From e3480a61fca72d40d6dc4baaf37e94fcbfa95e19 Mon Sep 17 00:00:00 2001 From: Benjamin Tissoires Date: Thu, 30 Jan 2014 17:20:24 -0800 Subject: [PATCH] Input: uinput - add UI_GET_SYSNAME ioctl to retrieve the sysfs path uinput is used in the xorg-integration-tests suite and in the wayland test suite. These automated tests suites create many virtual input devices and then hook something to read these newly created devices. Currently, uinput does not provide the created input device, which means that we rely on an heuristic to guess which input node was created. The problem is that is heuristic is subjected to races between different uinput devices or even with physical devices. Having a way to retrieve the sysfs path allows us to find without any doubts the event node. Signed-off-by: Benjamin Tissoires Reviewed-by: David Herrmann Signed-off-by: Dmitry Torokhov --- drivers/input/misc/uinput.c | 43 +++++++++++++++++++++++++++++++++++++ include/linux/uinput.h | 2 ++ include/uapi/linux/uinput.h | 13 ++++++++++- 3 files changed, 57 insertions(+), 1 deletion(-) diff --git a/drivers/input/misc/uinput.c b/drivers/input/misc/uinput.c index d8ae08d12abf..856936247500 100644 --- a/drivers/input/misc/uinput.c +++ b/drivers/input/misc/uinput.c @@ -20,6 +20,8 @@ * Author: Aristeu Sergio Rozanski Filho * * Changes/Revisions: + * 0.4 01/09/2014 (Benjamin Tissoires ) + * - add UI_GET_SYSNAME ioctl * 0.3 09/04/2006 (Anssi Hannula ) * - updated ff support for the changes in kernel interface * - added MODULE_VERSION @@ -670,6 +672,31 @@ static int uinput_ff_upload_from_user(const char __user *buffer, __ret; \ }) +static int uinput_str_to_user(void __user *dest, const char *str, + unsigned int maxlen) +{ + char __user *p = dest; + int len, ret; + + if (!str) + return -ENOENT; + + if (maxlen == 0) + return -EINVAL; + + len = strlen(str) + 1; + if (len > maxlen) + len = maxlen; + + ret = copy_to_user(p, str, len); + if (ret) + return -EFAULT; + + /* force terminating '\0' */ + ret = put_user(0, p + len - 1); + return ret ? -EFAULT : len; +} + static long uinput_ioctl_handler(struct file *file, unsigned int cmd, unsigned long arg, void __user *p) { @@ -679,6 +706,8 @@ static long uinput_ioctl_handler(struct file *file, unsigned int cmd, struct uinput_ff_erase ff_erase; struct uinput_request *req; char *phys; + const char *name; + unsigned int size; retval = mutex_lock_interruptible(&udev->mutex); if (retval) @@ -831,6 +860,20 @@ static long uinput_ioctl_handler(struct file *file, unsigned int cmd, goto out; } + size = _IOC_SIZE(cmd); + + /* Now check variable-length commands */ + switch (cmd & ~IOCSIZE_MASK) { + case UI_GET_SYSNAME(0): + if (udev->state != UIST_CREATED) { + retval = -ENOENT; + goto out; + } + name = dev_name(&udev->dev->dev); + retval = uinput_str_to_user(p, name, size); + goto out; + } + retval = -EINVAL; out: mutex_unlock(&udev->mutex); diff --git a/include/linux/uinput.h b/include/linux/uinput.h index 0a4487d3fb1e..0994c0d01a09 100644 --- a/include/linux/uinput.h +++ b/include/linux/uinput.h @@ -20,6 +20,8 @@ * Author: Aristeu Sergio Rozanski Filho * * Changes/Revisions: + * 0.4 01/09/2014 (Benjamin Tissoires ) + * - add UI_GET_SYSNAME ioctl * 0.3 24/05/2006 (Anssi Hannula ) * - update ff support for the changes in kernel interface * - add UINPUT_VERSION diff --git a/include/uapi/linux/uinput.h b/include/uapi/linux/uinput.h index fe46431593f9..0389b489bbba 100644 --- a/include/uapi/linux/uinput.h +++ b/include/uapi/linux/uinput.h @@ -20,6 +20,8 @@ * Author: Aristeu Sergio Rozanski Filho * * Changes/Revisions: + * 0.4 01/09/2014 (Benjamin Tissoires ) + * - add UI_GET_SYSNAME ioctl * 0.3 24/05/2006 (Anssi Hannula ) * - update ff support for the changes in kernel interface * - add UINPUT_VERSION @@ -35,7 +37,7 @@ #include #include -#define UINPUT_VERSION 3 +#define UINPUT_VERSION 4 struct uinput_ff_upload { @@ -73,6 +75,15 @@ struct uinput_ff_erase { #define UI_BEGIN_FF_ERASE _IOWR(UINPUT_IOCTL_BASE, 202, struct uinput_ff_erase) #define UI_END_FF_ERASE _IOW(UINPUT_IOCTL_BASE, 203, struct uinput_ff_erase) +/** + * UI_GET_SYSNAME - get the sysfs name of the created uinput device + * + * @return the sysfs name of the created virtual input device. + * The complete sysfs path is then /sys/devices/virtual/input/--NAME-- + * Usually, it is in the form "inputN" + */ +#define UI_GET_SYSNAME(len) _IOC(_IOC_READ, UINPUT_IOCTL_BASE, 300, len) + /* * To write a force-feedback-capable driver, the upload_effect * and erase_effect callbacks in input_dev must be implemented. -- 2.34.1