid_destroy_device(hid);
> + uhid->hid = NULL;
> + uhid->running = false;
> +err_free:
> + kfree(uhid->rd_data);
> + return ret;
> +}
> +
> static int uhid_dev_destroy(struct uhid_device *uhid)
> {
> if (!uhid->running)
> @@ -435,6 +498,17 @@ static int uhid_dev_input(struct uhid_device *uhid, struct uhid_event *ev)
> return 0;
> }
>
> +static int uhid_dev_input2(struct uhid_device *uhid, struct uhid_event *ev)
> +{
> + if (!uhid->running)
> + return -EINVAL;
> +
> + hid_input_report(uhid->hid, HID_INPUT_REPORT, ev->u.input2.data,
> + min_t(size_t, ev->u.input2.size, UHID_DATA_MAX), 0);
> +
> + return 0;
> +}
> +
> static int uhid_dev_feature_answer(struct uhid_device *uhid,
> struct uhid_event *ev)
> {
> @@ -571,12 +645,18 @@ static ssize_t uhid_char_write(struct file *file, const char __user *buffer,
> case UHID_CREATE:
> ret = uhid_dev_create(uhid, &uhid->input_buf);
> break;
> + case UHID_CREATE2:
> + ret = uhid_dev_create2(uhid, &uhid->input_buf);
> + break;
> case UHID_DESTROY:
> ret = uhid_dev_destroy(uhid);
> break;
> case UHID_INPUT:
> ret = uhid_dev_input(uhid, &uhid->input_buf);
> break;
> + case UHID_INPUT2:
> + ret = uhid_dev_input2(uhid, &uhid->input_buf);
> + break;
> case UHID_FEATURE_ANSWER:
> ret = uhid_dev_feature_answer(uhid, &uhid->input_buf);
> break;
> diff --git a/include/uapi/linux/uhid.h b/include/uapi/linux/uhid.h
> index 414b74b..1e3b09c 100644
> --- a/include/uapi/linux/uhid.h
> +++ b/include/uapi/linux/uhid.h
> @@ -21,6 +21,7 @@
>
> #include <linux/input.h>
> #include <linux/types.h>
> +#include <linux/hid.h>
>
> enum uhid_event_type {
> UHID_CREATE,
> @@ -34,6 +35,8 @@ enum uhid_event_type {
> UHID_INPUT,
> UHID_FEATURE,
> UHID_FEATURE_ANSWER,
> + UHID_CREATE2,
> + UHID_INPUT2,
> };
>
> struct uhid_create_req {
> @@ -50,6 +53,19 @@ struct uhid_create_req {
> __u32 country;
> } __attribute__((__packed__));
>
> +struct uhid_create2_req {
> + __u8 name[128];
> + __u8 phys[64];
> + __u8 uniq[64];
> + __u16 rd_size;
> + __u16 bus;
> + __u32 vendor;
> + __u32 product;
> + __u32 version;
> + __u32 country;
> + __u8 rd_data[HID_MAX_DESCRIPTOR_SIZE];
> +} __attribute__((__packed__));
> +
> #define UHID_DATA_MAX 4096
>
> enum uhid_report_type {
> @@ -63,6 +79,11 @@ struct uhid_input_req {
> __u16 size;
> } __attribute__((__packed__));
>
> +struct uhid_input2_req {
> + __u16 size;
> + __u8 data[UHID_DATA_MAX];
> +} __attribute__((__packed__));
> +
> struct uhid_output_req {
> __u8 data[UHID_DATA_MAX];
> __u16 size;
> @@ -100,6 +121,8 @@ struct uhid_event {
> struct uhid_output_ev_req output_ev;
> struct uhid_feature_req feature;
> struct uhid_feature_answer_req feature_answer;
> + struct uhid_create2_req create2;
> + struct uhid_input2_req input2;
We change the size of uhid_output_req here, but I think that is fine.
But you might wanna note that down in the commit-message.
Patch looks fine. If you fix the minor issues, this is:
Reviewed-by: David Herrmann <dh.herrmann@xxxxxxxxx>
And please always put Jiri on CC for all HID patches: "Jiri Kosina
<jkosina@xxxxxxx>"
Thanks
David
> } u;
> } __attribute__((__packed__));
>
> --
> 1.9.0.279.gdc9e3eb
>
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